Miracle-dz/UniFAR-FTUs huggingface dataset:
Learning Discriminative Distance Functions for Case Retrieval and Decision Support

The importance of learning distance functions is gradually being acknowledged by the machine learning community, and different techniques are suggested that can successfully learn a strong distance function in many various contexts. Nevertheless the studies in the area are still rather fragmentary; they lack systematic analysis and focus on a limited circle of application domains. In this paper, two techniques for learning discriminative distance function are evaluated and compared on biomedical data of different kind; learning from equivalence constraints and the intrinsic Random Forest similarity. Both techniques demonstrate competitive results with respect to plain learning; the Random Forest similarity exhibits a more robust behaviour and is shown to be less susceptible to missing data and noise.
Planning over Chain Causal Graphs for Variables with Domains of Size 5 Is NP-Hard

Recently, considerable focus has been given to the problem of determining the boundary between tractable and intractable planning problems. In this paper, we study the complexity of planning in the class Cn of planning problems, characterized by unary operators and directed path causal graphs. Although this is one of the simplest forms of causal graphs a planning problem can have, we show that planning is intractable for Cn (unless P = NP), even if the domains of state variables have bounded size. In particular, we show that plan existence for Ckn is NP-hard for k ≥ 5 by reduction from CNF-SAT. Here, k denotes the upper bound on the size of the state variable domains. Our result reduces the complexity gap for the class Ckn to cases k = 3 and k = 4 only, since C2n is known to be tractable.
The Vote is Cast: The Effect of Corporate Governance on Shareholder Value

This paper estimates the effect of corporate governance provisions on shareholder value and long-term outcomes in S&P1500 firms. We apply a regression discontinuity design to shareholder votes on governance proposals in annual meetings. A close-call vote around the majority threshold is akin to a random outcome, allowing us to deal with prior expectations and the endogeneity of internal governance rules. Passing a corporate governance provision generates a 1.3% abnormal return on the day of the vote with an implied market value per provision of 2.8%. We also find evidence of changes in investment behavior and long-term performance improvements.
Short crack fracture toughness in (1−x)(Na1/2Bi1/2)TiO3–xBaTiO3 relaxor ferroelectrics

The fracture toughness in the lead-free relaxor ferroelectric (1-x)(Na1/2Bi1/2)TiO3-xBaTiO3 was investigated utilizing the surface crack in flexure method. To allow a comprehensive assessment, unpoled and poled samples from the rhombohedral, the tetragonal, and the morphotropic phase regime were considered. It was found that the fracture toughness is up to 23% higher for the poled state. In order to cover the transition from ferroelectric to relaxor phase, the temperature dependence of 0.97(Na1/2Bi1/2)TiO3-0.03BaTiO3 was studied as well. Fracture toughness values of up to 2 MPam1/2 were determined, which are considerably above data for lead zirconate titanate materials. The results are rationalized using a simple transformation toughening-type model in conjunction with investigations into the ferroelastic behavior. The presented model can be applied without fitting parameters but utilizes measurements of the coercive stress and remanent strain as well as the elastic modulus. This article is protected by copyright. All rights reserved.
Comparison of Load Balancing Strategies on Cluster-based Web Servers

This paper focuses on an experimental analysis of the perfor mance and scalability of cluster-based web servers. We carry out the comparative studies using two experimental platforms, namely, a hardware testbed consisting of sixteen PCs, and a trace-driven discrete-event simulator. Dispatcher and web server service times used in the simulator are determined by carrying out a set of experiments on the testbed. The simulator is validated against stochastic queuing models and the testbed. Experiments on the testbed are limited by the hardware configu ration, but our complementary approach allows us to carry out scalability studies on the validated simulator. The three dis patcher-based scheduling algorithms analyzed are: round robin scheduling, least connected based scheduling, and least loaded based scheduling. The least loaded algorithm is used as the baseline (upper performance bound) in our analysis and the performance metrics include average waiting time, average re sponse time, and average web server utilization. A synthetic trace generated by the workload generator called SURGE, and a public-domain France Football World Cup 1998 trace are used. We observe that the round robin algorithm performs much worse in comparison with the other two algorithms for low to medium workload. However, as the request arrival rate increases, the performance of the three algorithms converge with the least con nected algorithm approaching the baseline algorithm at a much faster rate than the round robin. The least connected algorithm performs well for medium to high workload. At very low load, the average waiting time is two to six times higher than the baseline algorithm but the absolute value between these two waiting times is very small.
Effects of Increasing Concentrations of Sodium Sulfite on Deoxynivalenol and Deoxynivalenol Sulfonate Concentrations of Maize Kernels and Maize Meal Preserved at Various Moisture Content

Under moderate climatic conditions, deoxynivalenol (DON) contamination occurs frequently on cereals. Detoxification measures are required to avoid adverse effects on farm animals. In the present study, a wet preservation method with sodium sulfite (Na2SO3) and propionic acid was tested to titrate the optimum Na2SO3-dose for maximum DON reduction of contaminated maize kernels and meal and to examine the interaction between dose and moisture content in dependence on the preservation duration. The DON concentration decreased with increasing amounts of supplemented Na2SO3 and with increasing duration of the preservation period in a bi-exponential fashion. Additionally, the feed structure and moisture content had a significant influence on the decontaminating effect. Variants with 30% moisture content favored higher DON reduction rates compared to 14% moisture, but especially at low moisture contents, DON reduction was more pronounced in maize kernels than in maize meal. In addition to the decrease of DON, a concomitant formation of three different DON sulfonates was observed which differed in their formation pattern over the time course of preservation. The overall results and statistical analysis clarified that Na2SO3 addition of 10 g/kg maize at 30% moisture for eight days was necessary to obtain a complete DON reduction.
Time to and Predictors of CD4+ T-Lymphocytes Recovery in HIV-Infected Children Initiating Highly Active Antiretroviral Therapy in Ghana

Background. CD4+ T-lymphocyte monitoring is not routinely available in most resource-limited settings. We investigated predictors of time to CD4+ T-lymphocyte recovery in HIV-infected children on highly active antiretroviral (HAART) at Korle-Bu Teaching Hospital, Ghana. Methods. Time to CD4+ T-lymphocyte recovery was defined as achieving percent CD4+ T-lymphocytes of 25%. We used Cox proportional hazard models for identifying significant predictor variables. Results. Of the 233 children with complete CD4+ T-lymphocyte data, the mean age at HAART initiation was 5.5 (SD = 3.1) years. The median recovery time was 60 weeks (95% CL: 55–65). Evidence at baseline of severe suppression in CD4+ T-lymphocyte count adjusted for age, age at HAART initiation, gender, and having parents alive were statistically significant in predicting time to CD4+ T-lymphocyte recovery. Conclusions. A targeted approach based on predictors of CD4+ T-lymphocyte recovery can be a viable and cost-effective way of monitoring HAART in HIV-infected children in resource-limited settings.
Scanning Mutagenesis of a Janus-faced Atracotoxin Reveals a Bipartite Surface Patch That Is Essential for Neurotoxic Function*

The Janus-faced atracotoxins (J-ACTXs) are a family of insect-specific excitatory neurotoxins isolated from the venom of Australian funnel web spiders. In addition to a strikingly asymmetric distribution of charged residues, from which their name is derived, these toxins contain an extremely rare vicinal disulfide bond. To shed light on the mechanism of action of these toxins and to enhance their utility as lead compounds for insecticide development, we developed a recombinant expression system for the prototypic family member, J-ACTX-Hv1c, and mapped the key functional residues using site-directed mutagenesis. An alanine scan using a panel of 24 mutants provided the first complete map of the bioactive surface of a spider toxin and revealed that the entire J-ACTX-Hv1c pharmacophore is restricted to seven residues that form a bipartite surface patch on one face of the toxin. However, the primary pharmacophore, or hot spot, is formed by just five residues (Arg8, Pro9, Tyr31, and the Cys13-Cys14 vicinal disulfide). The Arg8–Tyr31 diad in J-ACTX-Hv1c superimposes closely on the Lys–(Tyr/Phe) diad that is spatially conserved across a range of structurally dissimilar K+channel blockers, which leads us to speculate that the J-ACTXs might target an invertebrate K+ channel.
Supplement to “Optimal Kernel Estimation of Spot Volatility of Stochastic Differential Equations”

where all stochastic processes (μ := {μt}t≥0, σ := {σt}t≥0, B := {Bt}t≥0, etc.) are defined on a complete filtered probability space (Ω,F ,F = {Ft}t≥0,P). We also assume that μ and σ are adapted to the filtration F and B := {Bt}t≥0 is a standard Brownian Motion (BM) adapted to F. We suppose that we observe the process X at the times ti := ti,n := i∆n, 0 ≤ i ≤ n, where ∆n := T/n. We will use ∆i X := ∆iX = ∆Xti−1 := Xti −Xti−1 to denote the increments of the process and ∆n = T/n to denote the time increments. We study the estimator:
Blood Pressure Reactivity to Psychological Stress in Young Adults and Cognition in Midlife: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

Background The classic view of blood pressure (BP) reactivity to psychological stress in relation to cardiovascular risks assumes that excess reactivity is worse and lower reactivity is better. Evidence addressing how stress‐induced BP reactivity in young adults is associated with midlife cognitive function is sparse. Methods and Results We assessed BP reactivity during a star tracing task and a video game in adults aged 20 to 32 years. Twenty‐three years later, cognitive function was assessed with use of the Digit Symbol Substitution Test (a psychomotor speed test), the Rey Auditory Verbal Learning Test (a verbal memory test), and the modified Stroop test (an executive function test). At the time of follow‐up, participants (n=3021) had a mean age of 50.2 years; 56% were women, and 44% were black. In linear regression models adjusted for demographic and clinical characteristics including baseline and follow‐up resting BP, lower systolic BP (SBP) reactivity during the star tracing and video game was associated with worse Digit Symbol Substitution Test scores (β [SE]: 0.11 [0.02] and 0.05 [0.02], respectively) and worse performance on the Stroop test (β [SE]: −0.06 [0.02] and −0.05 [0.02]; all P<0.01). SBP reactivity was more consistently associated than diastolic BP reactivity with cognitive function scores. The associations between SBP reactivity and cognitive function were mostly similar between blacks and whites. Conclusions Lower psychological stress‐induced SBP reactivity in younger adults was associated with lower cognitive function in midlife. BP reactivity to psychological stressors may have different associations with target organs in hypertension.
Efficiently Assessing Patient Health Literacy

Although health literacy limitations are common among patient populations, no efficient yet comprehensive health literacy assessment tool is available to nurses for use in busy health care settings. This study presents beginning evidence for the validity and reliability of a new health literacy assessment tool, the Brief Health Literacy Screen (BHLS). One hundred patients attending four primary care clinics completed the BHLS and the Test of Functional Health Literacy in Adults (TOFHLA) short form and answered questions about the health literacy tools. Findings indicated significant correlations between BHLS and shortened version of the TOFHLA (S-TOFHLA) scores, with higher correlations between BHLS items addressing written health literacy and the S-TOFHLA. Comparative discrimination findings were significant at BHLS cut point of 18 and S-TOFHLA cut point less than 23. Patients rated the BHLS significantly less difficult to complete than the S-TOFHLA. Results of preliminary testing indicate the BHLS is a potentially efficient, effective, and patient-friendly screening tool for health literacy.
Pulmonary Hemodynamic Effects of Antisheep Serum‐Induced Leukopenia

Antisheep antileukocyte serum (ALS) was produced in rabbits, purified, and adsorbed against erythrocytes and platelets. The ALS was infused intra‐arterially over a 3‐hour period into anesthetized sheep (n = 6) prepared with lung lymph fistulas. Pulmonary vascular resistance (PVR) and pulmonary lymph flow (Qlym) increased two‐ to threefold while the lymph‐to‐plasma protein concentration ratio (L/P) did not change from baseline, suggesting an increase in pulmonary vascular permeability to proteins. The arterial leukocyte count decreased from 4,935 ± 840 to 1,385 ± 325 cells/μl, the neutrophil count decreased from 1,045 ± 265 to 340 ± 130 cells/μl, and the platelet count decreased from 2.8 × 105 ± 0.2 × 105 to 0.65 × 105 ± 0.12 × 105 cells/μl. ALS induced neutrophil aggregation in vitro, but not platelet aggregation. In the present study, we also examined the effects of ALS‐induced leukopenia on the increase in pulmonary vascular permeability after intravenous α‐thrombin challenge to assess the role of leukocytes in mediating the increased permeability response. Sheep (n = 5) were made leukopenic by an intramuscular injection of ALS; Qlym was in the normal range 4 to 5 hours after the ALS administration. In the leukopenic group, thrombin challenge caused an increase in Qlym from 7.8 ± 0.7 to 12.9 ± 1.9 ml/hr (a 64% increase) while L/P decreased from 0.86 ± 0.04 to 0.70 ± 0.05 (a 19% decrease). In contrast, thrombin‐induced intravascular coagulation in control sheep (n = 5) produced a 250% increase in Qlym with an increase in L/P. The results indicate that leukocytes are required for the increase in lung vascular permeability after thrombin‐induced intravascular coagulation.
State of the science in health professional education: effective feedback

Background Effective feedback may be defined as feedback in which information about previous performance is used to promote positive and desirable development. This can be challenging as educators must acknowledge the psychosocial needs of the recipient while ensuring that feedback is both honest and accurate. Current feedback models remain reductionist in their approach. They are embedded in the hierarchical, diagnostic endeavours of the health professions. Even when it acknowledges the importance of two‐way interactions, feedback often remains an educator‐driven, one‐way process.
A high incidence of parthenogenesis in agricultural pests

Parthenogenetic species are assumed to represent evolutionary dead ends, yet parthenogenesis is common in some groups of invertebrates particularly in those found in relatively constant environments. This suggests that parthenogenetic reproduction might be common in pest invertebrates from uniform agricultural environments. Based on the evaluations of two databases from North America and Italy, we found that parthenogenetic species comprised 45 per cent (North America) or 48 per cent (Italy) of pest species derived from genera where parthenogenesis occurred, compared with an overall incidence of 10 per cent or 16 per cent in these genera. In establishing these patterns, we included only genera containing at least some member species that reproduced by parthenogenesis. The high incidence of parthenogenesis in pest species is spread across different families and several insect orders. Parthenogenetic reproduction may be favoured in agricultural environments when particular clones have a high ﬁtness across multiple generations. Increasing the complexity and variability of agricultural environments represents one way of potentially controlling parthenogenetic pest species.
Potential Benefits of Cattle Vaccination as a Supplementary Control for Bovine Tuberculosis

Vaccination for the control of bovine tuberculosis (bTB) in cattle is not currently used within any international control program, and is illegal within the EU. Candidate vaccines, based upon Mycobacterium bovis bacillus Calmette-Guérin (BCG) all interfere with the action of the tuberculin skin test, which is used to determine if animals, herds and countries are officially bTB-free. New diagnostic tests that Differentiate Infected from Vaccinated Animals (DIVA) offer the potential to introduce vaccination within existing eradication programs. We use within-herd transmission models estimated from historical data from Great Britain (GB) to explore the feasibility of such supplemental use of vaccination. The economic impact of bovine Tuberculosis for farmers is dominated by the costs associated with testing, and associated restrictions on animal movements. Farmers’ willingness to adopt vaccination will require vaccination to not only reduce the burden of infection, but also the risk of restrictions being imposed. We find that, under the intensive sequence of testing in GB, it is the specificity of the DIVA test, rather than the sensitivity, that is the greatest barrier to see a herd level benefit of vaccination. The potential negative effects of vaccination could be mitigated through relaxation of testing. However, this could potentially increase the hidden burden of infection within Officially TB Free herds. Using our models, we explore the range of the DIVA test characteristics necessary to see a protective herd level benefit of vaccination. We estimate that a DIVA specificity of at least 99.85% and sensitivity of >40% is required to see a protective benefit of vaccination with no increase in the risk of missed infection. Data from experimentally infected animals suggest that this target specificity could be achieved in vaccinates using a cocktail of three DIVA antigens while maintaining a sensitivity of 73.3% (95%CI: 61.9, 82.9%) relative to post-mortem detection.
On the Estimation of Discount Parameters for Language Model Smoothing

The goal of statistical language modeling is to find probability estimates for arbitrary word sequences. To obtain non-zero values, the probability distributions found in the training data need to be smoothed. In the widely-used Kneser-Ney family of smoothing algorithms, this is achieved by absolute discounting. The discount parameters can be computed directly using some approximation formulas minimizing the leaving-one-out log-likelihood of the training data. In this work, we outline several shortcomings of the standard estimators for the discount parameters. We propose an efficient method for computing the discount values on heldout data and analyze the resulting parameter estimates. Experiments on large English and French corpora show consistent improvements in perplexity and word error rate over the baseline method. At the same time, this approach can be used for language model pruning, leading to slightly better results than standard pruning algorithms.
Government Policy with Time Inconsistent Voters

Behavioral economics presents a "paternalistic" rationale for government intervention. Current literature focuses on benevolent government. This paper introduces politicians who may indulge/exploit these behavioral biases. We present an analysis of the novel features that arise when the political process is populated by voters who may be time inconsistent, a' la Phelps and Polak (1968) and Laibson (1997). Time inconsistent voters exhibit demand for commitment. We show that electorally accountable politicians may choose policies that interfere with individuals' desire to commit, and that government may not be very effective in satisfying the demand for commitment.
Photosynthetic Acclimation to Elevated CO2 Occurs in Transformed Tobacco with Decreased Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Content

Inhibition of net carbon assimilation rates during growth at elevated CO2 was studied in transgenic tobacco (Nicotiana tabacum L.) plants containing zero to two copies of antisense DNA sequences to the small subunit polypeptide (rbcS) gene of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). High- and low-Rubisco tobacco plants were obtained from the selfed progeny of the original line 3 transformant (S.R. Rodermel, M.S. Abbott, L. Bogorad [1988] Cell 55: 673–681). Assimilation rates of high- and low-Rubisco tobacco plants increased 22 and 71%, respectively, when transferred from 35- to 70-Pa CO2 chamber air at 900 [mu]mol m-2 s-1 photon flux density. However, CO2-dependent increases of net carbon assimilation rates of high- and low-Rubisco plants virtually disappeared after 9 d of growth in elevated CO2 chamber air. Total above-ground dry matter production of high- and low-Rubisco plants was 28 and 53% greater, respectively, after 9 d of growth at 70 Pa compared with 35 Pa CO2. Most of this dry weight gain was due to increased specific leaf weight. Rubisco activity, Rubisco protein, and total chlorophyll were lower in both high- and low-Rubisco plants grown in enriched compared with ambient CO2 chamber air. Soluble leaf protein also decreased in response to CO2 enrichment in high- but not in low-Rubisco tobacco plants. Decreased Rubisco activities in CO2-adapted high- and low-Rubisco plants were not attributable to changes in activation state of the enzyme. Carbonic anhydrase activities and subunit levels measured with specific antibodies were similar in high- and low-Rubisco tobacco plants and were unchanged by CO2 enrichment. Collectively, these findings suggested that photosynthetic acclimation to enriched CO2 occurred in tobacco plants either with or without transgenically decreased Rubisco levels and also indicated that the down-regulation of Rubisco in CO2-adapted tobacco plants was related to decreased specific activity of this enzyme.