This paper proposes a new theoretical stochastic model based on an abstraction of the opportunistic model for opportunistic networks. The model is capable of systematically computing the network ...parameters, such as the number of possible routes, the probability of successful transmission, the expected number of broadcast transmissions, and the expected number of receptions. The usual theoretical stochastic model explored in the methodologies available in the literature is based on Markov chains, and the main novelty of this paper is the employment of a percolation stochastic model, whose main benefit is to obtain the network parameters directly. Additionally, the proposed approach is capable to deal with values of probability specified by bounded intervals or by a density function. The model is validated via Monte Carlo simulations, and a computational toolbox (R-packet) is provided to make the reproduction of the results presented in the paper easier. The technique is illustrated through a numerical example where the proposed model is applied to compute the energy consumption when transmitting a packet via an opportunistic network.
This study presents a single-phase grid-tied photovoltaic (PV) system based on a global maximum power point tracking (MPPT) technique, which is performed by means of the particle swarm optimisation ...(PSO) method. The PSO-based MPPT technique is employed to solve problems related to mismatching phenomena, such as partial shading, in which the PV arrays are commonly submitted. Considering the search of the global maximum power point under partial shading, the effectiveness of the PSO-based MPPT technique is highlighted when compared with the well-known perturb and observe MPPT technique, since both the mentioned MPPT techniques are used to determine the dc-bus voltage reference to ensure a proper grid-tied inverter operation. A current generator algorithm based on a synchronous reference frame is proposed, which operates in conjunction with a dc-bus controller and MPPT algorithms, computing the reference current of the grid-tied inverter. In addition, the current generator controls the energy processed by the PV system to avoid over power rating of the grid-tied inverter, since the active power injection into the grid, reactive power compensation and harmonic currents suppression are carried out simultaneously. The performance and feasibility of the grid-tied PV system are evaluated by means of simulation and experimental results.
ABSTRACT
Introduction: Muscle morphology and architecture changes in response to 6 weeks of progressive resistance training were examined in healthy older adults. Methods: In this randomized, ...controlled design, muscle strength, quality, and architecture were evaluated with knee extension, DEXA, and ultrasound, respectively, in 25 older adults. Results: Resistance training resulted in significant increases in strength and muscle quality of 32% and 31%, respectively. Cross‐sectional area of the vastus lateralis increased by 7.4% (p ≤ 0.05). Physiological cross‐sectional area (PCSA) of the thigh, a composite measure of muscle architecture, was related significantly to strength (r = 0.57; p ≤ 0.01) and demonstrated a significant interaction after training (p ≤ 0.05). Change in PCSA of the vastus lateralis was associated with change in strength independent of any other measure. Conclusions: Six weeks of resistance training was effective at increasing strength, muscle quality, and muscle morphology in older adult men and women. Muscle Nerve 49:584–592, 2014
spp. are Gram-negative, facultative intracellular bacteria that cause brucellosis in humans and animals. Currently available live attenuated vaccines against brucellosis still have drawbacks. ...Therefore, subunit vaccines, produced using epitope-based antigens, have the advantage of being safe, cost-effective and efficacious. Here, we identified
small RNAs expressed during early infection with bone marrow-derived macrophages (BMDMs) and an apolipoprotein N-acyltransferase (Int) was identified as the putative target of the greatest expressed small RNA. Decreased expression of Int was observed during BMDM infection and the protein sequence was evaluated to rationally select a putative immunogenic epitope by immunoinformatic, which was explored as a vaccinal candidate. C57BL/6 mice were immunized and challenged with
, showing lower recovery in the number of viable bacteria in the liver, spleen, and axillary lymph node and greater production of IgG and fractions when compared to non-vaccinated mice. The vaccinated and infected mice showed the increased expression of
,
, and IL-6 following expression of the anti-inflammatory genes
and
in the liver, justifying the reduction in the number and size of the observed granulomas. BMDMs stimulated with splenocyte supernatants from vaccinated and infected mice increase the CD86+ marker, as well as expressing greater amounts of iNOS and the consequent increase in NO production, suggesting an increase in the phagocytic and microbicidal capacity of these cells to eliminate the bacteria.
Purpose
The purpose of this study was to compare the physiological responses of a high-volume (HV; 8 sets of 10 repetitions) versus high-intensity (HI; 8 sets of 3 repetitions) exercise protocol in ...resistance-trained men.
Methods
Twelve men (24.5 ± 4.2 years; 82.3 ± 8.4 kg; 175.2 ± 5.5 cm) with 6.3 ± 3.4 years of resistance training experience performed each protocol in a counterbalanced, randomized order. Performance counter movement jump peak power (CMJP), isokinetic (ISOK) and isometric leg extension (MVIC), isometric mid-thigh pull (IMTP), and isometric squat (ISQ) and muscle morphological cross-sectional area (CSA) of vastus lateralis assessments were performed at baseline (BL), 30-min (P-30 min), 24-h (P-24 h), 48-h (P-48 h), and 72-h (P-72 h) post-exercise for each testing session. In addition, endocrine (testosterone and cortisol), inflammatory interleukin-6 (IL-6) and C-reactive protein (CRP), and markers of muscle damage creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb) were assessed at the same time points.
Results
Significantly greater reductions in CMJP (
p
< 0.001), and peak torque during both ISOK (
p
= 0.003) and MVIC (
p
= 0.008) at P-30 min were detected in HV compared to HI protocol. MVIC was still impaired at P-72 h following the HV protocol, while no differences were noted following HI. Markers of muscle damage (LDH, CK, and Mb) were significantly elevated following both HV and HI (
p
< 0.05), while cortisol and IL-6 concentrations were significantly elevated at P-30 min following HV only (
p
< 0.001 and
p
< 0.05, respectively).
Conclusions
Results indicate that high-volume resistance exercise results in greater performance deficits, and a greater extent of muscle damage, than a bout of high-intensity resistance exercise.
Valid, reliable, and clinically relevant outcome measures are necessary in clinical studies of snake envenomation. The aim of this study was to evaluate the psychometric (validity and reliability) ...and clinimetric (minimal clinically important difference MCID) properties of the Patient-Specific Functional Scale (PSFS) in snakebite envenomation.
We performed a secondary analysis of two existing snakebite trials that measured clinical outcomes using the PSFS as well as other quality of life and functional assessments. Data were collected at 3, 7, 10, and 17 days. Reliability was determined using Cronbach's alpha for internal consistency and the intraclass correlation coefficient (ICC) for temporal stability at 10 and 17 days. Validity was assessed using concurrent validity correlating with the other assessments. The MCID was evaluated using the following criteria: (1) the distribution of stable patients according to both standard error of measurement (SEM) and responsiveness techniques, and (2) anchor-based methods to compare between individuals and to detect discriminant ability of a positive change with a receiver operator characteristic (ROC) curve and optimal cutoff point.
A total of 86 patients were evaluated in this study. The average PSFS scores were 5.37 (SD 3.23), 7.95 (SD 2.22), and 9.12 (SD 1.37) at 3, 7, and 10 days, respectively. Negligible floor effect was observed (maximum of 8% at 3 days); however, a ceiling effect was observed at 17 days (25%). The PSFS showed good reliability with an internal consistency of 0.91 (Cronbach's alpha) (95% CI 0.88, 0.95) and a temporal stability of 0.83 (ICC) (95% CI 0.72, 0.89). The PSFS showed a strong positive correlation with quality of life and functional assessments. The MCID was approximately 1.0 for all methods.
With an MCID of approximately 1 point, the PSFS is a valid and reliable tool to assess quality of life and functionality in patients with snake envenomation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The abuse of anabolic androgenic steroids (AAS) may cause side effects in several tissues. Oxidative stress is linked to the pathophysiology of most of these alterations, being involved in fibrosis, ...cellular proliferation, tumorigenesis, amongst others. Thus, the aim of this study was to determine the impact of supraphysiological doses of nandrolone decanoate (DECA) on the redox balance of liver, heart and kidney. Wistar male rats were treated with intramuscular injections of vehicle or DECA (1 mg.100 g(-1) body weight) once a week for 8 weeks. The activity and mRNA levels of NADPH Oxidase (NOX), and the activity of catalase, glutathione peroxidase (GPx) and total superoxide dismutase (SOD), as well as the reduced thiol and carbonyl residue proteins, were measured in liver, heart and kidney. DECA treatment increased NOX activity in heart and liver, but NOX2 mRNA levels were only increased in heart. Liver catalase and SOD activities were decreased in the DECA-treated group, but only catalase activity was decreased in the kidney. No differences were detected in GPx activity. Thiol residues were decreased in the liver and kidney of treated animals in comparison to the control group, while carbonyl residues were increased in the kidney after the treatment. Taken together, our results show that chronically administered DECA is able to disrupt the cellular redox balance, leading to an oxidative stress state.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The strategic buckets method is often posited as an approach to ensure the strategic alignment of an research and development (R&D) portfolio with firm's strategy. Despite its popularity, crafting ...the right set of buckets to allocate resources is not a straightforward task. We consider the question of how to establish a set of buckets that aligns the R&D portfolio with the business strategy. We carried out a case-based research and investigate seven companies in order to propose a framework to assist decision makers in designing this set of buckets. Our framework is composed of four strategic constructs, namely, technology, market, capabilities, and organizational processes. In addition to these four constructs, we suggest that the external environment also be taken into account. We discuss the key benefits and offer theoretical insights concerning the strategic constructs, which can be combined and divided, resulting in a set of buckets that better suits a company's strategy. In addition, we acknowledge the idiosyncratic nature of firms and, as opposed to prescribing a static approach for companies, we suggest the design of buckets as a dynamic process to be performed according to the four different constructs, together with a firm's interaction with the external environment. We close by discussing the implications of our approach.
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