Miracle-dz/UniFAR-FTUs huggingface dataset:
Perfect matchings in random uniform hypergraphs

Let ℋ︁k(n, p) be the random k‐uniform hypergraph on V = [n] with edge probability p. Motivated by a theorem of Erdős and Rényi 7 regarding when a random graph G(n, p) = ℋ︁2(n, p) has a perfect matching, the following conjecture may be raised. (See J. Schmidt and E. Shamir 16 for a weaker version.) Conjecture. Let k|n for fixed k ≥ 3, and the expected degree d(n, p) = p( k−1n−1 ). Then $$\hbox{Pr}[{\cal H}_k(n, p)\hbox{ has a perfect matching}] \rightarrow \left\{\matrix{0\hfill & \hbox{if }d(n, p) - \ln n \rightarrow -\infty\hfill\cr e^{-e^{-c}}\hfill & \hbox{if }d(n, p) - \ln n \rightarrow c,\hfill\cr 1\hfill & \hbox{if }d(n, p) - \ln n \rightarrow \,\infty. \hfill\cr}\right. $$ (Erdős and Rényi 7 proved this for G(n, p). ) Assuming d(n, p)/n1/2 → ∞, Schmidt and Shamir 16 were able to prove that ℋ︁k(n, p) contains a perfect matching with probability 1 − o(1). Frieze and Janson 8 showed that a weaker condition d(n, p)/n1/3 → ∞ was enough. In this paper, we further weaken the condition to $${{d(n, p)} \over {n^{1/(5+2/(k-1))}}} \rightarrow \infty. $$ A condition for a similar problem about a perfect triangle packing of G(n, p) is also obtained. A perfect triangle packing of a graph is a collection of vertex disjoint triangles whose union is the entire vertex set. Improving a condition p ≥ cn−2/3+1/15 of Krivelevich 12 , it is shown that if 3|n and p ≫ n−2/3+1/18, then $$\hbox{Pr}[G(n, p)\hbox{ has a perfect triangle packing}] = 1 - o(1). $$ © 2003 Wiley Periodicals, Inc. Random Struct. Alg. , 23: 111–132, 2003
The evolution of the mathematical research collaboration graph

We discuss some properties of the research collaboration graph for mathematicians, look at its evolution over time, and survey some random models that might produce graphs of this sort. Our approach is more experimental and statistical than theoretical. Further information is available on the Erd˝ os Number Project web site (especially the subpage The mathematics research collaboration graph C math has as its vertices all mathematicians who have published research papers. Two vertices are joined by an edge in C math if the two mathematicians have published a joint paper, with or without other coauthors. Using 60 years of data from Mathematical Reviews (MR, available electronically on the World Wide Web as MathSciNet [15]), from its beginning in 1940, we find that this graph currently has about 337,000 vertices and 496,000 edges. Traditional models of random graphs do not produce graphs that look at all like C math. For example, in C math (and similar " small world " graphs in the sense of Watts [23]) the number of vertices of a given degree is approximately proportional to a power (somewhere around −3) of the degree, whereas the traditional model gives a Poisson distribution. Recently a number of researchers in both mathematics and physics have suggested various random graph models to explain the structure and evolution of graphs like C math. In this paper we look at some details of the structure of C math. In addition to discussing the entire graph as it exists at the present time, we also study its evolution over the past 60 years. We believe that these data are interesting in their own right as a reflection of the way mathematical research gets done, apart from the mathematical questions raised about how to model and analyze social interactions. We also observe to what extent the structure of C math conforms to the predictions made by the various random graph models that have been proposed.
GROWTH RATES AND PREVALENCE OF PERKINSUS MARINUS PREVALENCE IN RESTORED OYSTER POPULATIONS IN MARYLAND

Since 1995, hatchery-produced juvenile oysters have been planted on numerous natural oyster bars in Maryland in an effort to restore degraded reefs. As part of the monitoring effort, 27 discrete hatchery plantings spanning 10 y of restoration were sampled during late summer and fall 2009. Oyster shell height, dry meat weight, shell weight, and clump height all increased significantly with age. Perkinsus marinus infections were low in all sampled populations, but increased with age. These data enable estimates of growth and shell production rates, and highlight the low prevalence of disease in restored Maryland oyster populations. The longevity of these dense patches suggests that local metapopulation restoration may provide substantial ecological services. The trends presented in this study may provide valuable insights for refining management tools, adapting ongoing restoration, and improving population modeling efforts.
The Impact of Welfare Reform on Living Arrangements

Labor market outcomes of welfare reform have been the subject of extensive research by economists, but there has been relatively little work on living arrangements, which was an important focus of reformers. Our research fills that gap by using data from the March CPS to examine the impacts of 1990s welfare waivers and the 1996 Federal welfare reform on living arrangements in samples of both children and women. Our findings suggest three main conclusions. First, welfare reform has had large effects on some important measures of living arrangements, including household size, parental co-residence among children, and marital status among women. Second, those effects are neither entirely aligned with the stated goals of reform nor entirely in spite of these goals. For example, in states that never had waivers, TANF was associated with a reduction of 14 percentage points in the fraction of Black children living in central cities who live with an unmarried parent. However, the fraction of these children living with neither parent rose by 8 percentage points, essentially doubling the baseline level. Third, there is a great deal of treatment heterogeneity both with respect to racial and ethnic groups, and with respect to whether reforms were waivers, TANF in states that had waivers, or TANF in states that did not (e.g., waiver effects on parental co-residence among Black, central-city children was much smaller than were TANF effects). Standard approaches - using only data on adult women, pooling the data across racial and ethnic groups, focusing only on high school dropouts, and/or assuming that TANF effects are the same in waiver and nonwaiver states - would generally not uncover these important changes in living arrangements.
An Improved Privacy Preserving Algorithm for Publishing Social Network Data

With the rapid growth of social networks, privacy issues have been raised for using or sharing data including user's information. Simply removing the identities of the vertices before publishing the social network data is considered an ill-advised practice due to privacy concerns, because the structure of the graph itself can reveal the identities of individuals. To mitigate this problem, a so-called graph k-degree anonymous method has been proposed in recent studies, in which the structure of the original graph is modified to ensure that there are at least k nodes having the same degree for each degree number in the modified graph. However, this approach arouses two key issues: the protecting algorithm has to be efficient especially for conducting on a great amount of graph data, and the modifications of the original graph should be minimized for keeping the data utility. To deal with these issues, we introduce a measurement for the modification cost of anonymizing a graph, and devise a novel privacy preserving algorithm for publishing social network data based on a new degree sequence partition algorithm. We conduct the algorithm on several real-world datasets. The experimental results show that the algorithm improve the performance of anonymizing the social network data and reduced the modifications of the original graph data.
Prevention of venous thromboembolism: adherence to the 1995 American College of Chest Physicians consensus guidelines for surgical patients.

BACKGROUND The American College of Chest Physicians addressed the dilemma of identifying optimal therapy for venous thromboembolism (VTE) prophylaxis and published their Fourth Consensus Conference on Antithrombotic Therapy in 1995, with recommendations for prophylactic therapy. Despite these recommendations, appropriate VTE prophylactic therapy is underused. OBJECTIVES To examine routine practices in the prevention of VTE in high-risk surgical patients and to determine the extent of adoption of grade A prophylactic therapies as recommended by the American College of Chest Physicians. METHODS Retrospective medical record review in 10 teaching or community-based hospitals located in the United States. Medical charts of 1907 patients were randomly selected for review from the population of patients who underwent high-risk major abdominal surgery, total hip replacement, hip fracture repair, or total knee replacement between January 1, 1996, and February 28, 1997. RESULTS Of 1907 patients, VTE prophylaxis was used in 89.3%; use was 93.7% in each of the 3 orthopedic surgery groups and 75.2% in the high-risk major abdominal surgery group. The percentage of patients receiving grade A therapy was highest in the hip replacement group (84.3%) vs. the other groups (knee replacement, 75.9%; hip fracture repair, 45.2%; abdominal surgery, 50.3%). CONCLUSIONS The use of grade A prophylaxis was related to the type of surgery, with the highest use seen in total hip replacement and the lowest in hip fracture repair. One in 4 patients who underwent high-risk major abdominal surgeries failed to receive any form of VTE prophylaxis. Publication of consensus statements alone may be insufficient to ensure the incorporation of important new clinical information into routine practice.
Bias in Cable News: Persuasion and Polarization

We measure the persuasive effects of slanted news and tastes for like-minded news, exploiting cable channel positions as exogenous shifters of cable news viewership. Channel positions do not correlate with demographics that predict viewership and voting, nor with local satellite viewership. We estimate that Fox News increases Republican vote shares by 0.3 points among viewers induced into watching 2.5 additional minutes per week by variation in position. We then estimate a model of voters who select into watching slanted news, and whose ideologies evolve as a result. We quantitatively assess media-driven polarization, and simulate alternative ideological slanting of news channels.
Revisiting the relationship between inflation and growth:a note on the role of exchange rate regimes

Drawing from recent advances in the classification of exchange rate regimes, this note revisits empirically the relationship between inflation and growth under alternative exchange rate regimes. The results, based on a panel of 125 industrialised and developing countries over the period 1980-2004, indicate that the costs of inflation for economic growth are significant only in the case of developing countries, and are higher for floating exchange rates than they are under fixed or intermediate regimes.
Diffusion asymptotics for linear transport with low regularity

We provide an asymptotic analysis of linear transport problems in the diffusion limit under minimal regularity assumptions on the domain, the coefficients, and the data. The weak form of the limit equation is derived and the convergence of the solution in the L 2 norm is established without artificial regularity requirements. This is important to be able to deal with problems involving realistic geometries and heterogeneous media. In a second step we prove the usual O(e) convergence rates under very mild additional assumptions. The generalization of the results to convergence in L p with p = 2 and some limitations
Social Support: Theory, Research, and Intervention

Conceptualizing Social Support Measurement of Social Support Social Support as a Transactional Process within an Ecological Context General Models of Social Support Effects on Well-Being Specific Models of Social Support Social Epidemiology and Support Support Through the Life-Cycle Social Support Interventions: Issues and Problems Social Support Interventions: Prospects Illustrative Support Interventions Social Support: Achievements and Agenda
Effect of a Specific and Selective A2B Adenosine Receptor Antagonist on Adenosine Agonist AMP and Allergen-Induced Airway Responsiveness and Cellular Influx in a Mouse Model of Asthma

It has been previously proposed that adenosine plays an important role in the pathogenesis of asthma. The proposed mechanism of action for nucleoside adenosine is to activate A2B adenosine receptors (AR) and to indirectly modulate levels of mediators in the lung. In vivo data supporting the role of A2B AR in airway reactivity and inflammation in allergic animal models are lacking. The present study describes the effects of a selective A2B AR antagonist, CVT-6883 [3-ethyl-1-propyl-8-[1-(3-trifluoromethylbenzyl)-1H-pyrazol-4-yl]-3,7-dihydropurine-2,6-dione], on airway reactivity and inflammation in an allergic mouse model of asthma. Mice were sensitized with ragweed (i.p.) on days 1 and 6 and challenged with 0.5% ragweed on days 11, 12, and 13. On day 14, airway reactivity to 5′-N-ethylcarboxamidoadenosine (NECA), AMP, or allergen challenge was measured in terms of enhanced pause (Penh). Aerosolized NECA elicited concentration-dependent increases in Penh, which were significantly attenuated by CVT-6883 (0.4, 1.0, or 2.5 mg/kg i.p.). Aerosolized AMP elicited significant increases in Penh in sensitized mice, and the effect was significantly attenuated by either CVT-6883 (1 mg/kg i.p.) or montelukast (1 mg/kg i.p.). Allergen challenge induced late allergic response in sensitized mice, which was inhibited by CVT-6883 (1 mg/kg i.p.). Allergen challenge also increased the number of cells in bronchoalveolar lavage fluid obtained from sensitized mice, and that was reduced by either CVT-6883 (6 mg/ml aerosolization for 5 min) or theophylline (36 mg/ml aerosolization for 5 min). These results suggest that A2BAR antagonism plays an important role in inhibition of airway reactivity and inflammation in this model of allergic asthma.
Modular Theory, Non-Commutative Geometry and Quantum Gravity ?

This paper contains the first written exposition of some ideas (announced in a previous survey) on an approach to quantum gravity based on Tomita-Takesaki modular theory and A. Connes non-commutative geometry aiming at the reconstruction of spec- tral geometries from an operational formalism of states and categories of observables in a covariant theory. Care has been taken to provide a coverage of the relevant background on modular theory, its applications in non-commutative geometry and physics and to the detailed discussion of the main foundational issues raised by the proposal.
Thickness of ventromedial prefrontal cortex in humans is correlated with extinction memory.

The ventromedial prefrontal cortex (vmPFC) has been implicated in fear extinction [Phelps, E. A. , Delgado, M. R. , Nearing, K. I. & Ledoux, J. E. (2004) Neuron 43, 897-905; Herry, C. & Garcia, R. (2003) Behav. Brain Res. 146, 89-96]. Here, we test the hypothesis that the cortical thickness of vmPFC regions is associated with how well healthy humans retain their extinction memory a day after having been conditioned and then extinguished. Fourteen participants underwent a 2-day fear conditioning and extinction protocol. The conditioned stimuli (CSs) were pictures of virtual lights, and the unconditioned stimulus (US) was an electric shock. On day 1, participants received 5 CS+US pairings (conditioning), followed by 10 CS trials with no US (extinction). On day 2, the CS was presented alone to test for extinction memory. Skin conductance response (SCR) was the behavioral index of conditioning and extinction. Participants underwent MRI scans to obtain structural images, from which cortical thickness was measured. We performed a vertex-based analysis across the entire cortical surface and a region-of-interest analysis of a priori hypothesized territories to measure cortical thickness and map correlations between this measure and SCR. We found significant, direct correlation between thickness of the vmPFC, specifically medial orbitofrontal cortex, and extinction retention. That is, thicker medial orbitofrontal cortex was associated with lower SCR to the conditioned stimulus during extinction recall (i.e., greater extinction memory). These results suggest that the size of the vmPFC might explain individual differences in the ability to modulate fear among humans.
First Mover Advantages, Blockaded Entry, and the Economics of Uneven Development

A two-sector, two-period trade model is developed in which one sector has increasing returns based on the creation of specialized intermediate inputs. One of the two (otherwise identical) countries is not able to enter the increasing returns sector in the first period through some "accident of history". A theoretical and numerical analysis solves for parameter regimes under which firms in the disadvantaged country are or are not able to enter the increasing returns sector in the second period. The welfare consequences of the two alternative second period outcomes are compared to one another and to an equilibrium with both countries entering in the first period. The disadvantaged country may fall further behind in the second period even when its firms are able to enter.
Happiness and Myopia : Evidence from a Random-Assignment Experiment

Myopia—time preference—has been shown to be commonplace and is believed to lead to a series of negative outcomes, such as overconsumption and addiction. Yet, little is known about the determinants of myopia. Using a random-assignment experiment, we investigate whether happiness decreases myopia. Subjects are randomly assigned to receive a happyor neutral-affect inducement. Immediately following the inducement, we measure their myopia using a 30 question instrument. The results indicate that the happy-affect inducement significantly decreases myopia. The findings are robust to various specifications checks. Finally, our results re-confirm the ubiquity of myopia and start to explore its determinants. (JEL D01, D90, D60)
Evaluation of the Moderate Resolution Imaging Spectroradiometer aerosol products at two Aerosol Robotic Network stations in China

[1] Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products have been used to address aerosol climatic issues in many parts of the world, but their quality has yet to be determined over China. This paper presents a thorough evaluation of aerosol optical depth (AOD) data retrieved from MODIS collections 4 (C004) and 5 (C005) at two AERONET sites in northern and southeastern China. Established under the aegis of the East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST-AIRE) project, the two sites, Xianghe and Taihu, have distinct ecosystems and climate regimes, resulting in differences in retrieval performance. At the rural northeastern site (Xianghe), MODIS C004 retrievals generally overestimate AOD at 550 nm during clean days, with the largest errors occurring during winter. In the warm and humid regions of southeastern China (Taihu), MODIS C004 retrievals overestimate AOD throughout the year. The systematic error at Xianghe is primarily due to the fixed surface reflectance ratio, while as the error at Taihu is mainly caused by the choice of the single scattering albedo (SSA) for the fine model aerosols. Both problems are alleviated considerably in the C005. The comparisons between C005 retrievals and AERONET data show much higher correlation coefficient, lower offset and a slope closer to unity. Also, the variability of AOD retrieval among neighboring pixels is reduced by several factors. The strong overestimation problem at small AOD values was fixed by using dynamic reflectance ratios that vary with the vegetation index and scattering angle. However, significant uncertainties remain because of the use of highly simplified aerosol models.
Differences in Patient Outcomes of Prevalence, Interval, and Screen-Detected Lung Cancers in the CT Arm of the National Lung Screening Trial

Lung cancer screening identifies cancers with heterogeneous behaviors. Some lung cancers will be identified among patients who had prior negative CT screens and upon follow-up scans develop a de novo nodule that was determined to be cancerous. Other lung cancers will be identified among patients who had one or more prior stable positive scans that were not determined to be lung cancer (indeterminate pulmonary nodules), but in follow-up scans was diagnosed with an incidence lung cancer. Using data from the CT arm of the National Lung Screening Trial, this analysis investigated differences in patient characteristics and survival endpoints between prevalence-, interval-, and screen-detected lung cancers, characterized based on sequence of screening results. Lung cancers immediately following a positive baseline (T0), and prior to the T1 screen, formed the prevalence cohort. Interval cancers were diagnosed following a negative screen at any time point prior to the next screening round. Two cohorts of screen-detected lung cancers (SDLC) were identified that had a baseline positive screen that was that was not determined to be lung cancer (i.e., an indeterminate pulmonary nodule), but in follow-up scans was diagnosed with an incidence lung cancer 12 (SDLC1) or 24 (SDLC2) months later. Two other incidence cohorts had screen-detected lung cancers that had baseline negative screen and upon follow-up scans developed a de novo nodule determined to be cancerous at 12 (SDLC3) or 24 (SDLC4) months later. Differences in patient characteristics, progression-free survival (PFS), and overall survival (OS) were assessed. The lung cancer-specific death rate was higher for SDLC3/SDLC4 compared to SDLC1/SDLC2 lung cancers (136.6/1,000 person-years vs. 71.3/1,000 person-years, P < 0.001). Moreover, PFS and OS were significantly lower for SDLC3/SDLC4 compared to SDLC1/SDLC2 (P < 0.004; P < 0.002, respectively). The findings were consistent when stratified by stage and histology. Multivariable Cox proportional models revealed that the SDLC3/SDLC4 case groups were associated with significantly poorer PFS (HR = 1.89; 95% CI 1.31–2.74) and OS (HR = 1.80; 95% CI 1.21–2.67) compared to SDLC1/SDLC2 lung cancers (HR = 1.00). Lung cancer patients who develop a de novo nodule that determined to be cancerous (i.e., at least one negative CT screen prior to cancer diagnosis) had poorer survival outcomes compared to patients who had at least one positive screen prior to cancer diagnosis. As such, the observation that de novo screen-detected are associated with poorer survival could be attributed to faster growing, more aggressive cancers that arose from a lung environment previously lacking focal abnormalities.
Daily Stressors, War Experiences, and Mental Health in Afghanistan

Working in Afghanistan's capital city of Kabul, the authors assessed the relative contribution of daily stressors and war-related experiences of violence and loss to levels of depression, PTSD, impaired functioning, and a culturally specific measure of general psychological distress. For women, daily stressors were a better predictor than war experiences of all mental health outcomes except for PTSD; for men, daily stressors were a better predictor of depression and functional impairment, while war experiences and daily stressors were similarly predictive of general distress. For men, daily stressors moderated the relationship between war experiences and PTSD, which was significant only under conditions of low daily stress. The study's implications for research and intervention in conflict and post-conflict settings are considered.