Globally, one billion people live in informal settlements, and that number is expected to triple by 2050. Studies suggests that health in informal settlements is a serious and growing concern, yet ...there is a paucity of research focused on health outcomes and the correlates of health in these settlements. Studies cite individual, environmental and social correlates to health in informal settlements, but they often lack empirical evidence. In particular, research suggests that high rates of violence against women (VAW) in informal settlements may be associated with detrimental effects on women's health, but few studies have investigated this link. The purpose of this study was to fill this gap by empirically exploring associations between women's experiences of intimate partner violence (IPV) and their physical and mental health. Data for this study were collected in August 2018 in Mathare Valley Informal Settlement in Nairobi, Kenya. A total of 550 randomly-selected women participated in surveys; however, analyses for this study were run on a subpopulation of the women (n = 361). Multivariate logistic regressions were used to investigate the link between psychological, sexual, and emotional IPV and women's mental and physical health. Results suggest that while some socioeconomic, demographic, and environmental variables were significantly associated with women's mental and physical health outcomes, all types of IPV emerged key correlates in this context. In particular, women's experiences of IPV were associated with lower odds of normal-high physical health component scores (based on SF-36); higher odds of gynecological and reproductive health issues, psychological distress (based on K-10), depression, suicidality, and substance use. Findings from this study suggest that policies and interventions focused on prevention and response to VAW in informal settlements may make critical contributions to improving health for women in these rapidly growing settlements.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
New Findings
What is the topic of this review?
Physiological complexity in muscle force and torque fluctuations, specifically the quantification of complexity, how neuromuscular complexityis altered ...by perturbations and the potential mechanism underlying changes in neuromuscular complexity.
What advances does it highlight?
The necessity to calculate both magnitude‐ and complexity‐based measures for the thorough evaluation of force/torque fluctuations. Also the need for further research on neuromuscular complexity, particularly how it relates to the performance of functional activities (e.g. manual dexterity, balance, locomotion).
Physiological time series produce inherently complex fluctuations. In the last 30 years, methods have been developed to characterise these fluctuations, and have revealed that they contain information about the function of the system producing them. Two broad classes of metrics are used: (1) those which quantify the regularity of the signal (e.g. entropy metrics); and (2) those which quantify the fractal properties of the signal (e.g. detrended fluctuation analysis). Using these techniques, it has been demonstrated that ageing results in a loss of complexity in the time series of a multitude of signals, including heart rate, respiration, gait and, crucially, muscle force or torque output. This suggests that as the body ages, physiological systems become less adaptable (i.e. the systems’ ability to respond rapidly to a changing external environment is diminished). More recently, it has been shown that neuromuscular fatigue causes a substantial loss of muscle torque complexity, a process that can be observed in a few minutes, rather than the decades it requires for the same system to degrade with ageing. The loss of torque complexity with neuromuscular fatigue appears to occur exclusively above the critical torque (at least for tasks lasting up to 30 min). The loss of torque complexity can be exacerbated with previous exercise of the same limb, and reduced by the administration of caffeine, suggesting both peripheral and central mechanisms contribute to this loss. The mechanisms underpinning the loss of complexity are not known but may be related to altered motor unit behaviour as the muscle fatigues.
Key points
Healthy physiological systems generate time series possessing complex structures, as seen for example in heart rate variability, respiratory rate and gait.
A loss of complexity in ...physiological time series has been associated with system dysfunction, and this loss is a characteristic feature of torque output from the ageing neuromuscular system.
We sought to determine the effect of neuromuscular fatigue on the complexity of knee extensor torque output in healthy young humans performing repeated maximal and submaximal contractions.
Fatigue resulted in a substantial loss of knee extensor torque complexity, with the noise in the torque signal becoming increasingly Brownian in character.
Complexity has been associated with system adaptability, and the fatigue‐induced loss of complexity, the physiological origin of which is obscure, may contribute to the inability to sustain physical exercise.
Neuromuscular fatigue increases the amplitude of fluctuations in torque output during isometric contractions, but the effect of fatigue on the temporal structure, or complexity, of these fluctuations is not known. We hypothesised that fatigue would result in a loss of temporal complexity and a change in fractal scaling of the torque signal during isometric knee extensor exercise. Eleven healthy participants performed a maximal test (5 min of intermittent maximal voluntary contractions, MVCs), and a submaximal test (contractions at a target of 40% MVC performed until task failure), each with a 60% duty factor (6 s contraction, 4 s rest). Torque and surface EMG signals were sampled continuously. Complexity and fractal scaling of torque were quantified by calculating approximate entropy (ApEn), sample entropy (SampEn) and the detrended fluctuation analysis (DFA) scaling exponent α. Fresh submaximal contractions were more complex than maximal contractions (mean ± SEM, submaximal vs. maximal: ApEn 0.65 ± 0.09 vs. 0.15 ± 0.02; SampEn 0.62 ± 0.09 vs. 0.14 ± 0.02; DFA α 1.35 ± 0.04 vs. 1.55 ± 0.03; all P < 0.005). Fatigue reduced the complexity of submaximal contractions (ApEn to 0.24 ± 0.05; SampEn to 0.22 ± 0.04; DFA α to 1.55 ± 0.03; all P < 0.005) and maximal contractions (ApEn to 0.10 ± 0.02; SampEn to 0.10 ± 0.02; DFA α to 1.63 ± 0.02; all P < 0.01). This loss of complexity and shift towards Brownian‐like noise suggests that as well as reducing the capacity to produce torque, fatigue reduces the neuromuscular system's adaptability to external perturbations.
Neuromuscular fatigue increases the amplitude of fluctuations in torque output during isometric contractions, but the effect of fatigue on the temporal structure, or complexity, of these fluctuations ...is not known. We hypothesised that fatigue would result in a loss of temporal complexity and a change in fractal scaling of the torque signal during isometric knee extensor exercise. Eleven healthy participants performed a maximal test (5 min of intermittent maximal voluntary contractions, MVCs), and a submaximal test (contractions at a target of 40% MVC performed until task failure), each with a 60% duty factor (6 s contraction, 4 s rest). Torque and surface EMG signals were sampled continuously. Complexity and fractal scaling of torque were quantified by calculating approximate entropy (ApEn), sample entropy (SampEn) and the detrended fluctuation analysis (DFA) scaling exponent α. Fresh submaximal contractions were more complex than maximal contractions (mean ± SEM, submaximal vs. maximal: ApEn 0.65 ± 0.09 vs. 0.15 ± 0.02; SampEn 0.62 ± 0.09 vs. 0.14 ± 0.02; DFA α 1.35 ± 0.04 vs. 1.55 ± 0.03; all P < 0.005). Fatigue reduced the complexity of submaximal contractions (ApEn to 0.24 ± 0.05; SampEn to 0.22 ± 0.04; DFA α to 1.55 ± 0.03; all P < 0.005) and maximal contractions (ApEn to 0.10 ± 0.02; SampEn to 0.10 ± 0.02; DFA α to 1.63 ± 0.02; all P < 0.01). This loss of complexity and shift towards Brownian-like noise suggests that as well as reducing the capacity to produce torque, fatigue reduces the neuromuscular system's adaptability to external perturbations.
The aim of this study was to examine whether social support mediated the relationship between economic abuse, a form of intimate partner violence, and mental health, specifically depression, among ...pregnant women. This cross‐sectional study used a sample of 193 pregnant women living in the United States who participated in an online Qualtrics panel survey in January 2021. Hayes Process Macro was used to assess a mediation model. Economic abuse was associated with increased odds of depressive sympto ms and fewer perceived social supports. Social support mediated the relationship between economic abuse and depression. Implications for research, policy, and practice are discussed. Notably, research focused on economic abuse and efforts to respond to it need to pay particularly close attention to the role that social supports may play in survivor's overall well‐being, as well as the impact that economic abuse may have on survivors' perceptions of social support. This may be particularly true for pregnant women experiencing economic abuse for whom social support‐related interventions have yielded positive health outcomes.
Key points
Economic abuse was associated with increased odds of depression and fewer perceived social supports.
Social supports nearly completely mediate the relationship between economic abuse and depression.
Pregnant survivors may benefit especially from interventions that foster social supports.
The temporal structure, or complexity, of muscle torque output decreases with neuromuscular fatigue. The role of central fatigue in this process is unclear.
PURPOSEWe tested the hypothesis that ...caffeine administration would attenuate the fatigue-induced loss of torque complexity.
METHODSEleven healthy participants performed intermittent isometric contractions of the knee extensors to task failure at a target torque of 50% maximal voluntary contraction, with a 60% duty factor (6-s contraction, 4-s rest), 60 min after ingesting 6 mg·kg caffeine or a placebo. Torque and surface EMG signals were sampled continuously. Complexity and fractal scaling of torque were quantified using approximate entropy (ApEn) and the detrended fluctuation analysis (DFA) α scaling exponent. Global, central, and peripheral fatigue was quantified using maximal voluntary contractions with femoral nerve stimulation.
RESULTSCaffeine ingestion increased endurance by 30% ± 16% (mean ± SD; P = 0.019). Complexity decreased in both trials (decreased ApEn, increased DFA α; both P < 0.01), as global, central, and peripheral fatigue developed (all P < 0.01). Complexity decreased significantly more slowly after caffeine ingestion (ApEn, −0.04 ± 0.02 vs –0.06 ± 0.01 (P = 0.004); DFA α, 0.03 ± 0.02 vs 0.04 ± 0.03 (P = 0.024)), as did the rates of global (−18.2 ± 14.1 vs –23.0 ± 17.4 N·m·min, P = 0.004) and central (−3.5 ± 3.4 vs –5.7 ± 3.9 %·min, P = 0.02) but not peripheral (−6.1 ± 4.1 vs –7.9 ± 6.3 N·m·min, P = 0.06) fatigue.
CONCLUSIONSCaffeine ingestion slowed the fatigue-induced loss of torque complexity and increased the time to task failure during intermittent isometric contractions, most likely through central mechanisms.
The complexity of knee extensor torque time series decreases during fatiguing isometric muscle contractions. We hypothesized that because of peripheral fatigue, this loss of torque complexity would ...occur exclusively during contractions above the critical torque (CT). Nine healthy participants performed isometric knee extension exercise (6 s of contraction, 4 s of rest) on six occasions for 30 min or to task failure, whichever occurred sooner. Four trials were performed above CT (trials S1-S4, S1 being the lowest intensity), and two were performed below CT (at 50% and 90% of CT). Global, central, and peripheral fatigue were quantified using maximal voluntary contractions (MVCs) with femoral nerve stimulation. The complexity of torque output was determined using approximate entropy (ApEn) and the detrended fluctuation analysis-α scaling exponent (DFA-α). The MVC torque was reduced in trials below CT by 19 ± 4% (means ± SE) in 90%CT, but complexity did not decrease ApEn for 90%CT: from 0.82 ± 0.03 to 0.75 ± 0.06, 95% paired-samples confidence intervals (CIs), 95% CI = -0.23, 0.10; DFA-α from 1.36 ± 0.01 to 1.32 ± 0.03, 95% CI -0.12, 0.04. Above CT, substantial reductions in MVC torque occurred (of 49 ± 8% in S1), and torque complexity was reduced (ApEn for S1: from 0.67 ± 0.06 to 0.14 ± 0.01, 95% CI = -0.72, -0.33; DFA-α from 1.38 ± 0.03 to 1.58 ± 0.01, 95% CI 0.12, 0.29). Thus, in these experiments, the fatigue-induced loss of torque complexity occurred exclusively during contractions performed above the CT.
This multicountry study used Demographic and Health Surveys (DHS) data from 138,097 women to explore the relationship between non-partner violence (NPV) and sanitation, water, and urbanization in ...sub-Saharan Africa (SSA). One out of 15 women reports having experienced physical and/or sexual violence by a non-partner during the previous 12 months; within the region, prevalence ranges from 2.3-11.3%. Explanatory models of NPV improve in 11 of the 20 countries when the built environment variables are included. The results suggest that sanitation and water access are associated with risk of NPV in a number of countries in the region, particularly in urban settings.
INTRODUCTIONNeuromuscular fatigue reduces the temporal structure, or complexity, of muscle torque output, purportedly through an effect on motor unit behaviour. Ischaemic pre-conditioning (IPC), an ...emerging ergogenic aid, has been demonstrated to have a potent effect on muscular output and endurance. We therefore tested the hypothesis that IPC would attenuate the fatigue-induced loss of muscle torque complexity.
METHODSTen healthy participants (6 male/4 female) performed intermittent isometric knee extension contractions (6 s contraction, 4 s rest) to task failure at 40% maximal voluntary contraction (MVC). Contractions were preceded by either IPC (three bouts of 5 minutes proximal thigh occlusion at 225 mmHg, interspersed with 5 minutes rest) or SHAM (as IPC, but occlusion at only 20 mmHg) treatments. Torque and EMG signals were sampled continuously. Complexity and fractal scaling were quantified using approximate entropy (ApEn) and the detrended fluctuation analysis (DFA) α scaling exponent. Muscle oxygen consumption (mVCombining Dot AboveO2) was determined using near-infrared spectroscopy.
RESULTSIPC increased time to task failure by 43 ± 13% (mean ± SEM, P = 0.047). Complexity decreased in both trials (decreased ApEn, increased DFA α; both P < 0.001), though the rate of decrease was significantly lower following IPC (ApEn, –0.2 ± 0.1 vs. –0.4 ± 0.1, P = 0.013; DFA α, 0.2 ± 0.1 vs. 0.3 ± 0.1, P = 0.037). Similarly, the rates of increase in EMG amplitude (P = 0.022) and mVCombining Dot AboveO2 (P = 0.043) were significantly slower following IPC.
CONCLUSIONThese results suggest the ergogenic effect of IPC observed here is of neural origin and accounts for the slowing of the rates of change in torque complexity, EMG amplitude and muscle oxygen consumption as fatigue develops.
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