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The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.
The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.
The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p–Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.
This paper summarizes current knowledge about Central African pholcids. Central Africa is here defined as the area between 10°N and 7°S and between 6°E and 18°E, including mainly the Lower Guinean subregion of the Guineo-Congolian center of endemism. This includes all of Gabon, Equatorial Guinea, São Tomé and Príncipe, most of Cameroon and Congo Republic, and parts of the neighboring countries. An annotated list of the 14 genera and 79 species recorded from this area is given, together with distribution maps and an identification key to genera. Seven species are newly described: Anansus kamwai sp. nov., Leptopholcus gabonicus sp. nov., Ninetis faro sp. nov., Pholcus punu sp. nov., P. rawiriae sp. nov., Spermophora abibae sp. nov., and S. awalai sp. nov. Additional new records are given for 16 previously described species, including 17 new country records. Distribution and diversity patterns are compared with data on West and East Africa. While West Africa contains a similar set of genera it is significantly less diverse than Central Africa. East Africa is taxonomically more distinct. It has similar levels of diversity as Central Africa, but appears to be less undersampled.
Daddy-long-leg giants: revision of the spider genus Artema Walckenaer, 1837 (Araneae, Pholcidae)
(2017)
This is the first revision of Artema Walckenaer, 1837, a genus consisting of large and phylogenetically interesting species. Even though Artema is not species-rich (now eight nominal species), it has suffered from poor descriptions and synonymies. Our main goal was to gather all available material and to clarify species limits. Four species are easily distinguished from other congeners: Artema atlanta Walckenaer, 1837, the type species; A. kochi Kulczyński, 1901 (revalidated); A. bunkpurugu Huber & Kwapong, 2013; and A. nephilit sp. nov. All other species are problematic for varying reasons: species limits are unclear between A. doriae Thorell, 1881 and A. transcaspica Spassky, 1934; A. magna Roewer, 1960 and A. ziaretana (Roewer, 1960) are problematic because they are based on female and juvenile types respectively and little new material is available. The material available to us suggests the existence of a few further species; however, they are not formally described, either because of small sample sizes (Artema sp. a and A. sp. b are represented by only one specimen each) or because of unclear species limits (between Artema sp. c, A. transcaspica and A. doriae).This study is the first serious step towards understanding the genus. Intensive collecting effort is needed in order to fully clarify species limits.
Künstlicher Traubenwicklerbefall : eine neue Möglichkeit zur Prüfung von Insektiziden im Weinbau
(2006)
Bei der Prüfung von Insektiziden gegen die Traubenwickler Lobesia botrana DEN. & SCHIFF. und Eupoecilia ambiguella HBN. (Lepidoptera: Tortricidae) im Freiland ist ein ausreichender Befall mit den Schadinsekten notwendig, um statistisch auswertbare Ergebnisse zu erzielen. Dem steht jedoch ein jährlich stark wechselnder Befallsdruck und ein oft stark geklusterter Befall, selbst innerhalb einer eng umgrenzten Rebanlage, entgegen. Hinzu kommen erhebliche Probleme mit dem richtigen Timing der Behandlung, bedingt durch eine sehr lange Flugzeit der Traubenwicklerarten, was häufig zu einer geringen Effizienz und schlechten Vergleichbarkeit der Mittel führt. Für die Entwicklung von Insektiziden bedingen diese Voraussetzungen eine große Anzahl von Versuchen, die mit hohen Kosten verbunden sind Abhilfe kann für viele Fragestellungen ein künstlich erzeugter Befall geben. Die Methode soll hier kurz vorgestellt und die Anwendung exemplarisch an Versuchen mit beiden Traubenwicklerarten dargestellt werden.
The North American-Caribbean genera Pholcophora Banks, 1896 and Tolteca Huber, 2000 are representatives of Ninetinae, a group of small, cryptic, and thus poorly known pholcid spiders. We present the first comprehensive revisions of the two genera, including extensive SEM data and descriptions of seven new species from Mexico (Pholcophora mazatlan Huber sp. nov., P. papanoa Huber sp. nov., P. tehuacan Huber sp. nov., Tolteca huahua Huber sp. nov., T. manzanillo Huber sp. nov., T. oaxaca Huber sp. nov., and T. sinnombre Huber sp. nov.). We add new CO1 sequences of nine species to previously published molecular data and use these for a preliminary analysis of relationships. We recover a North American-Caribbean clade including ‘true’ (mainland) Pholcophora, Tolteca (Mexico), and a Caribbean clade consisting of the genus Papiamenta Huber, 2000 (Curaçao) and Caribbean ‘Pholcophora’. First karyotype data for Tolteca (2n♂ = 13, X1X2Y and 15, X1X2Y, respectively) reveal a strong reduction of the number of chromosome pairs within the North American-Caribbean clade, and considerable karyotype differentiation among congeners. This agrees with considerable CO1 divergence among species of Tolteca but contrasts with very inconspicuous morphological divergence. Environmental niche analyses show that the widespread P. americana Banks, 1896 (western USA, SW Canada) occupies a very different niche than its Mexican congeners and other close relatives. Caribbean taxa also have a low niche overlap with ‘true’ Pholcophora and Tolteca, supporting the idea that Caribbean ‘Pholcophora’ are taxonomically misplaced.
We present a comprehensive revision of the pholcid spider collection of M.A. González-Sponga, who between 1998 and 2011 described 22 new genera and 51 new species of Pholcidae from Venezuela. In addition, we treat the pholcid material collected during three expeditions to Venezuela conducted between 2002 and 2020. Of González-Sponga’s pholcid taxa we recognize three genera and 24 species as valid. We describe 43 new species (all from males and females) in one new and 13 previously described genera; four genera are newly recorded for Venezuela. We describe the previously unknown females of 15 species, present new records for 46 previously described species, synonymize one genus and one species, and correct numerous minor errors in previous publications on Venezuelan pholcids. At the generic level, the Venezuelan pholcid fauna now appears fairly well known, but available data on distribution and endemism suggest that many species remain undiscovered and undescribed. Despite the obvious gaps, our data are congruent with previous studies on other taxa that have the highest levels of endemism in the Venezuelan Andes, the Coastal Ranges, and the Guyana Highlands. The Falcón Region in particular shows a complex mosaic of biogeographic relationships with other regions. We provide new biological data on numerous species. We document the first cases of evolutionary microhabitat shifts in the genera Mecolaesthus Simon, 1893 and Priscula Simon, 1893. We document several cases of close congeners sharing localities, usually in slightly to conspicuously different microhabitats, sometimes apparently in identical microhabitats. We document several cases of color polymorphism, mostly intersexual, in Metagonia conica (Simon, 1893) both intersexual and among males. We document further cases of two rare phenomena in Pholcidae: use of specific non-silken structures for retreats (in Pisaboa Huber, 2000) and egg parasitism (in Priscula).
The first measurement of two-pion Bose–Einstein correlations in central Pb–Pb collisions at √sNN=2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.
Inclusive transverse momentum spectra of primary charged particles in Pb–Pb collisions at √sNN=2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0–5% and 70–80% of the hadronic Pb–Pb cross section. The measured charged particle spectra in |η|<0.8 and 0.3<pT<20 GeV/c are compared to the expectation in pp collisions at the same sNN, scaled by the number of underlying nucleon–nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAA. The result indicates only weak medium effects (RAA≈0.7) in peripheral collisions. In central collisions, RAA reaches a minimum of about 0.14 at pT=6–7 GeV/c and increases significantly at larger pT. The measured suppression of high-pT particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb–Pb collisions at the LHC.