Iphimediidae of New Zealand (Crustacea, Amphipoda)

New Zealand species of Iphimediidae, Amphipoda, are revised. Based on new material from the Chatham Rise, east of New Zealand, two new species are described in detail: Labriphimedia meikae sp. nov. and Labriphimedia martinae sp. nov. A key to the six species belonging to three genera of New Zealand Iphimediidae is provided

In situ observations of trophic behaviour and locomotion of Princaxelia amphipods (Crustacea, Pardaliscidae) at hadal depths in four West Pacific Trenches

Peer reviewedPublisher PD

Do circum-Antarctic species exist in peracarid Amphipoda? A case study in the genus Epimeria Costa, 1851 (Crustacea, Peracarida, Epimeriidae)

The amphipod genus Epimeria is species rich in the Southern Ocean and at present eight of its 19 species are reported with circum-Antarctic distributions. For the first time, specimens of epimeriid species from the Antarctic Peninsula, the Weddell Sea and the Ross Sea were analysed using partial COI genes sequences and morphological characters. In total 37 specimens of 14 species of Epimeria and two species of Epimeriella were analysed and the resulting molecular topology checked by critically reviewing taxonomic characters. The genus Epimeriella, genetically grouping within Epimeria is synonymised with the genus Epimeria. Sequences distances between populations of the nominal species Epimeria robusta from the Weddell and Ross Sea led to detailed morphological investigations, resulting in the description of Epimeria robustoides sp. n. from the Weddell Sea. Epimeria robusta Barnard, 1930 from the Ross Sea is redescribed. Sequences of a damaged Epimeria specimen of a species new to science from the lower continental shelf of the eastern Weddell Sea were included. Based on the current study, the hypothesis of circum-Antarctic species' distributions in brooding amphipods proved to be unlikely

Dropout intent of students with disabilities

We examine the mechanisms explaining the dropout intentions of students with disabilities by integrating Tinto’s model of student integration, the student attrition model, the composite persistence model, and insights from social stratification research. The resulting theoretical model posits that not only students' academic and social integration, but also their private resources (financial, home learning, and personal resources) are crucial for academic success. Analysing data from a 2020 Germany-wide student survey, we find that students with disabilities are substantially more likely to intend to drop out of higher education than students without disabilities. Linear regressions and Kitagawa-Oaxaca-Blinder decompositions show that their lower academic integration and fewer personal resources are most relevant for explaining this difference, while their lower social integration, home learning, and financial resources play subordinate roles. Further analyses reveal that dropout intent is highest among students with psychic disabilities, followed by students with learning disabilities and students with physical disabilities. Regarding all three disability groups, less academic integration and fewer personal resources are most relevant for explaining their higher dropout intent (compared to students without disabilities). However, the disability groups differ regarding the importance of the different explanatory factors. Overall, our results highlight the importance of considering both students' integration into higher education and their private resources for understanding student-group-specific dropout intent

Regulation der 11b-Hydroxysteroid-Dehydrogenase Typ 1 im Verlauf einer Kalorienrestriktion

Die 11b-Hydroxysteroid-Dehydrogenase Typ 1 (11b-HSD1) fungiert in vivo hauptsächlich als Reduktase, indem inaktives Cortison in rezeptor-aktives Cortisol umgesetzt wird. Mehrere Studien weisen darauf hin, dass es einen kausalen Zusammenhang zwischen der 11b-HSD1, Adipositas und den damit verbundenen metabolischen Erkrankungen gibt. Die Expression und Aktivität der 11b-HSD1 ist dabei in der Leber bei übergewichtigen Patienten entweder unverändert oder nur leicht verringert. Andererseits wurden erhöhte Level im Fettgewebe gefunden. Weiterhin zeigten übergewichtige Patienten mit Typ-2-Diabetes erhöhte 11b-HSD1-Expressionslevel in den Myotuben der Skelettmuskulatur. Die genauen gewebsspezifischen Mechanismen der veränderten 11b-HSD1-Expression sind zum größten Teil unbekannt. Daher kann die Identifizierung der Faktoren und Mechanismen, die die 11b-HSD1-Expression und Enzymaktivität regulieren, zu einem besseren Verständnis der Pathogenese und möglicherweise neuen Therapieansätzen führen. Es wurde der Einfluss einer Kalorienrestriktion auf die 11b-HSD1-Expression und Enzymaktivität in verschiedenen Geweben in zwei unterschiedlichen Kalorienrestriktions und Wiederanfütterungsmodellen bestimmt. Hinweise aus der Literatur deuten darauf hin, dass die Expression und Aktivität der 11b-HSD1 nach einer Kalorienrestriktion in der Leber erhöht, im viszeralen Fettgewebe und Skelettmuskulatur erniedrigt sind. Die Untersuchung erfolgte mittels RT-PCR, Western-Blot Analyse und HPLC in Mausleber, Schweineleber, Schweinedarmfett und Schweineskelettmuskulatur. Insgesamt zeigen die Ergebnisse dieser Untersuchung Spezies-abhängige Unterschiede der 11b-HSD1-Regulation nach einer Kalorienrestriktion und lassen vermuten, dass es zusätzliche Regulationsschritte in Mausleber und/oder weitere Mediatoren bei der 11b-HSD1-Regulation im Verlauf einer Kalorienrestriktion gibt. Die genauen Mechanismen bleiben weiterhin unklar.11b-hydroxysteroid dehydrogenase type 1 (11b-HSD1) acts predominantly as a reductase by converting inactive cortisone to active cortisol. Multiple studies have pointed out a causal role for 11b-HSD1 in the current obesity epidemic and its related metabolic disorders. Interestingly, 11b-HSD1 expression and activity in the liver of subjects with obesity is either maintained or modestly lowered. On the other hand, elevated levels are found in adipose tissue. Moreover, obese patients with type 2 diabetes show increased 11b-HSD1 expression in skeletal muscle myotubes. However, the underlying tissue-specific mechanisms of altered 11b-HSD1 expression are largely unknown. Therefore, the identification of factors and mechanisms regulating 11b-HSD1 expression and activity could shed light on pathogenesis and possibly identify new therapeutic targets. In order to investigate the influence of caloric restriction on 11b-HSD1 in more detail, expression and activity of 11b-HSD1 were assessed in several tissues in two independent caloric restriction and re-feeding animal models. Evidence in the current literature suggests that expression and activity of 11b-HSD1 is elevated in the liver and reduced in visceral adipose tissue and skeletal muscle following caloric restriction. In this study mouse liver, pig liver, pig visceral adipose tissue and pig skeletal muscle were analyzed. Overall, the results demonstrate species-dependent differences in the regulation of 11b-HSD1 following caloric restriction and suggest the presence of an additional regulation step for 11b-HSD1 activity in mouse liver

Differenzierung des Bildungssystems und soziale Ungleichheit: Haben sich mit dem Ausbau der beruflichen Bildungswege die Ungleichheitsmechanismen verändert?

Despite growing educational participation less privileged groups are still underrepresented at universities. Several studies indicate that patterns of social inequality have changed in the course of educational expansion. While these changes have been widely discussed from a theoretical point of view, empirical evidence for the described pattern of changing mechanisms is lacking. With respect to the transition to higher education this article focuses on the question whether increasing educational participation is associated with a diversion of less privileged groups into less prestigious colleges of applied sciences (Fachhochschulen). Results indicate that with the expansion of vocational pathways to higher education children of less privileged groups more often attain upper secondary education. These changes have consequences on subsequent educational opportunities in the transition to higher education. For this reason social differences in the decision to enter on academic studies at a university have increased in the past thirty years. However, the reason for these growing differences cannot be attributed to processes of diversion, distinction, or heterogenization of ability; rather, they can rather be found in biographical differences and an increasing cost-sensitivity on the part of women from less privileged groups.Trotz der Bildungsexpansion sind die unteren Sozialschichten in den Universitäten weiterhin stark unterrepräsentiert. Verschiedene Indizien sprechen dafür, dass sich mit der Bildungsexpansion die Ungleichheitsmechanismen verändert haben und sich mittlerweile auf einer horizontalen Ebene abspielen. Während mögliche Gründe dieserVeränderungen theoretisch breit diskutiert wurden, fehlen bislang entsprechende empirische Belege. Der vorliegende Beitrag richtet den Blick auf den Übergang ins Studium und beschäftigt sich sowohl in theoretischer als auch in empirischer Hinsicht mit der Frage, ob die gestiegene Bildungsbeteiligung der traditionell bildungsfernen Gruppen mit einer Ablenkung in die eher praxisorientierten Fachhochschulstudiengänge einhergegangen ist. Die Ergebnisse zeigen, dass mit dem Ausbau der beruflichen Schulen zunehmend Kinder aus bildungsfernen Familien eine Hochschulzugangsberechtigung erhalten haben und diese Entwicklung nicht folgenlos für die Wahl des weiteren Bildungsweges geblieben ist. Bei der Aufnahme eines universitären Studiums zeichnet sich in den vergangenen dreißig Jahren jedoch eine Zunahme herkunftsspezifischer Unterschiede ab. Die Ursache hierfür liegt weniger in Ablenkungs-, Distinktions- oder Heterogenisierungsprozessen, sondern in erster Linie in früheren bildungsbiografischen Entscheidungen und einer zunehmenden Kostensensibilität von Frauen aus bildungsfernen Familien

First Molecular Evidence for Underestimated Biodiversity of Rhachotropis (Crustacea, Amphipoda), with Description of a New Species

The crustacean genus Rhachotropis has a worldwide distribution and amongst the largest bathymetric range known from any amphipod genus. DNA barcoding of new material from around New Zealand and the Ross Sea indicated depth-related biogeographic patterns. New Zealand Rhachotropis do not form a monophyletic clade. Species from bathyal depths on the Chatham Rise, east of New Zealand, show lower sequence divergence to bathyal species from California and the Arctic than to abyssal New Zealand species. Species sampled in the Kermadec Trench, north of New Zealand below 5000 m, seem to be more closely related to Ross Sea abyssal species than to the New Zealand shelf species. The worldwide geographic and bathymetric distribution for all Rhachotropis species is presented here. Depth may have a greater influence on phylogeny than geographic distance. Molecular and morphological investigations of Rhachotropis specimens from the Chatham Rise, New Zealand revealed a species new to science which is described in detail, including scanning electron microscopy. This increases the number of described species of Rhachotropis to 60 worldwide

Studierende mit Beeinträchtigung: Abbruchrisiko steigt

Studierende mit Beeinträchtigung stehen im Studium oft vor besonderen Herausforderungen. Im Zuge der Corona-Pandemie haben sich ihre Studienbedingungen nochmals erschwert. Welche Auswirkungen hatte das auf das Abbruchrisiko dieser Studierendengruppe

Investigation of the Amathillopsidae (Amphipoda, Crustacea), including the description of a new species, reveals a clinging lifestyle in the deep sea worldwide

Amathillopsidae is a widely distributed, but rarely sampled family of deep-sea amphipods. During a recent expedition to the North Atlantic, specimens were filmed clinging to a polychaete tube in situ at abyssal depths by a Remote Operated Vehicle and then sampled for further study. The species was new to science and is described in detail herein. A barcode sequence is provided. Further investigations of photographic and video records revealed the genus Amathillopsis to be more widely distributed, both geographically and bathymetrically, than indicated by current literature records, and that these species occur at abyssal depths in all oceans. Specimens of Amathillopsis are reported clinging to a variety of different organisms whose erect structures provide the means to raise these charismatic deep-sea predators above the seafloor facilitating feeding opportunities

An inquiline deep-water bryozoan/amphipod association from New Zealand : including the description of a new genus and species of Chevaliidae

For the first time Amphipoda have been discovered living in Bryozoa. A new genus and species of the amphipod family Chevaliidae, Bryoconversor tutus gen. et sp. nov. is described from New Zealand at depths of 530–1500 m. The species lives in an inquiline relationship with the cheilostome bryozoan Onchoporoides moseleyi (Calwelliidae), inhabiting an abfrontal basal coelom of the bryozoan beneath the membranous ectocyst (cuticularized epithelium) that conceals and protects the amphipods. The colony is strengthened along all edges by a unique intracoelomic rod of calcium carbonate that is formed within the marginal kenozooids of the colony. The potential benefits and costs to the bryozoan are discussed