361 research outputs found

    Pearls of Elschnig

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    This is a Photo Essay and does not contain an abstract

    Bowhead and Gray Whale Distributions, Sighting Rates, and Habitat Associations in the Eastern Chukchi Sea, Summer and Fall 2009–15, with a Retrospective Comparison to 1982–91

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    We analyzed data from line-transect aerial surveys for marine mammals conducted in the eastern Chukchi Sea (67˚–72˚ N, 157˚–169˚ W) in July to October of 2009–15 to investigate bowhead and gray whale distributions, behaviors, sighting rates, and habitat selection preferences, the last of which allowed direct comparison with results from data collected in this area in 1982–91. Bowhead whales use the eastern Chukchi Sea primarily for migrating between the Beaufort Sea and the Bering Sea, while gray whales use the area to feed on locally abundant benthic amphipods and other prey. Bowhead whales were observed during all survey months and were distributed up to 300 km offshore west and southwest of Point Barrow, Alaska, but without a defined migratory corridor in either summer (July-August) or fall (September-October). Bowhead whale sighting rates (whales per km on effort) were highest in the shelf/trough (51–200 m North) depth zone in the northeastern Chukchi Sea in both summer and fall. This pattern was reflected in habitat selection ratios, which found bowhead whales in summer and fall selecting primarily shelf/trough habitat in the northeastern Chukchi Sea, with shelf habitat (36 – 50 m) being preferred secondarily. Gray whales were observed in all survey months and were distributed primarily within ~95 km of shore between Point Barrow and Icy Cape in the northeastern Chukchi Sea, and about 60–115 km southwest of Point Hope in the southern Chukchi Sea. In both summer and fall, gray whale sighting rates and habitat selection ratios were highest in the shelf/trough (51–200 m South) depth zone in the southern Chukchi Sea. In the northeastern part of the study area, gray whale sighting rates and habitat selection ratios both identified coastal habitat (≀ 35 m) as preferred habitat in summer and shelf/trough (51–200 m North) as preferred habitat in fall. Distribution and habitat associations of bowhead and gray whales remained similar over the 34-year time span with one exception: gray whale preference for shelf/trough habitat in the southern Chukchi Sea is now evident throughout summer and fall, whereas three decades ago gray whale preference for that area was limited to fall only.Nous avons analysĂ© les donnĂ©es provenant de levĂ©s aĂ©riens par transects linĂ©aires Ă  l’égard de mammifĂšres marins, levĂ©s effectuĂ©s dans l’est de la mer des Tchouktches (67˚–72˚ N, 157˚–169˚ O) d’octobre Ă  juillet 2009 Ă  2015 afin de prĂ©lever des donnĂ©es sur la rĂ©partition des baleines borĂ©ales et des baleines grises, sur leurs comportements, sur leurs taux d’observation et sur leurs prĂ©fĂ©rences en matiĂšre d’habitat. Ce dernier Ă©lĂ©ment nous a permis de faire des comparaisons directes avec les rĂ©sultats de la collecte de donnĂ©es effectuĂ©e dans cette rĂ©gion entre 1982 et 1991. Les baleines borĂ©ales se servent principalement de l’est de la mer des Tchouktches pour migrer entre la mer de Beaufort et la mer de BĂ©ring, tandis que les baleines grises empruntent cette rĂ©gion pour se nourrir des amphipodes benthiques qui y abondent ainsi que d’autres proies. Des baleines borĂ©ales ont Ă©tĂ© observĂ©es pendant tous les mois visĂ©s par les levĂ©s, et celles-ci Ă©taient rĂ©parties sur une distance allant jusqu’à 300 km au large, Ă  l’ouest et au sud-ouest de Point Barrow, en Alaska, sans toutefois emprunter un couloir migratoire particulier Ă  l’étĂ© (juillet et aoĂ»t) ou Ă  l’automne (septembre et octobre). Les taux d’observation de baleines borĂ©ales (nombre de baleines par km Ă  l’effort) Ă©taient plus Ă©levĂ©s dans la zone de profondeur de plateformes et de dĂ©pressions (de 51 Ă  200 m nord) faisant partie du nord-est de la mer des Tchouktches, tant Ă  l’étĂ© qu’à l’automne. Cette tendance se reflĂšte dans les rapports de sĂ©lection d’habitats, selon lesquels les baleines borĂ©ales choisissent principalement, l’étĂ© et l’automne, un habitat de plateformes et de dĂ©pressions dans le nord-est de la mer des Tchouktches, l’habitat des plateformes (de 36 Ă  50 m) constituant une prĂ©fĂ©rence secondaire. Des baleines grises ont Ă©tĂ© observĂ©es pendant tous les mois visĂ©s par les levĂ©s. Elles se rĂ©partissaient principalement Ă  l’intĂ©rieur de ~95 km de la cĂŽte, entre Point Barrow et Icy Cape, dans le nord-est de la mer des Tchouktches, et Ă  environ 60 Ă  115 km au sud-ouest de Point Hope, dans le sud de la mer des Tchouktches. Tant Ă  l’étĂ© qu’à l’automne, les taux d’observation et les rapports de sĂ©lection d’habitats des baleines grises Ă©taient Ă  leur point le plus Ă©levĂ© dans la zone de profondeur des plateformes et des dĂ©pressions (de 51 Ă  200 m sud) du sud de la mer des Tchouktches. Dans le secteur nord-est de la rĂ©gion visĂ©e par l’étude, les taux d’observation et les ratios de sĂ©lection d’habitats des baleines grises ont tous deux permis d’affirmer que l’habitat cĂŽtier (≀ 35 m) Ă©tait l’habitat prĂ©fĂ©rĂ© pendant l’étĂ©, et que l’habitat des plateformes et des dĂ©pressions (de 51 Ă  200 m nord) Ă©tait l’habitat prĂ©fĂ©rĂ© Ă  l’automne. Les associations en matiĂšre de rĂ©partition et d’habitat des baleines borĂ©ales et des baleines grises sont demeurĂ©es semblables au cours de la pĂ©riode de 34 ans, Ă  une exception prĂšs : la prĂ©fĂ©rence de la baleine grise pour l’habitat des plateformes et des dĂ©pressions dans le sud de la mer des Tchouktches est maintenant Ă©vidente Ă  l’étĂ© et Ă  l’automne, tandis qu’il y a trois dĂ©cennies, la prĂ©fĂ©rence de la baleine grise pour cet habitat se limitait Ă  l’automne

    Local Production and Developing Core Regions: Ceramic Characterization in the Lake PĂĄtzcuaro Basin, Western Mexico

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    A core region is the first place for expected shifts in archaeological materials before, during, and after political changes like state emergence and imperial consolidation. Yet, studies of ceramic production have shown that there are sometimes limited or more subtle changes in the ceramic economy throughout such political fluctuations. This article synthesizes recent efforts to address political economic changes via geochemical characterization (neutron activation analysis; NAA) in the Lake Påtzcuaro Basin in western Mexico. This region was home to the Purépecha state and then empire (Tarascan; ca. AD 1350-1530), one of the most powerful kingdoms in the Americas before European arrival. The combined ceramic dataset from four sites in the region result in eight geochemical groups. Our analysis indicates that the region experienced long-term and relatively stable ceramic production that was not substantially altered by the emergence of the state and empire. In addition, we find evidence for (1) dispersed, localized production; (2) long-lived compositional ceramic recipes; and (3) a complex ceramic economy with differential community participation. We discuss why documenting local ceramic production and craft production more generally is important for the study of past political economies

    Fragment screening reveals salicylic hydroxamic acid as an inhibitor of <em>Trypanosoma brucei</em> GPI GlcNAc-PI de-N-acetylase

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    The zinc-metalloenzyme GlcNAc-PI de-N-acetylase is essential for the biosynthesis of mature GPI anchors and has been genetically validated in the bloodstream form of Trypanosoma brucei, which causes African sleeping sickness. We screened a focused library of zinc-binding fragments and identified salicylic hydroxamic acid as a GlcNAc-PI de-N-acetylase inhibitor with high ligand efficiency. This is the first small molecule inhibitor reported for the trypanosome GPI pathway. Investigating the structure activity relationship revealed that hydroxamic acid and 2-OH are essential for potency, and that substitution is tolerated at the 4- and 5-positions

    When innovation outpaces regulations:The legal challenges for direct-to-patient supply of investigational medicinal products

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    AIMS: We profile the lack of specific regulation for direct‐to‐patient postal supply (DTP) of clinical trial medications (investigational medicinal products, IMPs) calling for increased efficiency of patient‐centred multi‐country remote clinical trials. METHODS: Questionnaires emailed to 28 European Economic Area (EEA) Medical Product Licensing Authorities (MPLAs) and Swissmedic MPLA were analysed in 2019/2020. The questionnaire asked whether DTP of IMPs was legal, followed by comparative legal analysis profiling relevant national civil and criminal liability provisions in 30 European jurisdictions (including The Netherlands), finally summarising accessible COVID‐19‐related guidance in searches of 30 official MPLA websites in January 2021. RESULTS: Twenty MPLAs responded. Twelve consented to response publication in 2021. DTP was not widely authorised, though different phrases were used to explain this. Our legal review of national laws in 29 EEA jurisdictions and Switzerland did not identify any specific sanctions for DTP of IMPs; however, we identified potential national civil and criminal liability provisions. Switzerland provides legal clarity where DTP of IMPs is conditionally legal. MPLA webpage searches for COVID‐19 guidance noted conditional acceptance by 19 MPLAs. CONCLUSIONS: Specific national legislation authorising DTP of IMPs, defining IMP categories, and conditions permitting the postage and delivery by courier in an EEA‐wide clinical trial, would support innovative patient‐centred research for multi‐country remote clinical trials. Despite it appearing more acceptable to do this between EU Member States, provided each EU MPLA and ethics board authorises it, temporary Covid‐19 restrictions in national Good Clinical Practice (GCP) guidance discourages innovative research into the safety and effectiveness of clinical trial medications

    Developmental stage of oligodendrocytes determines their response to activated microglia in vitro

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    <p>Abstract</p> <p>Background</p> <p>Oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes are both lost in central nervous system injury and disease. Activated microglia may play a role in OPC and oligodendrocyte loss or replacement, but it is not clear how the responses of OPCs and oligodendrocytes to activated microglia differ.</p> <p>Methods</p> <p>OPCs and microglia were isolated from rat cortex. OPCs were induced to differentiate into oligodendrocytes with thyroid hormone in defined medium. For selected experiments, microglia were added to OPC or oligodendrocyte cultures. Lipopolysaccharide was used to activate microglia and microglial activation was confirmed by TNFα ELISA. Cell survival was assessed with immunocytochemistry and cell counts. OPC proliferation and oligodendrocyte apoptosis were also assessed.</p> <p>Results</p> <p>OPCs and oligodendrocytes displayed phenotypes representative of immature and mature oligodendrocytes, respectively. Activated microglia reduced OPC survival, but increased survival and reduced apoptosis of mature oligodendrocytes. Activated microglia also underwent cell death themselves.</p> <p>Conclusion</p> <p>Activated microglia may have divergent effects on OPCs and mature oligodendrocytes, reducing OPC survival and increasing mature oligodendrocyte survival. This may be of importance because activated microglia are present in several disease states where both OPCs and mature oligodendrocytes are also reacting to injury. Activated microglia may simultaneously have deleterious and helpful effects on different cells after central nervous system injury.</p

    Tumor Necrosis Factor Alpha Mediates GABAA Receptor Trafficking to the Plasma Membrane of Spinal Cord Neurons In Vivo

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    The proinflammatory cytokine TNFα contributes to cell death in central nervous system (CNS) disorders by altering synaptic neurotransmission. TNFα contributes to excitotoxicity by increasing GluA2-lacking AMPA receptor (AMPAR) trafficking to the neuronal plasma membrane. In vitro, increased AMPAR on the neuronal surface after TNFα exposure is associated with a rapid internalization of GABAA receptors (GABAARs), suggesting complex timing and dose dependency of the CNS's response to TNFα. However, the effect of TNFα on GABAAR trafficking in vivo remains unclear. We assessed the effect of TNFα nanoinjection on rapid GABAAR changes in rats (N = 30) using subcellular fractionation, quantitative western blotting, and confocal microscopy. GABAAR protein levels in membrane fractions of TNFα and vehicle-treated subjects were not significantly different by Western Blot, yet high-resolution quantitative confocal imaging revealed that TNFα induces GABAAR trafficking to synapses in a dose-dependent manner by 60 min. TNFα-mediated GABAAR trafficking represents a novel target for CNS excitotoxicity

    Comparison of alterations of chromosome 17 in carcinoma of the ovary and of the breast

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     Breast and ovarian carcinomas share a region of allelic loss on chromosome 17q25, suggesting that these tumours may arise by similar molecular pathways. We analysed paraffin-embedded tissues from 84 sporadic ovarian carcinomas and 42 sporadic infiltrating ductal carcinomas of the breast for abnormalities on chromosome 17. Loss of heterozygosity (LOH) of at least one informative marker on 17q was identified in 49 of 82 (60%) ovarian carcinomas, as against only 6 of 40 (15%) informative breast carcinomas ( P <0.0001). In ovarian carcinoma, LOH was most commonly observed for GH on 17q23 (56%), and was also frequently observed at 17q21 (46%). In contrast, LOH of D17S1330/CTT16 on 17q25 was observed in only 19% of ovarian tumours. LOH in breast carcinomas was most frequently observed at 17q21 (16%), less frequently at 17q23 (7%) and not identified at all at 17q25 in any breast cancers. Immunohistochemical analysis demonstrated overexpression of the p53 gene product in 38 of 84 (45%) ovarian carcinomas, as against 10 of 42 (24%) breast carcinomas ( P =0.0195). p53 immunoreactivity was significantly associated with LOH in ovarian and breast cancers. Immunohistochemical expression of HER2/ neu was observed in 6 of 84 (7%) ovarian and 3 of 42 (7%) breast carcinomas. There was no relationship between HER2/ neu immunoreactivity and LOH. Although sporadic carcinomas of breast and ovary share some regions of allelic loss on chromosome 17q, differences in other alterations on this chromosome suggest divergent pathways of tumour development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42250/1/428-434-6-517_94340517.pd

    "Appearance potent"? A content analysis of UK gay and straight men's magazines.

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    With little actual appraisal, a more 'appearance potent' (i.e., a reverence for appearance ideals) subculture has been used to explain gay men's greater body dissatisfaction in comparison to straight men's. This study sought to assess the respective appearance potency of each subculture by a content analysis of 32 issues of the most read gay (Attitude, Gay Times) and straight men's magazines (Men's Health, FHM) in the UK. Images of men and women were coded for their physical characteristics, objectification and nudity, as were the number of appearance adverts and articles. The gay men's magazines featured more images of men that were appearance ideal, nude and sexualized than the straight men's magazines. The converse was true for the images of women and appearance adverts. Although more research is needed to understand the effect of this content on the viewer, the findings are consistent with a more appearance potent gay male subculture
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