Release from masking: Behavioral and physiological masking level differences

Binaural hearing offers several advantages over monaural hearing and is believed to be one factor that is involved in the ability to understand speech in background noise. Binaural hearing involves analysis of interaural timing and intensity differences in signals arriving at the two ears which provides listeners with sound localization cues as well as signal in noise detection. When sounds arrive at each ear at slightly different times, there may be a release from the effects of background noise, allowing listeners to detect softer sounds in noise. Masking Level Differences (MLDs) have been widely used to evaluate behavioral binaural processing. However, the literature inconsistently reports a release from masking in physiological responses. The purposes of this study were 1) to establish the feasibility of measuring physiological masking level differences using the frequency-following response (FFR), and 2) to characterize the relationship between behavioral and physiological measures of masking level differences (MLDs). Fourteen young adults (ages 21-26) with clinically normal hearing sensitivity participated in this study. Stimuli for behavioral and physiological conditions were 500 Hz tonebursts presented in one-third octave narrowband noise. Three phase conditions were tested: SoNo, SoNπ, and SπNo. Behavioral MLDs were assessed using an adaptive 2AFC procedure. Physiological MLDs were assessed using the frequency-following response, an auditory evoked potential reliant on phase-locked neural activity. FFR analysis focused on amplitude measures. Speech-in-noise understanding was also tested using the Words-in-Noise test (WIN). Behavioral MLDs were 8.29 dB (std. dev = 4.09) for SoNπ and 10.03 dB (std. dev = 4.96) for the SπNo condition. Physiological MLDs did not indicate a robust release from masking, especially for the SπNo condition. Correlations between behavioral and physiological MLDs were not significant. However, FFR amplitude differences between having the signal, or 500 Hz tone, in phase between the ears (e.g., SoNo) and 180° out of phase (i.e., SπNo) predicted behavioral SπNo MLDs. These findings may help to clarify which scalp-recorded auditory evoked potentials reflect binaural processing in humans and report the first brainstem auditory evoked potentials in humans that can predict behavioral masking level differences

Facilitating goal-oriented behaviour in the Stroop task: when executive control is influenced by automatic processing.

A portion of Stroop interference is thought to arise from a failure to maintain goal-oriented behaviour (or goal neglect). The aim of the present study was to investigate whether goal- relevant primes could enhance goal maintenance and reduce the Stroop interference effect. Here it is shown that primes related to the goal of responding quickly in the Stroop task (e.g. fast, quick, hurry) substantially reduced Stroop interference by reducing reaction times to incongruent trials but increasing reaction times to congruent and neutral trials. No effects of the primes were observed on errors. The effects on incongruent, congruent and neutral trials are explained in terms of the influence of the primes on goal maintenance. The results show that goal priming can facilitate goal-oriented behaviour and indicate that automatic processing can modulate executive control

The Effects of Training Involving Simultaneous Walking with Isometric Exercise on Resting Blood Pressure in Young Healthy Adults

Introduction In separate studies, walking and isometric training have been shown to reduce resting blood pressure. Combined aerobic and resistance training, where participants undertake one element of the training programme followed by the second has been seen to produce larger reductions in resting blood pressure (BP) compared to a single exercise protocol such as, walking (Calders et al. 2010). To date, no studies have investigated the effects of simultaneous, combined training on resting BP. Therefore, this study aims to determine the effect of 6-weeks simultaneous, combined isometric (handgrip) and walking training (HGW) on resting systolic (SBP) and diastolic blood pressure (DBP), compared to a walking training programme (WLK). Methods A total of 26 healthy sedentary participants (male, n = 16; female, n = 10; age 21.3±2yrs; mass 69.2±12.5kg; height 170.4±9cm) were randomly allocated, into three groups walking training (WLK; n=12), simultaneous walking and handgrip training (HGW; n=12) or controls. Resting SBP, DBP and mean arterial blood pressure (MAP) were measured at baseline and post-training. Analysis of covariance was used to determine if post-training measures were significantly different to baseline, using the baseline values as the covariate. Results The preliminary data show that, in the three groups, resting SBP was reduced after the 6-weeks, by -12.3, -6.7 and -0.4 mmHg, for HGW, WLK and CON groups respectively. DBP was reduced by -6.4, -3.3 and -0.2 mmHg and MAP by -3.3, -2.2 and -0.2 mmHg. Whilst all changes in the HGW and WLK groups were significant (P<0.05), there were no significant changes in any of the resting blood pressure measured in the control group. Discussion The results indicate that combining walking with simultaneous handgrip isometric exercise, caused greater reductions in resting SBP, DBP and MAP, than walking only. The magnitude of the changes in the HGW group are substantially greater than those observed in previous walking only studies (7.4-1.9 mmHg; Murphy et al. 2007) despite a considerably shorter training intervention. The reductions are also greater than many of the previous studies involving handgrip only training in normotensive participants (McGowan et al. 2007). These sizeable reductions in resting BP emphasise the antihypertensive potential of simultaneous combined exercise training especially since they are evident even in individuals whose BP is considered to be in the normal range. Calders P, Elmahgoub S, Roman de Mettelinge T, Vanderbroeck C, Dewandele I Rombaut L, Vandevelde A, Cambier D. (2011). Clin. Rhab. 25, 1097-1108. McGowan CL, Levy AS, McCartney N, MacDonald MJ. (2007). Clin. Sci. 112, 403-409. Murphy MH, Nevill AM, Murtagh EM, Holder RL. (2007). Preventive Med. 44, 377-385

Reductions in resting blood pressure in young adults when isometric exercise is performed whilst walking

Aerobic and isometric training have been shown to reduce resting blood pressure, but simultaneous aerobic and isometric training have not been studied. The purpose of this study was to compare the changes in resting systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) after 6 weeks of either (i) simultaneous walking and isometric handgrip exercise (WHG), (ii) walking (WLK), (iii) isometric handgrip exercise (IHG), or control (CON). Forty-eight healthy sedentary participants (age 20.7 ± 1.7 yrs, mass 67.2 ± 10.2 kg, height 176.7 ± 1.2 cm, male , and female ) were randomly allocated, to one of four groups ( in each). Training was performed 4 × week−1 and involved either treadmill walking for 30 minutes (WLK), handgrip exercise 3 × 10 s at 20% MVC (IHG), or both performed simultaneously (WHG). Resting SBP, DBP, and MAP were recorded at rest, before and after the 6-week study period. Reductions in resting blood pressure were significantly greater in the simultaneous walking and handgrip group than any other group. These results show that simultaneous walking and handgrip training may have summative effects on reductions in resting blood pressure

Recruitment of trimeric eIF2 by phosphatase non-catalytic subunit PPP1R15B

Regulated protein phosphorylation controls most cellular processes. The protein phosphatase PP1 is the catalytic subunit of many holoenzymes that dephosphorylate serine/threonine residues. How these enzymes recruit their substrates is largely unknown. Here, we integrated diverse approaches to elucidate how the PP1 non-catalytic subunit PPP1R15B (R15B) captures its full trimeric eIF2 substrate. We found that the substrate-recruitment module of R15B is largely disordered with three short helical elements, H1, H2, and H3. H1 and H2 form a clamp that grasps the substrate in a region remote from the phosphorylated residue. A homozygous N423D variant, adjacent to H1, reducing substrate binding and dephosphorylation was discovered in a rare syndrome with microcephaly, developmental delay, and intellectual disability. These findings explain how R15B captures its 125 kDa substrate by binding the far end of the complex relative to the phosphosite to present it for dephosphorylation by PP1, a paradigm of broad relevance.</p

Negative area compressibility in silver(i) tricyanomethanide

The metal–organic framework copper(I) tricyanomethanide, Cu(tcm), undergoes a ferroelastic transition on cooling below Tf = 240 K. Thermal expansion measurements reveal an order-of-magnitude variation in framework flexibility across Tf. The low-temperature phase α-Cu(tcm) exhibits colossal positive and negative thermal expansion that is the strongest ever reported for a framework material. On exposure to acetonitrile, Cu(tcm) undergoes a reconstructive solid-phase transition to acetonitrilocopper(I) tricyanomethanide. This transition can be reversed by heating under vacuum. Infrared spectroscopy measurements are sensitive to the phase change, suggesting that Cu(tcm) may find application in solid-phase acetonitrile sensing

A Systematic Review of Individual and Contextual Factors Affecting ART Initiation, Adherence, and Retention for HIV-Infected Pregnant and Postpartum Women

BACKGROUND: Despite progress reducing maternal mortality, HIV-related maternal deaths remain high, accounting, for example, for up to 24 percent of all pregnancy-related deaths in sub-Saharan Africa. Antiretroviral therapy (ART) is effective in improving outcomes among HIV-infected pregnant and postpartum women, yet rates of initiation, adherence, and retention remain low. This systematic literature review synthesized evidence about individual and contextual factors affecting ART use among HIV-infected pregnant and postpartum women. METHODS: Searches were conducted for studies addressing the population (HIV-infected pregnant and postpartum women), intervention (ART), and outcomes of interest (initiation, adherence, and retention). Quantitative and qualitative studies published in English since January 2008 were included. Individual and contextual enablers and barriers to ART use were extracted and organized thematically within a framework of individual, interpersonal, community, and structural categories. RESULTS: Thirty-four studies were included in the review. Individual-level factors included both those within and outside a woman’s awareness and control (e.g., commitment to child’s health or age). Individual-level barriers included poor understanding of HIV, ART, and prevention of mother-to-child transmission, and difficulty managing practical demands of ART. At an interpersonal level, disclosure to a spouse and spousal involvement in treatment were associated with improved initiation, adherence, and retention. Fear of negative consequences was a barrier to disclosure. At a community level, stigma was a major barrier. Key structural barriers and enablers were related to health system use and engagement, including access to services and health worker attitudes. CONCLUSIONS: To be successful, programs seeking to expand access to and continued use of ART by integrating maternal health and HIV services must identify and address the relevant barriers and enablers in their own context that are described in this review. Further research on this population, including those who drop out of or never access health services, is needed to inform effective implementation

Anomalous Lattice Dynamics in AgC4N3: Insights From Inelastic Neutron Scattering and Density Functional Calculations

We have performed temperature dependent inelastic neutron scattering measurements to study the anharmonicity of phonon spectra of AgC4N3. The analysis and interpretation of the experimental spectra is done using ab-initio lattice dynamics calculations. The calculated phonon spectrum over the entire Brillouin zone is used to derive linear thermal expansion coefficients. The effect of van der Waals interaction on structure stability has been investigated using advanced density functional methods. The calculated isothermal equation of states implies a negative linear compressibility along the c-axis of the crystal, which also leads to a negative thermal expansion along this direction. The role of elastic properties inducing the observed anomalous lattice behavior is discussed

Incorporating connectivity into conservation planning for the optimal representation of multiple species and ecosystem services

Funding was provided by the Rainforest Trust foundation. Support was also provided by the Sabah Forest Department, Forest Research Centre, the South East Asia Rainforest Research Partnership, the U.N. Development Programme, the Universiti Malaysia Sabah (FRGS0414-STWN-1/2015), PACOS Trust, BC Initiative, the Natural Environment Research Council UK (grant NE/R009597/1), and the Universities of Aberdeen, Montana, and York. We are grateful to the numerous researchers that collected the data used in our analyses, as well as the local communities and government staff who manage forested areas across Sabah.Peer reviewedPostprin

Long-term responders on olaparib maintenance in high-grade serous ovarian cancer: Clinical and molecular characterization

Purpose: Maintenance therapy with olaparib has improved progression-free survival in women with high-grade serous ovarian cancer (HGSOC), particularly those harboring BRCA1/2 mutations. The objective of this study was to characterize long-term (LT) versus short-term (ST) responders to olaparib. Experimental Design: A comparative molecular analysis of Study 19 (NCT00753545), a randomized phase II trial assessing olaparib maintenance after response to platinum-based chemotherapy in HGSOC, was conducted. LT response was defined as response to olaparib/placebo > 2 years, ST as < 3 months. Molecular analyses included germline BRCA1/2 status, three-biomarker homologous recombination deficiency (HRD) score, BRCA1 methylation, and mutational profiling. Another olaparib maintenance study (Study 41; NCT01081951) was used as an additional cohort. Results: Thirty-seven LT (32 olaparib) and 61 ST (21 olaparib) patients were identified. Treatment was significantly associated with outcome (P < 0.0001), with more LT patients on olaparib (60.4%) than placebo (11.1%). LT sensitivity to olaparib correlated with complete response to chemotherapy (P < 0.05). In the olaparib LT group, 244 genetic alterations were detected, with TP53, BRCA1, and BRCA2 mutations being most common (90%, 25%, and 35%, respectively). BRCA2 mutations were enriched among the LT responders. BRCA methylation was not associated with response duration. High myriad HRD score (>42) and/or BRCA1/2 mutation was associated with LT response to olaparib. Study 41 confirmed the correlation of LT response with olaparib and BRCA1/2 mutation. Conclusions: Findings show that LT response to olaparib may be multifactorial and related to homologous recombination repair deficiency, particularly BRCA1/2 defects. The type of BRCA1/2 mutation warrants further investigation. (C) 2017 AACR