181 research outputs found

    Foraging and Caching Behavior of the Plateau Mouse (Peromyscus melanophrys)

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    This study explores the foraging and caching behavior of the Peromyscus melanophrys. Subjects consisted of twelve randomly selected first generation lab-raised Peromyscus melanophrys—six mature males and six mature females. Subjects were kept on a 15L:9D summer photoperiod with their environment maintained at 20-25°C. Subjects were allowed to become habituated to their surroundings in the nest box, with food and water, for several days before experimental sessions began, however, subjects were not allowed access to a runway section of their boxes until sessions began. Subjects were randomly divided into a food satiated and a food unsatiated group, with the three individuals of each sex randomly assigned to each group. The first group was the food satiated group, who had free access to food until 1.5 hours before each experimental session. The other group—the unsatiated food group—was deprived of food for 25.5 hours before each session. Each run consisted of eight experimental sessions, which included two unrecorded trial session to accustom subjects to the runways. The remaining sessions were each spaced 44 hours apart and consisted of two experiments at varying distances. Thirty rat chow blocks—10 small (1.5g), 10 intermediate (3.5g), and 10 large (5g)—were placed in bins at the end of each runway. Each session consisted of a three hour period beginning 1.5 hours after the beginning of the dark period, during which subjects accessed the runways. Researchers recorded foraging activity (any activity where the subject contacted, moved, or consumed the food provided) and caching activity (removing the food to the next box). Recorded data included the interval in which it was cached, the location of the blocks within the nest chamber at the end of the session, and the exact weight of the food blocks before and after the session to determine the amount of food consumed. Researchers observed that there is a great deal of normal variation in P. melanophrys’ foraging and caching behavior. Researchers note that there may be a range of minimum and maximum distances that an animal will travel when foraging, however that range varies from species to species and is affected by environmental conditions. Distance may play an important role in subjects’ foraging/caching strategies, with subjects hauling larger loads over longer distances. No significant differences between male and female subjects’ foraging/caching behaviors were observed, contradicting earlier research

    Guidelines of the American Society of Mammalogists for the use of wild mammals in research

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    Guidelines for use of wild mammal species are updated from the American Society of Mammalogists (ASM) 2007 publication. These revised guidelines cover current professional techniques and regulations involving mammals used in research and teaching. They incorporate additional resources, summaries of procedures, and reporting requirements not contained in earlier publications. Included are details on marking, housing, trapping, and collecting mammals. It is recommended that institutional animal care and use committees (IACUCs), regulatory agencies, and investigators use these guidelines as a resource for protocols involving wild mammals. These guidelines were prepared and approved by the ASM, working with experienced professional veterinarians and IACUCs, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals in their natural environments. The most current version of these guidelines and any subsequent modifications are available at the ASM Animal Care and Use Committee page of the ASM Web site (http://mammalsociety.org/committees/index.asp).American Society of Mammalogist

    Loss of Free Fatty Acid Receptor 2 leads to impaired islet mass and beta cell survival

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    The regulation of pancreatic β cell mass is a critical factor to help maintain normoglycemia during insulin resistance. Nutrient-sensing G protein-coupled receptors (GPCR) contribute to aspects of β cell function, including regulation of β cell mass. Nutrients such as free fatty acids (FFAs) contribute to precise regulation of β cell mass by signaling through cognate GPCRs, and considerable evidence suggests that circulating FFAs promote β cell expansion by direct and indirect mechanisms. Free Fatty Acid Receptor 2 (FFA2) is a β cell-expressed GPCR that is activated by short chain fatty acids, particularly acetate. Recent studies of FFA2 suggest that it may act as a regulator of β cell function. Here, we set out to explore what role FFA2 may play in regulation of β cell mass. Interestingly, Ffar2(-/-) mice exhibit diminished β cell mass at birth and throughout adulthood, and increased β cell death at adolescent time points, suggesting a role for FFA2 in establishment and maintenance of β cell mass. Additionally, activation of FFA2 with Gαq/11-biased agonists substantially increased β cell proliferation in in vitro and ex vivo proliferation assays. Collectively, these data suggest that FFA2 may be a novel therapeutic target to stimulate β cell growth and proliferation

    2016 Guidelines of the American Society of Mammalogists for the use of wild mammals in research and education.

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    Guidelines for use of wild mammal species in research are updated from Sikes et al. (2011). These guidelines cover current professional techniques and regulations involving the use of mammals in research and teaching; they also incorporate new resources, procedural summaries, and reporting requirements. Included are details on capturing, marking, housing, and humanely killing wild mammals. It is recommended that Institutional Animal Care and Use Committees (IACUCs), regulatory agencies, and investigators use these guidelines as a resource for protocols involving wild mammals, whether studied in the field or in captivity. These guidelines were prepared and approved by the American Society of Mammalogists (ASM), in consultation with professional veterinarians experienced in wildlife research and IACUCs, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals. The current version of these guidelines and any subsequent modifications are available online on the Animal Care and Use Committee page of the ASM website (http://mammalogy.org/uploads/committee_files/CurrentGuidelines.pdf). Additional resources pertaining to the use of wild animals in research are available at: http://www.mammalsociety.org/committees/animal-care-and-use#tab3. Resumen—Los lineamientos para el uso de especies de mamíferos de vida silvestre en la investigación con base en Sikes et al. (2011) se actualizaron. Dichos lineamientos cubren técnicas y regulaciones rofesionales actuales que involucran el uso de mamíferos en la investigación y enseñanza; también incorporan recursos nuevos, resúmenes de procedimientos y requisitos para reportes. Se incluyen detalles acerca de captura, marcaje, manutención en cautiverio y eutanasia de mamíferos de vida silvestre. Se recomienda que los comités institucionales de uso y cuidado animal (cifras en inglés: IACUCs), las agencias reguladoras y los investigadores se adhieran a dichos lineamientos como fuente base de protocolos que involucren mamíferos de vida silvestre, ya sea investigaciones de campo o en cautiverio. Dichos lineamientos fueron preparados y aprobados por la ASM, en consulta con profesionales veterinarios experimentados en investigaciones de vida silvestre y IACUCS, de quienes cuya experiencia colectiva provee un entendimiento amplio y exhaustivo de la biología de mamíferos no-domesticados. La presente version de los lineamientos y modificaciones posteriores están disponibles en línea en la página web de la ASM, bajo Cuidado Animal y Comité de Uso: http://mammalogy.org/uploads/committee_files/CurrentGuidelines.pdf). Recursos adicionales relacionados con el uso de animales de vida silvestre para la investigación se encuentran disponibles en (http://www.mammalsociety.org/committees/animal-care-and-use#tab3)

    British signals intelligence and the 1916 Easter Rising in Ireland

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    Historians for decades have placed Room 40, the First World War British naval signals intelligence organization, at the centre of narratives about the British anticipation of and response to the Easter Rising in Ireland in 1916. A series of crucial decrypts of telegrams between the German embassy in Washington and Berlin, it has been believed, provided significant advance intelligence about the Rising before it took place. This article upends previous accounts by demonstrating that Room 40 possessed far less advance knowledge about the Rising than has been believed, with most of the supposedly key decrypts not being generated until months after the Rising had taken place

    Distribution of immune cells in head and neck cancer: CD8+ T-cells and CD20+ B-cells in metastatic lymph nodes are associated with favourable outcome in patients with oro- and hypopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Tumour infiltrating lymphocytes (TIL) are generally considered to represent a host immune response directed against tumour antigens. TIL are also increasingly recognised as possible prognostic parameters. However, the effects observed are variable indicating that results cannot be extrapolated from type of tumour to another. Moreover, it has been suggested that primary solid tumours may be ignored by the immune system and that a meaningful immune response is only mounted in regional lymph nodes.</p> <p>Methods</p> <p>We have examined the local distribution of immune cells in tumour-related compartments in head and neck squamous cell carcinomas (HNSCC). In a second step, the prognostic impact of these cells on disease-free survival (DFS) was analysed. A total of 198 tissue cores from 33 patients were evaluated using tissue mircroarray technique and immunohistochemistry. Tumour-infiltrating immune cells were identified using antibodies specific for CD3, CD8, GranzymeB, FoxP3, CD20 and CD68 and quantified using an image analysis system.</p> <p>Results</p> <p>We demonstrate a relative expansion of FoxP3<sup>+ </sup>regulatory T-cells (Treg) and of cytotoxic T-cells among tumour infitrating T-cells. We also show that intratumoural CD20<sup>+ </sup>B-cells are significantly more frequent in metastatic deposits than in primary tumours. Furthermore, we observed a reduced number of peritumoural CD8<sup>+ </sup>T-cells in metastatic lymph nodes as compared to univolved regional nodes suggesting a local down-modulation of cellular immunity. All other immune cells did not show significant alterations in distribution. We did not observe an association of tumour infiltrating immune cells at the primary site with outcome. However, increased numbers of intraepithelial CD8<sup>+ </sup>TIL in metastatic tumours as well as large numbers of peritumoural B-cells in lymph node metastases were associated with favourable outcome. Unexpectedly, no effect on patient outcome was observed for Treg in any compartment.</p> <p>Conclusion</p> <p>Our results suggest that alterations in lymphocyte distribution in regional lymph nodes rather than at the primary tumour site may be relevant for patient prognosis. Moreover, we demonstrate that in addition to cellular immunity humoral immune responses may be clinically relevant in anti-tumour immunity.</p

    eXtraembryonic ENdoderm (XEN) Stem Cells Produce Factors that Activate Heart Formation

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    Initial specification of cardiomyocytes in the mouse results from interactions between the extraembryonic anterior visceral endoderm (AVE) and the nascent mesoderm. However the mechanism by which AVE activates cardiogenesis is not well understood, and the identity of specific cardiogenic factors in the endoderm remains elusive. Most mammalian studies of the cardiogenic potential of the endoderm have relied on the use of cell lines that are similar to the heart-inducing AVE. These include the embryonal-carcinoma-derived cell lines, END2 and PYS2. The recent development of protocols to isolate eXtraembryonic ENdoderm (XEN) stem cells, representing the extraembryonic endoderm lineage, from blastocyst stage mouse embryos offers new tools for the genetic dissection of cardiogenesis.Here, we demonstrate that XEN cell-conditioned media (CM) enhances cardiogenesis during Embryoid Body (EB) differentiation of mouse embryonic stem (ES) cells in a manner comparable to PYS2-CM and END2-CM. Addition of CM from each of these three cell lines enhanced the percentage of EBs that formed beating areas, but ultimately, only XEN-CM and PYS2-CM increased the total number of cardiomyocytes that formed. Furthermore, our observations revealed that both contact-independent and contact-dependent factors are required to mediate the full cardiogenic potential of the endoderm. Finally, we used gene array comparison to identify factors in these cell lines that could mediate their cardiogenic potential.These studies represent the first step in the use of XEN cells as a molecular genetic tool to study cardiomyocyte differentiation. Not only are XEN cells functionally similar to the heart-inducing AVE, but also can be used for the genetic dissection of the cardiogenic potential of AVE, since they can be isolated from both wild type and mutant blastocysts. These studies further demonstrate the importance of both contact-dependent and contact-independent factors in cardiogenesis and identify potential heart-inducing proteins in the endoderm
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