492 research outputs found

    Effects of Cultured Adrenal Chromaffin Cell Implants on Hindlimb Reflexes of the 6-OHDA Lesioned Rat

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    The effects of implantation of cultured adrenal medullary cells on the recovery of neurotransmitter specific reflex activity were studied in the rat spinal cord using electrophysiological testing methods. Cell suspensions of cultured neonatal adrenal medullary chromaffin (AM) cells (which produce catecholamines), or Schwann (Sc) cells (controls) were implanted into the lumbar region of the spinal cord 2 weeks after catecholamine (CA) denervation by intracisternal injection of 6-hydroxydopamine (6-OHDA). All cells were taken from 7 day neonates and cultured for 10 days in the presence of nerve growth factor (NGF). Three months after implantation, the extent of implant-associated recovery of reflex activity was determined by measuring electromyogram (EMG) activity and force associated with the long latency component of the hindlimb withdrawal reflex (which is CA modulated). After the electrophysiological testing, rats were anesthetized, and the spinal cords were rapidly removed and frozen. Spinal cords were sectioned longitudinally, and implanted cells were visualized using glyoxylic acid techniques. Labelled sections were examined to determine cell survival. Results indicate that 1) chromaffin cells survive for 3 months in the segments of the cord into which they have been implanted and 2) rats implanted with AM cells have significantly more forceful withdrawal reflexes than those that received Sc cells or received no implant after lesioning

    Explaining Strategic Coordination: Cognitive Hierarchy Theory, Strong Stackelberg Reasoning, and Team Reasoning Author Note

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    Abstract In common interest games, players generally manage to coordinate their actions on mutually optimal outcomes, but orthodox game theory provides no reason for them to play their individual parts in these seemingly obvious solutions and no justification for choosing the corresponding strategies. A number of theories have been suggested to explain coordination, among the most prominent being versions of cognitive hierarchy theory, theories of team reasoning, and social projection theory (in symmetric games). Each of these theories provides a plausible explanation but is theoretically problematic. An improved theory of strong Stackelberg reasoning avoids these problems and explains coordination among players who care about their co-players' payoffs and who act as though their co-players can anticipate their choices. Two experiments designed to test cognitive hierarchy, team reasoning, and strong Stackelberg theories against one another in games without obvious, payoff-dominant solutions suggest that each of the theories provides part of the explanation. Cognitive hierarchy Level-1 reasoning, facilitated by a heuristic of avoiding the worst payoff, tended to predominate, especially in more complicated games, but strong Stackelberg reasoning occurred quite frequently in the simpler games and team reasoning in both the simpler and the more complicated games. Most players considered two or more of these reasoning processes before choosing their strategies

    Men’s Experiences with the Hockey Fans in Training Weight Loss and Healthy Lifestyle Program

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    Background: Increasing rates of chronic disease, especially in men, have led to an increased effort to implement lifestyle interventions focusing on healthy eating and physical activity. Men are underrepresented in lifestyle programs and some studies have observed that males prefer men-only programs that occur in the context of sports. This paper reviews men’s feedback regarding motivation for joining and overall experience in a 12-week lifestyle intervention in the context of junior level ice hockey teams. Methods: Men age 35-65 with a BMI ?28 were recruited from local ice hockey team fan bases in London and Sarnia Ontario, Canada and randomized to the 12-week lifestyle intervention or control group. Those who attended at least 6 of the 12 weekly sessions, including at least one session in the final six weeks (n=30) were asked to complete an online questionnaire upon finishing the active phase of the intervention. The questionnaire elicited reasons for joining the program, changes seen following their participation, and the usefulness of specific components of the program. Results: For the 27 men who completed the questionnaire, weight loss and a desire to increase physical activity were the two main reasons cited for joining the program. After the intervention, 100% of the men reported eating a healthier diet and 78% increased their activity level. Program satisfaction was high and 96% of men believed both the classroom and exercise components were useful. Conclusion: Our results support previous research showing increased levels of satisfaction in men when lifestyle interventions are run in...

    Institutional-level drivers of gender-inequitable scientific career progression in sub-Saharan Africa

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    BACKGROUND: This study sought to determine how institutional environments, including values, policies, and their implementation, shape inequities in scientific career progression for women and men, and their disadvantages in relation to their multiple social identities in sub-Saharan Africa (SSA). The findings are drawn from a wider research study that was aimed at gaining an in-depth understanding of the barriers and enablers of gender-equitable scientific career progression for researchers in SSA. This was nested within the context of the Developing Excellence in Leadership, Training and Science in Africa (DELTAS Africa) programme—a health-based scientific research capacity-strengthening initiative. METHODS: The study adopted an exploratory qualitative cross-sectional study design. In-depth interviews (IDIs) with trainees/research fellows at various career stages supported and/or affiliated to three purposively selected DELTAS Africa Research Consortia were the main method of data collection. In addition, key informant interviews (KIIs) with consortia research leaders/directors, co-investigators, and the consortia management team were also conducted to corroborate information gathered from the IDIs, and also to provide additional insights on the drivers of intersectional gender-inequitable career progression. In total, 58 IDIs (32 female and 26 male) and 20 KIIs (4 female and 16 male) were conducted. The interviews were carried out in English between May and December 2018. The data were analysed inductively based on emergent themes. RESULTS: Three interrelated themes were identified: first, characterization of the institutional environment as highly complex and competitive with regard to advancement opportunities and funding structure; second, inequitable access to support systems within institutions; third, informal rules—everyday experiences of negative practices and culture at the workplace, characterized by negative stereotypical attitudes, gender biases, sexual harassment, and bullying and intimidation. CONCLUSIONS: We contend that understanding and addressing the social power relations at the meso-institutional environment and macro-level contexts could benefit career progression of both female and male researchers by improving work culture and practices, resource allocation, and better rules and policies, thus fostering positive avenues for systemic and structural policy changes

    Устройство советских мотоциклов

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    0|7|Введение [c. 7]0|11|Схема современного мотоцикла [c. 11]0|13|Принцип работы двигателя внутреннего сгорания [c. 13]0|28|Устройство деталей двигателей [c. 28]0|59|Охлаждение двигателя [c. 59]0|66|Смазка двигателя [c. 66]0|83|Карбюрация [c. 83]0|110|Электрооборудование мотоцикла [c. 110]0|150|Силовая передача [c. 150]0|172|Экипажная часть мотоцикла [c. 172]0|191|Органы управления мотоциклом [c. 191]0|198|Дополнительное оборудование мотоцикла [c. 198]0|199|Боковая прицепка [c. 199]0|202|Приспособления к мотоциклу для езды в условиях скользкого пути [c. 202]0|205|Управление мотоциклом [c. 205]0|212|Содержание [c. 212

    Identification and Characterization of Peripheral T-Cell Lymphoma-Associated SEREX Antigens

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    Peripheral T-cell lymphomas (PTCL) are generally less common and pursue a more aggressive clinical course than B-cell lymphomas, with the T-cell phenotype itself being a poor prognostic factor in adult non-Hodgkin lymphoma (NHL). With notable exceptions such as ALK+ anaplastic large cell lymphoma (ALCL, ALK+), the molecular abnormalities in PTCL remain poorly characterised. We had previously identified circulating antibodies to ALK in patients with ALCL, ALK+. Thus, as a strategy to identify potential antigens associated with the pathogenesis of PTCL, not otherwise specified (PTCL, NOS), we screened a testis cDNA library with sera from four PTCL, NOS patients using the SEREX (serological analysis of recombinant cDNA expression libraries) technique. We identified nine PTCL, NOS-associated antigens whose immunological reactivity was further investigated using sera from 52 B- and T-cell lymphoma patients and 17 normal controls. The centrosomal protein CEP250 was specifically recognised by patients sera and showed increased protein expression in cell lines derived from T-cell versus B-cell malignancies. TCEB3, BECN1, and two previously uncharacterised proteins, c14orf93 and ZBTB44, were preferentially recognised by patients' sera. Transcripts for all nine genes were identified in 39 cancer cell lines and the five genes encoding preferentially lymphoma-recognised antigens were widely expressed in normal tissues and mononuclear cell subsets. In summary, this study identifies novel molecules that are immunologically recognised in vivo by patients with PTCL, NOS. Future studies are needed to determine whether these tumor antigens play a role in the pathogenesis of PTCL

    The diversity, evolution and ecology of Salmonella in venomous snakes

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    BACKGROUND: Reptile-associated Salmonella bacteria are a major, but often neglected cause of both gastrointestinal and bloodstream infection in humans globally. The diversity of Salmonella enterica has not yet been determined in venomous snakes, however other ectothermic animals have been reported to carry a broad range of Salmonella bacteria. We investigated the prevalence and diversity of Salmonella in a collection of venomous snakes and non-venomous reptiles. METHODOLOGY/PRINCIPLE FINDINGS: We used a combination of selective enrichment techniques to establish a unique dataset of reptilian isolates to study Salmonella enterica species-level evolution and ecology and used whole-genome sequencing to investigate the relatedness of phylogenetic groups. We observed that 91% of venomous snakes carried Salmonella, and found that a diverse range of serovars (n = 58) were carried by reptiles. The Salmonella serovars belonged to four of the six Salmonella enterica subspecies: diarizonae, enterica, houtanae and salamae. Subspecies enterica isolates were distributed among two distinct phylogenetic clusters, previously described as clade A (52%) and clade B (48%). We identified metabolic differences between S. diarizonae, S. enterica clade A and clade B involving growth on lactose, tartaric acid, dulcitol, myo-inositol and allantoin. SIGNIFICANCE: We present the first whole genome-based comparative study of the Salmonella bacteria that colonise venomous and non-venomous reptiles and shed new light on Salmonella evolution. Venomous snakes examined in this study carried a broad range of Salmonella, including serovars which have been associated with disease in humans such as S. Enteritidis. The findings raise the possibility that venomous snakes could be a reservoir for Salmonella serovars associated with human salmonellosis
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