950 resultados para State Dependent Service Rate
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1) A large body of behavioral data conceming animal and human gaits and gait transitions is simulated as emergent properties of a central pattern generator (CPG) model. The CPG model incorporates neurons obeying Hodgkin-Huxley type dynamics that interact via an on-center off-surround anatomy whose excitatory signals operate on a faster time scale than their inhibitory signals. A descending cornmand or arousal signal called a GO signal activates the gaits and controL their transitions. The GO signal and the CPG model are compared with neural data from globus pallidus and spinal cord, among other brain structures. 2) Data from human bimanual finger coordination tasks are simulated in which anti-phase oscillations at low frequencies spontaneously switch to in-phase oscillations at high frequencies, in-phase oscillations can be performed both at low and high frequencies, phase fluctuations occur at the anti-phase in-phase transition, and a "seagull effect" of larger errors occurs at intermediate phases. When driven by environmental patterns with intermediate phase relationships, the model's output exhibits a tendency to slip toward purely in-phase and anti-phase relationships as observed in humans subjects. 3) Quadruped vertebrate gaits, including the amble, the walk, all three pairwise gaits (trot, pace, and gallop) and the pronk are simulated. Rapid gait transitions are simulated in the order--walk, trot, pace, and gallop--that occurs in the cat, along with the observed increase in oscillation frequency. 4) Precise control of quadruped gait switching is achieved in the model by using GO-dependent modulation of the model's inhibitory interactions. This generates a different functional connectivity in a single CPG at different arousal levels. Such task-specific modulation of functional connectivity in neural pattern generators has been experimentally reported in invertebrates. Phase-dependent modulation of reflex gain has been observed in cats. A role for state-dependent modulation is herein predicted to occur in vertebrates for precise control of phase transitions from one gait to another. 5) The primary human gaits (the walk and the run) and elephant gaits (the amble and the walk) are sirnulated. Although these two gaits are qualitatively different, they both have the same limb order and may exhibit oscillation frequencies that overlap. The CPG model simulates the walk and the run by generating oscillations which exhibit the same phase relationships. but qualitatively different waveform shapes, at different GO signal levels. The fraction of each cycle that activity is above threshold quantitatively distinguishes the two gaits, much as the duty cycles of the feet are longer in the walk than in the run. 6) A key model properly concerns the ability of a single model CPG, that obeys a fixed set of opponent processing equations to generate both in-phase and anti-phase oscillations at different arousal levels. Phase transitions from either in-phase to anti-phase oscillations, or from anti-phase to in-phase oscillations, can occur in different parameter ranges, as the GO signal increases.
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This article describes feasible and improved ways towards enhanced nanowire growth kinetics by reducing the equilibrium solute concentration in the liquid collector phase in a vapor-liquid-solid (VLS) like growth model. Use of bi-metallic alloy seeds (AuxAg1-x) influences the germanium supersaturation for a faster nucleation and growth kinetics. Nanowire growth with ternary eutectic alloys shows Gibbs-Thompson effect with diameter dependent growth rate. In-situ transmission electron microscopy (TEM) annealing experiments directly confirms the role of equilibrium concentration in nanowire growth kinetics and was used to correlate the equilibrium content of metastable alloys with the growth kinetics of Ge nanowires. The shape and geometry of the heterogeneous interfaces between the liquid eutectic and solid Ge nanowires were found to vary as a function of nanowire diameter and eutectic alloy composition.
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The nuclear respiratory factor-1 (NRF1) gene is activated by lipopolysaccharide (LPS), which might reflect TLR4-mediated mitigation of cellular inflammatory damage via initiation of mitochondrial biogenesis. To test this hypothesis, we examined NRF1 promoter regulation by NFκB, and identified interspecies-conserved κB-responsive promoter and intronic elements in the NRF1 locus. In mice, activation of Nrf1 and its downstream target, Tfam, by Escherichia coli was contingent on NFκB, and in LPS-treated hepatocytes, NFκB served as an NRF1 enhancer element in conjunction with NFκB promoter binding. Unexpectedly, optimal NRF1 promoter activity after LPS also required binding by the energy-state-dependent transcription factor CREB. EMSA and ChIP assays confirmed p65 and CREB binding to the NRF1 promoter and p65 binding to intron 1. Functionality for both transcription factors was validated by gene-knockdown studies. LPS regulation of NRF1 led to mtDNA-encoded gene expression and expansion of mtDNA copy number. In cells expressing plasmid constructs containing the NRF-1 promoter and GFP, LPS-dependent reporter activity was abolished by cis-acting κB-element mutations, and nuclear accumulation of NFκB and CREB demonstrated dependence on mitochondrial H(2)O(2). These findings indicate that TLR4-dependent NFκB and CREB activation co-regulate the NRF1 promoter with NFκB intronic enhancement and redox-regulated nuclear translocation, leading to downstream target-gene expression, and identify NRF-1 as an early-phase component of the host antibacterial defenses.
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Attention has recently focussed on stochastic population processes that can undergo total annihilation followed by immigration into state j at rate αj. The investigation of such models, called Markov branching processes with instantaneous immigration (MBPII), involves the study of existence and recurrence properties. However, results developed to date are generally opaque, and so the primary motivation of this paper is to construct conditions that are far easier to apply in practice. These turn out to be identical to the conditions for positive recurrence, which are very easy to check. We obtain, as a consequence, the surprising result that any MBPII that exists is ergodic, and so must possess an equilibrium distribution. These results are then extended to more general MBPII, and we show how to construct the associated equilibrium distributions.
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The transient receptor potential melastatin 8 (TRPM8) channel has been characterized as a cold and menthol receptor expressed in a subpopulation of sensory neurons but was recently identified in other tissues, including the respiratory tract, urinary system, and vasculature. Thus TRPM8 may play multiple functional roles, likely to be in a tissue- and activation state-dependent manner. We examined the TRPM8 channel presence in large arteries from rats and the functional consequences of their activation. We also aimed to examine whether these channels contribute to control of conscious human skin blood flow. TRPM8 mRNA and protein were detected in rat tail, femoral and mesenteric arteries, and thoracic aorta. This was confirmed in single isolated vascular myocytes by immunocytochemistry. Isometric contraction studies on endothelium-denuded relaxed rat vessels found small contractions on application of the TRPM8-specific agonist menthol (300 microM). However, both menthol and another agonist icilin (50 microM) caused relaxation of vessels precontracted with KCl (60 mM) or the alpha-adrenoceptor agonist phenylephrine (2 microM) and a reduction in sympathetic nerve-mediated contraction. These effects were antagonized by bromoenol lactone treatment, suggesting the involvement of Ca(2+)-independent phospholipase A(2) activation in TRPM8-mediated vasodilatation. In thoracic aorta with intact endothelium, menthol-induced inhibition of KCl-induced contraction was enhanced. This was unaltered by preincubation with either N(omega)-nitro-l-arginine methyl ester (l-NAME; 100 nM), a nitric oxide synthase inhibitor, or the ACh receptor antagonist atropine (1 microM). Application of menthol (3% solution, topical application) to skin caused increased blood flow in conscious humans, as measured by laser Doppler fluximetry. Vasodilatation was markedly reduced or abolished by prior application of l-NAME (passive application, 10 mM) or atropine (iontophoretic application, 100 nM, 30 s at 70 microA). We conclude that TRPM8 channels are present in rat artery vascular smooth muscle and on activation cause vasoconstriction or vasodilatation, dependent on previous vasomotor tone. TRPM8 channels may also contribute to human cutaneous vasculature control, likely with the involvement of additional neuronal mechanisms.
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Ring-opened metathesis polymers and copolymers have been formed from norbornene, norbornadiene, a range of their derivatives, and cyclopentene using RuCl2(CHPh)(PCy3)(2), as catalyst. C-13 NMR analysis of the polymers illustrate a rather selective propagation reaction. The catalyst is highly regioselective, and the polymers are generally high trans with a strong isotactic bias. However, polymers from diene monomers tend to be less isotactic than those from the corresponding monoenes, and in the case of 7-methylnorbornadiene the polymer has an overall syndiotactic bias. A rate enhancing effect, noted previously, due to an oxygen atom proximate to the monomer double bond, is less pronounced than with other initiators. Catalyst activity, in the case of certain diene monomers, was shown to be monomer dependent and rate enhancements were also achieved using phenol as solvent. The results are interpreted in terms of the steric and electronic properties of both the catalyst and the monomers.
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We present the fifth release of the UMIST Database for Astrochemistry (UDfA). The new reaction network contains 6173 gas-phase
reactions, involving 467 species, 47 of which are new to this release. We have updated rate coefficients across all reaction types.
We have included 1171 new anion reactions and updated and reviewed all photorates. In addition to the usual reaction network, we
also now include, for download, state-specific deuterated rate coefficients, deuterium exchange reactions and a list of surface binding
energies for many neutral species. Where possible, we have referenced the original source of all new and existing data. We have tested
the main reaction network using a dark cloud model and a carbon-rich circumstellar envelope model. We present and briefly discuss
the results of these models.
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Cloning of observables, unlike standard cloning of states, aims at copying the information encoded in the statistics of a class of observables rather then on quantum states themselves. In such a process the emphasis is on the quantum operation (evolution plus measurement) necessary to retrieve the original information. We analyze, for qubit systems, the cloning of a class generated by two noncommuting observables, elucidating the relationship between such a process and joint measurements. This helps in establishing an optimality criterion for cloning of observables. We see that, even if the cloning machine is designed to act on the whole class generated by two noncommuting observables, the same optimal performances of a joint measurement can be attained. Finally, the connection with state dependent cloning is enlightened.
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The first Australian palliative care nurse practitioner (NP) was endorsed in 2003. In 2009 the Victoria Department of Health funded the development of the Victorian Palliative Care Nurse Practitioner Collaborative (VPCNPC). Its aim was to promote the NP role, develop resources, and provide education and mentorship to NPs, nurse practitioner candidates (NPCs), and health service managers. Four key objectives were developed: identify the demographic profile of palliative care NPCs in Victoria; develop an education curriculum and practical resources to support the training and education of palliative care NPCs and NPs; provide mentorship to NPs, NPCs, and service managers; and ensure effective communication with all key stakeholders. An NPC survey was also conducted to explore NPC demographics, models of care, the hours of study required for the role, the mentoring process, and education needs. This paper reports on the establishment of the VPCNPC, the steps taken to achieve its objectives, and the results of the survey. The NP role in palliative care in Australia continues to evolve, and the VPCNPC provides a structure and resources to clearly articulate the benefits of the role to nursing and clinical services. The advanced clinical practice role of the nurse practitioner (NP) has been well established in North America for several decades and across a range of specialties (Ryan-Woolley et al, 2007; Poghosyan et al, 2012). The NP role in Australia and the UK is a relatively new initiative that commenced in the early 2000s (Gardner et al, 2009). There are over 1000 NPs across all states and territories of Australia, of whom approximately 130 work in the state of Victoria (Victorian Government Health Information, 2012). Australian NPs work across a range of specialties, including palliative, emergency, older person, renal, cardiac, respiratory, and mental health care. There has been increasing focus nationally and internationally on developing academic programmes specifically for nurses working toward NP status (Gardner et al, 2006). There has been less emphasis on identifying the comprehensive clinical support requirements for NPs and NP candidates (NPCs) to ensure they meet all registration requirements to achieve and/or maintain endorsement, or on articulating the ongoing requirements for NPs once endorsed. Historically in Australia there has been a lack of clarity and limited published evidence on the benefits of the NP role for patients, carers, and health services (Quaglietti et al, 2004; Gardner and Gardner, 2005; Bookbinder et al, 2011; Dyar et al, 2012). An NP is considered to be at the apex of clinical nursing practice. The NP role typically entails comprehensively assessing and managing patients, prescribing medicines, making direct referrals to other specialists and services, and ordering diagnostic investigations (Australian Nursing and Midwifery Council, 2009). All NPs in Australia are required to meet the following generic criteria: be a registered nurse, have completed a Nursing and Midwifery Board of Australia approved postgraduate university Master's (nurse practitioner) degree programme, and be able to demonstrate a minimum of 3 years' experience in an advanced practice role (Nursing and Midwifery Board of Australia, 2011). An NPC in Victoria is a registered nurse employed by a service or organisation to work toward meeting the academic and clinical requirements for national endorsement as an NP. During the period of candidacy, which is of variable duration, NPCs consolidate their competence to work at the advanced practice level of an NP. The candidacy period is a process of learning the new role while engaging with mentors (medical and nursing) and accessing other learning opportunities both within and outside one's organisation to meet the educational requirements. Integral to the NP role is the development of a model of care that is responsive to identified service delivery gaps that can be addressed by the skills, knowledge, and expertise of an NP. These are unique to each individual service. The practice of an Australian NP is guided by national standards (Nursing and Midwifery Board of Australia 2014). It is defined by four overarching standards: clinical, education, research, and leadership. Following the initial endorsement of four Victorian palliative care NPs in 2005, there was a lull in recruitment. The Victoria Department of Health (DH) recognised the potential benefits of NPs for health services, and in 2008 it provided funding for Victorian public health services to scope palliative care NP models of care that could enhance service delivery and patient outcomes. The scoping strategy was effective and led to the appointment of 16 palliative care nurses to NPC positions over the ensuing 3 years. The NPCs work across a broad range of care settings, including inpatient, community, and outpatient in metropolitan, regional, and rural areas of Victoria. At the same time, the DH also funded the Centre for Palliative Care to establish the Victorian Palliative Care Nurse Practitioner Collaborative (VPCNPC) to support the NPs and NPCs. The Centre is a state-wide service that is part of St Vincent's Hospital Melbourne and a collaborative Centre of the University of Melbourne. Its primary function is to provide training and conduct research in palliative care. The purpose of the VPCNPC was to provide support and mentorship and develop resources targeted at palliative care NPs, NPCs, and health service managers. Membership of the VPCNPC is open to all NPs, NPCs, health service managers, and nurses interested in the NP role. The aim of this paper is to describe the development of the VPCNPC, its actions, and the outcomes of these actions.
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The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.
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The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.
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The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.
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The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.
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The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.
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The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.