451 research outputs found

    Studies of Learned Helplessness in Honey Bees (Apis Mellifera Ligustica)

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    The current study provides evidence of learned helplessness in the honey bee (Apis mellifera L.). Bees received either avoidable or unavoidable shock during a discriminative compartment restriction task in an automated shuttle box. Decreased avoidance behavior was observed when bees received unavoidable shock prior to avoidable shock tests, conserving a non-preference response pattern. Prior training with avoidable shock created a preference that was conserved when shock was later unavoidable. Length of the training time impacted how pronounced the conserved behavior was in subsequent tests. Unlike existing learned helplessness studies in other animals, no decrease in general activity was observed. These findings identify honey bees as a unique model organism to explore the process of learned helplessness.Psycholog

    Serum Micronutrient Status, Sleep Quality and Neurobehavioral Function Among Early Adolescents

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    Objective: To examine associations between serum micronutrients and neurobehavioral function and the mediating role of sleep quality in early adolescents. Design: In this cross-sectional study, peripheral blood samples were analyzed for iron and zinc levels. The Pittsburgh Sleep Quality Index and Penn Computerized Neurocognitive Battery were used to assess sleep quality and neurobehavioral function, respectively. The generalized linear regressions (bootstrap) were performed to estimate the associations. Setting: Jintan, China Participants: 226 adolescents (106 females) from the Jintan Child Cohort study. Results: Adolescents with low iron (\u3c 75 ug/dl) (OR=1.29, p=0.04) and low zinc (\u3c 70 ug/dl) (OR=1.58, p0.05). Conclusion: Iron and zinc deficiencies may possibly be associated with poor sleep and neurobehavioral function among early adolescents. Poor sleep may partially mediate the relationship between micronutrients and neurobehavioral function

    Literatur-Rundschau

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    Edmund Schalkowski: Rezension und Kritik; Stefan Porombka: Kritiken schreiben. Ein Trainingsbuch (Gunter Reus)Manfred L. Pirner/Thomas Breuer (Hg.): Medien - Bildung - Religion. Zum Verhältnis von Medienpädagogik und Religionspädagogik in Theorie, Empirie und Praxis (Rüdiger Funiok)Angela M. T. Reinders: Zugänge und Analysen zur religiösen Dimension des Cyberspace (Veit Neumann)Philomen Schönhagen: Soziale Kommunikation im Internet. Zur Theorie und Systematik computervermittelter Kommunikation vor dem Hintergrund der Kommunikationsgeschichte (Klaus Meier)Walter Hömberg/Renate Hackel-de Latour (Hg.): Studienführer Journalismus, Medien, Kommunikation (Marcus Nicolini)Volker Wolff: ABC des Zeitungs- und Zeitschriftenjournalismus (Ralf Hohlfeld)Dennis Eick: Drehbuchtheorien. Eine vergleichende Analyse; Philip Parker: Die Kreative Matrix. Kunst und Handwerk des Drehbuchschreibens (Michaela Petek-Dinges)Peter Brummund: Struktur und Organisation des Pressevertriebs. Absatzformen, Absatzhelfer und Absatzwege in der Vertriebsorganisation der Zeitungs- und Zeitschriftenverlage (Steffen W. Hillebrecht)Markus Lehmkuhl: Massenmedien und interpersonale Kommuni- kation. Eine explorative Studie am Beispiel BSE (Klaus Arnold)Peter Stein: Schriftkultur. Eine Geschichte des Schreibens und Lesens (Juliane Matthey)

    Superantigens from Staphylococcus aureus induce procoagulant activity and monocyte tissue factor expression in whole blood and mononuclear cells via IL-1beta.

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    Background: Staphylococcus aureus is one of the most common bacteria in human sepsis, a condition in which the activation of blood coagulation plays a critical pathophysiological role. During severe sepsis and septic shock microthrombi and multiorgan dysfunction are observed as a result of bacterial interference with the host defense and coagulation systems. Objectives: In the present study, staphylococcal superantigens were tested for their ability to induce procoagulant activity and tissue factor (TF) expression in human whole blood and in peripheral blood mononuclear cells. Methods and results: Determination of clotting time showed that enterotoxin A, B and toxic shock syndrome toxin 1 from S. aureus induce procoagulant activity in whole blood and in mononuclear cells. The procoagulant activity was dependent on the expression of TF in monocytes since antibodies to TF inhibited the effect of the toxins and TF was detected on the surface of monocytes by flow cytometry. In the supernatants from staphylococcal toxin-stimulated mononuclear cells, interleukin (IL)-1beta was detected by ELISA. Furthermore, the increased procoagulant activity and TF expression in monocytes induced by the staphylococcal toxins were inhibited in the presence of IL-1 receptor antagonist, a natural inhibitor of IL-1beta. Conclusions: The present study shows that superantigens from S. aureus activate the extrinsic coagulation pathway by inducing expression of TF in monocytes, and that the expression is mainly triggered by superantigen-induced IL-1beta release

    A Unique Radiation Scheme for the Treatment of High-Grade Non-Metastatic Soft Tissue Sarcoma: The Detroit Medical Center Experience

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    Purpose:This is the initial report on the utilization of combined photon irradiation followed by a neutron boost irradiation for the initial management of patients with high-grade non-metastatic soft tissue sarcoma (STS). We present data on local control, complications, disease-free survival and overall survival in patients at high risk for local relapse

    Impact of Extended-Duration Shifts on Medical Errors, Adverse Events, and Attentional Failures

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    BACKGROUND: A recent randomized controlled trial in critical-care units revealed that the elimination of extended-duration work shifts (≥24 h) reduces the rates of significant medical errors and polysomnographically recorded attentional failures. This raised the concern that the extended-duration shifts commonly worked by interns may contribute to the risk of medical errors being made, and perhaps to the risk of adverse events more generally. Our current study assessed whether extended-duration shifts worked by interns are associated with significant medical errors, adverse events, and attentional failures in a diverse population of interns across the United States. METHODS AND FINDINGS: We conducted a Web-based survey, across the United States, in which 2,737 residents in their first postgraduate year (interns) completed 17,003 monthly reports. The association between the number of extended-duration shifts worked in the month and the reporting of significant medical errors, preventable adverse events, and attentional failures was assessed using a case-crossover analysis in which each intern acted as his/her own control. Compared to months in which no extended-duration shifts were worked, during months in which between one and four extended-duration shifts and five or more extended-duration shifts were worked, the odds ratios of reporting at least one fatigue-related significant medical error were 3.5 (95% confidence interval [CI], 3.3–3.7) and 7.5 (95% CI, 7.2–7.8), respectively. The respective odds ratios for fatigue-related preventable adverse events, 8.7 (95% CI, 3.4–22) and 7.0 (95% CI, 4.3–11), were also increased. Interns working five or more extended-duration shifts per month reported more attentional failures during lectures, rounds, and clinical activities, including surgery and reported 300% more fatigue-related preventable adverse events resulting in a fatality. CONCLUSIONS: In our survey, extended-duration work shifts were associated with an increased risk of significant medical errors, adverse events, and attentional failures in interns across the United States. These results have important public policy implications for postgraduate medical education

    Location and arrangement of campaniform sensilla in Drosophila melanogaster

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    Sensory systems provide input to motor networks on the state of the body and environment. One such sensory system in insects is the campaniform sensilla (CS), which detect deformations of the exoskeleton arising from resisted movements or external perturbations. When physical strain is applied to the cuticle, CS external structures are compressed, leading to transduction in an internal sensory neuron. In Drosophila melanogaster, the distribution of CS on the exoskeleton has not been comprehensively described. To investigate CS number, location, spatial arrangement, and potential differences between individuals, we compared the front, middle, and hind legs of multiple flies using scanning electron microscopy. Additionally, we imaged the entire body surface to confirm known CS locations. On the legs, the number and relative arrangement of CS varied between individuals, and single CS of corresponding segments showed characteristic differences between legs. This knowledge is fundamental for studying the relevance of cuticular strain information within the complex neuromuscular networks controlling posture and movement. This comprehensive account of all D. melanogaster CS helps set the stage for experimental investigations into their responsivity, sensitivity, and roles in sensory acquisition and motor control in a light-weight model organism

    Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men

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    Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed. Results In the control group, none of the parameters changed. In the experimental group, heart rate increased from 60 +/- 1.8 beats per minute (bpm) at BL, to 63 +/- 1.1 bpm after SR and further to 65 +/- 1.8 bpm after REC. In addition, whole day low-frequency to-high frequency (LF/HF) power ratio of heart rate variability increased from 4.6 +/- 0.4 at BL to 6.0 +/- 0.6 after SR. Other parameters, including salivary NPY and cortisol levels, remained unaffected. Conclusions Increased heart rate and LF/HF power ratio are early signs of an increased sympathetic activity after prolonged sleep restriction. To reliably interpret the clinical significance of these early signs of physiological stress, a follow-up study would be needed to evaluate if the stress responses escalate and lead to more unfavourable reactions, such as elevated blood pressure and a subsequent elevated risk for cardiovascular health problems.Peer reviewe

    A Novel Core Genome-Encoded Superantigen Contributes to Lethality of Community-Associated MRSA Necrotizing Pneumonia

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    Bacterial superantigens (SAg) stimulate T-cell hyper-activation resulting in immune modulation and severe systemic illnesses such as Staphylococcus aureus toxic shock syndrome. However, all known S. aureus SAgs are encoded by mobile genetic elements and are made by only a proportion of strains. Here, we report the discovery of a novel SAg staphylococcal enterotoxin-like toxin X (SElX) encoded in the core genome of 95% of phylogenetically diverse S. aureus strains from human and animal infections, including the epidemic community-associated methicillin-resistant S. aureus (CA-MRSA) USA300 clone. SElX has a unique predicted structure characterized by a truncated SAg B-domain, but exhibits the characteristic biological activities of a SAg including Vβ-specific T-cell mitogenicity, pyrogenicity and endotoxin enhancement. In addition, SElX is expressed by clinical isolates in vitro, and during human, bovine, and ovine infections, consistent with a broad role in S. aureus infections of multiple host species. Phylogenetic analysis suggests that the selx gene was acquired horizontally by a progenitor of the S. aureus species, followed by allelic diversification by point mutation and assortative recombination resulting in at least 17 different alleles among the major pathogenic clones. Of note, SElX variants made by human- or ruminant-specific S. aureus clones demonstrated overlapping but distinct Vβ activation profiles for human and bovine lymphocytes, indicating functional diversification of SElX in different host species. Importantly, SElX made by CA-MRSA USA300 contributed to lethality in a rabbit model of necrotizing pneumonia revealing a novel virulence determinant of CA-MRSA disease pathogenesis. Taken together, we report the discovery and characterization of a unique core genome-encoded superantigen, providing new insights into the evolution of pathogenic S. aureus and the molecular basis for severe infections caused by the CA-MRSA USA300 epidemic clone
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