2,913 research outputs found

    Conditioning of Food Intake in the Mother - Kid - Relation in Goats

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    Titelblatt, Inhaltsverzeichnis, Lebenslauf Einleitung Aufgabenstellung Eigene Untersuchungen Statistische Methoden Ergebnisse Diskussion Schlussfolgerungen Zusammenfassung Summary Anhang LiteraturDie Konsequenzen der Futteraufnahme beeinflussen das Fressverhalten von Tieren. Junge Pflanzenfresser erwerben aber auch durch soziales Lernen eine Präferenz für ein von der Mutter gern gefressenes Futtermittel. In dieser Arbeit wird die Frage untersucht, ob diese konditionierte Präferenz durch das Beispiel der Mutter die spätere Futtermittelselektion der Kitze bestimmt, oder ob vielmehr das Kitz dem mütterlichen Beispiel zwar folgt, letztendlich jedoch das postingestive feedback aus dem Verdauungstrakt bestimmender Faktor für die Futterselektion des Kitzes ist. Die Hypothese war daher, dass das mütterliche Beispiel die Futterselektion ihrer Kitze nachhaltig beeinflusst, unabhängig vom postingestive feedback der Futtermittel. Fünfzehn Ziegenkitze wurden in eine Versuchsgruppe A und eine Versuchsgruppe B aufgeteilt. Den Kitzen wurden zweimal täglich für eine begrenzte Zeit jeweils zwei energiereiche Futtermittel angeboten; morgens zwei Futtermittel mit unterschiedlichem Gehalt an Tannin und abends Futtermittel mit unterschiedlichen Aromastoffen vermischt. Während einer mehrwöchigen Lernphase konnten die Kitze zunächst die Futtermittel zusammen mit der Mutterziege fressen. Danach wurde während zweier Testphasen die Futteraufnahme der Kitze ohne die Mutterziege gemessen. Allen Kitzen wurden während der Lernphase zwei der Futtermittel so angeboten, dass sie ein Futtermittel simultan mit der Mutter an der von der Mutter bevorzugten Futterstelle (Futterstelle mit maternaler Präferenz) fressen konnten oder ein anderes Futtermittel an einer Futterstelle fanden, an der die Mutterziege nur sehr wenig fraß (Futterstelle mit maternaler Aversion). Die Kitze der Versuchsgruppe A bekamen während der Lernphase an sechs Tagen morgens ein von der Mutterziege wenig gefressenes Futtermittel (Futtermittel mit relativer maternaler Aversion) an der Futterstelle mit maternaler Präferenz angeboten. Gleichzeitig wurde ein von der Mutterziege bevorzugtes Futtermittel an der Futterstelle mit maternaler Aversion angeboten. Die Kitze der Versuchsgruppe B dagegen bekamen das Futtermittel, das die Mutterziege bevorzugt fraß, an der Futterstelle mit maternaler Präferenz angeboten und ein von der Mutterziege wenig gefressenes Futtermittel an der Futterstelle mit maternaler Aversion. Zusätzlich wurden abends unterschiedlich aromatisierte Futtermittel entweder an der Futterstelle mit maternaler Präferenz oder Aversion angeboten. Während der anschließenden zwei Testphasen wurde die Futteraufnahme der Kitze beider Gruppen ohne die Mutterziege gemessen. Folgende Ergebnisse wurden erzielt: 1) Das Beispiel der Mutter beeinflusste während der Lernphase die Futterauswahl der Kitze (siehe Abb. 5-8, Abb. 17 und 20). Die von den Kitzen in wiederholten Versuchen während der Lernphase getroffene Futterwahl und die aufgenommene Futtermenge demonstrieren, dass die Futterselektion der Kitze durch die Wahl des Futterplatzes der Mutter beeinflusst war. 2) In Abwesenheit des Muttertieres (Testphasen) hatte die Futterselektion der Mutter keinen Einfluss auf die Futterselektion der Kitze (siehe Abb. 9-16). Die Selektion der Kitze erfolgte nach den negativen postingestiven Konsequenzen der Aufnahme von Futtermitteln. Die Konzentration an Tannin im Futtermittel (1% und 8%) hatte einen negativen Effekt auf die Futteraufnahme. Es konnte gezeigt werden, dass Futtermittel deren Aufnahme sich im postingestiven feedback Aufnahme nicht unterschied (aromatisierte Futtermittel), auch in gleichen Mengen von den Kitzen aufgenommen wurden. 3) Während der Phase, in der Kitze lernen eine geeignete Diät zu selektieren, beeinflusst das Beispiel der Mutterziege die Wahl des Futterplatzes und dadurch die Futterselektion des Kitzes. Indem Mutterziege und Kitz simultan fressen (co-feeding), erhöht sich für das Kitz der Bekanntheitsgrad derjenigen Pflanzen, welche die Mutterziege selektiert. Die Mutterziege überträgt ihre Futterselektion auf ihre Kitze indem sie deren Neophobie vor Futtermitteln verringert. 4) Negative postingestive Konsequenzen der Aufnahme eines Futtermittels begrenzen die individuell aufgenommene Futtermenge bei Ziegenkitzen in Abwesenheit der Mutter. Die Übertragung der Futterselektion von Mutterziege auf das Kitz entspricht daher einer Nachahmung des mütterlichen Verhaltens, nicht aber einer Nahrungsprägung durch die Mutter. Aus den Ergebnissen lässt sich schließen, dass das Training der Kitze mit ihren Müttern nicht zu einer permanenten Nachahmung mütterlicher Futterselektion führt. Vielmehr sind es die negativen Konsequenzen der Futteraufnahme die die Futterselektion bestimmen. Das Lernen am Beispiel der Mutter spielt demgegenüber nur eine untergeordnete Rolle.Conditioning of Food Intake in the Mother-Kid-Relation in Goats This study investigated the consequences of food intake and social learning, both of which have a major influence on foraging behavior. Young herbivores acquire a preference for food that is preferred by their mothers. This preference which is acquired early in life from the mother's example may significantly determine food selection later in life. In addition to the mother's influence, postingestive feedback from the gastro-intestinal tract, such as the negative consequences of ingesting food with high concentration of tannin have a major influence on diet selection. The conditioning of kid's food intake by mother's example may compete with the learning of postingestive consequences in kid's food selection learning. We determined whether goat kids would follow their mother's example even if negative postingestive feedback favored a different food selection. We hypothesized that the mother's example influences food selection of her kids, persistently and independently of the food's postingestive feedback. Fifteen goat kids were divided into two groups. High- energy foods were given twice daily for a 5-minute period six times during the learning period with their mothers. In this period the kids could observe their mother's diet selection. This was followed by two test periods without their mothers for five and four days, respectively. Two foods differing in tannin concentration were used to provoke two different consequences after intake; two foods differing in flavor were used as distinguishable foods without differences in consequences after intake. In each feeding the kids had a choice between two foods. For the morning feeding the choice was between two foods differing in tannin concentration, in the evening the feeding choice was between two foods differing in flavor. During the learning period the kids were four to eight weeks of age. After this time the kids underwent two test periods. The first test phase, which lasted five days occurred when the kids were 11 weeks old; the second test phase, which lasted four days, occurred when the kids were 14 weeks old. During these periods all the kid's food intake of tannin containing or flavor containing high-energy food was measured. During the initial learning period food was simultaneously given to the mother and her kid in such a manner that they could eat together from one of two food boxes. These food boxes were fixed at two feeding places three meters apart in a pen. The boxes were subdivided with two plastic containers that were open either to the mother or to the kid. With the access to their food separate mother and kid could eat at the same place even though each received different food. Kids of group A were offered food that the mother would reject in a feeding place of mother's preference, whereas both kids and mothers of group B were offered identical foods at both feeding places. We compared food intake of kids during learning period and test periods. The following results were obtained: 1) The mother's example influenced food selection of the kids in the learning period. The kid's food selection was positively influenced by their mother's choice of a feeding place. 2) The mother influenced their kid's food selection when she was present, but the mother's prior example had no influence on the kid's later diet-selection. In the mother's absence the kid's diet selection was consistent with food selection learning from postingestive feedback. The concentration of tannin in the food had a negative influence on food selection, whereas different aromas had no influence on food selection, even though the mother favored one aroma by choosing a feeding place during the learning period. 3) When developing feeding behavior, the example of the mother's diet selection competes with learning from postingestive consequences. By feeding simultaneously, the mother's example increases the familiarity with her selection and facilitates similar diet selection. 4) However, if a food causes negative postingestive feedback in the kid, their own experiences determine the kid's diet selection despite their mother's example. Negative postingestive feedback limits food intake in goat kids in the absence of a mother. These results support the fact that the training of goat kids by manipulating their food choice with their mother's example does not result in a permanent change in diet selection. Food intake is limited by the capacity of the animal to cope with the negative postingestive consequences, learning from mother's example has a minor influence on food selection

    Curriculumsreform des Bachelor-Studiengangs Information Science an der HTW Chur

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    Der Lehrplan für den Studiengang Bachelor Information Science an der HTW Chur wurde beginnend im Herbst 2013 grundlegend überarbeitet und auf die Bedürfnisse des Arbeitsmarktes und der Studierenden ausgerichtet. Im Beitrag wird aufgezeigt, wie bei der Curriculumsreform vorgegangen wurde, welche Überlegungen bei der Neuausrichtung angestellt wurden und wie der neue Lehrplan schliesslich ausgestaltet wurde

    Dialectica Socratica dux criticae Platonicae et Xenophonteae: specimen tertium

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    https://repository.brynmawr.edu/digitizedbooks/1008/thumbnail.jp

    ORD-Xplore: Bridging Open Research Data Collections through Modality Abstractions

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    We present ORD-Xplore, an approach to bridge gaps between digital editions, which represent valuable collections of multiple digitized research artifacts. However, digital editions often co-exist isolated, making it difficult for researchers to access, find, and re-use open research data from multiple digital editions. An ultimate goal is to unify library services across editions, even for editions with heterogeneity. In ORD-Xplore, we utilize abstraction methods from visualization research to help digital librarians identify unifying data modalities, as one important step towards standardization of heterogeneous digital editions

    Reduced representation bisulfite sequencing for comparative high-resolution DNA methylation analysis

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    We describe a large-scale random approach termed reduced representation bisulfite sequencing (RRBS) for analyzing and comparing genomic methylation patterns. BglII restriction fragments were size-selected to 500–600 bp, equipped with adapters, treated with bisulfite, PCR amplified, cloned and sequenced. We constructed RRBS libraries from murine ES cells and from ES cells lacking DNA methyltransferases Dnmt3a and 3b and with knocked-down (kd) levels of Dnmt1 (Dnmt[1(kd),3a(−/−),3b(−/−)]). Sequencing of 960 RRBS clones from Dnmt[1(kd),3a(−/−),3b(−/−)] cells generated 343 kb of non-redundant bisulfite sequence covering 66212 cytosines in the genome. All but 38 cytosines had been converted to uracil indicating a conversion rate of >99.9%. Of the remaining cytosines 35 were found in CpG and 3 in CpT dinucleotides. Non-CpG methylation was >250-fold reduced compared with wild-type ES cells, consistent with a role for Dnmt3a and/or Dnmt3b in CpA and CpT methylation. Closer inspection revealed neither a consensus sequence around the methylated sites nor evidence for clustering of residual methylation in the genome. Our findings indicate random loss rather than specific maintenance of methylation in Dnmt[1(kd),3a(−/−),3b(−/−)] cells. Near-complete bisulfite conversion and largely unbiased representation of RRBS libraries suggest that random shotgun bisulfite sequencing can be scaled to a genome-wide approach

    Tumor-specific T cells signal tumor destruction via the lymphotoxin β receptor

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    BACKGROUND: Previously, we reported that adoptively transferred perforin k/o (PKO), and IFN-γ k/o (GKO), or perforin/IFN-γ double k/o (PKO/GKO) effector T cells mediated regression of B16BL6-D5 (D5) pulmonary metastases and showed that TNF receptor signaling played a critical role in mediating tumor regression. In this report we investigated the role of lymphotoxin-α (LT-α) as a potential effector molecules of tumor-specific effector T cells. METHODS: Effector T cells were generated from tumor vaccine-draining lymph node (TVDLN) of wt, GKO, LT-α deficient (LKO), or PKO/GKO mice and tested for their ability to mediate regression of D5 pulmonary metastases in the presence or absence of LT-βR-Fc fusion protein or anti-IFN-γ antibody. Chemokine production by D5 tumor cells was determined by ELISA, RT-PCR and Chemotaxis assays. RESULTS: Stimulated effector T cells from wt, GKO, or PKO/GKO mice expressed ligands for LT-β receptor (LT-βR). D5 tumor cells were found to constitutively express the LT-βR. Administration of LT-βR-Fc fusion protein completely abrogated the therapeutic efficacy of GKO or PKO/GKO but not wt effector T cells (p < 0.05). Consistent with this observation, therapeutic efficacy of effector T cells deficient in LT-α, was greatly reduced when IFN-γ production was neutralized. While recombinant LT-α1β2 did not induce apoptosis of D5 tumor cells in vitro, it induced secretion of chemokines by D5 that promoted migration of macrophages. CONCLUSION: The contribution of LT-α expression by effector T cells to anti-tumor activity in vivo was not discernable when wt effector T cells were studied. However, the contribution of LT-β R signaling was identified for GKO or PKO/GKO effector T cells. Since LT-α does not directly induce killing of D5 tumor cells in vitro, but does stimulate D5 tumor cells to secrete chemokines, these data suggest a model where LT-α expression by tumor-specific effector T cells interacts via cross-linking of the LT-βR on tumor cells to induce secretion of chemokines that are chemotactic for macrophages. While the contribution of macrophages to tumor elimination in our system requires additional study, this model provides a possible explanation for the infiltration of inate effector cells that is seen coincident with tumor regression

    Management of Febrile Neutropenia - a German Prospective Hospital Cost Analysis in Lymphoproliferative Disorders, Non-Small Cell Lung Cancer, and Primary Breast Cancer

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    Background: Febrile neutropenia/leukopenia (FN/FL) is the most frequent dose-limiting toxicity of myelosuppressive chemotherapy, but German data on economic consequences are limited. Patients and Methods: A prospective, multicentre, longitudinal, observational study was carried out to evaluate the occurrence of FN/FL and its impact on health resource utilization and costs in non-small cell lung cancer (NSCLC), lymphoproliferative disorder (LPD), and primary breast cancer (PBC) patients. Costs are presented from a hospital perspective. Results: A total of 325 consecutive patients (47% LPD, 37% NSCLC, 16% PBC; 46% women; 38% age >= 65 years) with 68 FN/FL episodes were evaluated. FN/FL occurred in 22% of the LPD patients, 8% of the NSCLC patients, and 27% of the PBC patients. 55 FN/FL episodes were associated with at least 1 hospital stay (LPD n = 34, NSCLC n = 10, PBC n = 11). Mean (median) cost per FN/FL episode requiring hospital care amounted to (sic) 3,950 ((sic) 2,355) and varied between (sic) 4,808 ((sic) 3,056) for LPD, (sic) 3,627 ((sic) 2,255) for NSCLC, and (sic) 1,827 ((sic) 1,969) for PBC patients. 12 FN/FL episodes (LPD n = 9, NSCLC n = 3) accounted for 60% of the total expenses. Main cost drivers were hospitalization and drugs (60 and 19% of the total costs). Conclusions: FN/FL treatment has economic relevance for hospitals. Costs vary between tumour types, being significantly higher for LPD compared to PBC patients. The impact of clinical characteristics on asymmetrically distributed costs needs further evaluation

    Polycarbonate microchannel network with carpet of Gold NanoWires as SERS-active device

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    A polycarbonate (PC) microchannel network supporting gold nanowires was developed to be a SERSactive microchip. Observations of large increases in a Raman cross-section, allowed us to collect vibrational signatures which are not easily detectable by Raman techniques due to the high fluorescence level of bare PC. Compared to other SERS experiments, this study relies on the use of dielectric polymer/metal surfaces which are well defined at microscale and nanoscale levels. This device seems a promising tool for sensing the adsorption of biomolecules
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