Miracle-dz/UniFAR-FTUs huggingface dataset:
Some connections between mathematical logic and complexity theory

However difficult the fundamental problems of theoretical computer science may seem, there is very little to suggest that they are anything more than knotty combinatorial problems. So, when we look for reasons for our inability to resolve P = NP and related questions, we most likely find them dealing with a lack of understanding of particular computational problems and their lower bounds. This is the sense of Hopcroft's prediction: “. within the next five years, nobody will prove that any of these problems takes more than let's say n2 time. I think that's a reasonably safe conjecture and it also illustrates how little we know about lower bounds. ” [MT]. Hopcroft's guess is uncanny in its accuracy—after six years and considerable effort by many researchers, his conjecture remains unchallenged. The results in this paper offer a possible explanation for our failure to resolve these problems. Roughly, the main result of the sequel links lower bounds and a branch of mathematical logic known as model theory. In particular, we prove that the existence of nonpolynomial lower bounds is equivalent to the existence of nonstandard models of a sizable fragment of arithmetic. Since these are deep logical issues and there are very few techniques for handling them, and since the nonstandard models in question are non-effective, it seems plausible that this linking of complexity theory and logic explains our failure to obtain nontrivial lower bounds. One of the aims of mathematical logic is to clarify the relation between mathematical theories and their interpretations—or models.
Do the Costs of a Carbon Tax Vanish When Interactions with Other Taxes are Accounted for?

Previous analyses of U.S. carbon taxes have tended to ignore interactions between this tax and other, pre-existing U.S. taxes. This paper assesses the effects of the carbon tax using a model that addresses these interactions. The model is unique in integrating a detailed treatment of taxes and attention to nonrenewable resource supply dynamics within a disaggregated general equilibrium framework. We find that the GNP and welfare costs of the carbon tax are significantly lower than what would be predicted if tax interactions were disregarded. When the revenues are used to finance reductions in marginal taxes at the personal or corporate level, the welfare costs are 25-32 percent lower than when the revenues finance lump-sum reductions in taxes. Pre-existing distortions -- specifically, the relatively light taxation of fossil-fuel-producing industries in comparison with other industries -- imply that the gross efficiency costs of carbon taxes are about 15 percent lower than would be the case if fossil-fuel-producing industries were not initially tax-favored.
Crime, Transitory Poverty, and Isolation: Evidence from Madagascar

This article investigates the relationship between poverty and crime. Following a disputed presidential election, fuel supply to the highlands of Madagascar was severely curtailed in early 2002, resulting in a massive increase in poverty and transport costs. Using original survey data collected in June 2002 at the height of the crisis, we find that crop theft increases with transitory poverty. Theft thus appears to be used by some of the rural poor as a risk‐coping strategy. Increased transport costs led to a rise in cattle and crop theft, confirming earlier findings that in Madagascar geographical isolation is associated with certain forms of crime. We also find that an increase in law enforcement personnel locally reduces cattle theft that in Madagascar is a form of organized crime.
Increased Brain Injury and Worsened Neurological Outcome in Interleukin-4 Knockout Mice After Transient Focal Cerebral Ischemia

Background and Purpose— Stroke causes brain injury with activation of an inflammatory response that can contribute to injury. We tested the hypothesis that the anti-inflammatory cytokine interleukin-4 (IL-4) reduces injury after stroke using IL-4 knockout (KO) adult male mice. Methods— IL-4 KO and wild-type mice were subjected to transient middle cerebral artery occlusion. Outcome was assessed by triphenyltetrazolium chloride staining for infarct volume, neuroscore and spontaneous activity for behavioral outcome, and immunostaining and stereological counting for cellular response. Results— Infarction volume at 24 hours was significantly larger in IL-4 KO mice, neurological score was significantly worse, and spontaneous activity was reduced compared with wild-type mice. Increased macrophage/microglial infiltration, increased numbers of myeloperoxidase-positive cells, and increased Th1/Th2 ratio were observed in the infarct core in IL-4 KO mice. Reduced astrocyte activation was observed in the cortical penumbra in IL-4 KO mice. Recombinant IL-4 administered intracerebroventricularly before middle cerebral artery occlusion significantly reduced infarct volume, improved neurological score, reduced macrophages/microglia, and lowered the Th1/Th2 ratio in IL-4 KO mice, but not in wild-type. Conclusions— Loss of IL-4 signaling in KO mice was associated with worse outcome, and this was reversed by giving exogenous IL-4. Worsened outcome was associated with increased inflammation in the core, which was reversed in IL-4 KO but not significantly changed in wild-type mice by exogenous IL-4. This is consistent with IL-4 signaling leading to reduced inflammation in the core and a possible beneficial role for activated astrocytes in the penumbra.
Systematic uncertainties in the analysis of star cluster parameters based on broad-band imaging observations

High-resolution Hubble Space Telescope (HST) imaging observations of star cluster systems provide a very interesting and useful alternative for stellar population analyses to spectroscopic studies with 8m-class telescopes. Here, we assess the systematic uncertainties in (young) cluster age, mass, and – to a lesser extent – extinction and metallicity determinations, based on broad-band imaging observations with the HST. Our aim here is to intercompare the results obtained using a variety of commonly used modelling techniques, specifically with respect to our own extensively tested multi-dimensional approach. Any significant differences among the resulting parameters are due to the details of the various, independently developed modelling techniques used, rather than to the stellar population models themselves. Despite the model uncertainties and the selection effects inherent to most methods used, we find that the peaks in the relative age and mass distributions of a given young (. 10 9 yr) cluster system can be derived relatively robustly and consistently, to accuracies of σt ≡ �h log(Age/yr)i ≤ 0.35 and σM ≡ �h log(Mcl/M⊙)i ≤ 0.14, respectively, assuming Gaussian distributions in cluster ages and masses for reasons of simplicity. The peaks in the relative mass distributions can be obtained with a higher degree of confidence than those in the relative age distributions, as exemplified by the smaller spread among the peak values of the mass distributions derived. This implies that mass determinations are mostly insensitive to the approach adopted. We reiterate that as extensive a wavelength coverage as possible is required to obtain robust and internally consistent age and mass estimates for the individual objects, with reasonable uncertainties. Finally, we conclude that the actual filter systems used for the observations should be used for constructing model colours, instead of using conversion equations, to achieve more accurate derivations of ages and masses.
Bioinformatics Applications Note Sequence Analysis Cd-hit Suite: a Web Server for Clustering and Comparing Biological Sequences

CD-HIT is a widely used program for clustering and comparing large biological sequence datasets. In order to further assist the CD-HIT users, we significantly improved this program with more functions and better accuracy, scalability and flexibility. Most importantly, we developed a new web server, CD-HIT Suite, for clustering a user-uploaded sequence dataset or comparing it to another dataset at different identity levels. Users can now interactively explore the clusters within web browsers. We also provide downloadable clusters for several public databases (NCBI NR, Swissprot and PDB) at different identity levels.
Bag-of-Task Scheduling on Power-Aware Clusters Using a DVFS-Based Mechanism

Energy reduction is very important nowadays. A large percentage of the workload submitted to large-scale systems is bag-of-tasks (BoT) applications. Each BoT is a collection of independent tasks that do not communicate with each other. They are used in astronomy, Monte Carlo simulations, data mining, fractal calculations, image processing and massive searches. Due to their importance, BoT scheduling is extensively studied regarding performance. In this paper we view BoT scheduling from an energy efficiency perspective. In order to save energy, we apply a Dynamic Voltage/Frequency Scaling (DVFS) mechanism to a heterogeneous cluster environment where BoTs are submitted. A cluster environment is selected due to the fact that clusters are often used as underlying basic components in grids and clouds. In order for our simulation experiments to be more realistic regarding the workload applied in the system, we also consider high-priority tasks. Extensive simulation experiments show that by applying the proposed DVFS mechanism when BoTs are executed, we can achieve energy savings up to 13% without affecting the execution of high-priority tasks.
A taxonomy of generic clinical questions: classification study

Abstract Objective: To develop a taxonomy of doctors' questions about patient care that could be used to help answer such questions. Design: Use of 295 questions asked by Oregon primary care doctors to modify previously developed taxonomy of 1101 clinical questions asked by Iowa family doctors. Setting: Primary care practices in Iowa and Oregon. Participants: Random samples of 103 Iowa family doctors and 49 Oregon primary care doctors. Main outcome measures: Consensus among seven investigators on a meaningful taxonomy of generic questions; interrater reliability among 11 individuals who used the taxonomy to classify a random sample of 100 questions: 50 from Iowa and 50 from Oregon. Results: The revised taxonomy, which comprised 64 generic question types, was used to classify 1396 clinical questions. The three commonest generic types were “What is the drug of choice for condition x? ” (150 questions, 11%); “What is the cause of symptom x? ” (115 questions, 8%); and “What test is indicated in situation x? ” (112 questions, 8%). The mean interrater reliability among 11 coders was moderate (κ=0.53, agreement 55%). Conclusions: Clinical questions in primary care can be categorised into a limited number of generic types. A moderate degree of interrater reliability was achieved with the taxonomy developed in this study. The taxonomy may enhance our understanding of doctors' information needs and improve our ability to meet those needs.
Comparison of Trihalomethanes in Tap Water and Blood: A Case Study in the United States

Background: Epidemiological studies have used various measures to characterize trihalomethane (THM) exposures, but the relationship of these indicators to exposure biomarkers remains unclear. Objectives: We examined temporal and spatial variability in baseline blood THM concentrations and assessed the relationship between these concentrations and several exposure indicators (tap water concentration, water-use activities, multiroute exposure metrics). Methods: We measured water-use activity and THM concentrations in blood and residential tap water from 150 postpartum women from three U.S. locations. Results: Blood ΣTHM [sum of chloroform (TCM), bromodichloromethane (BDCM), dibromo-chloromethane (DBCM), and bromoform (TBM)] concentrations varied by site and season. As expected based on variable tap water concentrations and toxicokinetic properties, the proportion of brominated species (BDCM, DBCM, and TBM) in blood varied by site (site 1, 24%; site 2, 29%; site 3, 57%) but varied less markedly than in tap water (site 1, 35%; site 2, 75%; site 3, 68%). The blood–water ΣTHM Spearman rank correlation coefficient was 0.36, with correlations higher for individual brominated species (BDCM, 0.62; DBCM, 0.53; TBM, 0.54) than for TCM (0.37). Noningestion water activities contributed more to the total exposure metric than did ingestion, but tap water THM concentrations were more predictive of blood THM levels than were metrics that incorporated water use. Conclusions: Spatial and temporal variability in THM concentrations was greater in water than in blood. We found consistent blood–water correlations across season and site for BDCM and DBCM, and multivariate regression results suggest that water THM concentrations may be an adequate surro-gate for baseline blood levels.
A hybrid scheduling technique for grid workflows in advance reservation environments

Scheduling workflows in Grids with the goal of minimizing the completion time is a challenging optimisation problem. Communication times between dependent tasks affect the schedule length only if the tasks are scheduled on different resources, and this makes it difficult to predict the critical path of the scheduled workflow. To address this difficulty, we introduce a new variation of critical path scheduling that ignores communication times between dependent tasks under certain conditions. Furthermore, we propose a hybrid scheduling method that computes five different schedules, based on the combination of two resource selection rules with four job selection rules, and then uses the best of the five. In simulation experiments for workflow scheduling in an advance reservation environment conducted with GridSim, it is shown that the proposed hybrid scheduling method achieves makespan improvements of up to 25.5% on benchmark workflows, compared to previous methods.
The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response

The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility.
PAN1/NALP2/PYPAF2, an Inducible Inflammatory Mediator That Regulates NF-κB and Caspase-1 Activation in Macrophages*

Genes encoding proteins with PYRIN/PAAD/DAPIN domains, a nucleotide binding fold (NACHT), and leucine rich repeats have recently been recognized as important mediators in autoimmune inflammatory disorders. Here we characterize the expression and function of a member of the PYRIN and NACHT domain (PAN) family, PAN1 (also known as NALP2 and PYPAF2). PAN1 protein expression is regulated by lipopolysaccharide (LPS) and interferons (IFNβ and IFNγ) in THP-1 macrophage cells. In gene transfection studies PAN1 manifests an inhibitory influence on NF-κB activation induced by various pro-inflammatory stimuli, including tumor necrosis factor TNFα and interleukin-1β (IL-1β). Gene transfer-mediated elevations in PAN1 protein also suppressed activation of IκB kinases induced by inflammatory cytokines. Conversely, reducing endogenous levels of PAN1 using small interfering RNA enhanced LPS-induced production of ICAM-1 (intercellular adhesion molecule 1), an NF-κB-dependent gene. We also show here that PAN1 binds via its PYRIN domain to ASC, an adapter protein involved in caspase-1 activation. This binding is disrupted by mutation of the α1 helix of ASC. In gene transfer experiments PAN1 enhances caspase-1 activation and IL-1β secretion in collaboration with ASC. Conversely, reducing endogenous levels of PAN1 using small interfering RNA significantly reduced LPS-induced secretion of IL-1β in monocytes. We propose that PAN1 functions as a modulator of the activation of NF-κB and pro-caspase-1 in macrophages.
Selective Inactivation of p53 Facilitates Mouse Epithelial Tumor Progression without Chromosomal Instability

ABSTRACT We examined the selective pressure for, and the impact of, p53 inactivation during epithelial tumor evolution in a transgenic brain tumor model. In TgT121 mice, cell-specific inactivation of the pRb pathway in brain choroid plexus epithelium initiates tumorigenesis and induces p53-dependent apoptosis. We previously showed that p53 deficiency accelerates tumor growth due to diminished apoptosis. Here we show that in a p53+/− background, slow-growing dysplastic tissue undergoes clonal progression to solid angiogenic tumors in all animals. p53 is inactivated in all progressed tumors, with loss of the wild-type allele occurring in 90% of tumors. Moreover, similar progression occurs in 38% of TgT121p53+/+ mice, also with loss of at least one p53 allele and inactivation of p53. Thus, the selective pressure for p53 inactivation, likely based on its apoptotic function, is high. Yet, in all cases, p53 inactivation correlates with progression beyond apoptosis reduction, from dysplasia to solid vascularized tumors. Hence, p53 suppresses tumor progression in this tissue by multiple mechanisms. Previous studies of fibroblasts and hematopoietic cells show that p53 deficiency can be associated with chromosomal instability, a mechanism that may drive tumor progression. To determine whether genomic gains or losses are present in tumors that progress in the absence of p53, we performed comparative genomic hybridization analysis. Surprisingly, the only detectable chromosomal imbalance was partial or complete loss of chromosome 11, which harbors the p53 gene and is thus the selected event. Flow cytometry confirmed that the majority of tumor cells were diploid. These studies indicate that loss of p53 function is frequent under natural selective pressures and furthermore that p53 loss can facilitate epithelial tumor progression by a mechanism in addition to apoptosis reduction and distinct from chromosomal instability.
DATA ANALYSIS IN PUBLIC SOCIAL NETWORKS

Public social networks affect significant number of people with different professional and personal background. Presented paper deals with data analysis and in addition with safety of information managed by online social networks. We will show methods for data analysis in social networks based on its scale-free characteristics. Experimental results will be discussed for the biggest social network in Slovakia which is popular for more than 10 years. 1 , big data 2 , scale-free networks 3 , data security 4 , graph theory 5
Questionable assumptions and unintended consequences : a critical assessment of the international donor community's fight against corruption in Sub-Saharan Africa

Following 15 years of high policy attention to curbing corruption in developing countries, this thesis concerns the effects of polices induced by the international donor community on curbing corruption in sub-Saharan Africa. I approach this question by assessing, in three stand-alone empirical chapters, the effects increased political competition, economic liberalisation, and the use of judicial punishment for corruption-related crimes have had on curbing corruption in sub-Saharan Africa. In the first empirical chapter, I assess the effect on corruption from increased political competition following the third wave of democratisation. While popular theories propose that political competition helps curb corruption by inducing political accountability, I find instead, in the sub-Saharan African context that in times of tense political competition the incumbent ensures his victory by buying the loyalty of the elite through distributing state resources for private means. This prebendal politics is, in turn, associated with higher levels of corruption. In the second empirical chapter, which concerns economic liberalisation and its effect on corruption, I ask what happens to corruption as the formal institutions governing the market change. Using insights from a case study on Rwanda, I find that corruption transforms rather than disappears in the advent of economic liberalisation. The third empirical chapter concerns the use of punishment for corruption-related crimes. By using politically contextualised information on prosecutions, I find that such anti-corruption interventions risk being used for political ends instead of curbing high level impunity. The overarching conclusion from this research endeavour is that corruption in the subSaharan African context has a political function which makes the reforms prescribed by the donor community difficult, or illogical, to fully comply with. The political functionality of corruption must therefore constitute the analytical cornerstone when developing anti-corruption policies in order to set realistic expectations and avoid unintended consequences.
FACTORS INFLUENCING THE ADOPTION OF E-LEARNING AT UOB

With the aid of the internet, many organizations and institutes have adopted the idea of applying the e-learning system, which is considered as one of the most important services provided by the internet. The University of Bahrain is one of the Arabic educational institutes that are in its way to adopt the e-learning system and convert all of its courses to be online by 2008. University of Bahrain believes that adopting e-learning system can help in addressing many challenges arise from the widening number of students locally and regionally compared to the available human, technical, and other resources. The purpose of this paper is to investigate the factors affecting the acceptance and use of e-learning system at the University of Bahrain. Through an extension of the Technology Acceptance Model (TAM), three factors that influence the intention to adopt the e-learning system will be examined. These factors include: computer self-efficacy, content quality, and subjective norms. In addition, some cultural factors that could affect the students’ attitude toward using the e-learning system will be also examined. A quantitative research methodology is used based on a survey that was distributed to a sample of 200 students from the University of Bahrain to form the primary data of the research. Regression analysis was used to observe the associations of the proposed constructs of the research model. Finding of this research can help the University of Bahrain, and any other Arabic educational institutes that intend to apply the e-learning system, to identify factors that influence the adoption of the e-learning system in their institute. Hence, they should be able to recognize different ways to enhance their students’ acceptance of the e-learning system.