Miracle-dz/UniFAR-FTUs huggingface dataset:
Biophysical Drivers of Tree Crop Performance in Shade Agroforestry Systems: The Case of Coffee in Costa Rica

Agroforestry production methods present one option for addressing growing concerns about the long term sustainability of intensive coffee production techniques. A study was designed to compare the effects of fertilization and shading from two leguminous species, Erythrina poeppigiana and Chloroleucon eurycyclum, on coffee grown at a Costa Rican research site. Coffee below biannually pruned, conventionally fertilized Erythrina exhibited the highest photosynthetic performance under both low and high light levels as well as greater biomass and higher N concentration. Soil P did not affect coffee performance, although shade trees on sites with higher soil P fixed more N compared to trees grown on low P sites, most of which were not found to be fixing. Results suggest shade mechanisms are the most important drivers of coffee adaptation in coffee agroforestry systems, though proper soil nutrient management and legume species pairing also appear to augment coffee response to microclimate conditions.
Modeling virtualized applications using machine learning techniques

With the growing adoption of virtualized datacenters and cloud hosting services, the allocation and sizing of resources such as CPU, memory, and I/O bandwidth for virtual machines (VMs) is becoming increasingly important. Accurate performance modeling of an application would help users in better VM sizing, thus reducing costs. It can also benefit cloud service providers who can offer a new charging model based on the VMs' performance instead of their configured sizes. In this paper, we present techniques to model the performance of a VM-hosted application as a function of the resources allocated to the VM and the resource contention it experiences. To address this multi-dimensional modeling problem, we propose and refine the use of two machine learning techniques: artificial neural network (ANN) and support vector machine (SVM). We evaluate these modeling techniques using five virtualized applications from the RUBiS and Filebench suite of benchmarks and demonstrate that their median and 90th percentile prediction errors are within 4.36% and 29.17% respectively. These results are substantially better than regression based approaches as well as direct applications of machine learning techniques without our refinements. We also present a simple and effective approach to VM sizing and empirically demonstrate that it can deliver optimal results for 65% of the sizing problems that we studied and produces close-to-optimal sizes for the remaining 35%.
Multidimensional scaling of systems in the Voice Conversion Challenge 2016

This study investigates how listeners judge the similarity of voice converted voices using a talker discrimination task. The data used is from the Voice Conversion Challenge 2016. 17 participants from around the world took part in building voice converted voices from a shared data set of source and target speakers. This paper describes the evaluation of similarity for four of the source-target pairs (two intra-gender and two cross-gender) in more detail. Multidimensional scaling was performed to illustrate where each system was perceived to be in an acoustic space compared to the source and target speakers and to each other.
The Red Queen Race between Parasitic Chytrids and Their Host, Planktothrix: A Test Using a Time Series Reconstructed from Sediment DNA

Parasitic chytrid fungi (phylum Chytridiomycota) are known to infect specific phytoplankton, including the filamentous cyanobacterium Planktothrix. Subspecies, or chemotypes of Planktothrix can be identified by the presence of characteristic oligopeptides. Some of these oligopeptides can be associated with important health concerns due to their potential for toxin production. However, the relationship between chytrid parasite and Planktothrix host is not clearly understood and more research is needed. To test the parasite - host relationship over time, we used a sediment core extracted from a Norwegian lake known to contain both multiple Planktothrix chemotype hosts and their parasitic chytrid. Sediment DNA of chytrids and Planktothrix was amplified and a 35-year coexistence was found. It is important to understand how these two antagonistic species can coexistence in a lake. Reconstruction of the time series showed that between 1979–1990 at least 2 strains of Planktothrix were present and parasitic pressure exerted by chytrids was low. After this period one chemotype became dominant and yet showed continued low susceptibility to chytrid parasitism. Either environmental conditions or intrinsic characteristics of Planktothrix could have been responsible for this continued dominance. One possible explanation could be found in the shift of Planktothrix to the metalimnion, an environment that typically consists of low light and decreased temperatures. Planktothrix are capable of growth under these conditions while the chytrid parasites are constrained. Another potential explanation could be due to the differences between cellular oligopeptide variations found between Planktothrix chemotypes. These oligopeptides can function as defense systems against chytrids. Our findings suggest that chytrid driven diversity was not maintained over time, but that the combination of environmental constraints and multiple oligopeptide production to combat chytrids could have allowed one Planktothrix chemotype to have dominance despite chytrid presence.
Robust H∞ optimal signal predictive quantization

This paper investigates optimal signal predictive quantization in the presence of source model uncertainties. It uses polytopic system model to represent the uncertainties in source signal and uses the recent results on robust filtering [8] to obtain a robust H∞ optimal design of signal predictor. Results of computational study is presented to demonstrate the advantages of the obtained design.
Dissociating Task Performance from fMRI Repetition Attenuation in Ventral Visual Cortex

Repeated visual stimuli elicit reduced neural responses compared with novel stimuli in various brain regions (repetition attenuation). This effect has become a powerful tool in fMRI research, allowing researchers to investigate the stimulus-specific neuronal representations underlying perception and cognition. Repetition attenuation is also commonly associated with behavioral priming, whereby response accuracy and speed increase with repetition. This raises the possibility that repetition attenuation merely reflects decreased processing time. Here, we report a full dissociation between repetition attenuation and behavioral performance by varying the task performed on identical visual stimuli. In the scene task, observers judged whether two photographs came from the same scene, and in the image task, they judged whether the two photographs were identical pixel for pixel. The two tasks produced opposite patterns of behavioral performance: in the scene task, responses were faster and more accurate when the photographs were very similar, whereas, in the image task, responses were faster and more accurate when the photographs were less similar. However, in the parahippocampal place area (PPA), a scene-selective region of ventral cortex, identical repetition attenuation was observed in both tasks: lower neural responses for the very similar pairs relative to the less similar pairs. Whereas the PPA was impervious to task modulation, responses from two frontal regions mirrored behavioral performance, consistent with their role in decision-making. Thus, although repetition attenuation and performance are often correlated, they can be dissociated, suggesting that attenuation in ventral visual areas reflects stimulus-specific processing independent of task demands.
Treatment of refractory unstable angina in geographically isolated areas without cardiac surgery. Invasive versus conservative strategy (TRUCS study).

AIMS We compared invasive (on-site coronary angioplasty or emergency air-ambulance transfer for bypass grafting surgery) vs conservative (persistent medical treatment) strategies in the management of refractory unstable angina in geographically isolated hospitals without cardiac surgical facilities. METHODS AND RESULTS One hundred and forty eight randomized patients with refractory unstable angina were compared on an intention-to-treat basis. Outcomes (invasive vs conservative): (a) in hospital: stabilization (96% vs 43%, P=0.0001), non-fatal myocardial infarction (2.6% vs 4.2%, P=ns), death (1.3% vs 8.3%, P=0.046), combined outcome (3.9% vs 12.5%, P=0.053) and hospitalization (11.4+/-6.3 vs 12.4+/-8.0 days, P=ns). (b) 30-days follow-up: non-fatal myocardial infarction (2.6% vs 4.2%, P=ns), death (2.6% vs 11.1%, P=0.030) and combined outcome (5.3% vs 15.3%, P=0.031). (c) 12 month follow-up: non-fatal myocardial infarction (3. 9% vs 4.2%, P=ns), death (3.9% vs 12.5%, P=0.053), combined outcome (7.9% vs 16.7%, P=ns), re-admissions for unstable angina: (17.1% vs 23.6%, P=ns), late coronary angioplasty: (15.8% vs 11.1%, P=ns) and (d) late coronary bypass grafting: (7.9% vs 12.5%, P=ns). CONCLUSION Invasive treatment of patients with refractory angina in remote areas without surgical back-up results in significant in-hospital stabilization and a reduction in major events in-hospital and at 30 days. Coronary angioplasty in stand-alone units and air-transfer of these patients seems safe.
Timing-Accurate Storage Emulation

Timing-accurate storage emulation fills an important gap in the set of common performance evaluation techniques for proposed storage designs: it allows a researcher to experiment with not-yet-existing storage components in the context of real systems executing real applications. As its name suggests, a timing-accurate storage emulator appears to the system to be a real storage component with service times matching a simulation model of that component. This paper promotes timing-accurate storage emulation by describing its unique features, demonstrating its feasibility, and illustrating its value. A prototype, called the Memulator, is described and shown to produce service times within 2% of those computed by its component simulator for over 99% of requests. Two sets of measurements enabled by the Memulator illustrate its power: (1) application performance on a modern Linux system equipped with a MEMS-based storage device (no such device exists at this time), and (2) application performance on a modern Linux system equipped with a disk whose firmware has been modified (we have no access to firmware source code).
The lifetime of galactic bars: central mass concentrations and gravity torques

Bars in gas-rich spiral galaxies are short-lived. They drive gas inflows through their gravity torques, and at the same time self-regulate their strength. Their robustness has been subject of debate, as it was thought that only the resulting central mass concentrations (CMCs) were weakening bars, and only relatively rare massive CMCs were able to completely destroy them. Through numerical simulations including gas dynamics, we find that with the gas parameters of normal spiral galaxies, the CMC is not sufficient to fully dissolve the bar. But another overlooked mechanism, the transfer of angular momentum from the infalling gas to the stellar bar, can also strongly weaken the bar. In addition, we show that gravity torques are correctly reproduced in simulations, and conclude that bars are transient features, with lifetime of 1–2 Gyr in typical Sb-Sc galaxies, because of the combined effects of CMCs and gravity torques, while most existing works had focussed on the CMC effects alone.
Living with chronic low back pain: a metasynthesis of qualitative research

Objectives The purpose of this qualitative metasynthesis is to articulate the knowledge gained from a review of qualitative studies of patients’ experiences of chronic low back pain. Methods Meta-ethnographic methodology guided the review of 33 articles representing 28 studies published in English in peer-reviewed journals between 2000 and 2012. A systematic comparison of the main themes from each study was conducted and ‘synthesised’ to create superordinate themes. Results Three overarching interrelated themes were identified: the impact of chronic low back pain on self; relationships with significant others that incorporated two streams – health professionals and the organisation of care and relationships with family and friends; coping with chronic low back pain. Coping strategies were predominantly physical therapies, medication and avoidance behaviours with very few successful strategies reported. Professional and family support, self-efficacy, motivation, work conditions and exercise opportunities influenced pain experiences. Review authors’ recommendations included psychological therapies, education, the facilitation of self-management strategies and support groups. Discussion The review substantiates chronic low back pain as complex, dynamic and multidimensional, underpinned by experiences of persistent distressing pain, loss, and lowered self-worth, stigma, depression, premature aging, fear of the future. Future research should address the paucity of longitudinal studies, loss and issues of ethnicity, gender, ageing.
Estimation of parameters and eigenmodes of multivariate autoregressive models

Dynamical characteristics of a complex system can often be inferred from analysis of a stochastic time series model fitted to observations of the system. Oscillations in geophysical systems, for example, are sometimes characterized by principal oscillation patterns, eigenmodes of estimated autoregressive (AR) models of first order. This paper describes the estimation of eigenmodes of AR models of arbitrary order. AR processes of any order can be decomposed into eigenmodes with characteristic oscillation periods, damping times, and excitations. Estimated eigenmodes and confidence intervals for the eigenmodes and their oscillation periods and damping times can be computed from estimated models parameters. As a computationally efficient method of estimating the parameters of AR models from high-dimensional data, a stepwise least squares algorithm is proposed. This algorithm computes models of successively decreasing order. Numerical simulations indicate that, with the least squares algorithm, the AR model coefficients and the eigenmodes derived from the coefficients and eigenmodes are rough approximations of the confidence intervals inferred from the simulaitons.
PTSD: from neurobiology to pharmacological treatments

Posttraumatic stress disorder (PTSD) is a chronic debilitating psychiatric disorder characterized by symptoms of re-experience, avoidance, and hyperarousal that can arise immediately or many years after exposure to a traumatic event and injury. Although extensive research has been done over the past 30 years, the etiology of PTSD remains largely unknown. Several neurobiological systems have been implicated in the pathophysiology and vulnerability for developing PTSD; however, first-line pharmacotherapies are limited. Less than 30% achieve full remission, and even then, approved pharmacological treatments often take weeks for therapeutic effect. This article aims to review the pathophysiology of PTSD within multiple neurobiological systems and how these mechanisms are used as pharmacologic targets of treatment, as well as their potential for future targets of intervention. Highlights of the article We reviewed the neurobiological abnormalities in PTSD as they relate to well-established, preliminary, and future targets for pharmacological interventions. Abnormalities across different neurotransmitter systems have been implicated in the pathophysiology of PTSD but none of these systems function uniformly among all patients with PTSD First-line pharmacotherapy for PTSD provides a suboptimal response rates. Future pharmacological targets for PTSD include the cannabinoid and oxytocin systems, as well glutamatergic modulating agents. Drug development for PTSD should specifically address various dimensions of PTSD symptomatology.
Sexual transmission of the hepatitis B virus among blood donors in a tertiary hospital in Nigeria.

INTRODUCTION Hepatitis B can be spread by several routes, including sexually. This study aimed to determine the prevalence of sexual transmission of the virus among the Nigerian population. METHODS This was a prospective cross-sectional study involving 234 blood donors in a Nigerian tertiary hospital. Each prospective donor was screened for hepatitis B surface antigen using an enzyme-linked immunosorbent assay test. A structured questionnaire was used to obtain information regarding the possible routes of hepatitis B acquisition and the number of lifetime heterosexual partners. Respondents were divided into three risk groups. The data obtained was analysed, and the frequencies, percentages, means and standard deviations were obtained. The chi-square test was used to compare categorical variables, and a p-value equal or less than 0.05 was considered statistically significant. RESULTS A total of 234 respondents aged 18 to 56 years (mean 27.3 years) participated in the study. 223 were male and 11 were female. The overall seroprevalence of hepatitis B was 17.1 percent. The seroprevalence was higher among participants without sexual partners (20.6 percent) and those with multiple sexual partners (20.0 percent), but lower among those with single sexual partners (15.0 percent). A history of needle injuries, jaundice and injections from quacks were statistically significant when these risks were combined with a sexual risk for hepatitis B virus infection (p-value is less than 0.05). CONCLUSION Sexual transmission of hepatitis B was not found to be an important factor. Preventive strategies should include universal hepatitis B vaccination and discouraging the indiscriminate use of sharp objects and unauthorised medical practices.
Patterns of infection and day care utilization and risk of childhood acute lymphoblastic leukaemia

To investigate if decreased exposure to common childhood infections is associated with risk of childhood acute lymphoblastic leukaemia (ALL) we conducted a case–control study of 1842 newly diagnosed and immunophenotypically defined cases of ALL under age 15, and 1986 matched controls in the US. Data regarding day care, sibship size and common childhood infections were obtained through parental interviews. Data were analysed stratified by leukaemia lineage and separately for ‘common’ childhood ALL (age 2–5 years, CD19, CD10-positive). Neither attendance at day care nor time at day care was associated with risk of ALL overall or ‘common’ ALL. Ear infections during infancy were less common among cases, with odds ratios of 0.86, 0.83, 0.71 and 0.69 for 1, 2–4, 5+ episodes, and continuous infections respectively (trend P = 0.026). No effect of sibship size or birth interval was seen. With one exception (ear infections), these data do not support the hypothesis that a decrease in the occurrence of common childhood infection increases risk of ALL. © 2000 Cancer Research Campaign
Using Performance-Based Pay to Improve the Quality of Teachers

Tying teachers' pay to their classroom performance should, says Victor Lavy, improve the current educational system both by clarifying teaching goals and by attracting and retaining the most productive teachers. But implementing pay for performance poses many practical challenges, because measuring individual teachers' performance is difficult. Lavy reviews evidence on individual and school-based incentive programs implemented in recent years both in the United States and abroad. Lavy himself evaluated two carefully designed programs in Israel and found significant gains in student and teacher performance. He observes that research evidence suggests, although not conclusively, that pay-for-performance incentives can improve teachers' performance, although they can also lead to unintended and undesired consequences, such as teachers' directing their efforts exclusively to rewarded activities. Lavy also offers general guidelines for designing effective programs. He emphasizes that the system must measure true performance in a way that minimizes random variation as well as undesired and unintended consequences. It must align performance with ultimate outcomes and must be monitored closely to discourage gaming if not outright fraud in measured output. Goals should be attainable. Incentives should balance individual rewards with school incentives, fostering a cooperative culture but not at the expense of free riding. All teachers should be eligible for the incentive offered, but only a subset of teachers should be rewarded in practice. If too many teachers are rewarded, teachers may not need to exert much extra effort to benefit. Many of the practical challenges faced by performance-related pay, Lavy says, can be addressed through careful design of the system. He emphasizes that setting up a performance-related pay system that works is not a one-time task. Even with the best preparation, initial implementation is likely to be problematic. But if the effort is seen as ongoing, it should be possible to make progress gradually in developing incentives that motivate the desired teaching behaviors and that will be perceived by teachers as fair and accurate.
Does On-Field Sprinting Performance in Young Soccer Players Depend on How Fast They Can Run or How Fast They Do Run?

Mendez-Villanueva, A, Buchheit, M, Simpson, B, Peltola, E, and Bourdon, P. Does on-field sprinting performance in young soccer players depend on how fast they can run or how fast they do run? J Strength Cond Res 25(9): 2634-2638, 2011—The aim of this study was to examine the impact of maximal sprinting speed (MSS) on the peak speed attained during soccer matches. Time-motion analysis of running activity was collected from 14 highly trained young male outfield footballers (8 wide midfielders [WM] and 6 central defenders [CD], 173.2 ± 0.06 m, 60.8 ± 8.1 kg, 16.7 ± 0.7 years) during 14 different friendly international club level matches. The 2 fastest players (a WM and a CD) were compared with the slower players who played in the same position. Each player's MSS was determined using the fastest 10-m split time during an electronically timed 40-m sprint. Game speed was recorded via portable global positioning systems. Faster players reached higher absolute peak running speeds in games than did their slower counterparts regardless of the playing position, with large to very large effect sizes and qualitative indications of “almost certain” and “very likely” positive effects associated with being fast. None of the players reached their MSS during the matches; however, the fastest CD attained a lower percentage of his MSS compared to both, his slower CD counterparts and the fastest WM. Given the higher peak speeds reached in games by the fastest players, and the fact that all players (irrespective of their MSS) used a high percentage of their MSS, these preliminary results provide direct support to the hypothesis that MSS can impact on what a player can do in actual playing conditions. Our results also indicate that playing position has an important role in influencing the expression of MSS.