821 research outputs found
Survival of Empoasca labae (Harris) (Cicadellidae, Homoptera) on Synthetic Media
Nymphs of the potato leafhopper were caged in small clear plastic snap boxes for individual survival studies. All experiments were conducted at 85°F in a darkened incubator, minimizing responses to light and varying temperature. The leafhopper nymphs were sustained on an agar gel matrix containing sugars and amino acids. Relative nutritional adequacy was evaluated by the time required to reach 50% survival. The lowest mortality rate occurred on a 7% sucrose-2% agar medium. Preferential utilization of the glucose fraction of sucrose was indicated. A medium composed of agar, sucrose, and the 10 amino acids essential for human and rat nutrition tripled the 50% survival time compared with agar controls
Gene Expression in Peripheral Blood Leukocytes in Monozygotic Twins Discordant for Chronic Fatigue: No Evidence of a Biomarker
Background: Chronic fatiguing illness remains a poorly understood syndrome of unknown pathogenesis. We attempted to identify biomarkers for chronic fatiguing illness using microarrays to query the transcriptome in peripheral blood leukocytes. Methods: Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue. Biological sampling conditions were standardized and RNA stabilizing media were used. These methodological features provide rigorous control for bias resulting from case-control mismatched ancestry and experimental error. Individual gene expression profiles were assessed using Affymetrix Human Genome U133 Plus 2.0 arrays. Findings: There were no significant differences in gene expression for any transcript. Conclusions: Contrary to our expectations, we were unable to identify a biomarker for chronic fatiguing illness in the transcriptome of peripheral blood leukocytes suggesting that positive findings in prior studies may have resulted fro
Understanding the dynamics of Toll-like Receptor 5 response to flagellin and its regulation by estradiol
© 2017 The Author(s). Toll-like receptors (TLRs) are major players of the innate immune system. Once activated, they trigger a signalling cascade that leads to NF-ΰ B translocation from the cytoplasm to the nucleus. Single cell analysis shows that NF-ΰ B signalling dynamics are a critical determinant of transcriptional regulation. Moreover, the outcome of innate immune response is also affected by the cross-talk between TLRs and estrogen signalling. Here, we characterized the dynamics of TLR5 signalling, responsible for the recognition of flagellated bacteria, and those changes induced by estradiol in its signalling at the single cell level. TLR5 activation in MCF7 cells induced a single and sustained NF-k B translocation into the nucleus that resulted in high NF-k B transcription activity. The overall magnitude of NF-k B transcription activity was not influenced by the duration of the stimulus. No significant changes are observed in the dynamics of NF-k B translocation to the nucleus when MCF7 cells are incubated with estradiol. However, estradiol significantly decreased NF-k B transcriptional activity while increasing TLR5-mediated AP-1 transcription. The effect of estradiol on transcriptional activity was dependent on the estrogen receptor activated. This fine tuning seems to occur mainly in the nucleus at the transcription level rather than affecting the translocation of the NF-k B transcription factor
Physiological and Cognitive Performance in F-22 Pilots During Day and Night Flying
The article of record as published may be found at https://doi.org/10.3357/AMHP.5508.2021Many workers routinely transition between day and night shifts—including pilots, where night flights are commonly considered more stressful. The physiological toll from this transition is not fully understood, though fatigue is a factor in many aviation accidents. This research investigated the changes in physiological markers of stress and cognitive performance as F-22 pilots transitioned from day flying to night flying
Performance Analysis of Data Traffic in Small Cells Networks with User Mobility
We analyze the impact of inter-cell mobility on data traffic performance in dense networks with small cells. To this end, a multi-class queuing system with impatience is proposed as a generic model that captures mobility through the sojourn time of users in the cell. We provide mathematical proofs for the stability and the regularity of this multi-class queuing system. We then show how the performance of a homogeneous network is amenable to the application of the generic model to a single representative cell. This model is applied to derive the throughput of both mobile and static users, along with the handover probability. Numerical evaluation and simulation results are provided to assess the accuracy of the approach; we show, in particular, that both classes of users benefit from a throughput gain induced by the opportunistic displacement of mobile users among cells
Cardiovascular roles of estrogen receptors: insights gained from knockout models
The effects of estrogen are mediated through two functionally distinct receptors, estrogen receptor α (ER- α ), and estrogen receptor β (ER- β ), both of which are expressed in the cardiovascular system. The etiology of cardiovascular disease is believed to result in part from the loss of endogenous estrogen, indicating that estrogen and its receptors may play important roles in the prevention of cardiovascular disease in women
Increased serum tumor necrosis factor α levels in patients with lenalidomide-induced hypothyroidism
As the use of lenalidomide expands, the poorly understood phenomenon of lenalidomide-induced thyroid abnormalities will increase. In this study we compared rates of therapy-induced hypothyroidism in 329 patients with DLBCL treated with conventional chemotherapy (DLBCL-c) or conventional chemotherapy plus lenalidomide (DLBCL-len). We measured serum levels of tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin-6 (IL-6), interleukin-12 (IL-12), and interleukin-15 (IL-15) before and after treatment. We found a significantly higher rate of therapy-induced hypothyroidism in the DLBCL-len group (25.8% vs 1.3%), and we found a statistically significant increase in serum TNF-α in patients with lenalidomide-induced hypothyroidism
Loss of α-catenin elicits a cholestatic response and impairs liver regeneration
The liver is unique in its capacity to regenerate after injury, during which hepatocytes actively divide and establish cell-cell contacts through cell adhesion complexes. Here, we demonstrate that the loss of α-catenin, a well-established adhesion component, dramatically disrupts liver regeneration. Using a partial hepatectomy model, we show that regenerated livers from α-catenin knockdown mice are grossly larger than control regenerated livers, with an increase in cell size and proliferation. This increased proliferation correlated with increased YAP activation, implicating α-catenin in the Hippo/YAP pathway. Additionally, α-catenin knockdown mice exhibited a phenotype reminiscent of clinical cholestasis, with drastically altered bile canaliculi, elevated levels of bile components and signs of jaundice and inflammation. The disrupted regenerative capacity is a result of actin cytoskeletal disorganisation, leading to a loss of apical microvilli, dilated lumens in the bile canaliculi, and leaky tight junctions. This study illuminates a novel, essential role for α-catenin in liver regeneration
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