2,344 research outputs found
Trade Unions and Industrial Injury in Great Britain
Anecdotal evidence suggests that trade unions succeed in ameliorating workplace health and safety, but no attempt has been made to link specific workplace injury rates with a respective union presence. Relying on WERS98, this paper establishes a cross-sectional link between trade unions and occupational injury rates, revealing that unions gravitate to accident-prone workplaces and react by reducing injury rates within these types of employment units. However, the ability for unions to reduce injury rates does not appear to increase monotonically as they progress along a workplace instrumentality continuum from recognition alone to a pre-entry closed shop.Unions, industrial injury, occupational injury, health and safety
Alien Registration- Litwin, Mary A. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/32026/thumbnail.jp
Alien Registration- Litwin, Mary A. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/32026/thumbnail.jp
Balanced neural architecture and the idling brain
A signature feature of cortical spike trains is their trial-to-trial variability. This variability is large in the spontaneous state and is reduced when cortex is driven by a stimulus or task. Models of recurrent cortical networks with unstructured, yet balanced, excitation and inhibition generate variability consistent with evoked conditions. However, these models produce spike trains which lack the long timescale fluctuations and large variability exhibited during spontaneous cortical dynamics. We propose that global network architectures which support a large number of stable states (attractor networks) allow balanced networks to capture key features of neural variability in both spontaneous and evoked conditions. We illustrate this using balanced spiking networks with clustered assembly, feedforward chain, and ring structures. By assuming that global network structure is related to stimulus preference, we show that signal correlations are related to the magnitude of correlations in the spontaneous state. Finally, we contrast the impact of stimulation on the trial-to-trial variability in attractor networks with that of strongly coupled spiking networks with chaotic firing rate instabilities, recently investigated by Ostojic (2014). We find that only attractor networks replicate an experimentally observed stimulus-induced quenching of trial-to-trial variability. In total, the comparison of the trial-variable dynamics of single neurons or neuron pairs during spontaneous and evoked activity can be a window into the global structure of balanced cortical networks. © 2014 Doiron and Litwin-Kumar
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Sexual well-being and diurnal cortisol after prostate cancer treatment.
Sexual dysfunction and psychological distress are common after prostate cancer. Research has not examined the role of neuroendocrine markers of stress (e.g. cortisol). This study examines whether sexual functioning or sexual bother is associated with diurnal cortisol. Men treated for prostate cancer completed the University of California-Los Angeles Prostate Cancer Index and provided saliva samples four times daily for cortisol assessment. Higher sexual bother, but not sexual functioning, was associated with steeper cortisol slope. Better sexual functioning, and not sexual bother, was significantly associated with the cortisol awakening response. Assessment of stress and stress-reducing interventions might be warranted in sexual rehabilitation after prostate cancer
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Dysregulated Choline, Methionine, and Aromatic Amino Acid Metabolism in Patients with Wilson Disease: Exploratory Metabolomic Profiling and Implications for Hepatic and Neurologic Phenotypes.
Wilson disease (WD) is a genetic copper overload condition characterized by hepatic and neuropsychiatric symptoms with a not well-understood pathogenesis. Dysregulated methionine cycle is reported in animal models of WD, though not verified in humans. Choline is essential for lipid and methionine metabolism. Defects in neurotransmitters as acetylcholine, and biogenic amines are reported in WD; however, less is known about their circulating precursors. We aimed to study choline, methionine, aromatic amino acids, and phospholipids in serum of WD subjects. Hydrophilic interaction chromatography-quadrupole time-of-flight mass spectrometry was employed to profile serum of WD subjects categorized as hepatic, neurologic, and pre-clinical. Hepatic transcript levels of genes related to choline and methionine metabolism were verified in the Jackson Laboratory toxic milk mouse model of WD (tx-j). Compared to healthy subjects, choline, methionine, ornithine, proline, phenylalanine, tyrosine, and histidine were significantly elevated in WD, with marked alterations in phosphatidylcholines and reductions in sphingosine-1-phosphate, sphingomyelins, and acylcarnitines. In tx-j mice, choline, methionine, and phosphatidylcholine were similarly dysregulated. Elevated choline is a hallmark dysregulation in WD interconnected with alterations in methionine and phospholipid metabolism, which are relevant to hepatic steatosis. The elevated phenylalanine, tyrosine, and histidine carry implications for neurologic manifestations and are worth further investigation
Myxococcus xanthus gliding motors are elastically coupled to the substrate as predicted by the focal adhesion model of gliding motility
Myxococcus xanthus is a model organism for studying bacterial social
behaviors due to its ability to form complex multi-cellular structures.
Knowledge of M. xanthus surface gliding motility and the mechanisms that
coordinate it are critically important to our understanding of collective cell
behaviors. Although the mechanism of gliding motility is still under
investigation, recent experiments suggest that there are two possible
mechanisms underlying force production for cell motility: the focal adhesion
mechanism and the helical rotor mechanism which differ in the biophysics of the
cell-substrate interactions. Whereas the focal adhesion model predicts an
elastic coupling, the helical rotor model predicts a viscous coupling. Using a
combination of computational modeling, imaging, and force microscopy, we find
evidence for elastic coupling in support of the focal adhesion model. Using a
biophysical model of the M. xanthus cell, we investigated how the mechanical
interactions between cells are affected by interactions with the substrate.
Comparison of modeling results with experimental data for cell-cell collision
events pointed to a strong, elastic attachment between the cell and substrate.
These results are robust to variations in the mechanical and geometrical
parameters of the model. We then directly measured the motor-substrate coupling
by monitoring the motion of optically trapped beads and find that motor
velocity decreases exponentially with opposing load. At high loads, motor
velocity approaches zero velocity asymptotically and motors remain bound to
beads indicating a strong, elastic attachment
Effect of differentiating agents (all-trans retinoic acid and phorbol 12-myristate 13-acetate) on drug sensitivity of HL60 and NB4 cells in vitro.
In vitro studies have shown that human myeloid leukemia cell lines: HL60 and NB4 can be stimulated to differentiation by various agents, for example, all-trans retinoic acid (ATRA) and phorbol 12-myristate 13-acetate (PMA). The purpose of this study was to investigate whether differentiation of HL60 and NB4 leukemia cell lines induced by ATRA and PMA alters their drug sensitivity. The differentiation along the neutrophil lineage (upon stimulation with ATRA) and along the monocyte/macrophage lineage (upon stimulation with PMA) was proved by decreased proliferative potential of cells, changes in their morphology, increased ability for NBT reduction and increased expression of CD11b and CD14 cell surface markers. The effect of drugs: cytosine arabinoside, daunorubicin, mitoxantrone and etoposide was examined by Alamar Blue test (proliferation and survival rates), as well as by evaluation of cell smears stained with Hoechst 33342 (apoptotic index). Differentiation resulted in the change of drug sensitivity in both cell lines: the differentiation along the neutrophil pathway (after stimulation with ATRA) increased sensitivity to cytosine arabinoside and mitoxantrone but decreased sensitivity to etoposide; the differentiation along the monocyte/macrophage pathway (induced by PMA) resulted in the decreased sensitivity of both cell lines to all drugs tested. In conclusion, we have shown that ATRA- and PMA-mediated differentiation of HL60 and NB4 cell lines results in the changes of their drug sensitivity. Our data may provide a contribution to a strategy aimed at a rational combination of differentiating agents and conventional anticancer drugs
INFLUENCE OF VARIOUS ANOMALIES IN THE VEHICLE AND TRACK PARAMETERS ON THE POSSIBILITY OF DERAILMENT
A detailed non linear model of the four-axle real vehicle, considering both vertical and lateral
vibrations has been proposed. Inertial and elastic-viscous properties of the track have
been taken into account. Comparison of the theoretical investigations and on-track tests
has confirmed the rather good authenticity of the model. The calculations for anomalies
either in track or in vehicle parameters as well as for their combinations have been
performed
Immunohistochemical analysis of spinal cord components in mouse model of experimental autoimmune encephalomyelitis
Introduction. Experimental autoimmune encephalomyelitis (EAE) is a widely used animal model for studying immunopathology of multiple sclerosis (MS) because it repeats the hallmarks of the human disease, such as focal inflammation and demyelination of the central nervous system, subsequently leading to axonal and neuronal loss. The interrelationships, timing and sequence of different pathological processes that lead to histologically observed lesions in SM are still incompletely understood.Material and methods. EAE was induced in female C57Bl/6 mice by active immunization with MOG35-55 antigen. Development of the neurological symptoms in the animals was monitored and on that basis spinal cords were collected in three successive phases of the disease (onset, peak, chronic). Total leukocytes, T cells, macrophages/microglia, oligodendrocytes, damaged axons and surviving neuronal cell bodies were visualized using appropriate immunohistochemical markers and their density was quantitatively assessed using image analysis software.Results. The density of all studied cells except neurons was significantly higher in EAE mice than in the control mice. The density of total leukocytes, T cells, and damaged axons increased from the onset to the peak phase and decreased in the chronic phase to reach values lower than those in the peak phase. The density of macrophages/microglia increased in the peak phase and remained at the elevated level in the chronic phase. Oligodendrocytes showed the highest density in the onset phase and gradually decreased afterwards. The density of neuronal cell bodies decreased only in the chronic phase of the disease.Conclusions. In mouse model of EAE, inflammatory cells predominate in the early phases of the disease. This study shows for the first time that inflammation precedes oligodendrocyte death and neuronal loss and that macrophages/ microglia are the only cells persisting in large numbers in the chronic phase of the disease, probably because of the switch from proinflammatory to anti-inflammatory phenotype
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