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The genus Casmaria H. Adams & A. Adams, 1853 (family Cassidae) is widespread in the tropical Indo-Pacific and has been documented from some Atlantic localities as well. Two Casmaria species, C. erinaceus (Linnaeus, 1758) and C. ponderosa (Gmelin, 1791), are common in Indo-Pacific shallow-water sandy bottom communities and are characterized by high morphological variability; both species encompass multiple, often sympatric forms of uncertain status. In the present study we carry out a phylogenetic analysis of some Philippine Casmaria morphs and demonstrate that one of the distinctive morphs earlier assigned to Casmaria ponderosa is in fact a different species, which we describe as Casmaria boblehmani sp. nov. The smooth form of Casmaria ponderosa, C. ponderosa ponderosa, and the solid nodulose form, widely called “form nodulosa” despite being strikingly different in shell morphology, are shown to be conspecific. Studied specimens of these two morphs even from different localities share the same haplotype of the CO1 gene. In light of these new data on the morphological variability of Casmaria species, we discuss criteria of species delimitation in the genus Casmaria and possible affinities of Casmaria boblehmani sp. nov. within the genus.
This work is concerned with two topics at the intersection of convex algebraic geometry and optimization.
We develop a new method for the optimization of polynomials over polytopes. From the point of view of convex algebraic geometry the most common method for the approximation of polynomial optimization problems is to solve semidefinite programming relaxations coming from the application of Positivstellensätze. In optimization, non-linear programming problems are often solved using branch and bound methods. We propose a fused method that uses Positivstellensatz-relaxations as lower bounding methods in a branch and bound scheme. By deriving a new error bound for Handelman's Positivstellensatz, we show convergence of the resulting branch and bound method. Through the application of Positivstellensätze, semidefinite programming has gained importance in polynomial optimization in recent years. While it arises to be a powerful tool, the underlying geometry of the feasibility regions (spectrahedra) is not yet well understood. In this work, we study polyhedral and spectrahedral containment problems, in particular we classify their complexity and introduce sufficient criteria to certify the containment of one spectrahedron in another one.
Halirages helgae sp. nov. is recorded from the shelf slopes of the Norwegian Sea at depths of 1000 to 2600 m in the Arctic cold water masses. A total of 50 specimens were found at five stations. The
species differs from other known species in the genus Halirages Boeck, 1871 by the bilobed posterior margin of pereonite 7. A synoptic table to the northeast Atlantic species of Halirages is provided.
Coevolution of viruses and their hosts represents a dynamic molecular battle between the immune system and viral factors that mediate immune evasion. After the abandonment of smallpox vaccination, cowpox virus infections are an emerging zoonotic health threat, especially for immunocompromised patients. Here we delineate the mechanistic basis of how cowpox viral CPXV012 interferes with MHC class I antigen processing. This type II membrane protein inhibits the coreTAP complex at the step after peptide binding and peptide-induced conformational change, in blocking ATP binding and hydrolysis. Distinct from other immune evasion mechanisms, TAP inhibition is mediated by a short ER-lumenal fragment of CPXV012, which results from a frameshift in the cowpox virus genome. Tethered to the ER membrane, this fragment mimics a high ER-lumenal peptide concentration, thus provoking a trans-inhibition of antigen translocation as supply for MHC I loading. These findings illuminate the evolution of viral immune modulators and the basis of a fine-balanced regulation of antigen processing.
A multiple filter test for the detection of rate changes in renewal processes with varying variance
(2014)
The thesis provides novel procedures in the statistical field of change point detection in time series.
Motivated by a variety of neuronal spike train patterns, a broad stochastic point process model is introduced. This model features points in time (change points), where the associated event rate changes. For purposes of change point detection, filtered derivative processes (MOSUM) are studied. Functional limit theorems for the filtered derivative processes are derived. These results are used to support novel procedures for change point detection; in particular, multiple filters (bandwidths) are applied simultaneously in oder to detect change points in different time scales.
Neurons of the mammalian neocortex are produced by proliferating cells located in the ventricular zone (VZ) lining the lateral ventricles. This is a complex and sequential process, requiring precise control of cell cycle progression, fate commitment and differentiation. We have analyzed publicly available databases from mouse and human to identify candidate genes that are potentially involved in regulating early neocortical development and neurogenesis. We used a mouse in situ hybridization dataset (The Allen Institute for Brain Science) to identify 13 genes (Cdon, Celsr1, Dbi, E2f5, Eomes, Hmgn2, Neurog2, Notch1, Pcnt, Sox3, Ssrp1, Tead2, Tgif2) with high correlation of expression in the proliferating cells of the VZ of the neocortex at early stages of development (E15.5). We generated a similar human brain network using microarray and RNA-seq data (BrainSpan Atlas) and identified 407 genes with high expression in the developing human VZ and subventricular zone (SVZ) at 8–9 post-conception weeks. Seven of the human genes were also present in the mouse VZ network. The human and mouse networks were extended using available genetic and proteomic datasets through GeneMANIA. A gene ontology search of the mouse and human networks indicated that many of the genes are involved in the cell cycle, DNA replication, mitosis and transcriptional regulation. The reported involvement of Cdon, Celsr1, Dbi, Eomes, Neurog2, Notch1, Pcnt, Sox3, Tead2, and Tgif2 in neural development or diseases resulting from the disruption of neurogenesis validates these candidate genes. Taken together, our knowledge-based discovery method has validated the involvement of many genes already known to be involved in neocortical development and extended the potential number of genes by 100's, many of which are involved in functions related to cell proliferation but others of which are potential candidates for involvement in the regulation of neocortical development.
Twenty new species of the millipede genus Chaleponcus Attems, 1914, are described from the Udzungwa Mountains: C. netus sp. nov., C. quasimodo sp. nov., C. malleolus sp. nov., C. scopus sp. nov., C. nikolajscharffi sp. nov., C. mwanihanensis sp. nov., C. basiliscus sp. nov., C. krai sp. nov., C. nectarinia sp. nov., C. circumvallatus sp. nov., C. ibis sp. nov., C. vandenspiegeli sp. nov., C. vilici sp. nov., C. teres sp. nov., C. hamerae sp. nov., C. termini sp. nov., C. gracilior sp. nov., C. mwabvui sp. nov., C. howelli sp. nov. and C. tintin sp. nov. Together with C. dabagaensis Kraus, 1958, they constitute the Chaleponcus dabagaensis-group, well characterized by apparently apomorphic gonopodal characters, presumably monophyletic, and the first example of a major radiation within the Udzungwas. All species are restricted to altitudes >1390 m, all but one were found in only one, rarely two forest reserves, and the vast majority of specimens were collected in montane forest. Chaleponcus gracilior sp. nov. was collected in four forest reserves, often in secondary habitats where other species were only exceptionally found. Co-occurrence of multiple species, inter-specific differences in body size and unusual tarsal setation of a few species tentatively suggest adaptive radiation.
This paper solves a dynamic model of households' mortgage decisions incorporating labor income, house price, inflation, and interest rate risk. It uses a zero-profit condition for mortgage lenders to solve for equilibrium mortgage rates given borrower characteristics and optimal decisions. The model quantifies the effects of adjustable vs. fixed mortgage rates, loan-to-value ratios, and mortgage affordability measures on mortgage premia and default. Heterogeneity in borrowers' labor income risk is important for explaining the higher default rates on adjustable-rate mortgages during the recent US housing downturn, and the variation in mortgage premia with the level of interest rates.
Reintroductions of plant species are increasingly popular in conservation practice. Steppe grasslands contain many rare and endangered plant species that are potential objects for such reintroductions. Most reintroduction projects, however, can only target a restricted number of species, which raises the question of how species should be prioritised. Here, we present a method to select priority species for reintroduction based on species' characteristics that are widely used in conservation practice. We first determined the local species pool containing those vascular plant species that occurred both in our target region (Thuringia, Germany) and target habitat (steppe grasslands), yielding 369 species. With the help of an a priori filter that selected currently endangered species with limited distribution, 136 potential target species were determined. These potential target species had experienced stronger decline, had a narrower phytosociological amplitude and were more likely to be species of the Festuco-Brometea class and the Festucetalia valesiacae order than non-target species. Potential target species were then ranked by a points system based on ten conservation-relevant characteristics of the species from the categories "threat and protection status", "distribution and decline", and "habitat affiliation". In the ranking, six steppe grassland plant species (Astragalus exscapus, Bothriochloa ischaemum, Prunella laciniata, Pulsatilla pratensis subsp. nigricans, Scorzonera purpurea, and Seseli hippomarathrum) achieved the highest scores. An additional seven species not specifically characteristic for steppe grasslands also scored highly. A post hoc evaluation of these 13 highest scoring species based on additional conservation criteria left five species (Astragalus exscapus, Linum leonii, Orchis morio, Pulsatilla pratensis subsp. nigricans and Scorzonera purpurea) as species with highest priority for reintroductions and another five species as highly suitable for reintroductions. Associations between the ranking order and different ranking criteria revealed that a species’ threat and rarity in Thuringia and its protection status had the highest representation in the ranking, followed by threat in Germany, regional decline and habitat affiliation. In contrast, international threat and responsibility of Thuringia for its conservation had only low representation in the ranking, probably because these characteristics applied to only a few species. The ranking list gives a selection of species for reintroductions, which combined with additional information based on comprehensive local and floristic knowledge, allows the identification of the species with the highest priority. Our method can be transferred to other regions or habitat types.
On average, "young" people underestimate whereas "old" people overestimate their chances to survive into the future. We adopt a Bayesian learning model of ambiguous survival beliefs which replicates these patterns. The model is embedded within a non-expected utility model of life-cycle consumption and saving. Our analysis shows that agents with ambiguous survival beliefs (i) save less than originally planned, (ii) exhibit undersaving at younger ages, and (iii) hold larger amounts of assets in old age than their rational expectations counterparts who correctly assess their survival probabilities. Our ambiguity-driven model therefore simultaneously accounts for three important empirical findings on household saving behavior.
An adventive female Julidae (Julida), discovered in a moist, grassy depression in the Peninsula de Brunswick south of Punta Arenas, Chile, and assigned to Cylindroiulus Verhoeff, 1894, is the fi rst vouchered milliped from southern Patagonia. The southernmost milliped ever collected in Chile, South America, and the Western Hemisphere, it may also constitute the southernmost in the world as the site is only ~1,176 km (735 mi) northwest of the Antarctic Peninsula. Records are consolidated of the two families, three genera, and fi ve species of this Holarctic order that are known from South America. They are documented from Argentina, Chile, and southern Peru and Brazil; three species are known from the Juan Fernandez Islands.
A gomphid male from west-central Wisconsin (Eau Claire County, North Fork Eau Claire River, 11 June 1994, K. J. Tennessen leg) with characters that are intermediate between Ophiogomphus carolus Needham, 1897 and Ophiogomphus rupinsulensis (Walsh), 1862 is described and illustrated. The specimen appears to be a hybrid based on intermediate character states of 1) color pattern (slightly closer to O. carolus), 2) hamule morphology (shaped slightly more like those of O. carolus), and 3) anal appendage morphology (slightly more like those of O. rupinsulensis).
A grammar of Pite Saami
(2014)
Pite Saami is a highly endangered Western Saami language in the Uralic language family currently spoken by a few individuals in Swedish Lapland. This grammar is the first extensive book-length treatment of a Saami language written in English. While focussing on the morphophonology of the main word classes nouns, adjectives and verbs, it also deals with other linguistic structures such as prosody, phonology, phrase types and clauses. Furthermore, it provides an introduction to the language and its speakers, and an outline of a preliminary Pite Saami orthography. An extensive annotated spoken-language corpus collected over the course of five years forms the empirical foundation for this description, and each example includes a specific reference to the corpus in order to facilitate verification of claims made on the data. Descriptions are presented for a general linguistics audience and without attempting to support a specific theoretical approach, but this book should be equally useful for scholars of Uralic linguistics, typologists, and even learners of Pite Saami.
Irrigation intensifies land use by increasing crop yield but also impacts water resources. It affects water and energy balances and consequently the microclimate in irrigated regions. Therefore, knowledge of the extent of irrigated land is important for hydrological and crop modelling, global change research, and assessments of resource use and management. Information on the historical evolution of irrigated lands is limited. The new global Historical Irrigation Dataset (HID) provides estimates of the temporal development of the area equipped for irrigation (AEI) between 1900 and 2005 at 5 arc-minute resolution. We collected subnational irrigation statistics from various sources and found that the global extent of AEI increased from 63 million ha (Mha) in 1900 to 112 Mha in 1950 and 306 Mha in 2005. We developed eight gridded versions of time series of AEI by combining subnational irrigation statistics with different data sets on the historical extent of cropland and pasture. Different rules were applied to maximize consistency of the gridded products to subnational irrigation statistics or to historical cropland and pasture data sets. The HID reflects very well the spatial patterns of irrigated land in the western United States as shown on historical maps. Mean aridity on irrigated land increased and river discharge decreased from 1900–1950 whereas aridity decreased from 1950–2005. The dataset and its documentation are made available in an open data repository at https://mygeohub.org/publications/8 (doi:10.13019/M2MW2G).
BACKGROUND: Acetogenic bacteria are able to use CO2 as terminal electron acceptor of an anaerobic respiration, thereby producing acetate with electrons coming from H2. Due to this feature, acetogens came into focus as platforms to produce biocommodities from waste gases such as H2+CO2 and/or CO. A prerequisite for metabolic engineering is a detailed understanding of the mechanisms of ATP synthesis and electron-transfer reactions to ensure redox homeostasis. Acetogenesis involves the reduction of CO2 to acetate via soluble enzymes and is coupled to energy conservation by a chemiosmotic mechanism. The membrane-bound module, acting as an ion pump, was of special interest for decades and recently, an Rnf complex was shown to couple electron flow from reduced ferredoxin to NAD+ with the export of Na+ in Acetobacterium woodii. However, not all acetogens have rnf genes in their genome. In order to gain further insights into energy conservation of non-Rnf-containing, thermophilic acetogens, we sequenced the genome of Thermoanaerobacter kivui.
RESULTS: The genome of Thermoanaerobacter kivui comprises 2.9 Mbp with a G+C content of 35% and 2,378 protein encoding orfs. Neither autotrophic growth nor acetate formation from H2+CO2 was dependent on Na+ and acetate formation was inhibited by a protonophore, indicating that H+ is used as coupling ion for primary bioenergetics. This is consistent with the finding that the c subunit of the F1FO ATP synthase does not have the conserved Na+ binding motif. A search for potential H+-translocating, membrane-bound protein complexes revealed genes potentially encoding two different proton-reducing, energy-conserving hydrogenases (Ech).
CONCLUSIONS: The thermophilic acetogen T. kivui does not use Na+ but H+ for chemiosmotic ATP synthesis. It does not contain cytochromes and the electrochemical proton gradient is most likely established by an energy-conserving hydrogenase (Ech). Its thermophilic nature and the efficient conversion of H2+CO2 make T. kivui an interesting acetogen to be used for the production of biocommodities in industrial micobiology. Furthermore, our experimental data as well as the increasing number of sequenced genomes of acetogenic bacteria supported the new classification of acetogens into two groups: Rnf- and Ech-containing acetogens.
Futures markets are a potentially valuable source of information about market expectations. Exploiting this information has proved difficult in practice, because the presence of a time-varying risk premium often renders the futures price a poor measure of the market expectation of the price of the underlying asset. Even though the expectation in principle may be recovered by adjusting the futures price by the estimated risk premium, a common problem in applied work is that there are as many measures of market expectations as there are estimates of the risk premium. We propose a general solution to this problem that allows us to uniquely pin down the best possible estimate of the market expectation for any set of risk premium estimates. We illustrate this approach by solving the long-standing problem of how to recover the market expectation of the price of crude oil. We provide a new measure of oil price expectations that is considerably more accurate than the alternatives and more economically plausible. We discuss implications of our analysis for the estimation of economic models of energy-intensive durables, for the debate on speculation in oil markets, and for oil price forecasting.
We consider versions of the FIND algorithm where the pivot element used is the median of a subset chosen uniformly at random from the data. For the median selection we assume that subsamples of size asymptotic to c⋅nα are chosen, where 0<α≤12, c>0 and n is the size of the data set to be split. We consider the complexity of FIND as a process in the rank to be selected and measured by the number of key comparisons required. After normalization we show weak convergence of the complexity to a centered Gaussian process as n→∞, which depends on α. The proof relies on a contraction argument for probability distributions on càdlàg functions. We also identify the covariance function of the Gaussian limit process and discuss path and tail properties.