Miracle-dz/UniFAR-FTUs huggingface dataset:
Asymmetries in Conditional Mean and Variance: Modelling Stock Returns by Asma-Asqgarch

We propose a nonlinear time series model where both the conditional mean and the conditional variance are asymmetric functions of past information. The model is particularly useful for analysing financial time series where it has been noted that there is an asymmetric impact of good news and bad news on volatility (risk) transmission. We introduce a coherent framework for testing asymmetries in the conditional mean and the conditional variance, separately or jointly. To this end we derive both a Wald and a Lagrange multiplier test. Some of the new asymmetric model's moment properties are investigated. Detailed empirical results are given for the daily returns of the composite index of the New York Stock Exchange. There is strong evidence of asymmetry in both the conditional mean and the conditional variance functions. In a genuine out-of-sample forecasting experiment the performance of the best fitted asymmetric model, having asymmetries in both conditional mean and conditional variance, is compared with an asymmetric model for the conditional mean, and with no-change forecasts. This is done both in terms of conditional mean forecasting as well as in terms of risk forecasting. Finally, the paper presents some evidence of asymmetries in the index stock returns of the Group of Seven (G7) industrialized countries. Copyright © 2004 John Wiley & Sons, Ltd.
NMDA Receptor Subunit-Dependent [Ca2+] Signaling in Individual Hippocampal Dendritic Spines

Ca2+ influx through synaptic NMDA receptors (NMDA-Rs) triggers a variety of adaptive cellular processes. To probe NMDA-R-mediated [Ca2+] signaling, we used two-photon glutamate uncaging to stimulate NMDA-Rs on individual dendritic spines of CA1 pyramidal neurons in rat brain slices. We measured NMDA-R currents at the soma and NMDA-R-mediated [Ca2+] transients in stimulated spines (Δ[Ca2+]). Uncaging-evoked NMDA-R current amplitudes were independent of the size of the stimulated spine, implying that smaller spines contain higher densities of functional NMDA-Rs. The ratio of Δ[Ca2+] over NMDA-R current was highly variable (factor of 10) across spines, especially for small spines. These differences were not explained by heterogeneity in spine sizes or diffusional coupling between spines and their parent dendrites. In addition, we find that small spines have NMDA-R currents that are sensitive to NMDA-R NR2B subunit-specific antagonists. With block of NR2B-containing receptors, the range of Δ[Ca2+]/NMDA-R current ratios and their average value were much reduced. Our data suggest that individual spines can regulate the subunit composition of their NMDA-Rs and the effective fractional Ca2+ current through these receptors.
Including star formation and supernova feedback within cosmological simulations of galaxy formation

We investigate phenomenological models of star formation and supernova feedback in N-body/SPH simulations of galaxy formation. First, we compare different prescriptions in the literature for turning cold gas into stars neglecting feedback effects. We find that most prescriptions give broadly similar results: the ratio of cold gas to stars in the final galaxies is primarily controlled by the range of gas densities where star formation is allowed to proceed efficiently. In the absence of feedback, the fraction of gas that cools is much too high, resulting, for example, in a K-band luminosity function that is much brighter than observed. This problem is ameliorated by including a feedback model which either imparts radial kinetic perturbations to galactic gas or directly reheats such material and prevents it from cooling for a certain period of time. In both these models, a significant fraction of cold gas is heated and expelled from haloes with an efficiency that varies inversely with halo circular velocity. Increasing the resolution of a simulation allows a wider dynamic range in mass to be followed, but the average properties of the resolved galaxy population remain largely unaffected. However, as the resolution is increased, more and more gas is reheated by small galaxies; our results suggest that convergence requires the full mass range of galaxies to be resolved.
Ethical challenges in voluntary blood donation in Kerala, India

The National Blood Policy in India relies heavily on voluntary blood donors, as they are usually assumed to be associated with low levels of transfusion-transmitted infections (TTIs). In India, it is mandatory to test every unit of blood collected for hepatitis B, hepatitis C, HIV/AIDS, syphilis and malaria. Donors come to the blood bank with altruistic intentions. If donors test positive to any of the five infections, their blood is discarded. Although the blood policy advocates disclosure of TTI status, donors are not, in practice, informed about their results. The onus is on the donor to contact the blood bank. Out of approximately 16 000 donations in the past 2 years, 438 tested positive for TTI, including 107 for HIV. Only 20% of the donors contacted the blood bank; none of them were HIV positive. Disclosure by blood banks of TTI status by telephone or mail has resulted in serious consequences for some donors. Health providers face an ethical dilemma, in the absence of proper mechanisms in place for disclosure of test results, regarding notification to donors who may test positive but remain ignorant of their TTI status. Given the high cost of neglecting to notify infected donors, the authors strongly recommend the use of rapid tests before collecting blood, instead of the current practice, which takes 3 h to obtain results, and disclosure of results directly to the donor by a counsellor, to avoid dropouts and to ensure confidentiality.
Constraints on B and Higgs physics in minimal low energy supersymmetric models

We study the implications of minimal flavor violating low energy supersymmetry scenarios for the search of new physics in the B and Higgs sectors at the Tevatron collider and the LHC. We show that the already stringent Tevatron bound on the decay rate B{sub s} {yields} {mu}{sup +}{mu}{sup -} sets strong constraints on the possibility of generating large corrections to the mass difference {Delta} M{sub s} of the B{sub s} eigenstates. We also show that the B{sub s} {yields} {mu}{sup +}{mu}{sup -} bound together with the constraint on the branching ratio of the rare decay b {yields} s{gamma} has strong implications for the search of light, non-standard Higgs bosons at hadron colliders. In doing this, we demonstrate that the former expressions derived for the analysis of the double penguin contributions in the Kaon sector need to be corrected by additional terms for a realistic analysis of these effects. We also study a specific non-minimal flavor violating scenario, where there are flavor changing gluino-squark-quark interactions, governed by the CKM matrix elements, and show that the B and Higgs physics constraints are similar to the ones in the minimal flavor violating case. Finally we show that, in scenarios like electroweak baryogenesis which have light stops and charginos, there may be enhanced effects on the B and K mixing parameters, without any significant effect on the rate of B{sub s} {yields} {mu}{sup +}{mu}{sup -}.
Preventing Page Faults from Telling Your Secrets

New hardware primitives such as Intel SGX secure a user-level process in presence of an untrusted or compromised OS. Such "enclaved execution" systems are vulnerable to several side-channels, one of which is the page fault channel. In this paper, we show that the page fault side-channel has sufficient channel capacity to extract bits of encryption keys from commodity implementations of cryptographic routines in OpenSSL and Libgcrypt -- leaking 27% on average and up to 100% of the secret bits in many case-studies. To mitigate this, we propose a software-only defense that masks page fault patterns by determinising the program's memory access behavior. We show that such a technique can be built into a compiler, and implement it for a subset of C which is sufficient to handle the cryptographic routines we study. This defense when implemented generically can have significant overhead of up to 4000X, but with help of developer-assisted compiler optimizations, the overhead reduces to at most 29.22% in our case studies. Finally, we discuss scope for hardware-assisted defenses, and show one solution that can reduce overheads to 6.77% with support from hardware changes.
“Microscopic evidences of heavy metals distribution and anatomic alterations in breaching‐leaves of Cupressus lindleyi growing around mining wastes”

In this article a study of the distribution of heavy metals in Cupressus lindleyi breaching‐leaves was done in Taxco, Guerrero. At the same, heavy metals micro‐localization was conducted in the breaching‐leaves to understand the structural changes provoked by mining waste on plants. The most abundant contaminants in soils, tailings and different plant organs (roots, stems, and leaves) were Zn, Mn, and Pb. Nevertheless, As was more accumulated in the stem and breaching‐leaves. The translocation factor and the bio‐concentration factor were less than 1. The structural changes observed were the great accumulation of starch grains and phenolic compounds in the palisade parenchyma, changes in the hypodermis cell wall and necrotic zones in the palisade parenchyma. The distribution of heavy metals in breaching‐leaves tissues was homogeneous in most of the elements. These results showed that C. lindleyi is a species that can be employed in phytostabilization of contaminated zones with mining waste because it is a native plant that does not require a lot of conditions for its development. Microsc. Res. Tech. 77:714–726, 2014. © 2014 Wiley Periodicals, Inc.
Effects of 100 years wastewater irrigation on resistance genes, class 1 integrons and IncP-1 plasmids in Mexican soil

Long-term irrigation with untreated wastewater can lead to an accumulation of antibiotic substances and antibiotic resistance genes in soil. However, little is known so far about effects of wastewater, applied for decades, on the abundance of IncP-1 plasmids and class 1 integrons which may contribute to the accumulation and spread of resistance genes in the environment, and their correlation with heavy metal concentrations. Therefore, a chronosequence of soils that were irrigated with wastewater from 0 to 100 years was sampled in the Mezquital Valley in Mexico in the dry season. The total community DNA was extracted and the absolute and relative abundance (relative to 16S rRNA genes) of antibiotic resistance genes (tet(W), tet(Q), aadA), class 1 integrons (intI1), quaternary ammonium compound resistance genes (qacE+qacEΔ1) and IncP-1 plasmids (korB) were quantified by real-time PCR. Except for intI1 and qacE+qacEΔ1 the abundances of selected genes were below the detection limit in non-irrigated soil. Confirming the results of a previous study, the absolute abundance of 16S rRNA genes in the samples increased significantly over time (linear regression model, p < 0.05) suggesting an increase in bacterial biomass due to repeated irrigation with wastewater. Correspondingly, all tested antibiotic resistance genes as well as intI1 and korB significantly increased in abundance over the period of 100 years of irrigation. In parallel, concentrations of the heavy metals Zn, Cu, Pb, Ni, and Cr significantly increased. However, no significant positive correlations were observed between the relative abundance of selected genes and years of irrigation, indicating no enrichment in the soil bacterial community due to repeated wastewater irrigation or due to a potential co-selection by increasing concentrations of heavy metals.
Flames in the rain forest : origins, impacts and alternatives to Amazonian fires

Each year, fires in the Brazilian Amazon burn an area twice the size of Costa Rica as ranchers and farmers ignite their lands, converting forests into fields, reclaiming pastures from invading weeds, and inadvertently burning forests, grazing land and plantations in the process. The annual risk of accidental fire discourages landholders from investing in their property, and perpetuates the dominance of extensive ranching and slash and burn agriculture over fire-sensitive tree crops and forest management for timber production. Fire increases the flammability of Amazonian landscapes, initiating a vicious positive feedback cycle in which rainforests are replaced by fire-prone vegetation. This book presents an analysis of fire in the Brazilian Amazon with the goal of identifying means by which the negative effects of Amazon fires might be reduced. This book is the first comprehensive analysis of fire and its new, disturbing role in the Amazon. The book builds on a 1996 study commissioned by the World Bank that examined the causes of increasing forest clearing and fires at five sites along the Amazon region's arc of deforestation.
Bilingualism does not alter cognitive decline or dementia risk among Spanish-speaking immigrants.

OBJECTIVE Clinic-based studies suggest that dementia is diagnosed at older ages in bilinguals compared with monolinguals. The current study sought to test this hypothesis in a large, prospective, community-based study of initially nondemented Hispanic immigrants living in a Spanish-speaking enclave of northern Manhattan. METHOD Participants included 1,067 participants in the Washington/Hamilton Heights Inwood Columbia Aging Project (WHICAP) who were tested in Spanish and followed at 18-24 month intervals for up to 23 years. Spanish-English bilingualism was estimated via both self-report and an objective measure of English reading level. Multilevel models for change estimated the independent effects of bilingualism on cognitive decline in 4 domains: episodic memory, language, executive function, and speed. Over the course of the study, 282 participants developed dementia. Cox regression was used to estimate the independent effect of bilingualism on dementia conversion. Covariates included country of origin, gender, education, time spent in the United States, recruitment cohort, and age at enrollment. RESULTS Independent of the covariates, bilingualism was associated with better memory and executive function at baseline. However, bilingualism was not independently associated with rates of cognitive decline or dementia conversion. Results were similar whether bilingualism was measured via self-report or an objective test of reading level. CONCLUSIONS This study does not support a protective effect of bilingualism on age-related cognitive decline or the development of dementia. In this sample of Hispanic immigrants, bilingualism is related to higher initial scores on cognitive tests and higher educational attainment and may not represent a unique source of cognitive reserve.
Activating Transcription Factor 3 Activates p53 by Preventing E6-associated Protein from Binding to E6*

Genomic integration of human papillomavirus (HPV) DNA accounts for more than 90% of cervical cancers. High-risk genital HPVs encode E6 proteins that can interact with a cellular ubiquitin ligase E6-associated protein (E6AP) and target the tumor suppressor p53 for ubiquitin-mediated proteolysis. Currently, how this critical event is regulated is largely unknown. Here we report that activating transcription factor 3 (ATF3), a broad DNA damage sensor whose expression is frequently downregulated in cervical cancer, interacted with E6 and prevented p53 from ubiquitination and degradation mediated by the viral protein. Consistent with its role as a potent E6 antagonist, ATF3 expressed enforcedly in HPV-positive SiHa cells activated p53, leading to expression of p53-target genes (e.g. p21 and PUMA), cell cycle arrest and apoptotic cell death. The leucine zipper domain of ATF3 appears indispensable for these effects as an ATF3 mutant lacking this domain failed to interact with E6 and activate p53 in the cervical cancer cells. The prevention of p53 degradation was unlikely caused by binding of ATF3 to the tumor suppressor, but rather was a consequence of disruption of the E6-E6AP interaction by ATF3. These results indicate that ATF3 plays a key role in a mechanism defending against HPV-induced carcinogenesis, and could serve as a novel therapeutic target for HPV-positive cancers.
STREAM HEALTH AFTER URBANIZATION 1

ABSTRACT: Urban development has compromised the quality of physical elements offish habitat in low‐order spawning and rearing streams. In order to identify where priorities should lie in stream rehabilitation, field surveys of a number of streams were conducted near Vancouver, British Columbia. All of the streams were located in watersheds which were urbanized approximately 20 years earlier. The study watersheds ranged from 5 to 77 percent total impervious area (percent TIA). The urban streambeds were found to have less fine material and slightly higher values of intragravel dissolved oxygen than in rural streams. This improved gravel quality is attributed to the higher peak flows generated by impervious areas, and the reduced recruitment of fine material in the urban watersheds. Summer base flow was uniformly low when imperviousness was above 40 percent, evidenced by a decrease in velocity rather than water depth. Large woody debris (LWD) was scarce in all streams with > 20 percent TIA. A healthy buffer zone and abundant LWD were found to stabilize stream banks. The introduction of LWD is considered the most important strategy for stream rehabilitation. Stormwater detention ponds, in contrast, are concluded to have few hydrological benefits if constructed after a stream has reached its urban equilibrium.
Automatic Change Analysis in Satellite Images Using Binary Descriptors and Lloyd–Max Quantization

In this letter, we present a novel technique for unsupervised change analysis that leads to a method of ranking the changes that occur between two satellite images acquired at different moments of time. The proposed change analysis is based on binary descriptors and uses the Hamming distance as a similarity metric. In order to render a completely unsupervised solution, the obtained distances are further classified using vector quantization methods (i.e., Lloyd's algorithm for optimal quantization). The ultimate goal in the change analysis chain is to build change intensity maps that provide an overview of the severeness of changes in the area under analysis. In addition, the proposed analysis technique can be easily adapted for change detection by selecting only two levels for quantization. This discriminative method (i.e., between changed/unchanged zones) is compared with other previously developed techniques that use principal component analysis or Bayes theory as starting points for their analysis. The experiments are carried on Landsat images at a 30-m spatial resolution, covering an area of approximately 59×51 km2 over the surroundings of Bucharest, Romania, and containing multispectral information.
RECENT INCOME TRENDS FOR TOP EXECUTIVES: EVIDENCE FROM TAX RETURN DATA

We examine income trends for top executives, focusing on the years 2000 to 2010, with special emphasis on the period surrounding the Great Recession. First, we merge Execucomp executive compensation records with IRS tax records. We compare incomes from our Execucomp sample to top incomes reported by Piketty and Saez (2003). We disaggregate executive income trends by industry, showing which industries are driving the divergence in top executive incomes. We compare our results to findings from Bakija, Cole, and Heim (2010) and Kaplan and Rauh (2010), who examine trends in top incomes for broad occupation and industry categories for years prior to the Great Recession. We also decompose these income trends by income source to see which components are driving the observed changes. We find that stock options are by far the most volatile component of executive pay. Options are the key driver of both short-term swings and longer-term trends in top executive pay. However, stock awards are also a large and growing component. We find much greater variation in income across years than across industries. Executive incomes are most volatile at the very top of income distribution. In general, trends for top executives in finance and non-finance industries are quite similar; however; for those above the 99.9th percentile of the income distribution, the decline in income from 2006 to 2009 was much more pronounced for executives in finance.
An analysis of non-normal Markovian extremal droughts

In many arid and semi-arid environments of the world, years of extended droughts are not uncommon. The occurrence of a drought can be reflected by the deficiency of the rainfall or stream flow sequences below the long-term mean value, which is generally taken as the truncation level for the identification of the droughts. The commonly available statistics for the above processes are mean, coefficient of variation and the lag-one serial correlation coefficient, and at times some indication of the probability distribution function (pdf) of the sequences. The important elements of a drought phenomenon are the longest duration and the largest severity for a desired return period, which form a basis for designing facilities to meet exigencies arising as a result of droughts. The sequences of drought variable, such as annual rainfall or stream flow, may follow normal, log-normal or gamma distributions, and may evolve in a Markovian fashion and are bound to influence extremal values of the duration and severity. The effect of the aforesaid statistical parameters on the extremal drought durations and severity have been analysed in the present paper. A formula in terms of the extremal severity and the return period ‘T’ in years has been suggested in parallel to the flood frequency formula, commonly cited in the hydrological texts. © 1998 John Wiley & Sons, Ltd.
Standard Precautions and Infection Control, Medical Students’ Knowledge and Behavior at a Saudi University: The Need for Change

Background: No previous studies have reported the knowledge of Saudi medical students about Standard Precautions (SPs) and infection control. Objectives: The objectives of this study were to assess medical students’ knowledge in clinical years at King Faisal University, Saudi Arabia about SPs’ and to explore their attitudes toward the current curricular/training in providing them with effective knowledge and necessary skills with regard to SPs. Subjects and Methods: This cross sectional study targeted students in clinical stage at College of Medicine, King Faisal University, Saudi Arabia. A pre-tested anonymous self administered data collection form was used. Inquires about students’ characteristics, general concepts of infection control/SPs, hand hygiene, personal protective equipment, sharp injuries and disposal, and care of health providers were included. The main source of information for each domain was also inquired. The second part dedicated to explore the attitudes toward the curricular and teaching relevant to SPs. Results: A total of 251 students were included. Knowledge scores in all domains were considerably low, 67 (26.7%) students scored ≥ 24 (out of 41points) which was considered as an acceptable level of knowledge, 22.2% in 4th year, 20.5% in 5th year and 36.8% in 6th year. Sharp injuries, personal protective equipment and health care of the providers showed the least knowledge scores. The main sources of knowledge were self learning, and informal bed side practices The majority of students’ believed that the current teaching and training are insufficient in providing them with the necessary knowledge and skills regarding SPs. Conclusion: The overall knowledge scores for SPs were low especially in the domains of hand hygiene, sharp management, and personal protective equipment reflecting insufficient and ineffective instructions received by medical students through the current curriculum posing them vulnerable to health facilities related infections. Proper curricular reform and training are required to protect students and their patients.