Mixed Duration Research Articles

Energy-Efficient Joint Task Assignment and Migration in Data Centers: A Deep Reinforcement Learning Approach

Energy-efficient task scheduling in data centers is a critical issue and has drawn wide attention. However, the task execution times are mixed and hard to estimate in a real-world data center. It has been conspicuously neglected by existing work that scheduling decisions made at tasks’ arrival times are likely to cause energy waste or idle resources over time. To fill in such gaps, in this paper, we jointly consider assignment and migration for mixed duration tasks and devise a novel energy-efficient task scheduling algorithm. Task assignment can improve resource utilization, and migration is required when long-running tasks run in low-load servers. Specifically: 1) We formulate mixed duration task scheduling as a large-scale Markov Decision Process (MDP) problem; 2) To solve such a large-scale MDP problem, we design an efficient Deep Reinforcement Learning (DRL) algorithm to make assignment and migration decisions. To make the DRL algorithm more practical in real scenarios, multiple optimizations are proposed to achieve online training; 3) Experiments with real-world data have shown that our algorithm outperforms the existing baselines 14% on average in terms of energy consumption while keeping the same level of Quality of Service (QoS).

Role of Structured Career Counselling in Speciality Selection among Post Graduate Trainees

Aim: To highlight the relevance, importance and necessity of structured career counselling for medical graduates and post graduate trainees with regards to specialisation decision preferences. Study design Mixed method Place and duration of study: Study conducted at sandmen provincial hospital from 1st September to 30th December 2021. Methodology: This was two phase sequential mixed method study. The first phase involved qualitative exploration through a semi-structured interview with post graduate trainees from various specialties who walked into the radiology department of Sandman Provincial Hospital Quetta with identification of theme and subtheme to develop a questionnaire. Questionnaire was designed to collect various opinions on the theme and sub-theme. Questionnaire included 11 items with two open ended questions and all other closed ended questions. Questionnaire was distributed to target population and demand survey was conducted by collecting questionnaire after a week. It was anonymous to ensure confidentiality and autonomy to participants. Results: The response rate was 71% while omitting the incomplete questionnaire. It was divided into two groups, 1) changed of speciality CS 8(16%), M-3(37%), F-5 (62%) and 2) without changed of speciality 43(84%), M-21(49%), F-22(51%).Results were also compiled by combining both the groups as total participants to check the variation in opinion. The availability of structured career counselling for specialty selection will lessen the burden of decision making, total participants agreed were 44(86%), not in favour were 6(12%) and one answered with don’t know (2%), { NCS (36(84%); CS (8(100%)}. Conclusion: Based on results Medical Students are in demand of structured career counselling program to ease the decision of speciality preference and in favour of incorporating it in medical education to avoid stress and other difficulties faced by them. Keywords: Structured career counselling, change of speciality (CS), Post graduate trainee,

Perception of Undergraduate Medical Students about Integrated Modular Curriculum and Factors Affecting

Aim: To explore the perceptions of undergraduate medical students about integrated modular curriculum and to identify the factors affecting it. Study design: Mixed method study Place and duration of study: King Edward Medical University (KEMU) from 1st November 2021 to 30th April 2022. Methods: The questionnaires were distributed to 391 MBBS students. In depth interviews were conducted from 16 students and audio-recorded. Results: Three hundred and fifty seven (91.3%) considered integrated curriculum a useful approach, 88% preferred this approach over traditional, more than 70% considered it useful for clinical insight and improvement in academic performance. Many (43%) of the students complained that the institutional environment was not helpful regarding implementation of integrated curriculum which was further explored by in-depth interview. Conclusion: The majority of students have shown a positive response to the modular integrated curriculum .It has helped them in improving academic performance and clinical insight. There is a need to improve university environment to implement integrated assessment more effectively. Keywords: Integrated modular curriculum, undergraduate, medical students, perception

Mixed diapause duration in cohorts of four species of Osmia bees (Megachilidae) along an elevation and temperature gradient in Northern Utah (USA)

Several species of Osmia bees are parsivoltine, i.e., individuals of a cohort diapause for either one or two winters before emerging as adults. Frequently, contents of single nests are mixed, containing both one- and two-year morphs, commonly in an unpatterned array. We asked if the incidence of one- and two-year morphs, and mixed nests, was associated with elevation and decreasing average temperature. We also describe the arrangement of gender and year-morph of progeny within nests. Populations were sampled and reared from wood “trap-nests” at 1553–2436 m elevation at nine sites in northern Utah. Nearby weather stations supplied temperature records. Nine parsivoltine Osmia species were found. For the two most common species, O. coloradensis and O. montana, the percent of two-year morphs increased significantly with elevation and a decrease in average temperature. The most precipitous drop in temperature occurred between 1800 and 1930 m, the elevation span also associated with large increases in percent two-year morphs. The incidence of mixed nests was highest at intermediate elevations, and gender and year-morph were associated (females were significantly more likely than males to be two-year morphs) but only for O. coloradensis. For all species, the percentage of females declined from the first (innermost) to the last (outermost) brood cell in nests. We consider the merits of a diversified bet-hedging strategy as an explanation for parsivoltinism and offer a new interpretation that emphasizes the reduction in overwintering mortality, particularly of immatures produced later in the growing season, conferred by their ability to enter diapause at two distinct stages.

Twelve month oral contraceptive pill prescriptions: Role of policy mandates on utilization

Recent studies have suggested that extended duration oral contraceptive pills (OCP), such as the 12-month duration, have a positive impact on pregnancy rates but negative impact on pill wastage. Several states have since been mandating health plans to offer extended duration OCP as an option for women. The objective of the study was to evaluate the impact of these mandates on utilization of extended duration OCPs. Using claims data of a large pharmacy benefit manager for commercially insured women from 2018 to 2019, use, adherence, continuity, and wastage of OCPs by women dispensed one-month only, three-months only, 6 or 12-months only, and other months (which includes other months and mixed duration OCP) was retrospectively analyzed. OCP dispensed by year, and adherence, continuity, wastage over a 15-month period were summarized using Chi square and ANOVA. There were 874,420 and 875,914 women in this study in 2018 and 2019 respectively. Of these, 34% were from states with the mandate (SWM). Most women filled the one-month and three-month duration, with very low overall 6 or 12-month duration claims. Proportion of utilizers of 6 or 12- month duration was higher in SWM than in those without, although differences in absolute rates were very low. Patients with OCP discontinuation, gaps ≥7 and 14 days, were fewer among those filling 6 or 12-month duration but conversely, wastage was higher in this group compared to those filling one or three-month duration. Our findings suggest that, among commercially insured women, extended duration OCP mandates have so far not had much influence on use of 6 or 12-month duration OCP prescriptions.

Visual cortex cTBS increases mixed percept duration while a-tDCS has no effect on binocular rivalry.

Neuromodulation of the primary visual cortex using anodal transcranial direct current stimulation (a-tDCS) can alter visual perception and enhance neuroplasticity. However, the mechanisms that underpin these effects are currently unknown. When applied to the motor cortex, a-tDCS reduces the concentration of the inhibitory neurotransmitter gamma aminobutyric acid (GABA), an effect that has been linked to increased neuroplasticity. The aim of this study was to assess whether a-tDCS also reduces GABA-mediated inhibition when applied to the human visual cortex. Changes in visual cortex inhibition were measured using the mixed percept duration in binocular rivalry. Binocular rivalry mixed percept duration has recently been advocated as a direct and sensitive measure of visual cortex inhibition whereby GABA agonists decrease mixed percept durations and agonists of the excitatory neurotransmitter acetylcholine (ACH) increase them. Our hypothesis was that visual cortex a-tDCS would increase mixed percept duration by reducing GABA-mediated inhibition and increasing cortical excitation. In addition, we measured the effect of continuous theta-burst transcranial magnetic stimulation (cTBS) of the visual cortex on binocular rivalry dynamics. When applied to the motor or visual cortex, cTBS increases GABA concentration and we therefore hypothesized that visual cortex cTBS would decrease the mixed percept duration. Binocular rivalry dynamics were recorded before and after active and sham a-tDCS (N = 15) or cTBS (N = 15). Contrary to our hypotheses, a-tDCS had no effect, whereas cTBS increased mixed percepts during rivalry. These results suggest that the neurochemical mechanisms of a-tDCS may differ between the motor and visual cortices.

Rheumatoid arthritis risk in periodontitis patients: A systematic review and meta-analysis.

Many clinical studies have been carried out to investigate the relationship between periodontitis and rheumatoid arthritis (RA). Owing to limited evidence and inconsistent findings among these studies, it is unclear whether periodontitis would increase the risk for RA. This meta-analysis was performed to evaluate whether periodontitis represents a risk factor for RA. PubMed, Cochrane Library, Embase, Web of Science, and Wanfang were searched for eligible studies that compared periodontitis patients with controls. A pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to assessthe association between periodontitis and RA. Thirteen studies including a total of 706611 periodontitis patients and 349983 control subjects were included. The pooled OR of RA riskbetween periodontitis and controls was (OR: 1.69; 95% CI: 1.31-2.17; P<0.0001), indicating that the patients in periodontitis group had a 69% greater risk for RA than people in control group. When stratified by disease type, the pooled results showed periodontitis represents a risk factor for incident RA (OR=1.70, 95%CI: 0.75-3.85, P<0.001) and mixed RA (OR=1.61, 95%CI: 1.26-2.06; P<0.001). When stratified by disease duration, the pooled results showed periodontitis represents a risk factor for RA disease duration>5 years (OR=2.88, 95%CI: 0.66-12.62, P=0.018), disease duration<5 years (OR=2.59, 95%CI: 0.83-8.11, P<0.001), mixed disease duration (OR=1.53; 95%CI: 1.05-2.22, P<0.001). Our meta-analysis revealed an increased risk of RA in patients with periodontitis compared to healthy controls. Moreover, when stratified by disease type, there was a higher risk between incident RA and periodontitis. When stratified by disease duration, the patients with periodontitis might be more closely associated with the RA patients with disease duration >5 years.

Epidural corticosteroid injections for lumbosacral radicular pain.

Epidural corticosteroid injections for lumbosacral radicular pain.

Binocular rivalry dynamics associated with high levels of self-reported autistic traits suggest an imbalance of cortical excitation and inhibition

An imbalance in cortical excitation and inhibition (E/I) may underlie both social and non-social symptoms of autism spectrum conditions (ASC). Recent work suggests that an E/I imbalance may underlie some of the sensory differences that are characteristic of ASCs such as anomalous perception. Binocular rivalry dynamics are thought to reflect the balance of E/I in the brain and could serve as a behavioural biomarker for ASC. Previous studies of clinical ASC populations have found a slower rate of binocular rivalry transitions; increased duration of the mixed percept and reduced perceptual suppression. There are some mixed reports of altered rivalry dynamics in the neurotypical population with high self-reported levels of autistic traits. Therefore, we used simple grating stimuli to measure binocular rivalry dynamics in a sample of seventy-nine adults aged 18–55 years. We additionally measured the level of autistic traits with the AQ-10 and used CAPS as a measure of anomalous perception. Bayesian correlations showed that those with higher AQ scores had a slower rate of perceptual switching and a longer mixed percept duration. Significant regression models with CAPS and AQ score revealed that AQ score was a significant predictor of switch rate and mixed percept duration, whereas CAPS was not. We also report that CAPS significantly predicted perceptual suppression, whereas AQ score did not. Overall, our findings suggest that in a non-clinical population, autistic traits are a predictor of binocular rivalry dynamics and the cortical E/I imbalance thought to underlie symptoms of ASC may extend to the broader phenotype.

Is there a relationship between hematological parameters and duration of respiratory events in severe OSA

Aim: The aim of this study was to compare hematological parameters with the mean obstructive apnea duration (MOAD), mean mixed apnea duration (MMAD), mean central apnea duration (MCAD), mean total apnea duration (MTAD) and mean hypopnea duration (MHD), and blood oxygenation, other polysomnographic sleep parameters in patients with severe OSA.Material and methods: A retrospective study included 120 patients with severe OSA. The correlations between the hematological parameters with MOAD, MMAD, MCAD, MTAD, MHD, and blood oxygenation, other polysomnographic sleep parameters were analyzed.Results: There was a positive correlation between hgb with MOAD, MMAD, MTAD MCAD, MHD; mean oxygen desaturation, and the number of desaturation (≥5%). Also, hgb associated negatively with N1 sleep, WASO (wake time after sleep onset) and positively with REM, N2 sleep, total sleep time, and sleep efficiency. RDW and MOAD, MTAD, MHD were negatively related. Also, RDW related positively with sleep latency, WASO, and N1 sleep; negatively with sleep efficiency and REM sleep. There was no relationship between duration of respiratory events with NLR, PRL, and MPV.Conclusions: Hematological parameters, especially hgb and RDW, can be used to assess the severity of the disease in severe OSA patients in addition to AHI.

Which is more important: the number or duration of respiratory events to determine the severity of obstructive sleep apnea?

Aim: Apnea–hypopnea index (AHI) take account only the number of apnea and hypopnea regardless of their duration and morphology. The aim of this study was to compare the mean obstructive apnea duration (MOAD), mean mixed apnea duration (MMAD), mean central apnea duration (MCAD), mean total apnea duration (MTAD) and mean hypopnea duration (MHD) with the demographic parameters, blood oxygenation and other polysomnographic sleep parameters in patients diagnosed with severe obstructive sleep apnea (OSA).Materials and methods: A retrospective study included 121 patients who had a diagnosis of severe OSA. The correlations between the MOAD, MMAD, MCAD, MTAD, MHD and patient demographic parameters, blood oxygenation and other polysomnographic sleep parameters were analyzed.Results: Severe OSA patients with longer MOAD and MTAD had shorter Stage N3. Longer MOAD, MMAD, MCAD, MTAD, MHD were related to lower mean oxygen saturation. Longer MOAD and MTAD were associated with higher oxygen desaturation index. MOAD, MMAD, MTAD were positively associated with a duration below oxygen saturation 85%.Conclusions: Respiratory events can have different characteristics even though the average number of events per hour would be similar. Novel parameters like MOAD, MMAD, MCAD, MTAD, MHD could enhance the evaluation and classification of OSA in addition to AHI.

A Pulsed Electromagnetic Field Therapy Device for Non-Specific Low Back Pain: A Pilot Randomized Controlled Trial.

IntroductionLow back pain (LBP) poses a significant burden of disease worldwide, and identifying safe and effective non-pharmacologic treatment options for LBP is a research priority. The aim of this study was to pilot a clinical trial of a portable pulsed electromagnetic field (PEMF) therapy device for subjects with mixed duration non-specific LBP.MethodsThis work was a randomized, double-blind, sham-controlled, parallel-group study conducted at a chiropractic school outpatient clinic. The primary end point was functional capacity measured by the Oswestry Disability Index (ODI) at baseline, 6 weeks, and 12 weeks. Analysis was conducted on the intent-to-treat population and as a trend of change in pain scores over time using the Freidman test of repeated measures.ResultsForty-two participants were randomized to receive usual care plus PEMF therapy or usual care plus sham, and 25 completed the study. Significant improvements in ODI scores from baseline to week 6 were reported in the experimental group (χ2 = 14.68, p < 0.001, compared with patients in the sham group, χ2 = 4.00, p = 0.135, n.s.). This difference persisted at week-12 follow-up. Adverse events were rare and mild.ConclusionIt is feasible to conduct a clinical trial of a PEMF therapy device for non-specific LBP. This work shows that the device was safe and provides preliminary evidence of effectiveness in improving function in patients with non-specific LBP.Trial RegistrationClinicalTrials.gov identifier, NCT03053375.FundingAerotel Ltd.

Altering brain dynamics with transcranial random noise stimulation

Random noise can enhance the detectability of weak signals in nonlinear systems, a phenomenon known as stochastic resonance (SR). This concept is not only applicable to single threshold systems but can also be applied to dynamical systems with multiple attractor states, such as observed during the phenomenon of binocular rivalry. Binocular rivalry can be characterized by marginally stable attractor states between which the brain switches in a spontaneous, stochastic manner. Here we used a computational model to predict the effect of noise on perceptual dominance durations. Subsequently we compared the model prediction to a series of experiments where we measured binocular rivalry dynamics when noise (zero-mean Gaussian random noise) was added either to the visual stimulus (Exp. 1) or directly to the visual cortex (Exp. 2) by applying transcranial Random Noise Stimulation (tRNS 1 mA, 100–640 Hz zero -mean Gaussian random noise). We found that adding noise significantly reduced the mixed percept duration (Exp. 1 and Exp. 2). Our results are the first to demonstrate that both central and peripheral noise can influence state-switching dynamics of binocular rivalry under specific conditions (e.g. low visual contrast stimuli), in line with a SR-mechanism.

Correlation of non-vitamin K antagonist oral anticoagulant exposure and cerebral microbleeds in Chinese patients with atrial fibrillation

Background and purposeCerebral microbleeds (CMBs) are radiological markers which predict future intracerebral haemorrhage. Researchers are exploring how CMBs can guide anticoagulation decisions in atrial fibrillation (AF). The purpose of this...

Caffeine is a risk factor for osteopenia of prematurity in preterm infants: a cohort study

BackgroundCaffeine, the most commonly used medication in Neonatal Intensive Care Units, has calciuric and osteoclastogenic effects.MethodsTo examine the association between the cumulative dose and duration of therapy of caffeine and osteopenia of prematurity, a retrospective cohort study was conducted including premature infants less than 31 weeks and birth weight less than 1500 g. Osteopenia of prematurity was evaluated using chest X-rays on a biweekly basis over 12 weeks of hospitalization.ResultsThe cohort included 109 infants. 51% had osteopenia of prematurity and 8% had spontaneous rib fractures. Using the generalized linear mixed model, caffeine dose and duration of caffeine therapy showed a strong association with osteopenia of prematurity. Steroids and vitamin D were also significantly correlated with osteopenia of prematurity while diuretic use did not show a statistically significant effect.ConclusionThe cumulative dose and duration of therapy of caffeine, as well as steroid are associated with osteopenia of prematurity in this cohort. Future studies are needed to confirm these findings and determine the lowest dose of caffeine needed to treat effectively apnea of prematurity.

Job separation rates of immigrants and natives in the UK during the Great Recession

PurposeThe purpose of this paper is to assess the probability of job separations of immigrants and natives in the UK before and during the economic crisis of 2008.Design/methodology/approachA mixed proportional hazard duration model with a semi-parametric piecewise constant baseline hazard is used on a data sample of inflows into employment.FindingsIt is found that the crisis increased the probability of exits to unemployment for all groups, while immigrants from the new countries of the European Union seemed to have the lowest hazard towards unemployment even after controlling for their demographic and labour market characteristics. More specifically, even when we account for the fact that they tend to cluster in jobs that are most vulnerable to the business cycle, they are still less likely to exit dependent employment than natives. However, this migrant group is adversely affected by the crisis the most.Research limitations/implicationsPossible implications of out-migration of the lower performers are discussed.Originality/valueThis paper makes use of the panel element of the UK Quarterly Labour Force Survey, and uses duration analysis on the individual level to assess the labour market outcomes of natives and immigrants in the UK.

Numerical Research on Tribological Performance of Textured Liner Surface Under Different Combustion Modes

With the increasingly stringent requirements on energy saving and environmental-friendly for internal combustion (IC) engine, new concepts like novel combustion mode and surface texturing technology have emerged. In order to have deep understanding about the application effects of surface texturing into IC engine with new combustion mode, a mixed lubrication calculation model considering surface textures on cylinder liner together with different combustion modes has been built in the present work based on a four-cylinder diesel engine. The numerical research was conducted on the change of the surface tribological performance of textured cylinder liner under different combustion modes. The simulation results indicate that compared with the conventional combustion (CC) mode, the combustion phase of premixed charge combustion ignition (PCCI) mode and retarded injection (RI) mode varies and their in-cylinder peak pressure is different at the beginning of power stroke due to different injection strategies applied, which lead to significant differences between piston ring radial working loads. Near TDC, the mixed lubrication duration of PCCI and RI mode increases slightly in comparison to that of CC mode, and these three boundary lubrication durations are almost same. However, the thickness of lubricant film between friction pair of three modes is quite different, resulting in their different tribological properties. Among these parameters, the dimensionless total friction force (DTFF) and the dimensionless friction work of PCCI mode increase by 82.37% and 18.41% at most, respectively, while those of RI mode decrease by 36.50% and 12.45% at most, respectively, compared with the same parameters of CC mode. Therefore, the variations in tribological property of the textured cylinder liner–piston ring (CLPR) with different combustion modes should not be ignored.

Dynamic Short-Term Projections of Travel Time Distributions in Urban Signalized Networks utilizing Composite Information of Traffic Characteristics

Abstract: The estimation of experienced travel-time in road networks stands for an important feature in Advanced Traveler Information Systems (ATIS). In the era of data availability, the dissemination of accurate traffic information to travelers could have a huge impact on their trip choices and thus in systems’ performance. The scope of this paper is time travel modeling and prediction based on alternative configurations of mixed duration and time series models. The proposed framework enables the dynamic probabilistic estimation of travel time between a predefined set of Origin-Destinations (O-D) locations, by taking into account available spatial data. For achieving that, suitable formulated hazard models are combined with time series input, forming a hybrid methodological framework and compared to two different theoretical duration models. The resulted mechanism provides valuable probabilistic estimations for travel time for O-D pairs, able to cover extensive urban road networks. In particular, the proposed modeling approach uses past travel time observations as inputs and provides distributions of future travel times. The proposed application is tested on a realistic road network, namely that of Cyprus. The aim of the study is to provide reliable travel information to travelers in a methodologically sound, straightforward and comprehensible way.

Pain experienced during vaginal and anal intercourse with other-sex partners: findings from a nationally representative probability study in the United States.

Recent U.S. nationally representative data indicate that about 30% of women and 5% of men reported pain occurring during their most recent sexual event; however, little is known about the severity, duration, or context of such pain, or its prevalence during vaginal vs. anal intercourse. To document the prevalence and characteristics of pain during vaginal and anal intercourse among U.S. women and men (ages 18+) at their most recent other-sex sexual event, including the self-reported severity, duration, and location of their pain; how participants addressed their pain; and partner communication related to the pain. Data from a subsample of 1,738 women and men in the 2012 National Survey of Sexual Health Behavior, a nationally representative probability survey of Americans ages 18+ collected via the Internet, were analyzed. Participants responded to items about their background characteristics; whether they had vaginal or anal intercourse during their most recent sexual experience; the severity, duration, and location of any pain experienced during said sexual event; and whether they responded to or communicated about the pain. About 30% of women and 7% of men reported pain during vaginal intercourse events, and most of the reports of pain were mild and of short duration. About 72% of women and 15% of men reported pain during anal intercourse events, with more of these events including moderate or severe pain (for the women) and of mixed duration. Large proportions of Americans do not tell their partner when sex hurts. Pain is a relatively common, and often not discussed, aspect of both vaginal and anal intercourse events occurring between women and men. Individual and clinical implications are discussed.

Change in breastfeeding patterns in Scotland between 2004 and 2011 and the role of health policy

Substantial investments in promoting breastfeeding have taken place in the past 10 years in Scotland. This study assesses whether there were significant changes in breastfeeding initiation and mixed breastfeeding duration between 2004-2005 and 2010-2011. This study uses data from two nationally representative cohorts of babies in Scotland born between June 2004-May 2005 (N = 5030) and March 2010-February 2011 (N = 5838). Multivariate logistic regression for breastfeeding initiation and multivariate survival analysis for breastfeeding duration using cross-sectional data based on maternal recall were performed. An increase in breastfeeding initiation from 60 to 63% was not significant (P = 0.125), and controlling for covariates, there was no significant cohort effect when comparing breastfeeding initiation between cohorts [odds ratio (OR) 1.02, 95% confidence interval (CI) 0.91-1.13]. For breastfeeding duration of up to 1 month, the 2010-11 cohort was more likely to give up breastfeeding sooner (HR 1.23, 95%CI 1.12-1.34). However, for breastfeeding durations of >1-6 months, or ≥6 months, the 2010-11 cohort was significantly less likely to give up breastfeeding sooner (HR 0.79, 95%CI 0.70-0.88 and HR 0.79, 95%CI 0.68-0.92, respectively). Breastfeeding duration increased the most among mothers with fewer educational qualifications, and mothers with no qualifications in 2010-11 were far less likely to stop breastfeeding early compared with their counterparts in 2004-05 (HR 0.32, 95%CI 0.17-0.58). After the 1 month mark, babies born in 2010-11 were more likely to be breastfed for longer compared with those born in 2004-05, and this effect was particularly pronounced among more disadvantaged families. The potential causal role of health policy is discussed.