Miracle-dz/UniFAR-FTUs huggingface dataset:
. . . And the Cross-Section of Expected Returns

Hundreds of papers and hundreds of factors attempt to explain the cross-section of expected returns. Given this extensive data mining, it does not make any economic or statistical sense to use the usual significance criteria for a newly discovered factor, e.g., a t-ratio greater than 2.0. However, what hurdle should be used for current research? Our paper introduces a multiple testing framework and provides a time series of historical significance cutoffs from the first empirical tests in 1967 to today. Our new method allows for correlation among the tests as well as missing data. We also project forward 20 years assuming the rate of factor production remains similar to the experience of the last few years. The estimation of our model suggests that a newly discovered factor needs to clear a much higher hurdle, with a t-ratio greater than 3.0. Echoing a recent disturbing conclusion in the medical literature, we argue that most claimed research findings in financial economics are likely false.
A New Look at Pricing of the ”Russian Option“

The “Russian option” was introduced and calculated with the help of the solution of the optimal stopping problem for a two-dimensional Markov process in [10]. This paper proposes a new derivation of the general results [10]. The key idea is to introduce the dual martingale measure which permits one to reduce the “two-dimensional” optimal stopping problem to a “one-dimensional” one. This approach simplifies the discussion and explain the simplicity of the answer found in [10].
Lipoprotein assembly and function in an evolutionary perspective

Abstract Circulatory fat transport in animals relies on members of the large lipid transfer protein (LLTP) superfamily, including mammalian apolipoprotein B (apoB) and insect apolipophorin II/I (apoLp-II/I). ApoB and apoLp-II/I, constituting the structural (non-exchangeable) basis for the assembly of various lipoproteins, acquire lipids through microsomal triglyceride-transfer protein, another LLTP family member, and bind them by means of amphipathic α-helical and β-sheet structural motifs. Comparative research reveals that LLTPs evolved from the earliest animals and highlights the structural adaptations in these lipid-binding proteins. Thus, in contrast to apoB, apoLp-II/I is cleaved post-translationally by a furin, resulting in the appearance of two non-exchangeable apolipoproteins in the single circulatory lipoprotein in insects, high-density lipophorin (HDLp). The remarkable structural similarities between mammalian and insect lipoproteins notwithstanding important functional differences relate to the mechanism of lipid delivery. Whereas in mammals, partial delipidation of apoB-containing lipoproteins eventually results in endocytic uptake of their remnants, mediated by members of the low-density lipoprotein receptor (LDLR) family, and degradation in lysosomes, insect HDLp functions as a reusable lipid shuttle capable of alternate unloading and reloading of lipid. Also, during muscular efforts (flight activity), an HDLp-based lipoprotein shuttle provides for the transport of lipid for energy generation. Although a lipophorin receptor – a homolog of LDLR – was identified that mediates endocytic uptake of HDLp during specific developmental periods, the endocytosed lipoprotein appears to be recycled in a transferrin-like manner. These data highlight that the functional adaptations in the lipoprotein lipid carriers in mammals and insects also emerge with regard to the functioning of their cognate receptors.
Properties of planets in binary systems - The role of binary separation

Aims. The statistical properties of planets in binaries were investigated. Any difference to planets orbiting single stars can shed light on the formation and evolution of planetary systems. As planets were found around components of binaries with very different separation and mass ratio, it is particularly important to study the characteristics of planets as a function of the effective gravitational influence of the companion. Methods. A compilation of planets in binary systems was made; a search for companions orbiting stars recently shown to host planets was performed, resulting in the addition of two further binary planet hosts (HD 20782 and HD 109749). The probable original properties of the three binary planet hosts with white dwarfs companions were also investigated. Using this updated sample of planets in binaries we performed a statistical analysis of the distributions of planet mass, period, and eccentricity, fraction of multiplanet systems, and stellar metallicity for planets orbiting components of tight and wide binaries and single stars. Results. The only highly significant difference revealed by our analysis concerns the mass distribution of short-period planets. Massive planets in short period orbits are found in most cases around the components of rather tight binaries. The properties of exoplanets orbiting the components of wide binaries are compatible with those of planets orbiting single stars, except for a possible greater abundance of high-eccentricity planets. The previously suggested lack of massive planets with P > 100 days in binaries is not confirmed. Conclusions. We conclude that the presence of a stellar companion with separation smaller than 100-300 AU is able to modify the formation and/or migration and/or the dynamical evolution history of giant planets while wide companions play a more limited role.
Dynamic Ground-Holding Policies for a Network of Airports

The yearly congestion costs in the U.S. airline industry are estimated to be of the order of $2 billion. In P. B. Vranas, Dimitris J. Bertsimas, and A. R. Odoni, The multi-airport ground-holding problem in air traffic control, Operations Research , Vol. 42, pp. 249–261, 1994, we introduced and studied generic integer programming models for the static multi-airport ground-holding problem (GHP), the problem of assigning optimal ground holding delays in a general network of airports, so that the total (ground plus airborne) delay cost of all flights is minimized. The present paper is the first attempt to address the multi-airport GHP in a dynamic environment. We propose algorithms to update ground-holding decisions as time progresses and more accurate weather (hence capacity) forecasts become available. We propose several pure IP formulations (most of them 0–1), which have the important advantages of being remarkably compact while capturing the essential aspects of the problem and of being sufficiently flexible to accommodate various degrees of modeling detail. For example, one formulation allows the dynamic updating of the mix between departure and arrival capacities by modifying runway use. These formulations enable one to assign and dynamically update ground holds to a sizeable portion of the network of the major congested U.S. or European airports. We also present structural insights on the behavior of the problem by means of computational results, and we find that our methods perform much better than a heuristic which may approximate, to some extent, current ground-holding practices.
Dietary chia seed induced changes in hepatic transcription factors and their target lipogenic and oxidative enzyme activities in dyslipidaemic insulin-resistant rats

The present study analyses the effect of dietary chia seed rich in n-3 α-linolenic acid on the mechanisms underlying dyslipidaemia and liver steatosis developed in rats fed a sucrose-rich diet (SRD) for either 3 weeks or 5 months. The key hepatic enzyme activities such as fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), glucose-6-phosphate dehydrogenase (G-6-PDH), carnitine palmitoyltransferase-1 (CPT-1) and fatty acid oxidase (FAO) involved in lipid metabolism and the protein mass levels of sterol regulatory element-binding protein-1 (SREBP-1) and PPARα were studied. (1) For 3 weeks, Wistar rats were fed either a SRD with 11 % of maize oil (MO) as dietary fat or a SRD in which chia seed replaced MO (SRD+Chia). (2) A second group of rats were fed a SRD for 3 months. Afterwards, half the rats continued with the SRD while for the other half, MO was replaced by chia for 2 months (SRD+Chia). In a control group, maize starch replaced sucrose. Liver TAG and the aforementioned parameters were analysed in all groups. The replacement of MO by chia in the SRD prevented (3 weeks) or improved/normalised (5 months) increases in dyslipidaemia, liver TAG, FAS, ACC and G-6-PDH activities, and increased FAO and CPT-1 activities. Protein levels of PPARα increased, and the increased mature form of SREBP-1 protein levels in the SRD was normalised by chia in both protocols (1 and 2). The present study provides new data regarding some key mechanisms related to the fate of hepatic fatty acid metabolism that seem to be involved in the effect of dietary chia seed in preventing and normalising/improving dyslipidaemia and liver steatosis in an insulin-resistant rat model.
The Role of the Dynorphin/Kappa-opioid Receptor System and CREB in the Compulsive Behaviors Associated with Extended Access to Methamphetamine /

Psychostimulant addiction is a chronically relapsing disorder characterized by escalated drug intake and persistent drug craving, which are compulsive behavioral effects due to negative affective states experienced during withdrawal. When endogenous opioid dynorphin binds to kappa-opioid receptors (KORs) in the mesolimbic system, transmission of dopamine to the nucleus accumbens (NAc) is decreased. It is theorized that increased activity of the dynorphin/KOR system mediates the dysphoric component of psychostimulant withdrawal and thus facilitates the transition from occasional psychostimulant use to chronic dependence. This thesis examines two aspects of how upregulation of the dynorphin/KOR system drives the transition toward methamphetamine dependence. Dynorphin activates KORs, which leads to increased activity of transcription factor cyclic adenosine monophosphate response element-binding protein (CREB) within the NAc; in turn, increased CREB activity leads to expression of more dynorphin. Experiment 1 explored the relationship between elevated NAc CREB activity and the compulsive drug--taking behavior associated with extended access to methamphetamine. Immunoreactivity of phospho-CREB within the NAc core and shell was compared to access condition (1 h limited- or 6 h extended-access) and overall escalation of methamphetamine self-administration. The positive correlation between NAc phospho-CREB and methamphetamine intake implicates mesolimbic CREB activity in compulsive methamphetamine-taking behavior. Experiment 2, which examined the effects of KOR antagonist nor-Binaltorphamine (nor-BNI) on re-escalation of drug-taking and reinstatement of drug-seeking, showed that the compulsive behaviors associated with chronic methamphetamine abuse are reversible. The combined results of this thesis preliminarily identify NAc CREB as a potential therapeutic target for treatment of pre-existing methamphetamine addiction
Low-Reynolds-number swimming in a capillary tube

Abstract We use the boundary element method to study the low-Reynolds-number locomotion of a spherical model microorganism in a circular tube. The swimmer propels itself by tangential or normal surface motion in a tube whose radius is of the order of the swimmer size. Hydrodynamic interactions with the tube walls significantly affect the average swimming speed and power consumption of the model microorganism. In the case of swimming parallel to the tube axis, the locomotion speed is always reduced (respectively, increased) for swimmers with tangential (respectively, normal) deformation. In all cases, the rate of work necessary for swimming is increased by confinement. Swimmers with no force dipoles in the far field generally follow helical trajectories, solely induced by hydrodynamic interactions with the tube walls, and in qualitative agreement with recent experimental observations for Paramecium. Swimmers of the puller type always display stable locomotion at a location which depends on the strength of their force dipoles: swimmers with weak dipoles (small $\alpha $ ) swim in the centre of the tube while those with strong dipoles (large $\alpha $ ) swim near the walls. In contrast, pusher swimmers and those employing normal deformation are unstable and end up crashing into the walls of the tube. Similar dynamics is observed for swimming into a curved tube. These results could be relevant for the future design of artificial microswimmers in confined geometries.
Subverting Massive MIMO by Smart Jamming

We consider uplink transmission of a massive multiuser multiple-input multiple-output (MU-MIMO) system in the presence of a smart jammer. The jammer aims to degrade the sum spectral efficiency of the legitimate system by attacking both the training and data transmission phases. First, we derive a closed-form expression for the sum spectral efficiency by taking into account the presence of a smart jammer. Then, we determine how a jammer with a given energy budget should attack the training and data transmission phases to induce the maximum loss to the sum spectral efficiency. Numerical results illustrate the impact of optimal jamming specifically in the large limit of the number of base station (BS) antennas.
Constructing a Clinicopathologic Prognostic Model for Triple-Negative Breast Cancer

Introduction Triple-negative breast cancer (TNBC) is a unique classification of breast malignancy characterized by its lack of expression of the estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor (HER2) receptors. This phenotype accounts for approximately 15% of all invasive breast cancers and carries a particularly poor prognosis due to its biologically aggressive nature and compounded by the lack of targeted therapy available for use. There are several features of the triple-negative phenotype that have shifted our understanding TNBC as a unique entity within the breast cancer classification. Several epidemiological factors such as age, ethnicity, and body mass index (BMI) have been hypothesized to affect survival outcome in a TNBC population. Studies have demonstrated that the TNBC phenotype is a unique entity among breast cancer types showing higher rates of disease in younger women and women of African or Hispanic ancestry as well as women with higher BMI. Two clinicopathologic variables which have been investigated among a greater breast population, however deserve more investigation specifically within the triple negative (TN) histology are lymphovascular invasion (LVI) and the use of preoperative MRI. LVI is an important component in the complex process of tumor metastasis but its prognostic value for various breast cancer types remains debatable. Current literature also suggests that imaging features of TNBC differ significantly from other breast cancer Abstract
Intestinal parasitic infection among school children.

BACKGROUND Intestinal parasitosis is a major public health problem of developing countries, children being major victims. Higher prevalence has been reported among school children, mostly in hilly regions of Nepal. This study aims at assessing prevalence of intestinal parasitosis among school children of a school in a border town of Nepal and the associated factors. METHODS Fecal samples from the students were examined by direct smear technique and result was correlated with their socioeconomic status and hygienic behavior. The chi-square test was used for analytical assessment. RESULTS The prevalence rate was 13.9%, girls being highly infected (19.1%) than boys (10.3%) (P>0.05). Entamoeba histolytica (36.0%) was the commonest parasite followed by A. lumbricoides (28.0%). The highest positive rate was found among children of 5 years and less age (29.2%) and least among those above 12 years (5.3%) (P>0.05). Those from family size 5 and less than 5 were least infected (10.5%). Children of illiterate parents (16.7%) and farmers (17.1%) were more infected than literate ones and non-farmers (P>0.05). 8.7% of positive children had multi-parasitic infection. Children drinking untreated water (15.0%) were more infected than those drinking treated water (5.5%) (P>0.05). CONCLUSIONS Intestinal parasitic infection was found among 17% school children. Awareness on infectious diseases, improving hygiene, and application of supportive programs for parents to elevate socioeconomic conditions may reduce the burden of infection.
A link between the semimajor axis of extrasolar gas giant planets and stellar metallicity

The fact that most extrasolar planets found to date are orbiting metal-rich stars lends credence to the core accretion mechanism of gas giant planet formation over its competitor, the disc instability mechanism. However, the core accretion mechanism is not refined to the point of explaining orbital parameters such as the unexpected semimajor axes and eccentricities. We propose a model that correlates the metallicity of the host star with the original semimajor axis of its most massive planet, prior to migration, assuming that the core accretion scenario governs giant gas planet formation. The model predicts that the optimum regions for planetary formation shift inwards as stellar metallicity decreases, providing an explanation for the observed absence of long-period planets in metal-poor stars. We compare our predictions with the available data on extrasolar planets for stars with masses similar to the mass of the Sun. A fitting procedure produces an estimate of what we define as the zero-age planetary orbit (ZAPO) curve as a function of the metallicity of the star. The model hints that the lack of planets circling metal-poor stars may be partly caused by an enhanced destruction probability during the migration process, because the planets lie initially closer to their central star.
Modeled Full-Flight Aircraft Emissions Impacts on Air Quality and Their Sensitivity to Grid Resolution

Aviation is a unique anthropogenic source with four‐dimensional varying emissions, peaking at cruise altitudes (9–12 km). Aircraft emission budgets in the upper troposphere lower stratosphere region and their potential impacts on upper troposphere and surface air quality are not well understood. Our key objective is to use chemical transport models (with prescribed meteorology) to predict aircraft emissions impacts on the troposphere and surface air quality. We quantified the importance of including full‐flight intercontinental emissions and increased horizontal grid resolution. The full‐flight aviation emissions in the Northern Hemisphere contributed ~1.3% (mean, min–max: 0.46, 0.3–0.5 ppbv) and 0.2% (0.013, 0.004–0.02 μg/m3) of total O3 and PM2.5 concentrations at the surface, with Europe showing slightly higher impacts (1.9% (O3 0.69, 0.5–0.85 ppbv) and 0.5% (PM2.5 0.03, 0.01–0.05 μg/m3)) than North America (NA) and East Asia. We computed seasonal aviation‐attributable mass flux vertical profiles and aviation perturbations along isentropic surfaces to quantify the transport of cruise altitude emissions at the hemispheric scale. The comparison of coarse (108 × 108 km2) and fine (36 × 36 km2) grid resolutions in NA showed ~70 times and ~13 times higher aviation impacts for O3 and PM2.5 in coarser domain. These differences are mainly due to the inability of the coarse resolution simulation to capture nonlinearities in chemical processes near airport locations and other urban areas. Future global studies quantifying aircraft contributions should consider model resolution and perhaps use finer scales near major aviation source regions.
Cutaneous Leishmaniasis in dogs: is high seroprevalence indicative of a reservoir role?

SUMMARY American cutaneous leishmaniasis (ACL) is a complex disease with a rich diversity of animal host species. This diversity imposes a challenge, since understanding ACL transmission requires the adequate identification of reservoir hosts, those species able to be a source of additional infections. In this study we present results from an ACL cross-sectional serological survey of 51 dogs (Canis familiaris), where we used diagnostic tests that measure dog's exposure to Leishmania spp. parasites. We did our research in Panamá, at a village that has undergone significant ecosystem level transformations. We found an ACL seroprevalence of 47% among dogs, and their exposure was positively associated with dog age and abundance of sand fly vectors in the houses of dog owners. Using mathematical models, which were fitted to data on the proportion of positive tests as function of dog age, we estimated a basic reproductive number (R 0 ± s.e.) of 1·22 ± 0·09 that indicates the disease is endemically established in the dogs. Nevertheless, this information by itself is insufficient to incriminate dogs as ACL reservoirs, given the inability to find parasites (or their DNA) in seropositive dogs and previously reported failures to experimentally infect vectors feeding on dogs with ACL parasites.
Local geoelectrical models of the Martian subsurface for shallow groundwater detection using sounding radars

Received 15 February 2002; revised 20 July 2002; accepted 28 August 2002; published 6 March 2003. [1] Low-frequency sounding radars should be able to probe the Martian subsurface layers down to varying depths, depending on the geoelectrical properties of the sounded sites. We present in this work four frequency-dependent geoelectrical models of the Martian subsurface in the 1–20 MHz frequency band, based on laboratory electromagnetic characterization of Martian soil analogues. Those models correspond to local Martian sites that we considered to be of particular interest in the search for water using mainly the Ground-Penetrating Radar (GPR) instrument of the Netlander mission. Results and discussion are also valid for both sounding experiments MARSIS and SHARAD. The four models of the Martian subsurface are designed to represent terrains where recent fluviallike features suggest the presence of near-subsurface ground ice and probably liquid water. We performed measurements on volcanic and sedimentary materials that may be present on these sites under the appropriate geophysical conditions that may exist in those terrains. We then simulated the backscattered radar echo arising from each site in the 2 MHz frequency band, using the Finite Difference Time Domain (FDTD) algorithm, in order to evaluate the instrument performances to probe the subsurface stratigraphy of each site. Our results confirm that the near-subsurface rich iron oxide mineralogy controls the instrument performances in terms of penetration depth and signal-to-noise ratio in the 2 MHz frequency band. We finally discuss the geophysical and geoelectrical sounding conditions that could lead to an ambiguous detection of shallow subsurface water on Mars for the Netlander GPR. INDEX TERMS: 3210 Mathematical Geophysics: Modeling; 1794 History of Geophysics: Instruments and techniques; 5144 Physical Properties of Rocks: Wave attenuation; 5109 Physical Properties of Rocks: Magnetic and electrical properties; KEYWORDS: Mars, hydrology, GPR, sounding, simulation, FDTD
Coronary Ectasia In A Patient With Unstable Angina: Case Report And Literature Review

Coronary ectasia is a little common angiographic finding. Its prevalence varies between 0.3-5.3% in different series, although a recent study reports until 6.7%. Coronary ectasia is suffered mainly by males, and may be produced by different causes; however in most of the patients it seems to be related to coronary atherosclerosis. In fact, some authors consider it like a variant of the atherosclerotic disease of coronary arteries. We report the case of a 54-year-old white male who was admitted on intensive care unit because of ustable angina with electrocardiographic changes. Coronary angiography revealed severe coronary ectasia, mainly of the left main coronary artery and the proximal portion of left anterior descending artery. The greatest ectasia of the left main coronary artery that we have found in reviewed literature had 15.0 millimeters and ours sized 12.9 millimeters. Angiographic images are shown