cssi/SciSciGPT-SciSciNet huggingface dataset:
Financial Constraints and Girls' Secondary Education: Evidence from School Fee Elimination in The Gambia

This study analyzes the impact of large-scale fee elimination for secondary school girls in The Gambia on the quantity, composition, and achievement of students. The gradual rollout of the program across geographic regions provides identifying variation in the policy. The program increased the number of girls taking the high school exit exam by 55 percent. The share of older test takers increased in poorer districts, expanding access for students who began school late, repeated grades, or whose studies had been interrupted. Despite these changes in the quantity and composition of students, there are robustly positive point estimates of the program on test scores, with suggestive evidence of gains for several subgroups of both girls and boys. Absence of learning declines is notable in a setting where expanded access could strain limited resources and reduce school quality. The findings suggest that financial constraints remain serious barriers to post-primary education, and that efforts to expand access to secondary education need not come at the expense of learning in low-income countries like The Gambia.
Detecting Intervention Effects in a Cluster-Randomized Design Using Multilevel Structural Equation Modeling for Binary Responses

Multilevel modeling (MLM) is frequently used to detect group differences, such as an intervention effect in a pre-test-post-test cluster-randomized design. Group differences on the post-test scores are detected by controlling for pre-test scores as a proxy variable for unobserved factors that predict future attributes. The pre-test and post-test scores that are most often used in MLM are summed item responses (or total scores). In prior research, there have been concerns regarding measurement error in the use of total scores in using MLM. To correct for measurement error in the covariate and outcome, a theoretical justification for the use of multilevel structural equation modeling (MSEM) has been established. However, MSEM for binary responses has not been widely applied to detect intervention effects (group differences) in intervention studies. In this article, the use of MSEM for intervention studies is demonstrated and the performance of MSEM is evaluated via a simulation study. Furthermore, the consequences of using MLM instead of MSEM are shown in detecting group differences. Results of the simulation study showed that MSEM performed adequately as the number of clusters, cluster size, and intraclass correlation increased and outperformed MLM for the detection of group differences.
Noisy Stochastic Games

This paper establishes existence of a stationary Markov perfect equilibrium in general stochastic games with noise—a component of the state that is nonatomically distributed and not directly affected by the previous period's state and actions. Noise may be simply a payoff-irrelevant public randomization device, delivering known results on the existence of correlated equilibrium as a special case. More generally, noise can take the form of shocks that enter into players' stage payoffs and the transition probability on states. The existence result is applied to a model of industry dynamics and to a model of dynamic electoral competition.
Child sexual abuse

Multiple obstacles can hinder the medical evaluation of suspected child sexual abuse in pediatric primary care. The need for diagnostic accuracy is high. Knowledge of sexual abuse risk factors, an understanding of the victimization process, and awareness of the varied clinical presentations of sexual abuse can be of assistance. Open-ended questioning of the suspected victim is the most critical component of the evaluation. Skillful medical interviewing requires time, training, patience, and practice. Pediatricians lacking any of these four requirements should defer interviewing in sexual abuse cases to other professionals. Abnormal physical findings from sexual abuse are uncommon. Colposcopy has assisted pediatricians greatly in reaching consensus regarding diagnostic physical findings. Cases of acute sexual assault require familiarity with the forensic rape examination, STD screening and prophylaxis, and pregnancy prevention. Victimization from sexual abuse continues long after the abusive acts end, often requiring long-term therapeutic intervention. An emerging standard of care for medical evaluations of suspected child sexual abuse recognizes the requirement for patience and compassion while retaining objectivity. The pediatrician's primary concern must be for the child's physical and emotional well-being.
The Punishment Consequences of Lacking National Membership in Germany, 1998–2010

The comparative study of immigrants’ legal rights has become a key focus of sociological inquiry in recent decades. However, research in this vein has focused primarily on the highest levels of European judiciaries. As a result, we know comparatively little about the implementation of immigrant rights in the lower courts that are charged with enforcing the legal protections of foreigners. Using prosecution data from German criminal courts between 1998 and 2010, this study addresses this gap by investigating (1) the punishment consequences of lacking national membership; (2) sentencing differences between EU and non-EU immigrants; and (3) how the punishment of noncitizens has changed over time. The findings suggest that foreigners punished in German courts receive harsher penalties than comparable German citizens. This punishment gap is observed for both EU and non-EU immigrants; however, there is clear evidence that the punishment gap between German and non-German citizens has waned over the past decade. Taken together, these findings inform ongoing debates on the continued significance of national membership in Western societies and have important implications for understanding contemporary trends in sociolegal inequality.
Depression treatment and health-related quality of life among adults with diabetes and depression.

Previous findings regarding depression treatment and its consequences on health-related quality of life (HRQoL) of adults with diabetes were inconsistent and targeted certain groups of population. Therefore, there is a critical need to conduct a population-based study that focuses on a general population with diabetes and depression. The primary aim of this study was to examine the physical and mental HRQoL associated with depression treatment during the follow-up year. We adopted a longitudinal design using multiple panels (2005–2011) of the Medical Expenditure Panel Survey to create a baseline year and follow-up year. We included adults with diabetes and depression. We categorized the baseline depression treatment into: (1) antidepressant use only; (2) psychotherapy with or without antidepressants; and (3) no treatment. HRQOL was measured using SF-12 version 2 physical component summary (PCS) and SF-12 mental component summary (MCS) scores during both baseline year and follow-up year. Ordinary least squares (OLS) were used to estimate the association between depression treatment and the HRQoL measures. The OLS regression controlled for predisposing, enabling, need, external environment factors, personal health practices, and baseline HRQoL measures. After controlling for all the independent variables and the baseline PCS, individuals who received psychotherapy with or without antidepressants had higher PCS scores as compared to those without any treatment for depression (beta = 1.28, p < 0.001). Individuals who reported using only antidepressants had lower PCS scores (beta = −0.54, p < 0.001) as compared to those without depression treatment. On the contrary, individuals who reported receiving psychotherapy with or without antidepressants had lower MCS scores as compared to those without depression treatment (beta = −1.43, p < 0.001). Those using only antidepressants had higher MCS scores as compared to those without depression treatment (beta = 0.56, p < 0.001). The associations between depression treatment and the HRQoL varied by the type of depression treatment and the component of the HRQoL measures.
Space–Time Patterns of Rank Concordance: Local Indicators of Mobility Association with Application to Spatial Income Inequality Dynamics

In the study of income inequality dynamics, the concept of exchange mobility plays a central role. Applications of classical rank correlation statistics have been used to assess the degree to which individual economies swap positions in the income distribution over time. These classic measures ignore the underlying geographical pattern of rank changes. Rey (2004) introduced a spatial concordance statistic as an extension of Kendall's rank correlation statistic, a commonly employed measure of exchange mobility. This article suggests local forms of the global spatial concordance statistic: local indicators of mobility association (LIMA). The LIMA statistics allow for the decomposition of the global measure into the contributions associated with individual locations. They do so by considering the degree of concordance (stability) or discordance (exchange mobility) reflected within an economy's local spatial context. Different forms of the LIMAs derive from alternative expressions of the neighborhood and neig...
Avoidance and Mitigation of Public Harm

This paper studies the optimal design of a liability sharing arrangement as an infinitely repeated game. We construct a schematic, non-cooperative, 2-player model where an active agent can take a costly, unobservable action to try to avert a crisis, and then when a crisis occurs, both agents decide how much to contribute mitigating it. The model is able to generate any combination of avoidance/mitigation patterns as static Nash equilibrium. We then consider perfect public equilibrium (PPE) of the infinitely repeated game. When the avoidance cost is higher than the expected loss of crisis for the active agent, the first best is not a static Nash equilibrium of the stage game and cannot be implemented as a PPE of the repeated game. For this case we find a PPE that dominates the repetition of the static Nash. At this equilibrium, the frequency of the active agent taking the costly avoidance action is endogenously determined, hence the equilibrium crisis rate is also endogenously determined. In the period when no action is taken and crisis occurs, the passive agent "bails out" the active agent by paying more than his share of the mitigation cost.
Soldered contact effect on wire array Z-pinches

Experiments are conducted on the 16-wire aluminum Z-pinch arrays with both slow and fast risetimes wherein the initiation, ablation, implosion, and stagnation phases are compared for both soldered and unsoldered arrays. Time-dependent X-ray signals and self-emission data are measured and collected using a XUV 4-frame camera and an optical streak camera. Results show that in negative polarity, soldering appeared to produce a smaller radius pinch and improve X-ray yield variability in properly massed arrays.
E-cigarette use among US adolescents: secondhand smoke at home matters

Objectives To examine the association of family smoking status and exposure to secondhand smoke (SHS) at home with the use of electronic cigarettes among US adolescents, in particular the medication effect of SHS on the association between family smoking status and electronic cigarette use.
Welfare reform and immigrant fertility

Immigration policy is at the forefront of US policy discussions, and the use of welfare benefits by immigrants has been hotly debated. In 1996, Congress enacted welfare reform legislation, which imposed strict restrictions on welfare eligibility for noncitizens. However, a number of states restored access to welfare benefits to immigrants that had been cut out in the federal welfare reform law. Using data from the Current Population Survey, we examine whether immigrant women adjusted their childbearing in response to changes in the generosity of welfare benefits at the state-level. We find that noncitizen women reduced their fertility in response to cutbacks imposed by the legislation. Our findings, which prove robust to a number of identification and robustness checks, underscore how immigrants respond to state-level policies and provide insight into the potential impacts of comprehensive immigration reform, particularly the components related to the path to citizenship and access to public benefits.
The Impact of Innovation in the Multinational Firm

What is the private return to innovation? When firms operate production sites in multiple countries, improvements developed at one site may be shared across others for efficiency gain. We develop a dynamic model that explicitly accounts for such transfer within the firm, and apply it to measure innovation returns for a comprehensive panel of U.S. multinationals during 1989--2009. We find that the data, which include detailed measures of affiliate production and innovation, are consistent with innovation generating returns at firm locations beyond the innovating site. Accounting for cross-plant effects of innovation, our estimates indicate the average firm realizes between 10 and 30 percent of the return to its U.S. parent R&D abroad, suggesting single-plant estimates may understate firms' gain from innovation.
Laser-assisted oxidation of multi-layer tungsten diselenide nanosheets

We report the structural and electrical characterization of tungsten oxides formed by illuminating multi-layer tungsten diselenide (WSe2) nanosheets with an intense laser beam in the ambient environment. A noninvasive microwave impedance microscope (MIM) was used to perform electrical imaging of the samples. The local conductivity ∼102 S/m of the oxidized product, measured by the MIM and conventional transport experiments, is much higher than that of the pristine WSe2, suggesting the formation of sub-stoichiometric WO3-x polycrystals with n-type carriers. With further efforts to improve the conductivity of the oxides, the laser-assisted oxidation process may be useful for patterning conductive features on WSe2 or forming electrical contacts to various transition metal dichalcogenides.
Mean Field Equilibria for Competitive Exploration in Resource Sharing Settings

We consider a model of nomadic agents exploring and competing for time-varying location-specific resources, arising in crowdsourced transportation services, online communities, and in traditional location-based economic activity. This model comprises a group of agents, and a set of locations each endowed with a dynamic stochastic resource process. Each agent derives a periodic reward determined by the overall resource level at her location, and the number of other agents there. Each agent is strategic and free to move between locations, and at each time decides whether to stay at the same node or switch to another one. We study the equilibrium behavior of the agents as a function of dynamics of the stochastic resource process and the nature of the externality each agent imposes on others at the same location. In the asymptotic limit with the number of agents and locations increasing proportionally, we show that an equilibrium exists and has a threshold structure, where each agent decides to switch to a different location based only on their current location's resource level and the number of other agents at that location. This result provides insight into how system structure affects the agents' collective ability to explore their domain to find and effectively utilize resource-rich areas. It also allows assessing the impact of changing the reward structure through penalties or subsidies.
Factors Influencing Adoption of VSH Queens in the Honey Bee Breeding Industry

The Varroa mite is a threat to honey bees and beekeepers across the U.S. and is suspected to be one contributor to colony collapse disorder (CCD). In 2006, Varroa Sensitive Hygiene (VSH) bees were developed in response to this problem in the beekeeping industry. The hygienic behavior of VSH bees helps reduce susceptibility of colonies to Varroa mites, results in stronger colonies and decrease susceptibility to CCD. The objective of this paper is to identify factors that significantly influence the adoption of VSH technology. A probit model is used to identify factors these factors. Results indicate risk aversion, education and income significantly influence adoption decision.
Testing for Complementarity: Glyphosate Tolerant Soybeans and Conservation Tillage

Many decisions in agriculture are made over combinations of inputs and/or practices that may form a technology system linked through complementarity. The presence of complementarity among producer decisions can have far-reaching implications for market outcomes and for the effectiveness of policies intended to influence them. Identifying complementarity relations, however, is made difficult by the presence of unobserved heterogeneity. Drawing on recent methodological advances, in this paper we develop a test for complementarity between glyphosate tolerant soybeans and conservation tillage that overcomes certain limitations of previous studies. Specifically, we develop a structural discrete choice framework of joint soybean-tillage adoption that explicitly models both complementarity and the correlation induced by unobserved heterogeneity. The model is estimated with a large unbalanced panel of farm-level choices spanning the 1998–2011 period. We find that glyphosate tolerant soybeans and conservation tillage are complementary practices. In addition, our estimation shows that farm operation scale promotes the adoption of both conservation tillage and glyphosate tolerant seed, and that all of higher fuel prices, more droughty conditions, and soil erodibility increase use of conservation tillage. We apply our results to simulate annual adoption rates for both conservation tillage and no-tillage in a scenario without glyphosate tolerant soybeans available as a choice. We find that the adoption of conservation tillage and no-tillage have been about 10% and 20% higher, respectively, due to the advent of glyphosate tolerant soybeans.
Diastereoselective synthesis of vicinal tertiary and N -substituted quaternary stereogenic centers by catalytic hydroalkylation of dienes

An efficient and diastereoselective (CDC)–Rh-catalyzed hydroalkylation of dienes with 1,3-oxazol-5(4H)-ones is reported. Aryl and alkyl substituted dienes are converted to α,α-substituted oxazolones (24 examples) by the formation of N-substituted quaternary carbon stereogenic centers in good yields (up to 96%) and with high diastereoselectivity (>20 : 1 dr). The reaction is tolerant of a range of dienes and oxazolones bearing various functional groups. Utility of the oxazolone products is illustrated through hydrolysis to form α,β-substituted α-amino acid analogues and stereoselective epoxidation of the resultant alkene to create four contiguous stereocenters.
A Theory of Rational Demand for Index Insurance

Abstract Rational demand for index insurance products is shown to be fundamentally different to that for indemnity insurance products due to the presence of basis risk. In particular, optimal demand is zero for infinitely risk-averse individuals, and is nonmonotonic in risk aversion, wealth, and price. For a given belief, upper bounds are derived for the optimal demand from risk-averse and decreasing absolute risk-averse decision makers. A simple ratio for monitoring basis risk is presented and applied to explain the low level of demand for consumer hedging instruments as a rational response to deadweight costs and basis risk. (JEL D14, D81, G13, G22, Q14)
Online Budgeted Allocation with General Budgets

We study the online budgeted allocation (also called Adwords) problem, where a set of impressions arriving online are allocated to a set of budget-constrained advertisers to maximize revenue. Motivated by connections to Internet advertising, several variants of this problem have been studied since the seminal work of Mehta, Saberi, Vazirani, and Vazirani (FOCS 2005). However, this entire body of work focuses on a single budget for every advertising campaign, whereas in order to fully represent the actual agenda of an advertiser, an advertising budget should be expressible over multiple tiers of user-attribute granularity. A simple example is an advertising campaign that is constrained by an overall budget but is also accompanied by a set of sub-budgets for each target demographic. In such a contract scheme, an advertiser can specify their true user-targeting goals, allowing the publisher to fulfill them through relevant allocations. In this paper, we give a complete characterization of the Adwords problem for general advertising budgets. In the most general setting, we show that, unlike in the single-budget Adwords problem, obtaining a constant competitive ratio is impossible and give asymptotically tight upper and lower bounds. However for our main result, we observe that in many real-world scenarios (as in the above example), multi-tier budgets have a laminar structure, since most relevant consumer or product classifications are hierarchical. For laminar budgets, we obtain a competitive ratio of e/(e-1) in the small bids case, which matches the best known Adwords result for single budgets. Our algorithm has a primal-dual structure and generalizes the primal-dual analysis for single-budget Adwords first given by Buchbinder, Jain, and Naor (ESA 2007). However many new ideas are required to overcome the barriers introduced by laminar budgets---our algorithm uses a novel formulation that overcomes non-monotonicity in the syntactically defined dual variables, as well as a dynamically maintained labeling scheme that tracks the ``most-limiting" budgets in the hierarchy.
Learning, Confidence, and Business Cycles

Abstract We argue that information accumulation provides a quantitatively successful propagation mechanism that challenges and empirically improves on the conventional New Keynesian models with many nominal and real rigidities. In particular, we build a tractable heterogeneous-firm business cycle model where firms face Knightian uncertainty about their profitability and learn it through production. The feedback between uncertainty and economic activity maps fundamental shocks into an as if procyclical equilibrium confidence process, generating co-movement driven by demand shocks, amplified and hump-shaped dynamics, countercyclical correlated wedges in the equilibrium conditions for labor, risk-free and risky assets, and countercyclical firm-level and aggregate dispersion of forecasts.
Stress-Strain Equation for Rubber in Tension

A stress‐strain equation is derived for a homogeneous, isotropic material with the assumptions that for any given homogeneous simple tensile strain, the components of the stress tensor are to the first approximation linear, homogeneous functions of the components of the strain tensor and that no volume change occurs during the deformation. Utilizing the dependence of Poisson's ratio upon the extension referred to the initial coordinates, one elastic coefficient, C12, is found to be sufficient to roughly characterize the first stretch stress‐strain curve. Although experimentally this elastic coefficient is found to be essentially constant for extensions greater than 250% its value increases rapidly as zero extension is approached. This behavior agrees qualitatively with data by Blanchard and Parkinson as to the distribution of secondary bond strengths, wherein they found a large number of relatively low‐energy bonds which would be effective only at small extensions in contributing to modulus reinforcement. Various aspects of stress strain and cure behavior are examined with the derived equation as a basis.
Mild Copper-Mediated Fluorination of Aryl Stannanes and Aryl Trifluoroborates

This communication describes a mild copper-mediated fluorination of aryl stannanes and aryl trifluoroborates with N-fluoro-2,4,6-trimethylpyridinium triflate. This protocol demonstrates broad substrate scope and functional group tolerance, and does not require the use of any noble metal additives. The reaction is proposed to proceed via an arylcopper(III) fluoride intermediate.
Object Boundary Guided Semantic Segmentation

Semantic segmentation is critical to image content understanding and object localization. Recent development in fully-convolutional neural network (FCN) has enabled accurate pixel-level labeling. One issue in previous works is that the FCN based method does not exploit the object boundary information to delineate segmentation details since the object boundary label is ignored in the network training. To tackle this problem, we introduce a double branch fully convolutional neural network, which separates the learning of the desirable semantic class labeling with mask-level object proposals guided by relabeled boundaries. This network, called object boundary guided FCN (OBG-FCN), is able to integrate the distinct properties of object shape and class features elegantly in a fully convolutional way with a designed masking architecture. We conduct experiments on the PASCAL VOC segmentation benchmark, and show that the end-to-end trainable OBG-FCN system offers great improvement in optimizing the target semantic segmentation quality.
Peptic ulcer disease in children

Primary duodenal ulcer disease occurs in children of all ages, but is most often seen in those over 10 years. As in the adult, it often pursues a chronic course. Primary gastric ulcer is seen in children under 6 years, is more unusual, and does not tend to recur. Stress ulcers are seen most often in infants and in critically ill children and are asymptomatic until the complications of hemorrhage or perforation appear. Drug-related ulcers are being seen more frequently as the use of nonsteroidal anti-inflammatory agents increases. With the use of new therapeutic agents, management has been simplified and surgical intervention has become a rarity. Helicobacter pylori is now a recognized cause of antral gastritis and ulceration in the child.
Target financial reporting quality and M&A deals that go bust*

This study investigates the role of financial reporting quality in merger and acquisition (M&A) deals that are ultimately terminated (i.e., go bust). If a target is a U.S. publicly traded company, an acquirer’s initial assessment of the potential benefits associated with the acquisition of the company is based on publicly available information. Generally, the acquirer obtains limited private information from the target prior to announcing the deal, but engages in transactional due diligence after signing the acquisition agreement to affirm that the financial reporting warranties made by the target are accurate. We construct a low-quality financial reporting score based on measures prior research identifies as being associated with less reliable, less relevant, and less precise financial reporting. We find that acquirers offer higher premiums for targets with low-quality financial reporting. However, we also find that low-quality financial reporting increases the likelihood of deal renegotiation, and contributes to the probability of deals going bust. We document that failed targets are more likely to restate their financial statements after the announcement of the deal, supporting our conjecture that low-quality financial reporting contributes to deals being terminated. Our research develops a new measure of low-quality financial reporting, documents that the measure is related to M&A deal outcomes and financial restatements, and provides insights into the consequences of M&A transactional due diligence.
Rapid synthesis of 3,3' bis-arylated BINOL derivatives using a C-H borylation in situ Suzuki-Miyaura coupling sequence.

The increased interest in BINOL derived catalysts for asymmetric transformations has encouraged us to disclose a rapid and scalable method of preparing 3,3′ bis-arylated BINOL derivatives 1 using a one-pot CH borylation/Suzuki–Miyaura coupling sequence. The use of an aldehyde additive was found to be crucial to the success of this in situ tandem approach. This method was applied to the preparation of 10 BINOL derivatives, each completed within 24 h. Notably, this approach requires only a single purification step.
Thirty Years of Change in Subalpine Forest Cover from Landsat Image Analysis in the Sierra Nevada Mountains of California

Landsat imagery was analyzed to understand changes in subalpine forest stands since the mid-1980s in the Sierra-Nevada region of California. At locations where long-term plot measurements have shown that stands are becoming denser in the number of small tree stems (compared to the early 1930s), the 30-year analysis of Landsat greenness index (NDVI) indicated that no consistent increases in canopy leaf cover have occurred at these same locations since the mid-1980s. Interannual variations in stand NDVI closely followed snow accumulation amounts recorded at nearby stations. In contrast, at eastern Sierra whitebark pine stand locations where it has been observed that widespread tree mortality has occurred, decreasing NDVI trends over the past 5-10 years were consistent with rapid loss of forest canopy cover. Landsat imagery was further analyzed to understand patterns of post-wildfire vegetation recovery, focusing on high burn severity (HBS) patches within burned areas dating from the late 1940s. Analysis of landscape metrics showed that the percentage of total HBS area comprised by the largest patch of recovered woody cover was relatively small in all fires that occurred since 1995, but increased rapidly with time since fire. Patch complexity of recovered woody cover decreased notably after more than 50 years of regrowth, but was not readily associated with time for fires that occurred since the mid 1990s. The aggregation level of patches with recovery of woody cover increased steadily with time since fire. The study approach using satellite remote sensing can be expanded to assess the consequences of stand-replacing wildfires in all forests of the region.
Financing Sustainable Development - What can we learn from the Australian experience of reform?

Finance is fundamental to supporting sustainable development. It drives investment and jobs, which is the way most people escape poverty. Countries in the developing world face significant financing needs as they seek to modernize their economies, hence the importance of mobilizing all forms of finance (domestic, international, public and private) and ensuring they are put to their most effective use.
Acid catalyzed condensation of levulinic acid with glyoxylic acid: synthesis of 1-methyl-2,8-dioxabicyclo[3.3.0]oct-4-ene-3,7-dione

Abstract The sulfuric acid catalyzed condensation of levulinic acid with glyoxylic acid at 80 °C, for 24 h under neat conditions gives 1-methyl-2,8-dioxabicyclo[3.3.0]oct-4-ene-3,7-dione in 92% yield. Catalytic reduction of this unsaturated bis-lactone provides a facile route to produce polyester monomer 1-methyl-2,8-dioxabicyclo[3.3.0]octane-3,7-dione from renewable feedstocks.
Scalable Betweenness Centrality Maximization via Sampling

Betweenness centrality (BWC) is a fundamental centrality measure in social network analysis. Given a large-scale network, how can we find the most central nodes? This question is of great importance to many key applications that rely on BWC, including community detection and understanding graph vulnerability. Despite the large amount of work on scalable approximation algorithm design for BWC, estimating BWC on large-scale networks remains a computational challenge. In this paper, we study the Centrality Maximization problem (CMP): given a graph G = (V,E) and a positive integer k, find a set S* ⊆ V that maximizes BWC subject to the cardinality constraint |S*| ≤ k. We present an efficient randomized algorithm that provides a (1 -- 1/e -- e)-approximation with high probability, where e > 0. Our results improve the current state-of-the-art result [40]. Furthermore, we provide the first theoretical evidence for the validity of a crucial assumption in betweenness centrality estimation, namely that in real-world networks O(|V|2) shortest paths pass through the top-k central nodes, where k is a constant. This also explains why our algorithm runs in near linear time on real-world networks. We also show that our algorithm and analysis can be applied to a wider range of centrality measures, by providing a general analytical framework. On the experimental side, we perform an extensive experimental analysis of our method on real-world networks, demonstrate its accuracy and scalability, and study different properties of central nodes. Then, we compare the sampling method used by the state-of-the-art algorithm with our method. Furthermore, we perform a study of BWC in time evolving networks, and see how the centrality of the central nodes in the graphs changes over time. Finally, we compare the performance of the stochastic Kronecker model [28] to real data, and observe that it generates a similar growth pattern.
Graph Orientations and Linear Extensions

Given an underlying undirected simple graph, we consider the set of its acyclic orientations. Each of these orientations induces a partial order on the vertices of our graph and, therefore, we can count the number of linear extensions of these posets. We want to know which choice of orientation maximizes the number of linear extensions of the corresponding poset, and this problem will be solved essentially for comparability graphs and odd cycles, presenting several proofs. The corresponding enumeration problem for arbitrary simple graphs will be studied, including the case of random graphs; this will culminate in (1) new bounds for the volume of the stable set polytope and (2) strong concentration results for our enumerative statistic and for the graph entropy, which hold true a.s. for random graphs. We will then argue that our problem springs up naturally in the theory of graphical arrangements and graphical zonotopes.
Synthesis of strontium ferrite/iron oxide exchange coupled nano-powders with improved energy product for rare earth free permanent magnet applications

We present a simple, scalable synthesis route for producing exchange coupled soft/hard magnetic composite powder that outperforms pure soft and hard phase constituents. Importantly, the composites are iron oxide based (SrFe12O19 and Fe3O4) and contain no rare earth or precious metals. The two step synthesis process consists of first precipitating an iron oxide/hydroxide precursor directly on top of SrFe12O19 nano-flakes, ensuring a very fine degree of mixing between the hard and the soft magnetic phases. The second step involves the reduction of the precursor to create the appropriate soft magnetic phase and create the intimate interface necessary for exchange coupling. We establish a clear processing window; at temperatures below this window the desired soft phase is not produced, while the use of higher temperatures results in deleterious reaction at the soft/hard phase interfaces, causing an improper ratio of soft to hard phases. Improvements in Mr, Ms, and (BH)max are 42%, 29% and 37%, respectively, in the SrFe12O19/Fe3O4 composite compared to the pure hard phase (SrFe12O19). We provide evidence of coupling (exchange spring behavior) with hysteresis curves, first order reversal curve (FORC) analysis and recoil measurements.
A Classification-based Quantitative Approach for SILAC Data

A practical and powerful approach for stable isotope labeling is stable isotope labeling by amino acids in cell culture (SILAC). A key advantage of SILAC is the ability to detecting simultaneously the isotopically labeled peptides in a single instrument run and so guarantees relative quantitation for a large number of peptides without introducing any variation caused by separate experiments. In this work, we introduce a new quantitative approach to dealing with SILAC protein-level summary using classification-based methodologies. Unlike existing methods, our approach depends mainly on the protein ratio summary and is not restricted only to the proteins with two or more peptide hits. In particular, our approach uses Gaussian mixture model and a stochastic, metaheuristic global optimization algorithm, particle swarm optimization (PSO), to avoid either a premature of convergence or being stuck in a local optimum. Our simulation studies show that the proposed method performs the best in terms of F1 score.
Vesicovaginal Fistulas on One Urological Service

Abstract: Of 92 vesicovaginal fistulas 57 (62 per cent) were closed, at least temporarily, with 1 or more operations. Functional closure was not attempted in 23 per cent of the cases and failed in 15 per cent. Various techniqueswere used in these cases. The favorite method involved a combination of colpocieisis, splitting the posterior wall of the bladder suprapubically and a temporary cystostomy on low pressure suction. Five patients (5.4 per cent) died postoperatively.
Massive impact-induced release of carbon and sulfur gases in the early Earth's atmosphere

Abstract Recent revisions to our understanding of the collisional history of the Hadean and early-Archean Earth indicate that large collisions may have been an important geophysical process. In this work we show that the early bombardment flux of large impactors (>100 km) facilitated the atmospheric release of greenhouse gases (particularly CO2) from Earth's mantle. Depending on the timescale for the drawdown of atmospheric CO2, the Earth's surface could have been subject to prolonged clement surface conditions or multiple freeze-thaw cycles. The bombardment also delivered and redistributed to the surface large quantities of sulfur, one of the most important elements for life. The stochastic occurrence of large collisions could provide insights on why the Earth and Venus, considered Earth's twin planet, exhibit radically different atmospheres.
MR Evaluation of Large Intracranial Aneurysms Using Cine Low Flip Angle Gradient-Refocused Imaging

MR imaging has proved to be useful in evaluating large intracranial aneurysms. The parent artery and patent lumen can be identified as flow voids and differentiated from thrombus. However, in the presence of slow flow, even-echo rephasing, and motion artifact, increased intraluminal signal may be present, which may be difficult to distinguish from thrombus. Aneurysms are also dynamic lesions and exert pulsatile mass effect on adjacent structures. Further definition of vascular anatomy and physiology may aid in therapeutic planning and assessment. Cine MR is a new technique using a movie loop of sequential GRASS (gradient-recalled acquisition in the steady state) images obtained during various pOints in the cardiac cycle. The combination of GRASS images and cardiac gating thus allows cinegraphic display of vascular structures. A comparison of this method with routine T1- and T2-weighted MR imaging and angiography was made in a group of 13 patients with intracranial aneurysms greater than 1.5 cm in diameter. Eight of these patients underwent transvascular detachable balloon occlusion. With cine MR, flowing blood has high intensity due to flow-related enhancement. Turbulent and high-velocity flow can be recognized on the basis of signal loss, which occurs during systole. Thrombus demonstrated variable signal intensity, which remained unchanged during the cardiac cycle. Compared with routine MR sequences, there was less image degradation from phase-encoding artifacts and improved visualization of the neck of the aneurysm. Pulsatile mass effect was uniquely assessed. After transvascular embolization, cine MR demonstrated improved conspicuity of acute thrombus and higher contrast between flowing blood and the occlusion balloon when compared with routine MR. Confirmation of flow within the parent vessel, residual aneurysm lumen, and distal arterial branches is possible. If the parent vessel was occluded, cine MR yielded greater information than angiography. Cine MR provides additional anatomic and physiologic data in the evaluation and assessment of therapy of intracranial aneurysms. Information can be obtained that is not available with either routine MR or angiography. The inherent limitations of this new technique include partial-volume artifacts, less than optimal flow-related enhancement or spatial resolution, and poor data acquisition due to cardiac arrhythmias.
Linear Quadratic Mean Field Type Control and Mean Field Games with Common Noise, with Application to Production of an Exhaustible Resource

We study a general linear quadratic mean field type control problem and connect it to mean field games of a similar type. The solution is given both in terms of a forward/backward system of stochastic differential equations and by a pair of Riccati equations. In certain cases, the solution to the mean field type control is also the equilibrium strategy for a class of mean field games. We use this fact to study an economic model of production of exhaustible resources.
Ba and Sr Binary Phosphides: Synthesis, Crystal Structures, and Bonding Analysis.

Synthesis, crystal structures, and chemical bonding are reported for four binary phosphides with different degrees of phosphorus oligomerization, ranging from isolated P atoms to infinite phosphorus chains. Ba3P2 = Ba4P(2.67)□(0.33) (□ = vacancy) crystallizes in the anti-Th3P4 structure type with the cubic space group I43d (no. 220), Z = 6, a = 9.7520(7) A. In the Ba3P2 crystal structure, isolated P(3-) anions form distorted octahedra around the Ba(2+) cations. β-Ba5P4 crystallizes in the Eu5As4 structure type with the orthorhombic space group Cmce (no. 64), Z = 4, a = 16.521(2) A, b = 8.3422(9) A, c = 8.4216(9) A. In the crystal structure of β-Ba5P4, one-half of the phosphorus atoms are condensed into P2(4-) dumbbells. SrP2 and BaP2 are isostructural and crystallize in the monoclinic space group P2₁/c (no. 14), Z = 6, a = 6.120(2)/6.368(1) A, b = 11.818(3)/12.133(2) A, c = 7.441(2)/7.687(2) A, β = 126.681(4)/126.766(2)° for SrP2/BaP2. In the crystal structures of SrP2 and BaP2, all phosphorus atoms are condensed into ∞(1)P(1-) cis-trans helical chains. Electronic structure calculations, chemical bonding analysis via the recently developed solid-state adaptive natural density partitioning (SSAdNDP) method, and UV-vis spectroscopy reveal that SrP2 and BaP2 are electron-balanced semiconductors.
Hospitalists and the Decline of Comprehensive Care

Increasing reliance on hospitalists in the United States entails a number of risks and costs for everyone involved in the health care system — most critically, for the patients that the system is meant to serve.
BLOOD MANAGEMENT METHODS IN PRIMARY TOTAL KNEE REPLACEMENT: IS THERE A DIFFERENCE IN OUTCOME?

Traditional use of tourniquets and reinfusion drains in total knee replacement (TKR) has recently been challenged. Many studies have challenged the benefits of their use. Our aim was to compare the outcomes of three different blood management techniques in primary TKR. We conducted a prospective randomised study of 87 patients with a mean age of 71 years. All patients were randomised into three groups: Group A (29 patients without tourniquet and drain), Group B (27 patients without tourniquet or drain but cell salvage system) and Group C (31 patients with the use of tourniquet and drain). The results showed no difference between the postoperative haemoglobin drop and blood transfusion rate between the groups. At day two, range of knee movements (Group A: 80.2 degree; Group B: 79.6 degree; Group C: 77.9 degree) showed no significant difference. Two Group C patients (6.4%) had postoperative thromboembolic events (one DVT, one TIA). Knee stiffness leading to readmission (Group A: 6.8%; Group B: 7.4%; Group C: 3.2%) and superficial wound problems did not reveal any significant difference. The average operative time and hospital stay were the same in all groups and there was no wound haematoma or deep infection in any groups. There was no statistical difference between the groups for any outcome measure assessed thus the use of tourniquets and drains in total knee arthroplasty are controversial and questionable. We can conclude that all techniques are safe and it is the surgeon9s choice as to which they apply routinely in their clinical practice.
On handlebody structures of rational balls

It is known that for coprime integers $p>q\geq 1$, the lens space $L(p^2,pq-1)$ bounds a rational ball, $B_{p,q}$, arising as the 2-fold branched cover of a (smooth) slice disk in $B^4$ bounding the associated 2-bridge knot. Lekilli and Maydanskiy give handle decompositions for each $B_{p,q}$. Whereas, Yamada gives an alternative definition of rational balls, $A_{m,n}$, bounding $L(p^2,pq-1)$ by their handlebody decompositions alone. We show that these two families coincide - answering a question of Kadokami and Yamada. To that end, we show that each $A_{m,n}$ admits a Stein filling of the "standard" contact structure, $\bar{\xi}_{st}$, on $L(p^2,pq-1)$ investigated by Lisca.
Evidence of nodes in the order parameter of the superconducting doped topological insulator Nb x Bi 2 Se 3 via penetration depth measurements

The low-temperature variation of the London penetration depth $\ensuremath{\lambda}(T)$ in the candidate topological superconductor ${\mathrm{Nb}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3} (x=0.25)$ is reported for several crystals. The measurements were carried out by means of a tunnel-diode oscillator technique in both field orientations (${H}_{\mathrm{rf}}\ensuremath{\parallel}c$ and ${H}_{\mathrm{rf}}\ensuremath{\parallel}ab$ planes). All samples exhibited power-law behavior at low temperatures ($\mathrm{\ensuremath{\Delta}}\ensuremath{\lambda}\ensuremath{\sim}{T}^{2}$) clearly indicating the presence of point nodes in the superconducting order parameter. The results presented here are consistent with a nematic odd-parity spin-triplet ${E}_{u}$ pairing state in ${\mathrm{Nb}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$.
High atmospheric demand for water can limit forest carbon uptake and transpiration as severely as dry soil

When stressed by low soil water content (SWC) or high vapor pressure deficit (VPD), plants close stomata, reducing transpiration and photosynthesis. However, it has historically been difficult to disentangle the magnitudes of VPD compared to SWC limitations on ecosystem-scale fluxes. We used a thirteen-year record of eddy covariance measurements from a forest in south-central Indiana, USA to quantify how transpiration and photosynthesis respond to fluctuations in VPD vs. SWC. High VPD and low SWC both explained reductions in photosynthesis relative to its long-term mean, as well as reductions in transpiration relative to potential transpiration estimated with the Penman-Monteith equation. Flux responses to typical fluctuations in SWC and VPD had similar magnitudes. Integrated over the year, VPD fluctuations accounted for significant reductions of GPP in both non-drought and drought years. Our results suggest that increasing VPD under climatic warming could reduce forest CO2 uptake regardless of changes in SWC.
Visual sensitivity of frontal eye field neurons during the preparation of saccadic eye movements

Primates make frequent saccades to inspect their surroundings and yet must maintain perceptual stability across saccades. The oculomotor system has long been posited to play a role in perceptual st...
Why do Estimates of the EMU Effect on Trade Vary so Much

Larger data sets, with more countries and a longer span of time, exhibit systematically larger effects of European monetary union on trade. I establish this stylized fact with meta-analysis and confirm it by estimating a plain-vanilla gravity model. I then explain this finding by examining systematic biases in “multilateral resistance to trade” manifest in time-varying country fixed effects; bias grows as the sample is truncated by dropping small poor countries.