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A comparison of different APTT-reagents, heparin-sensitivity and detection of mild coagulopathies
(1992)
The activated partial thromboplastin time (aPTT) is widely used to detect coagulation abnormalities or to monitor heparin treatment.
Many commercial aPTT-reagents are available which contain different phospholipid reagents and activators. In the present study 3 aPTT-reagents (aPTT-D, Instrumentation Laboratory, Neothromtin, Behring, PTTa, Boehringer) were compared using a computerized centrifugal analyzer. One aPTT-reagent (Pathromtin, Behring) was tested on a semiautomated coagulometer. Instrument precision was evaluated using aPTT-D as reagent.
Comparative tests were performed on plasma samples of 40 healthy donors, 3 patients with mild von Willebrand's disease (vWd), W patients with heaemophilia or subhaemophilia A, 1 patient with subhaemophilia A and vWd, 8 patients treated with subcutaneous injection of unfractionated heparin (UFH) and 14 patients treated with subcutaneous injection of a low molecular weight heparin (LMWH).
aPTT-D was the most sensitive reagent to detect mild vWd while Pathromtin detected none of these defects. In patients with heamophilia A and subhaemophilia A aPTT-D, Neothromtin and PTTa detected the abnormality in nearly all tested samples while Pathromtin was less sensitive.
Patients treated with subcutaneously applied UFH or LMWH often had a prolonged aPTTt especially when aPTT-D and Neothromtin were used as reagents.
Herpes simplex virus type 2 (HSV-2) is the main cause of herpes genitalis, a recurrent sexually transmitted disease. By the use of routine Serologie methods (complement fixation test, enzyme immunoassay), virus carriers are difficult to identify because of strong antibody cross reactions with antigens of HSV-1 which is ubiquitously spread throughout the population. We introduce a microtechnique Western blot system loaded with HSV-1 and HSV-2 type-specific and common antigens on separated nitrocellulose strips. By the simultaneous evaluation of Immunologie reactions with both strips, the occurrence of HSV-2 specific antibodies can be sensitively detected in serum specimens containing antibodies to HSV-1. A total of 158 serum specimens were analyzed and the results obtained by Western blot were compared to those of a screening ELISA and virus isolation performed with smears of herpes lesions.
An agreement of 97.9 % was assessed between Western blot and virus isolation to detect an HSV-1 and HSV-2 infection. Less specific serologic results were produced by the screening ELISA on HSV-2 antibodies which correlated in 85.4 % (41/48) with virus isolation and typing. Concerning HSV-2 antibody testing, Western blot and ELISA showed an overall agreement in 89.8 % of the sera investigated.
As shown by our data, the HSV type specific Western blot proved to be a specific, reproducible and standardized technique. It can be utilized for both sero-epidemiological surveys and determination of the HSV immune status.
Young poplar cuttings (Populus nigra L. cv. Loenen and P. maximowiczii Henry x P. nigra L. cv. Rochester) were exposed for six weeks in open-top chambers to realistic concentrations of pollutant mixtures: 1) control; 2) SO2/NOx; 3)O3/ NOx and 4)SO2/O3/NOx. In this sequence of fumigation variants, the degree of influence of the various parameters of the nitrogen metabolism and of premature leaf drop increased very frequently compared to the control plants, P. nigra L. proving to be the more sensitive species.
The elevated Kjeldahl nitrogen content of the fumigated leaves was accompanied by either an increase in free amino acids or in total protein or, in the case of particularly large rises (SO2/O3/NOx variants), by increases in both substance groups. Proteolytic processes as a cause of the elevated content of free amino acids could be excluded to a large extent. A diminished de novo synthesis of proteins obviously led to a shift in the amino acid/protein relationship. In the younger fumigated leaves, the total concentration of free amino acids exceeded the values of the older leaves. The elevated amino acid content of the fumigated leaves was produced to a high degree by the glycolate pathway and the Krebs cycle. The increased turnover of the carbon skeletons was connected with a drastic starch degradation, especially in the older leaves.
The interaction of the amino acid and carbohydrate metabolisms is probably an important regulator in the promotion of rapid growth of young leaves in order to compensate premature leaf loss.
The sesquiterpenoic alcohol nerolidol was separated into its 4 stereoisomers by MPLC of the diastereomeric (1 S, 4 R)-camphanoates.
An analytical GC method was found by which both the enantiomeric pairs of (Z)- and (E)-nerolidol are resolved on a chiral cyclodextrin stationary phase. The olfactoric properties of the nerolidol stereoisomers were investigated.
Nitric oxide causes ADP-ribosylation and inhibition of glyceraldehyde-3-phosphate dehydrogenase
(1992)
Nitric oxide and nitric oxide-generating agents like 3-morpholinosydnonimine (SIN-1) stimulate the mono-ADP-ribosylation of a cytosolic, 39-kDa protein in various tissues. This protein was purified from human platelet cytosol by conventional and fast protein liquid chromatography techniques. N-terminal sequence analysis identified the isolated protein as the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Nitric oxide stimulates the auto-ADP-ribosylation of GAPDH in a time and concentration-dependent manner with maximal effects after about 60 min. Associated with ADP-ribosylation is a loss of enzymatic activity. NAD(+)-free enzyme is not inhibited by SIN-1, indicating the absolute requirement of NAD+ as the substrate of the ADP-ribosylation reaction. Inhibition of the glycolytic enzyme GAPDH may be relevant as a cytotoxic effect of NO complementary to its inhibitory actions on iron-sulfur enzymes like aconitase and electron transport proteins of the respiratory chain.
Metaleptea, vol. 14, no. 1, july 1992 : the orthopterists' newsletter / The Orthoperists' Society
(1992)
This paper is part of an ongoing investigation into the nature of grammatical relations in the Sino-Tibetan language family. The ultimate goal of this investigation is to develop a hypothesis on the typological nature of word order and grammatical relations in the mother language which gave rise to all of the many languages within the Sino Tibetan language family. As the verb agreement (pronominalization) systems of Tibeto-Burman have been said to be a type of ergative marking, and to have been a part of Proto-Tibeto-Burman grammatical relations, the questions of the dating and nature of the agreement systems in Tibeto-Burman are relevant to the discussion of the nature of grammatical relations in Proto-Sino-Tibetan.
Using arguments based on the data on verb agreement (pronominalization) in Tibeto-Burman, LaPolla 1989 (see also LaPolla 1992) argues that Proto-Tibeto-Burman should be reconstructed as a language with no inflectional morphology. In that paper it is argued that the Proto-Tibeto- Burman system of grammatical relations1 was closer to the typical 'role-dominated' (Van Valin & Foley 1980) Burmese-Yipho system (epitomized by Lahu—see Matisoff 1973). That is, a system where there is no definable 'subject' or 'direct object'; a system where semantic and pragmatic principles govern the organization of discourse, not syntactic functions. In this paper we look at the nature of 'objects' in Tibeto-Burman languages, and here also find support for this view of Proto-Tibeto-Burman grammatical relations. From a survey of ninety-five reliable grammars or descriptions of languages in the Tibeto-Burman family, I found eleven languages with no nominal object marking, twenty languages with nominal morphology consistently marking the patient as object, regardless of clause type, and sixty-four languages with a type of marking where the patient in monotransitve clauses is often or always marked with the same postposition as the goal or beneficiary (dative) in ditransitve clauses. This type of marking is discussed in Dryer 1986 as Primary Object marking. I argue that this type of marking in the Tibeto-Burman languages reflects the semantically based nature of grammatical relations in Proto-Tibeto-Burman.
Vsevolod M. Garshin's story "Four Days" ("Четыре дня") made the author famous when it was published in 1877. Intended as a strong anti·war statement and based on a true incident during the Russian-Turkish war (1877-78), "Four Days" is the interior monologue of a wounded soldier left for dead on an empty battlefield. His last name, Ivanov, which is traditionally considered to be the most common one in Russia, may suggest the idea of "everyman" in order to generalize the protagonists terrible experience on the battlefield into a broad anti-war message. The protagonist finds himself pinned down next to 0the body of a Turkish soldier whom he had killed just before being wounded. Forced to look at the corpse for a long time, Ivanov experiences terrible guilt, since he has never killed before. After four days of physical and mental agony, during which Ivanov reassesses his formerly idealistic attitude toward war and ends up condemning it as something far from glorious and noble, the protagonist is found by his regiment, and, unlike his real-life prototype, he survives (Henry. 47). Throughout the text we do not lave the confines of the protagonist's mind; as a result, the intense, relentless focus on his mental and physical anguish created by the interior monologue: immobilized by his wound, he becomes a prisoner of his own mind; as a result, the intense, relentless focus on his mental and physical anguish created by the interior monologue technique enhances the "horrors of war" effect intended by the author. At the same time the war-related situation and setting provide motivation for the wounded man's interior monologue: immobilized by his wound, he becomes a prisoner of his own mind and its therefore forced by circumtances to think through his entire predicament and its causes.
In literary translation 'correctness' is rarely ratified by linguistic rules; it is more often a question of what a sensitive translator feels to be correct. Intuition will therefore play a major part. This intuition is seen here neither as instinctive reaction prompted by experience, nor as native competence, but as an inquiring, self-moderating influence inspired by the language itself. It is treated in this respect as an informed intuition, that is, as having a linguistic base for sensitive judgement. This assumes that the literary translator is both a creative writer and his own critical reader as well as a fine judge of language potential. This line is applied to translating meaning and sense, transferring the very language, imitating the form and style, re-creating the features, and above all, to capturing those unique qualities of the original. After dealing with word-accuracy, the question of literary input demanded by form and style is examined. The treatment of language used for effect features in a section on Kafka. The merits and the problems of translating dialect as dialect for its own sake are looked at closely and in a positive way as are the possibilities of reproducing 'oddities' of language. The immense task of translating the language of Joyce ('Ulysses ') with all its vagaries and skilful manipulation of words is examined for the possibility of providing an accurate copy. The ultimate test of reproducing a uniqueness of artistic creation together with the profound thought which inspired it, is reserved for a section on Hopkins. While it is recognized that, owing to the constrictions imposed by the extreme and sensitive use of language, no translation can fully include all that there is in his poems, it might be possible to capture enough of their essence to give an impression of a 'German' Hopkins at work. A major objective throughout is the establishment of a linguistic base for the part played by intuition in literary translation.
Botanical history has recorded significant contributions of bryology to its conceptual development and to man’s scientific knowledge. The discovery of sexual chromosomes in plants by Allen and the production of the first polyploids by Wettstein are but two scientific achievments in which bryophytes had an outstanding role. Currently, their use in environmental monitoring and the identification of active principles, make bryophytes objects of great pragmatic interest.
214 Lichen and 38 bryophyte species are reported from Cerro Guaiquinima, a sandstone table mountain in southeastern Venezuela, thus fas almost unexplored for these groups and apparently undisturbed by man. Slightly over half of these species have also been reported from the north slope of Mount Roraima and surroundings, a nearby area with similar edaphic and climatological conditions.
The pleurocarpous moss genus Isopterygium (Hypnaceae) is revised for Latin America. Although as many as 92 species and varieties have been reported for the region over past years, these are currently accommodated by the present revision into only eight species. The most common taxon throughout most of Latin America, Isopterygium tenerum (Sw.) Mitt, is also the most polymorphic and presently 45 taxa are recognized as synonyms. The other seven species are I. affusum Mitt., I. acutifolium Irel., I. byssobolax Par., I. jamaicense Buck Broth., I. subglobosum Herz., and I. tenerifolium Mitt.+
References are made to cytotoxic and/or antitumor compounds that have been isolated - ansamitocin P-3 from Claopodium crispifolium (Hook.) Ren. & Card. and Anomodon attenuatus Hueb., or an associated actinomycete, and ohioensins and pallidisetums from Polytrichum spp. Several hundred collections, which have been obtained from temperate regions of North America during 1990 and 1991, are currently being screened in new bioassays; active sesquiterpene lactones have been recently isolated from species of Porella. The methodologies of collecting and screening bryophyte samples are discussed with consideration to costs based on expected number of samples that might be collected in a day, the diversity in the collections as related to phytogeography and vegetation types, and the bryophyte cover that is vanishing in many forest regions of the United States. The difficulties in obtaining large collections for isolation of active agents are also discussed by examplerecollection of Claopodium crispifolium.
Phenological observations and sex ratios in Marchantia chenopoda L. (Hepaticae: Marchantiaceae)
(1992)
Sex ratios were determined for 15 populations of Marchantia chenopoda L. along Puerto Rico. Sex was determined for twenty randomly selected individuals from each population. A female bias was observed in most populations. A census of reproductive structures of M. chenopoda was performed every two weeks in order to determine phenology. The highest archegoniophore count was observed to occur in January and February; minimum and maximum fertilization distances were 0.7 cm and 65 cm, respectively. Young sporophytes were most frequently observed at the beginning of the rainy season, in April and May. The highest frequency of mature sporophytes occurred during the dry season, in January and February. Capsules opened mostly during the heavy rainy season, from August to November. Protonemata were observed in the periphery of the population. Most young sporophytes aborted at the end of the moderate to heavy rainy season, from June to August. Immature gemmae cups were most frequent at the beginning of the rainy season, in April and May. Mature gemmae cups were observed throughout the rainy season, but were most frequent in September.
Tropical deforestation, inevitably, leads to the local loss of bryophyte species. Recent studies show that the degree of species loss may vary considerably and depends on the scale or amount of habitat change that has occurred. Predictably, the shade epiphytes are most seriously affected by disturbance. An estimated 10% of the bryophyte species of neotropical rain forests are under threat. Based on data from recent monographs, a first list of 19 endangered and 27 rare species of these forests is presented. Critical areas for threatened species include Costa Rica and Panama, the Greater Antilles, the Chocó, southeastern Brazil, and parts of Amazonia. Protection of as much as possible of the remaining natural rain forest area seems the best approach to the conservation of the tropical bryophyte flora.
The Index of Atmospheric Purity (IAP) was used to make a preliminary evaluation of epiphytic moss response to atmospheric pollution in the urban area of Mexico City. Areal analysis indicates that there is a significant negative correlation (p < 0.5) between IAP values and SO2, NO2, NOx, Pb and temperature values of -0.45, -0.90, -0.80, -0.80, -0.90. Significant positive correlation (p < 0.05) between IAP values and O3, rainfall and relative atmospheric humidity with values of 0.70, 0.80, 0.90. Increase in atmospheric pollutants in Mexico City have promoted a gradual decrease in frequency and cover of epiphytic mosses even though some ecological factors may show the oposite effect.
Scanning electron microscopy and light microscopy were used to elucidate the morphology of Metzgeria conjutata Lindb. and confirm the presence of 2 rows of epidermal cells on the dorsal surface, (21-3) rows on the ventral surface, midrib with cells in (3-51-6) tiers; hirsute, short hairs, straight on the thallus-margin and on the ventral surface of midrib; marginal hairs paired, single or in groups of three; male branches globose or subglobose; female involucres obovate and hirsute at the margin, calyptra fleshy, pyriform to club-shaped, hirsute on the outer surface, hairs long and straight.
The vascular flora of Chiapas, Mexico, has been the subject of a long term study by Dennis Breedlove of the California Academy of Sciences. This has stimulated a related project dealing with the bryophyte flora of the region. A collecting expedition in 1988 generated 1420 collections of bryophytes. Specialists from 13 institutions assisted with identifications. Approximately 70% of the collections have been determined. Checklists of species of bryophytes of Chiapas are presented. These lists are based on collections at CAS and literature citations. A total of 364 species of mosses and 310 species of hepatics and hornworts are reported from Chiapas.
There is very little information on the biogeochemical ecology of Sphagnum species in tropical regions. The majority of the ecological information on Sphagnum species in the tropics consists of general habitat information and pH values that are reported in new species descriptions and regional floras such as those of Crum (1980, 1989), Crum and Buck (1988), Karlin (1991), and McQueen (1989).
Cheilolejeunea subgenus Xenolejeunea Kachroo & Schust. is emended to account for variability observed in stem anatomy and lobule structure. Cheilolejeunea subgenus Tegulilejeunea Schust. is reduced to synonymy with subgenus Xenolejeunea. A new sectional classification of subgenus Xenolejeunea is proposed (sections Gigantae, Meyenianae, and Xenolejeunea). A key distinguishes among the sections and the 10 species accepted in the subgenus, which is known from Australasia, Oceania and tropical Asia. A nomenclator and discussion is provided for each species. Comments on excluded species conclude the treatment .
Lichen exploration of the Upper Mazaruni District, Guyana yielded 273 species, of which 179 were found for the first time in the Guianas and 13 were as yet undescribed. A list of all taxa encountered is presented, with indications of habitat and distribution in the investigated area as well as first descriptions for the following 7 species: Buellia aptrootii, Byssoloma farkasii, Myriotrema guianense, M. neofrondosum, M. subdactyliferum, Ocellularia astrolucens, and Thelotrema albomaculatum. Mazosia bambusae is recorded for the first time from the Neotropics. The richest areas for lichens appear to be the rocky tablelands with scrub vegetation on top of the lower mountains. The slopes of Mount Roraima are of special interest because they support some montane species which are unlikely to be found elsewhere in the Guianas; otherwise they are less rich in lichens, probably because of the high humidity, which favours bryophyte growth.
A bryophyte inventory along an altitudinal gradient on Cerro Pirre (1200 m), Darién National Park, Panama, demonstrates that the different rain forest types along the gradient (inundatedlowland, hillside-lowland, submontane, montane elfin forest) have very different species assemblages. The montane forest has the largest number of exclusive species and the largest bryophyte biomass. Species richness is greatest in the submontane forest. The bryophyte flora of Cerro Pirre is not exceedingly rich in species owing to the rather low elevation of the mountain and the seasonal climate in the adjacent coastal plain. Nevertheless, the distinct altitudinal diversification and the occurrence of a considerable number of rare hepatic taxa, demonstrate the importance of Darién National Park as an area of plant conservation. Forty hepatic species are reported as new to Panama.
Four types of asexual reproduction in Plagiochila and the Plagiochilaceae are known: propagules, caducous leaves, gemmae and cladia. Plagiochila pluma Steph. has caducous leaves and teeth with regenerants. The terms for asexual reproduction modes in liverworts are briefly discussed and new definitions proposed.
The genera Meteoridium and Zelometeorium are described and illustrated from 73 collections made by the author in Bolivia. Barbella tenuissima (Hook. & Wils.) Fleisch. is transferred to the genus Meteoridium as Meteoridium tenuissimum (Hook. & Wils.) M. Lewis comb. nov. Due to its hypnobryoid peristome and other characters, the genus Meteoridium is placed in the Brachytheciaceae. Meteoridium remotifolium (C. Müll.) Manuel shows marked variation over its altitudinal range and four ecoforms are recognized. Distribution records show that the species of these two genera have distinct ranges, with only Meteoridium remotifolium overlapping the ranges of the other species. Habitat data shows that none of the species treated are obligate epiphytes, and that they grow equally well in terrestrial habitats.
Breutelia microdonta (Mitt.) Broth., described originally from Brazil, is the oldest name for a disjunct widespread tropical species that includes as synonyms B. angustifolia Rehm. ex Sim of Southern Africa and B. merrillii Broth. of the Philippines. Breutelia kilaueae (C. Muell.) Broth. of Hawaii is considered a synonym of the austral Pacific species B. affinis (Hook.) Mitt., and B. brachyphylla Broth. of Ecuador is reduced to synonymy under the North Andean B. squarrosa Jaeg. Breutelia anacolioides Herz. of Bolivia is removed to Philonotis as a synonym of the North Andean P. incana (Tayl.) H. Robins. Differences in spore ornamentation offer an additional character distinguishing Breutelia from Philonotis.
“El Refugio” Biological Station will be open as of Juni 1989 for persons or organizations of all nationalities. The station offers logistic support for activities with educational, conservational or research purposes. The station is located in a mountainous region at elevations of 1600 to 1900 m, on the western versant of the western cordillera of Colombia. It lies 23 km away from Cali (see below), on the road to Buenaventura, the most important road crossing the Chocó biogeographical region (Buenaventura is the most important seaport on the Colombian Pacific coast). The biological station includes 14 ha of relatively undisturbed, species-rich forest, and 9 ha of open lands. The latter include orchard, pasture and garden areas. “El Refugio” is owned by a colomian family concerned with the conservation of natural resources and especially with endangered plant species. Since its acquisition 10 years ago, the open areas have been considerably enriched with numerous living collections of andean plants.
The neotropical genus Potamium as described by Mitten (1869) included species that had little more in common than a growth form adapted to a semi-aquatic habitat. Brotherus divided the genus in section Eu-Potamium and section Potamiopsis, based on peristome characters. This study shows that all species of section Eu-Potamium belong to Sematophyllum, including P. lonchophyllum which was designated as lectotype of Potamium by Buck (1990). In section Potamiopsis two species are recognized: P. vulpinum (Mont.) Mitt. (syn. nov.: Sematophyllum maguireorum Buck) and P. deceptivum Mitt. (syn. nov.: P. leucodontaceum (C.Müll.) Broth., Meiothecium negrense Mitt. and Maguireella vulpina (Mont.) Buck). The genus Potamium is characterized by capsules with an endostome consisting of a low basal membrane and filiform segments, which are often reduced in P. deceptivum. P. vulpinum is designated as lectotype of Potamium and the lectotypification of Buck is rejected. Descriptions, illustrations and a key are provided to the species of Potamium and allied semiaquatic taxa of Sematophyllum.
Remarks on deixis
(1992)
The prevailing conception of deixis is oriented to the idea of 'concrete' physical and perceptual characteristics of the situation of speech. Signs standardly adduced as typical deictics are I, you, here, now, this, that. I and you are defined as meaning "the person producing the utterance in question" and "the person spoken to", here and now as meaning "where the speaker is at utterance time" and "at the moment the utterance is made" (also, "at the place/time of the speech exchange"); similarly, the meanings of this and that are as a rule defined via proximity to speaker's physical location. The elements used in such definitions form the conceptual framework of most of the general characterisations of deixis in the literature. [...] There is much in the literature, of course, that goes far beyond this framework . A great variety of elements, mostly with very abstract meanings, have been found to share deictic characteristics although they do not fit into the personnel-place-time-of-utterance schema. The adequacy of that schema is also called into question by many observations to the effect that the use of such standard deictics as here, now, this, that cannot really be accounted for on its basis, and by the far-reaching possibilities of orienting deictics to reference points in situations other than the situation of speech, to 'deictic centers' other than the speaker. [...] Analyses along the lines of the standard conception regularly acknowledge the existence of deviations from the assumed basic meanings. One traditional solution attributes them to speaker's "subjectivity", or to differences between "physical" and "psychological" space or time; in a similar vein, metaphorical extensions may be said to be at play, or a distinction between prototypical and non-prototypical meanings invoked. Quite apart from the question of the relative merits of these explanatory principles, which I do not wish to discuss here, the problem with all such accounts is that the definitions of the assumed basic meanings themselves are founded on axiom rather than analysis of situated use. The logical alternative, of course, is to set out for more abstract and comprehensive meaning definitions from the start. In fact, a number of recent, discourse-oriented, treatments of the demonstratives proceed this way; they view those elements as processing instructions rather than signs with inherently spatial denotation (Isard 1975, Hawkins 1978, Kirsner 1979, Linde 1979 , Ehlich 1982.)
This paper is concerned with developing Joan Bybee's proposals regarding the nature of grammatical meaning and synthesizing them with Paul Hopper's concept of grammar as emergent. The basic question is this: How much of grammar may be modeled in terms of grammaticalization? In contradistinction to Heine, Claudi & Hünnemeyer (1991), who propose a fairly broad and unconstrained framework for grammaticalization, we try to present a fairly specific and constrained theory of grammaticalization in order to get a more precise idea of the potential and the problems of this approach. Thus, while Heine et al. (1991:25) expand – without discussion – the traditional notion of grammaticalization to the clause level, and even include non-segmental structure (such as word order), we will here adhere to a strictly 'element-bound' view of grammaticalization: where no grammaticalized element exists, there is no grammaticalization. Despite this fairly restricted concept of grammaticalization, we will attempt to corroborate the claim that essential aspects of grammar may be understood and modeled in terms of grammaticalization. The approach is essentially theoretical (practical applications will, hopefully, follow soon) and many issues are just mentioned and not discussed in detail. The paper presupposes a familiarity with the basic facts of grammaticalization and it does not present any new facts.
Current results of an arachnological survey of some sandstone rock sites in Bohemia (so called 'rock cities'). The spider fauna of the Adrspach·Tepllce rocks was investigated. Some records on spider fauna of other nine sandstone rock areas are included. The phenomenon of 'rock cities' manifests itself in three aspects: (1) In the bottom parts are microclimatically cold spaces, frequently hosting northern or mountain species of invertebrates, which here have an azonal occurrence. (2) The sun exposed tops of rocks can host thermophilous species. (3) Some species are limited to the surface of rocks and boulders. These are referred to as lithophilous or lithobiont species.
On tradition
(1992)
Synonymies, new combinations, new status, revalidations, and generic transfers are presented for Western Hemisphere Cerambycidae. In the subfamily Prioninae, taxa are in the tribes Macrodontiini and Mallaspidini; in the subfamily Cerambycinae in the tribesCerambycini, Elaphidiini, Molorchini, Rhinotragini, Compsocerini, Callidiini, Clytini, Cleomenini, Heteropsini and Trachyderini; and in the subfamily Lamiinae in the tribes Pannenini, Lamiini, Onciderini, Pteropliini, Pogonocherini, Desmiphorini, Acanthoderini, Acanthocinini, Aerenicini and Calluni.
The fauna of Curculionoidea (exclusive of the subfamilies Scolytinae and Platypodinae of the Curculionidae) is surveyed for Dade and Monroe Counties in southern Florida. Numbers of genera and species represented are as follows: Anthribidae (12 genera, 22 species), Belidae (1 genus, 2 species), Attelabidae (3 genera, 3 species), Brentidae (6 genera, 14 species) and Curculionidae (115 genera, 249 species). No Nemonychidae are recorded from southern Florida. Included in the totals are 26 species considered as introduced to the region and 5 species likely not established in the region. Twenty apparently undescribed species are recorded. Fifteen are assignable to genera as follows; Ormiscus (2) (Anthribidae), and Podapion (1) (Brentidae), and Prosaldius (1), Acalles (6), Calles (1), Zascelis (1), Notolomus (1), Lixus (1), and Conotmchelus (1) (Curculionidae). The generic placement of 5 undescribed species of Curculionidae is uncertain and descriptions of new genera may be required. New generic records for the United States of America are Homocloeus Jordan (Anthribidae), and Stenotrupis Wollaston (Curculionidae; Cossoninae) and Heilus Kuschel (Curculionidae; Curculioninae). New species records for the United States are Homocloeus distentm Frieser and Homochw sexverrucatm (Suffrian) (Anthribidae) and Stenotrupis acicula Wollaston, Caulophilus rufotestuceus (Champion), Minominus minimus (Boheman) (Curculionidae; Cossoninae), and Anthonomus rubricosus Boheman and Heilus bioculatus (Boheman) (Curculionidae; Curculioninae). Particularly well-represented in terms of species diversity is the anthribid genus Ormiscus (6), the brentid genus Apion (9) and the curculionid genera Listronotus (21), Anthonomus (14), Acalles (13), Conotrachelus (11), Tyloderma (10) and Sphenophorus (10).
The names of previously described South American species of Oxybelus are listed, annotated, and synonymy given. Nomenclature changes are: brethesi is a new name for interruptus Brethes 1913; decipiens Brethes 1913 and pamparum Brethes 1913 are synonyms of catamarcensis Schmttky 1909; fritzi is a new name for modestus Brethes 1913; agnitus Brethes 1913 is a synonym of marginatus F. Smith 1866; joergenseni Brethes 1913 is a synonym of paraguayensis Brethes 1909; and tarijensis Brethes 1913 is a synonym of platensis Brethes 1901. Neotypes are established for platensis and catamarcensis, and lectotypes for americanus, argentinus, modestus, marginatus, and tarijensis.
The New World species formerly placed in Borborillus Duda (Sphaeroceridae: Copromyzinae) are transfemdto Norrbomia Papp. These are: N. lacteipennis (Malloch), n. comb., N. fumipennis (Stenhammar), n. comb., N. frigipennis (Spuler), n. comb., N. scripta (Malloch), n. comb., and N. sordida (Zetteretedt). Norrbomia fulvipennis, N. singusta, N. mexicana, N. triglabra, and N. yukonensis are described as new. Borborus articus Malloch is synonymized with N. fumipennis, and Borborus singularis Spuler is synonymized with N. scripta. All ten New World species of Norrbomia are keyed, illustrated and described. Their relationships are discussed and a cladogram is provided. Species in two of the defined clades are kleptoparasitic on dung rolling scarab beetles.
Males of Neohermes concolor (Davis) from the interior highlands of Arkansas, Oklahoma, and Missouri, and from Illinois, Indiana, and Kentucky exhibited considerable variation in male terminalia. Differences occurred in the size of the dorsal membrane of the ninth sternite and in the shape of the tenth tergite (anal plate) which varied from rounded to truncate-shaped. This observed variation does not appear to be geographically correlated. Females of N. concolor did not exhibit broad variation in terminalii. Little variation was observed among males of N. angusticollis (Hagen) and N. matheri Flint. The broad range of variation observed in the tenninalia of N. concolor could result in misidentification by collectors who rely only on the shape of the anal plate rather than the more constant shape of the aedeagus.
The following new species are described: Lydipta humeralis, sp. n. and Cacostola obliquata, sp. n., from Ecuador; Lochmaeocles leuripennis, sp. n., and Carenesycha velezi, sp. it., from Colombia; Oltcideres marauara, sp. it., from Brazil (Amazonas). Oncideres minuta Thomson, 1865, is recorded from Ecuador.
A specimen of Rhizophagus sayi Schaeffer collected in a flight trap at 29°34½'N82°29'W in Alachua County, Florida, on 23-1-1993, by R.W. Lundgren prompted a search of unidentified specimens in the Florida State Collection of Arthropods. The search resulted in the discovery of seven additional Florida specimens with the following data: "FLA., Dixie Co. 3.5mi. N. Old Town 13-1-1980 Coll. M.C. Thomas", 2; "FLORIDA: Alachua Co. Gainesville 3-XII-1983 Coll. M.C. Thomas", 1; "FLORIDA: Alachua Co. San Felasco Hammock 4-11-1983 M.C. Thomasn, 3; same, except date is 12-II-1983. These specimens comprise a new state record for R. sayi, which Bousquet (1990) recorded from most of the eastern United States except for Florida and Georgia.
Book Review: Species in the genus Spermophagus are found in all of the Old World regions except Australia. Prior to this fine monograph, the taxonomy was a hodgepodge of local faunal treatments and single species descriptions with few usable keys or illustrations. Now we have available keys to 90 species with full descriptions, geographical distributions, and excellent illustrations of dorsal habitus, male genitalia, and many of the female genital valves.
The annulatipes group of the genus Forcipomyia Meigen, subgenus Lepidohelea Kieffer, is represented in the Western Hemisphere by 12 species. Keys are presented for their identification, and to distinguish them from other groups of the subgenus Lepidohelea. The three previously known species, annulatipes Macfie, brasiliensis Macfie, and kuanoskeles Macfie, from southern Brazil, as well as the following nine new species, are described and illustrated: bahiensis, basifemoralis, bifida, convexipenis, euthystyla, gravesi, herediae, hobbsi, and weemsi.
The following new species are described: Nyctonympha andersoni, sp. n., and N. howdenarum, sp. n., both from Colombia; N. genieri, sp. n., from Ecuador; N. taeniata, sp. n., from Trinidad; Falsamblesthis microps, sp. n., from Venezuela; Bactriola circundata, sp. n., from Brazil (Rio de Janeiro); B. maculata, sp. n., from Venezuela and Ecuador; and B. falsa, sp. n., from Brazil (Minas Gerais to Rio Grande do Sul). A redescription of Bactriola vittulata Bates, 1886, herein designated as the type species of the genus, is provided. Accurate data on the occurrence of Saepiseuthes chilensis Thomson, 1868, in Chile are given. Keys to the species of Bactriola Bates, 1886 and Nyctonympha Thomson, 1868 are added.
Twenty nine species of Delphacidae are recorded from the Yukon Territory, Canada, two additional ones from an adjacent region of Northwest Territories, and one species from coastal Alaska. Two new genera are described: Aschedelphax Wilson and Yukonodelphax Wilson. Six new species are described: Aschedelphax hochae Wilson, Delphacodes anufrievi Wilson, D. emeljanovi Wilson, Javesella lla Wilson, Nothodelphax glacia Wilson, and Yukonodelphax kendallae Wilson. Aschedelphax coloradensis (Beamer), Javesella kilmani (Van Duzee), Yukonodelphax pediforma (Beamer) and Y. stramineosa (Beamer) are new combinations. Kusnezoviella matisi Anufriev and Emeljanov is a junior synonym of K. macleani Wilson and Delphacodes hyalina Beamer is a junior synonym of Nothodelphax albocarinata (Stil). Of the 32 species included in the study, 18 have a Holarctic distribution - 10 of these are amphi-Beringian. The remaining 14 species are restricted to the Nearctic, 5 of these are recorded only from the Yukon and Northwest Territories.
Only five species of Bruchidae have been recorded from the Dominican Republic D.R) per se although records exist for “Hispaniola” and Haiti. Collections made during a recent trip (1992) by R. Turnbow and M.C. Thomas have added data for five additional species, one of which is a new West Indian record whereas the other three are range extensions of species previously known from the West Indies. Geographical ranges for each species are briefly indicated.
The following subgenera of Apion Herbst are elevated to generic status: Bothryopteron Wagner (type species: Apion grallarium Sharp); Coelocephiilapion Wagner (type species: Apion bryanti Wagner); Coelopterapion Wagner (type species: Apion testaceum Wagner); Fallapion Kissinger (type species: Apien impunctistriatum Smith); and Stenapion Wagner (type Species: Apion constricticolle Sharp). Twelve areas of apionid rostral sulci and carinae are defined and illustrated. Six new species of Coelooephalapien are described: four similar to C. bryanti, (Wagner): Jumentum (panama and Honduras), kektaon (Belize), pelor (Panama), and schema (panama); and two similar to C. spretissimum (Sharp): adhocum (Mexico) and pigrae (Venezuela). C. pilirostre (Wagner), near bryanti, is redescribed from Mexico and Honduras with neotype designation.
Affinities, diagnoses, and descriptions are provided for two new species of Plusiotis: P. spectabilis from an unknown locality in Central America and P. dianae from Veracruz state in Mexico. Plusiotis spectabilis is described from a single female and is the largest species in the genus (41 mm in length).
An undescribed genus and species of flightless longhorned beetle, Apteralcidion lupierrei new genus, new species, in the subfamily Lamiinae, has been collected from giant thistle, Cirsium subcoriaccum, at high elevations in Costa Rica and Panama. This new taxon appears most-closely related to genera in the tribe Acanthocini.
One hundred forty-five species of caddisflies representing 15 families and 46 genera are reported from Oklahoma. Thirty-nine species are new state records. Families having the greatest species richness were Hydroptilidae (44 species), Leptoceridae (31 species), Hydropsychidae (26 species), and Polycentropodidae (13 species).
Book Review: A comprehensive treatment of the ecology of aquatic insects in one place is needed for both students and researchers. Professor Ward is doing this in two volumes. The first volume covers the biology and habitats, as indicated in the subtitle, of the 13 insect orders that are either entirely aquatic at some stage, or those with some members aquatic at some stage. The second volume will be devoted entirely to the feeding ecology of these aquatic species.
Specific Alaskan and Canadian localities are recorded for the chilopod Scolopocryptops sexspinosus (Say) (Cryptopidae), the only indigenous Nearctic scolopendromorph species occurring north of the lower 48 states. It occurs west of the crest of the Coast Range in British Columbia, extending northward to the southernmost islands of Alaska, and is recorded for the first time from eastern Canada, from Niagara Gorge, Ontario. Reports of S. rubiginosus Koch from southern Alaska are based on a misidentification of S. sexspinosus, and records from the north-central United States are too distant from the international border for it to be plausible for Manitoba and western Ontario. This centipede does not occur along the Pacific Coast and is improbable for any other part of Canada.
Vincent Golia, Delray Beach, Florida, collected a single female specimen of the tamarind seed beetle, Caryedon serratus, in an orange grove near Homestead. This is the first record of this bruchid for continental United States although the species is recorded from the Hawaiian Islands, and is often intercepted during port inspections.
New records of the xystodesmid diplopod Stenodesmus tuobitus (Chamberlin) extend its range and those of the family and suborder Chelodesmidea into southwestern New Mexico, west of the Rio Grande. They confirm that it inhabits arid juniper environments at relatively low elevations as well as moist deciduous fir forests at high elevations, thereby lending credence to past records from the former habitat in Lincoln County. Discovery of the milliped in neighboring mountain ranges to the north and west is now likely, with the distant possibility that it may occur in eastern Arizona.
Ommatius fimbriatus and O. subtus are based upon four specimens embedded in Dominican amber from the El Mamey Formation in the Dominican Republic. The amber is from the Lower Oligocene - Upper Eocene, originating between 25 and 40 million years ago. The specimens are the first reported fossils of Ommatius. Both species are described and compared with modern species. Significant characters are illustrated and/or photographed.
A brief account of the present state of weevil taxonomy is followed by a detailed study of certain structures used in their classification, namely the venter, abdominal tergites, sternite 8 of the male, apex of the hind tibia and deciduous mandibular processes. A key to some 50 families and subfamilies of Curculionoidea is followed by a list of family-group taxa. The following changes are made: Brachyceridae, Erirhinidae. Cryptolnryngidae und Raymondionymidae are promoted to family rank from Curculiollidne; Antliarhininae is demoted to a subfamily of Brentidae, and Allocoryninae to a subfamily of Oxycorynidne; Coptonotini is demoted to a tribe of Curculionidue Scolytinae; Carinae, sufam. n. is erected for Car Blackburn (genus incertae sedis) in Belidae; Dinomor'phini is demoted to a tribe of Molytinae and Brachyccropsidinae is revived from synonymy with Dinomorphinae (Curclliionidae); Urachyderini, Eremnini, Otiorhynchini and Sitonini are demoted to tribes of Entiminue; Desmidophorinae is transferred from Brentidae to Brachyccridae, Ocladiini is promoted to a tribe of Desmidophorinae (from Curculionidae-Cryptorhynchinae); Campyloseelini (including Phaenomerina) is transferred from Rhynchophoridae to Curculionidae-Zygopinae; Carphodicticinae is promoted to subfamily rank and transferred from Curculionidae-Scolytinae to Platypodidae; Perieges; Schönherr is transferred from Curculionidae-Thecesterninae to Cryptoiaryngidae and Agriochaeta Pascoe from Cryptorhynchinae to Hyperinae (Curculionidae); Schadlarius Wood and Mecopelmus Blackman are transferred from Coptonotidae to Platypodidae.
The theoretical concept of the biological species and the multidimensional species category, as currently applied by a majority of ornithologists and by many other biologists, replaced the typological-morphological species concept during the first half of this century and became a central tenet of the synthetic theory of evolution. The concept of biospecies is a 'horizontal' concept referring to contemporary reproductive communities at any particular period, e.g. the Recent period or any other time level of the geological past. Historical 'species' concepts as applied by cladists and palaeontologists refer to artificially delimited portions of 'vertical' phyletic lineages for which the application of the term 'species' causes severe problems. Discussions would be simplified if the concept and term 'species' was to be restricted to cross sections of phyletic lineages at any time level and a separate taxonomy outside the Linnaean system of genera and species was to be conceived to deal with phyletic lineages. Under each of the theoretical species concepts, species taxa are assigned broadly to intermediate or narrowly defined taxonomic species categories. Ornithologists of the 19th century applied morphological species concepts, emphasizing morphological character differences between species (rather than distinctness) and the fertility of con specific individuals (rather than the isolation from non-conspecific populations). Nearly all leading museum ornithologists in 19th-century Europe delineated monotypic Linnaean species, whereas the explorer-naturalists of the Gloger-Middendorff school (including Panas, Faber, Gloger, Nordmann, Middendorff, Schrenck, Radde, as well as Schlegel and Blasius) delimited widely circumscribed species taxa. Their researches in the vast territories of eastern Europe, Siberia and the Far East from the late 18th century to the 1880s and, in particular, their rich specimen material, demonstrated direct intergradation of many taxa (geographical varieties) of birds, thus revealing the conspecific nature of numerous narrowly conceived morphospecies previously described by museum workers. The ornithologists of the Gloger-Middendorff school also studied several conspicuous phenomena of geographical character variation in birds (and mammals) across Eurasia, especially plumage colouration (and pelage) and body size, but none of them was an evolutionist. They an adhered to a typological-creationist theoretical species concept. During the late 19th century, the museum specialists' taxonomic notion of narrow morphospecies dominated systematic ornithology in Europe, overtaking the work of the naturalists of the Gloger-Middendorff school, which fell into oblivion. The ornithologists of the Bairdian school in North America (Baird, Coues, Allen, Ridgway) further developed the concept of subspecies after the 1850s and especially from the 1870s onward. Their views were fully in accord with Darwin's theories of evolution' thus they defined the subspecies in a somewhat simplified manner as 'nascent species': These ornithologists were able to base their studies on collections of extensive specimen material which they had obtained during a series of exploring expeditions across the North American continent. Their studies led to the discovery of many aspects of both individual and geographic variation in birds. There are interesting historical similarities between the coinciding taxonomic interpretations and the comparable application of fairly broad limits of morphospecies by the North American ornithologists and the earlier exploring ornithologists in Europe, arrived at Independently by these, research groups, The study of specimens in 'series' (,suites'), beginninng with the naturalists of the Gloger-Middendorff school and, in particular, with the naturalists of the Bairdian school in North America, eventually led to the overcoming of the prevating typological view of variation and the development of 'population thinking'. Influenced by the work of Henry Seebohm in Britain and that of the North American ornithologists, Hartert in England and Kleinschmidt in Germany jointly succeeded in overcoming the strong opposition of the leadi.ng ornithologists in Europe during the 1890s and early 19008 and introduced a concept which soon developed into the biological species concept through the work of Stresemann, Rensch, and in particular, Ernst Mayr. Hopefully, ornithologists will continue the study of taxa at low, intermediate and high levels of microtaxonomic differentiation and will identify the subspecies groups, biological species and the biogeographical species in the world's avifaunas. Cladistic analyses will provide historical {'vertical'} overviews of phyletic lineages at different taxonomic levels.
Speakers of various Southern german dialects may be heard to use two syntactic variants of subordinate clauses which are represented by the following Swabian examples: (1) daß er den net will komme lasse (2) daß er den net komme lasse will Of these two variants of the three-element verbal complex, only the non-dialect counterpart of (2) is accepted as standard modern written German: (3) daß er ihn nicht kommen lassen will In earlier periods of the German language, however, both variants were used by authors of written texts.
Classical mutagenesis
(1992)
Classical genetic analyses require the presence of at least two different alleles per locus. Until the mid 1920's for the different alleles the investigators had to rely on spontaneous mutations. Since then mutagenic agents (mutagens) became available and these discoveries greatly enhanced the power of genetic analyses. Mutation is defined here as a heritable chemical alteration within the gene or the mutation process bringing about the change. Mutant is the individual (cell) containing the mutation. Point mutations are assumed to be free of loss, gain or rearrangement within the nucleotide sequence. Fonvard mutations are changes from the wild type allele (the allele predominant in wild populations) to a new allele, and the reverse process is backmutation. The frequency o/mutation per locus per generation (mutation rate) must be distinguished from mutant frequency, indicating simply the number of mutants in a population. Mutation in the broad sense involves also hereditary changes in chromosome number (polyploidy and aneuploidy) and chromosome structure, visible through the light microscope. The latter types are frequently called chromosomal aberrations. Arabidopsis, without further qualifications, in this context, will refer to Arabidopsis thaliana (L.) Heynh. in its diploid form (2n = 10). This species has three genomes, the nuclear, plastidic and the mitochondrial. Its nuclear genome (n = 5) is the smallest among higher plants (Leutweiler et al., 1984), containing about 0.7 - 1 x 108 bp, and redundancy is very low (Meyerowitz and Pruitt, 1985). The plastid genome is about the same size as that of the mcYority of higher plants, ca. 150 kb. The size of the mitochondrial genome is ca. 400 kb. Arabidopsis is an excellent tool for genetics and its critical features and known mutants have been reviewed (R&Iei , 1970, 1975a,b; Kranz, 1978; Meyerowitz and Pruitt, 1984; Meyerowitz, 1987, 1989; Estelle and Somerville, 1986; Bowman et al., 1988).
The study adressed 4 basic issues: (1) What are the substantive contents of human values? (2) Can we identify a comprehensive set of values? (3) To what extent is the meaning of particular values equivalent for different groups of people? (4) How are the relations among different values structured? These issues required resolution before the antecedents and consequences of value priorities, or cross-cultural differences in such priorities, could be studied effectively. Substantial progress has been made toward resolving each of these issues.
When in 1934, Robert BLEICHSTEINER published the Caucasian language specimina contained in the "travel book" of the 17th century Turkish writer Evliya Çelebi , he was struck by the amount of reliability he found in Evliya’s notations: "(Die Sprachproben) sind, von einzelnen Mißverständnissen abgesehen, und wenn man die falschen Punktierungen und Irrtümer der Kopisten abrechnet, außerordentlich gut, ja zuweilen mit einem gewissen phonetischen Geschick wiedergegeben, was der Auffassungsgabe und dem Eifer Evliyas ein hohes Zeugnis ausstellt. Man muß bedenken, wie schwer das arabische Alphabet, ohne weitere Unterscheidungszeichen, wie sie die islamischen Kaukasusvölker anwenden, die verwickelten, oft über 70 verschiedene Phoneme umfassenden Lautsysteme wiederzugeben imstande ist. Wenn trotzdem die Entzifferung der Sprachproben zum größten Teil geglückt ist, so muß man der ungewöhnlichen Begabung des türkischen Reisenden und Gelehrten schrankenlose Bewunderung zollen" (85). ...
The paper focuses on business negotiation in settings in which participants from different mothertongue backgrounds choose French, English andfor German as one of their languages of communication. A general scheme of the action-pattem of buying and selling will be sketched out which allows us to analyze specific Courses of verbal actions according ta their communicative functions within the negotiation process. In particular, the discourse of business communication is to be specified as a decision making process on the part of the buyer which is executed in a step-by-step order, and which is Open to the application of a bundle of the seller's strategies, tactics, and communicative techniques. In international negotiations, effects of unobserved miscommunication are, among others, far-stretched communicative circles, prolongation of negotiation time, non-functional explanations and several other repetitive structures. 1. Languages of trade and commerce - languages of communication 2. Communication in a Buy-Sell-Context is patterned 2.1. Entering the Pattern 2.2. The Main Phase 2.3. The Bidding Phase 2.4. The Specifc Conditions 2.5. Negotiating the Contract 3. The Central Point 3.1. The Buyer's Decision-Making Process 3.2 Decision-Making and Role-Playing 3.3. Intercultural Difference of the Decision-Making Process 4. Bridging the Buyer's Gap of Knowledge 5. The Language of Trade and Commerce 6. The Needs of Further Research: Data References
Crépin (1891) arranged 55 species of Rosa into 15 sections. Three of those sections contain taxa native to the British Isles, and members of several further sections have been reported as naturelized. In the discussion below, accepted names are shown in bold, while rejected names are given in italics.
The properties of nuclear matter are studied in the framework of quantum hadrodynamics. Assuming an ω-meson field, periodic in space, a self-consistent set of equations is derived in the mean-field approximation for the description of nucleons interacting via σ-meson and ω-meson fields. Solutions of these self-consistent equations have been found: The baryon density is constant in space, however, the baryon current density is periodic. This high density phase of nuclear matter can be produced by anisotropic external pressure, occurring, e.g., in relativistic heavy ion reactions. The self-consistent fields developing beyond the instability limit have a special screw symmetry. In the presence of such an ω field, the energy spectrum of the relativistic nucleons exhibits allowed and forbidden bands, similar to the energy spectrum of the electrons in solids.
We investigate the production of heavy quarks in continuum and bound states in nuclear collisions. Creation rates for free bb and tt quark pairs and for bottomonium and toponium in the ground state are computed at energies of the BNL Relativistic Heavy Ion Collider, CERN Large Hadron Collider (LHC), and Superconducting Super Collider. Central and peripheral heavy-ion collisions are discussed. For top-quark creation we assumed a mass range of 90≤mt≤250 GeV. The creation rate for top quarks in peripheral collisions is estimated to be by a factor 40 to 130 smaller compared with corresponding central collisions. For mt=130 GeV we calculated a creation rate of about 4760 top-quark pairs per day at the LHC (3.5 TeV/nucleon) for Pb-Pb collisions.
We discuss the multiplicity distribution of electron-positron pairs created in the strong electromagnetic fields of ultrarelativistic heavy-ion transits. Based on nonperturbative expressions for the N-pair creation amplitudes, the Poisson distribution is derived by neglecting interference terms. The source of unitarity violation is identified in the vacuum-to-vacuum amplitude, and a perturbative expression for the mean number of pairs is given.
Relativistic heavy ion collisions constitute a prolific source of hyperons: tens of hyperons per event are predicted at energies E≥10 GeV/nucleon, providing a scenario for the formation of metastable exotic multihypernuclear objects. They may exhibit exceptional properties: bound neutral (e.g., 4M2Λ2n, 10M2Λ8n, pure Λ droplets, 8Λ) and even negatively charged composites objects with positive baryon number (e.g., 4M2Σ-2n, 6M2Λ2Ξ-2n) could be formed in rare events. Such negative nuclei can easily be identified in a magnetic spectrometer. They could be considerably more abundant than antinuclei of the same A. We use the relativistic meson-baryon field theory—which gives an excellent description of normal nuclear and single-Λ hypernuclear properties—to calculate the rich spectrum of such exotic objects, their stability, and their structure. We also find solutions for a large variety of bound short-lived nuclei (e.g., 8M2Λ,2Σ-2p2n), which may decay strongly via formation of cascade (Ξ) particles. Multi-Ξ hypernuclei are also evaluated. A variety of potential candidates for such metastable exotic nuclei is presented. It turns out that the properties of such exotic multihypernuclear objects reveal quite similar features as the strangelet proposed as a unique signature for quark-gluon plasma formation in heavy ion collisions.
A quasiclassical Pauli potential is used to simulate the Fermi motion of nucleons in a molecular dynamical simulation of heavy ion collisions. The thermostatic properties of a Fermi gas with and without interactions are presented. The inclusion of this Pauli potential into the quantum molecular dynamics (QMD) approach yields a model with well defined fermionic ground states, which is therefore also able to give the excitation energies of the emitted fragments. The deexcitation mechanisms (particle evaporation and multifragmentation) of the new model are investigated. The dynamics of the QMD with Pauli potential is tested by a wide range of comparisons of calculated and experimental double-differential cross sections for inclusive p-induced reactions at incident energies of 80 to 160 MeV. Results at 256 and 800 MeV incident proton energy are presented as predictions for completed experiments which are as yet unpublished.
Stopping power and thermalization in relativistic heavy ion collisions is investigated employing the quantum molecular dynamics approach. For heavy systems stopping of the incoming nuclei is predicted, independent of the energy. The influence of the quantum effects and their increasing importance at low energies, is demonstrated by inspection of the mean free path of the nucleons and the n-n collision number. Classical models, which neglect these effects, overestimate the stopping and the thermalization as well as the collective flow and squeeze out. The sensitivity of the transverse and longitudinal momentum transfer to the in-medium cross section and to the pressure is investigated.
Experimental results are presented on the charge, velocity, and angular distributions of intermediate mass fragments (IMFs) for the reaction Fe+Au at bombarding energies of 50 and 100 MeV/nucleon. Results are compared to the quantum molecular dynamics (QMD) model and a modified QMD which includes a Pauli potential and follows the subsequent statistical decay of excited reaction products. The more complete model gives a good representation of the data and suggests that the major source of IMFs at large angles is due to multifragmentation of the target residue.
Strong correlations between baryon stopping in the projectile rapidity hemisphere and target excitation have been found in the light-ion-induced reactions at the BNL Alternating Gradient Synchrotron (AGS) (E814 group). Results in the framework of the relativistic molecular dynamics approach (RQMD) describe recent E814 data quite well. We discuss the RQMD results together with proton and pion data from the E802 group near midrapidity. They have raised the question of whether partial transparency could be seen in these experiments. The RQMD results indicate strong transverse baryon flow in central Si+Au collisions after the projectile has been stopped in the target.
We present a calculation of antiproton yields in Si+Al and Si+Au collisions at 14.5A GeV in the framework of the relativistic quantum molecular dynamics approach (RQMD). Multistep processes lead to the formation of high-mass flux tubes. Their decay dominates the initial antibaryon yield. However, the subsequent annihilation in the surrounding baryon-rich matter suppresses the antiproton yield considerably: Two-thirds of all antibaryons are annihilated even for the light Si+Al system. Comparisons with preliminary data of the E802 experiment support this analysis.
By replacing the irises in an electron linac by a slit one gets a structure capable of focussing/defocussing an electron beam (rf-quadrupoles). Therefore one can think of a combination of rf- and conventional magnetic quadrupoles for transversal focussing in linear-colliders. Furthermore they can meet the demands of BNS-damping without initial energy spread. Considering multibunch-operation of a collider, the long-range wake behaviour of this kind of structure has to be investigated. A three-cell structure has been built and investigated for dipole-type transversal long-range wakes. The experimental results are compared to numerical simulations done with MAFIA.
Determination of field strength and quality factor of heavily HOM damped accelerator cavities
(1992)
Two methods of of measuring field strength in accelerator cavities, heavily damped with respect to higher order modes (HOM), are presented. From the results of the field measurements the coupling (damping) factor and thus the quality factor of the damped resonator can be derived. Measurements of a pillbox resonator with heavily damped TM110-mode (Q < 20) demonstrate the usefulness of the techniques presented, even in this extreme range.
The energy dependence of rapidity distributions and flow effects was studied in central Ar+Pb collisions at 400, 800, and 1800 MeV/nucleon using a streamer chamber. Rapidity distributions for proton and pions are found to have a Gaussian shape whereas those for deuterons exhibit a two-peak structure at the two higher energies. The average in-plane transverse momentum per/nucleon and per/event shows saturation of flow around 800 MeV/nucleon for this asymmetric system. The aspect ratio of the sphericity tensor is closely correlated with the flow angle. This correlation appears to be independent of beam energy. The number of participating nucleons in central collisions varies from 213 at 400 to 135 at 1800 MeV/nucleon indicating that at the lowest energy almost the entire target nucleus participates in the collision.
The general subset sum problem is NP-complete. However, there are two algorithms, one due to Brickell and the other to Lagarias and Odlyzko, which in polynomial time solve almost all subset sum problems of sufficiently low density. Both methods rely on basis reduction algorithms to find short nonzero vectors in special lattices. The Lagarias-Odlyzko algorithm would solve almost all subset sum problems of density < 0.6463 . . . in polynomial time if it could invoke a polynomial-time algorithm for finding the shortest non-zero vector in a lattice. This paper presents two modifications of that algorithm, either one of which would solve almost all problems of density < 0.9408 . . . if it could find shortest non-zero vectors in lattices. These modifications also yield dramatic improvements in practice when they are combined with known lattice basis reduction algorithms.
Other than in Belgium, German banks may hold even controlling equity participations in industrial firms (and such firms may own banks) and do so to a large extent. Vis-a-vis the European development this leads to two questions: From the perspective of the (Belgian and other) competitors of these banks, whether their own domestic System might be disadvantageous to them. And from a public interest perspective, which advantages and drawbacks are connected with the different regulations in Europe. The article first informs about the legal framework and some statistical facts. Then the various and different reasons why banks acquire and hold shares on own account are analyzed. The following Parts deal with the various public policy arguments whether equity links between banks and industrial firms should be prohibited or not (safety and soundness of banking; autonomie de Ia fonction bancaire ; abuse of confidential information and conflicts of interest; antitrust considerations; negative and positive impacts on the respective firm). In its last part the article deals with recent proposals in the German political debate to limit stockholdings of banks. The article argues that a step-by-step approach to the Single Problems and issues (conflict of interests; anticompetitive effects etc.) should be preferred to a general limitation of stock ownership of banks.
The corporate governance Systems in the U.K. and in Germany differ markedly. German large firms have a two-board structure, they are subject to employee codetermination, their managements are not confronted with public hostile takeover bids, and banks play a major role in corporate governance, through equity stakes, through proxies given to them by small investors, and through bankers positions on the supervisory boards of these firms. One of the main issues of corporate governance in large firms, the Problem of shareholders passivity in monitoring management in Berle-Means type corporations, is thus addressed by an institutional Provision, the role of the banks, rather than by a market-oriented Solution as we find it in the U.K. with its market for corporate control through the threat of hostile takeovers. These two different approaches to corporate governance have been compared several times recently, and it was argued that a bank-based or institutional Solution has clear advantages and should be preferred. Cosh, Hughes and Singh, for example, argue at the conclusion of their discussion of takeovers and short-termism in the U.K. that the institutional shareholder [in the UK] should take a much more active and vigorous part in the internal governance of corporations. . . . In Order for such a proposal to be effective both in disciplining inefficient managements and promoting long-term investments, far reaching changes in the internal workings and behaviour of the financial institutions would be required. The financial institutions would need to pool their resources together, set up specialised departments for promoting investment and innovations - in other words behave like German banks. The following remarks seek to continue this discussion from the German perspective. The article will first attempt to evaluate the monitoring potential of our domestic bank or institution-oriented corporate governance System and then, in a further patt, compare it with that of a market-oriented Solution. lt will be argued that both Systems focus on different Problems and have specific advantages and drawbacks, and that there are still quite a few puzzles to be solved until all pros and cons of each of these monitoring devices tan be assessed. The perception that both Systems focus on different Problems suggests combining institutional monitoring with a market for corporate control rather than considering them to be contrasting and incompatible approaches. The article is organized as follows. Section II will describe the legal structure of the large corporation in Germany in more detail. Section Ill explains why a market for corporate control by the threat of public hostile takeover bids does not exist in Germany. Section IV then Shows how corporate governance in publicly held corporations with small investors is organized instead, and deals with the role of banks in corporate governance in these firms. Section V of the atticle then will try to compare the monitoring potential of a marketoriented and our bank or institution-oriented corporate governance System. Concluding remarks follow.