cssi/SciSciGPT-SciSciNet huggingface dataset:
Mutual dimension and random sequences

Abstract If S and T are infinite sequences over a finite alphabet, then the lower and upper mutual dimensions m d i m ( S : T ) and M d i m ( S : T ) are the upper and lower densities of the algorithmic information that is shared by S and T. In this paper we investigate the relationships between mutual dimension and coupled randomness, which is the algorithmic randomness of two sequences R 1 and R 2 with respect to probability measures that may be dependent on one another. For a restricted but interesting class of coupled probability measures we prove an explicit formula for the mutual dimensions m d i m ( R 1 : R 2 ) and M d i m ( R 1 : R 2 ) , and we show that the condition M d i m ( R 1 : R 2 ) = 0 is necessary but not sufficient for R 1 and R 2 to be independently random. We also identify conditions under which Billingsley generalizations of the mutual dimensions m d i m ( S : T ) and M d i m ( S : T ) can be meaningfully defined; we show that under these conditions these generalized mutual dimensions have the “correct” relationships with the Billingsley generalizations of d i m ( S ) , D i m ( S ) , d i m ( T ) , and D i m ( T ) that were developed and applied by Lutz and Mayordomo; and we prove a divergence formula for the values of these generalized mutual dimensions.
A hybrid technique to address exposure keratopathy secondary to facial nerve paresis: A combination of a lateral tarsorrhaphy and lateral wedge resection.

Abstract Purpose To present the results of treating combined lower eyelid laxity, retraction and midface descent secondary to facial nerve weakness with a hybrid surgical procedure. Materials and methods A retrospective analysis of patients from January 2015 to January 2017 who underwent a hybrid surgical technique for the treatment of corneal exposure secondary to facial nerve paresis with a single surgeon was performed. Age, gender, and presence of exposure symptoms were recorded pre-operatively. Outcomes assessed included improvement of lower eyelid laxity and position, operative complications, and post-operative symptomatic relief. Results A total of 11 patients underwent unilateral eyelid surgery. All patients had symptomatic relief and good functional outcomes defined as improvement in eyelid laxity, lower eyelid position, and objective corneal exposure. No cases required reoperation during an average follow up of 174.5 days. Conclusions Combining portions of a tarsorrhaphy and lateral wedge resection technique is a simple and effective procedure to improve lower eyelid position and limit corneal exposure secondary to facial nerve paresis.
Varifocal zoom imaging with large area focal length adjustable metalenses

Varifocal lenses are essential components of dynamic optical systems with applications in photography, mixed reality, and microscopy. Metasurface optics has strong potential for creating tunable flat optics. Existing tunable metalenses, however, typically require microelectromechanical actuators, which cannot be scaled to large area devices, or rely on high voltages to stretch a flexible substrate and achieve a sufficient tuning range. Here, we build a 1 cm aperture varifocal metalens system at 1550 nm wavelength inspired by an Alvarez lens, fabricated using high-throughput stepper photolithography. We demonstrate a nonlinear change in focal length by minimally actuating two cubic phase metasurfaces laterally, with focusing efficiency as high as 57% and a wide focal length change of more than 6 cm (>200%). We also test a lens design at visible wavelength and conduct varifocal zoom imaging with a demonstrated 4× zoom capability without any other optical elements in the imaging path.
Job Crafting as Reaction to Organizational Change

Change recipients are not just negative and passive, but positive and active shapers of organizational change; we draw on job crafting to reflect positive and proactive behaviors individuals displa...
Reading comprehension development in at-risk vs. not at-risk first grade readers: The differential roles of listening comprehension, decoding, and fluency

Abstract This study examined the relations between and predictive power of three important subcomponents skills of reading comprehension: decoding, listening comprehension , and reading fluency . Through a series of structural equation models, we examine the relations within a full sample of first grade students at the beginning of the year ( N = 290). Next, we conducted analyses to determine if differential relations exist between the variables in students who are identified as at-risk for reading failure, and potentially reading disability (n = 141) and those who are not (n = 149). Results indicate that in early first grade, the relations between the subcomponent skills are different dependent upon risk status. For the full sample, fluency was the strongest predictor of reading comprehension, followed by decoding and listening comprehension. When the sample was split based on early reading skills at the beginning of first grade, for the not at-risk students, fluency, decoding, and listening comprehension each made individual contributions to reading comprehension. For the at-risk students, decoding was only significantly related to reading comprehension via fluency; listening comprehension did not significantly predict reading comprehension for this subsample. The findings are discussed and related to implications for the development and implementation of early reading interventions for students who are identified as having reading difficulties and potentially reading disability.
An empirical study on Chinese adolescents' fashion involvement

Chinese adolescents are growing up with China's rapid economic growth and they represent the up and coming group of China's fashionistas. The aim of this study is to assess the effectiveness of consumer socialization on Chinese adolescents' fashion involvement. Using the data collected from 169 Chinese adolescents, the research provides empirical results about the impacts of different consumer socialization agents on Chinese adolescents' fashion involvement. The study results reveal the positive and significant impacts of fashion magazines, fashion websites and peers on Chinese adolescents' fashion involvement, but a negative and significant impact of Internet on adolescents' fashion involvement. In addition, parents and TV were found to have no significant impact on Chinese adolescents' fashion involvement. Such empirical research not only deepens our understanding of the nature and strength of the relationships between the consumer socialization agents and Chinese adolescents' fashion consumer behaviour, but also makes a meaningful contribution to improving the consumer socialization framework. We believe these findings will be useful to update current consumer socialization frameworks and make it more relevant and useful for studying the new generation of consumers in the emerging market context.
Fast Kinodynamic Bipedal Locomotion Planning with Moving Obstacles

In this paper, we present a sampling-based kino-dynamic planning framework for a bipedal robot in complex environments. Unlike other footstep planning algorithms which typically plan footstep locations and the biped dynamics in separate steps, we handle both simultaneously. Three primary advantages of this approach are (1) the ability to differentiate alternate routes while selecting footstep locations based on the temporal duration of the route as determined by the Linear Inverted Pendulum Model (LIPM) dynamics, (2) the ability to perform collision checking through time so that collisions with moving obstacles are prevented without avoiding their entire trajectory, and (3) the ability to specify a minimum forward velocity for the biped. To generate a dynamically consistent description of the walking behavior, we exploit the Phase Space Planner (PSP) [1] [2]. To plan a collision-free route toward the goal, we adapt planning strategies from non-holonomic wheeled robots to gather a sequence of inputs for the PSP. This allows us to efficiently approximate dynamic and kinematic constraints on bipedal motion, to apply a sampling-based planning algorithm such as RRT or RRT*, and to use the Dubin's path [3] as the steering method to connect two points in the configuration space. The results of the algorithm are sent to a Whole Body Controller [1] to generate full body dynamic walking behavior. Our planning algorithm is tested in a 3D physics-based simulation of the humanoid robot Valkyrie.
Stability of Vacuum for the Landau Equation with Moderately Soft Potentials

Consider the spatially inhomogeneous Landau equation with moderately soft potentials (i.e. with $$\gamma \in (-\,2,0)$$ ) on the whole space $${\mathbb {R}}^3$$ . We prove that if the initial data $$f_{\mathrm {in}}$$ are close to the vacuum solution $$f_{\mathrm {vac}} \equiv 0$$ in an appropriate norm, then the solution f remains regular globally in time. This is the first stability of vacuum result for a binary collisional model featuring a long-range interaction. Moreover, we prove that the solutions in the near-vacuum regime approach solutions to the linear transport equation as $$t\rightarrow +\,\infty $$ . Furthermore, in general, solutions do not approach a traveling global Maxwellian as $$t \rightarrow +\,\infty $$ . Our proof relies on robust decay estimates captured using weighted energy estimates and the maximum principle for weighted quantities. Importantly, we also make use of a null structure in the nonlinearity of the Landau equation which suppresses the most slowly-decaying interactions.
The Supersymmetric WKB Formalism Is Not Exact for All Additive Shape Invariant Potentials

Following the verification of the conjecture made by Comtet et al that the supersymmetry-inspired semiclassical method known as SWKB is exact for the conventional additive shape invariant potentials, it was widely believed that SWKB yields exact results for all additive shape invariant potentials. In this paper we present a concrete example of an additive shape invariant potential for which the SWKB method fails to produce exact results.
Control of Generalized Discrete-Time SIS Epidemics via Submodular Function Minimization

In this letter, we study a novel control method for a generalized SIS epidemic process. In particular, we use predictive control to design optimal protective resource distribution strategies which balance the need to eliminate the epidemic quickly against the need to limit the rate at which protective resources are used. We expect that such a controller may be useful in mitigating the spread of biological diseases which do not confer immunity to those who have been infected previously, with sexually transmitted infections being a prominent example of such. Technically, this letter provides a novel contribution in demonstrating that the particular combinatorial optimal control problem used to design resource allocations has an objective function which is submodular, and so can be solved in polynomial time despite its combinatorial nature. We test the performance of the proposed controller with numerical simulations, and provide some comments on directions for future work.
Automatic Detection of Vague Words and Sentences in Privacy Policies

Website privacy policies represent the single most important source of information for users to gauge how their personal data are collected, used and shared by companies. However, privacy policies are often vague and people struggle to understand the content. Their opaqueness poses a significant challenge to both users and policy regulators. In this paper, we seek to identify vague content in privacy policies. We construct the first corpus of human-annotated vague words and sentences and present empirical studies on automatic vagueness detection. In particular, we investigate context-aware and context-agnostic models for predicting vague words, and explore auxiliary-classifier generative adversarial networks for characterizing sentence vagueness. Our experimental results demonstrate the effectiveness of proposed approaches. Finally, we provide suggestions for resolving vagueness and improving the usability of privacy policies.
Combined Carpal Tunnel Release and Palmar Fasciectomy for Dupuytren's Contracture Does Not Increase the Risk for Complex Regional Pain Syndrome.

Background:Hand surgery dogma suggests that simultaneous surgical treatment of carpal tunnel syndrome and Dupuytren’s contracture results in an increased incidence of complex regional pain syndrome. As a result, many surgeons do not perform surgery for the two conditions concurrently. The authors’ g
Composable Rate-Independent Computation in Continuous Chemical Reaction Networks

Biological regulatory networks depend upon chemical interactions to process information. Engineering such molecular computing systems is a major challenge for synthetic biology and related fields. The chemical reaction network (CRN) model idealizes chemical interactions, allowing rigorous reasoning about the computational power of chemical kinetics. Here we focus on function computation with CRNs, where we think of the initial concentrations of some species as the input and the equilibrium concentration of another species as the output. Specifically, we are concerned with CRNs that are rate-independent (the computation must be correct independent of the reaction rate law) and composable ( $f\circ g$ f ∘ g can be computed by concatenating the CRNs computing $f$ f and $g$ g ). Rate independence and composability are important engineering desiderata, permitting implementations that violate mass-action kinetics, or even “well-mixedness”, and allowing the systematic construction of complex computation via modular design. We show that to construct composable rate-independent CRNs, it is necessary and sufficient to ensure that the output species of a module is not a reactant in any reaction within the module. We then exactly characterize the functions computable by such CRNs as superadditive, positive-continuous, and piecewise rational linear. Thus composability severely limits rate-independent computation unless more sophisticated input/output encodings are used.
Amazon Mechanical Turk workers can provide consistent and economically meaningful data

We explore the consistency of the characteristics of individuals who participate in studies posted on Amazon Mechanical Turk (AMT). The primary individuals analyzed in this study are subjects who participated in at least two of eleven experiments that were run on AMT between September of 2012 to January of 2018. We demonstrate subjects consistently report a series of demographic and personality characteristics. Further, subjective willingness to take risk is found to be significantly correlated with decisions made in a simple lottery experiment with real stakes - even when the subjective risk measure is reported months, sometimes years, in the past. This suggests the quality of data obtained via AMT is not significantly harmed by the lack of control over the conditions under which the responses are recorded.
Diseconomies of Scale in the Actively-Managed Mutual Fund Industry: What Do the Outliers in the Data Tell Us?

Diseconomies of Scale in the Actively-Managed Mutual Fund Industry: What Do the Outliers in the Data Tell Us?
Barriers and facilitators to implementing an urban co-responding police-mental health team

In an effort to reduce the increasing number of persons with mental illness (PMI) experiencing incarceration, co-responding police-mental health teams are being utilized as a way to divert PMI from the criminal justice system. Co-response teams are typically an inter-agency collaboration between police and mental health professionals, and in some cases include emergency medical personnel. These teams are intended to facilitate emergency response by linking patients to mental health resources rather than the criminal justice system, thus reducing burdens on both the criminal justice systems as well as local healthcare systems. The current study examines the barriers and facilitators of successfully implementing the Mobile Crisis Assistance Team model, a first-responder co-response team consisting of police officers, mental health professionals, and paramedics. Through content analysis of qualitative focus groups with team members and interviews with program stakeholders, this study expands previous findings by identifying additional professional cultural barriers and facilitators to program implementation while also exploring the role of clear, systematic policies and guidelines in program success. Findings demonstrate the value of having both flexible and formal policies and procedures to help guide program implementation; ample community resources and treatment services in order to successfully refer clients to needed services; and streamlined communication among participating agencies and the local healthcare community. A significant barrier to successful program implementation is that of role conflict and stigma. Indeed, members of the co-response teams experienced difficulty transitioning into their new roles and reported negative feedback from other first responders as well as from within their own agency. Initial agency collaboration, information sharing between agencies, and team building were also identified as facilitators to program implementation. The current study provides a critical foundation for the implementation of first-responder police-mental health co-response teams. Cultural and systematic barriers to co-response team success should be understood prior to program creation and used to guide implementation. Furthermore, attention must be directed to cultivating community and professional support for co-response teams. Findings from this study can be used to guide future efforts to implement first-response co-response teams in order to positively engage PMI and divert PMI from the criminal justice system.
Smap Radiometer Soil Moisture Downscaling in Conus

SMAP (Soil Moisture Active/Passive) and SMOS (Soil Moisture Ocean Salinity) provide soil moisture observations that can be used for studying the global hydrological cycle, agriculture, ecology, and land atmosphere interactions. SMAP provides soil moisture at two grid scales; 36 km (which is close to its native radiometer spatial resolution) and an enhanced grid resolution of 9 km. However, these scales are not compatible with some agricultural and watershed applications that require a higher spatial resolution. This study applied a downscaling algorithm to the SMAP Level-2 radiometer 36 km product and improved the grid resolution to 1 km over the CONUS (Contiguous United States). The downscaling algorithm is built on the thermal inertial relationship between daily temperature change and averaged soil moisture modulated by Normalized Difference Vegetation Index (NDVI). The average soil moisture and thermal inertia model functions were developed by using data from NLDAS (North America Land Data Assimilation System) and LTDR (Land Long Term Data Record) for 1981 – 2016. The algorithm is applied with the 1 km MODIS Aqua LST product and the downscaled SMAP 1 km soil moisture was validated by in situ soil moisture measurements from the ISMN (International Soil Moisture Network). The validation variables show improved accuracy of the downscaled soil moisture.
Common problems of plausibility and probabilism

In this response to Allen and Pardo’s Relative Plausibility and Its Critics, I argue that while relative plausibility presents certain advantages over probabilism, it also fails to avoid several pr...
Aggressive Policing and the Educational Performance of Minority Youth

An increasing number of minority youth experience contact with the criminal justice system. But how does the expansion of police presence in poor urban communities affect educational outcomes? Prev...
Item Response Theory (IRT) Models for Dichotomous Data

This entry provides an introduction to the topic of item response theory. Shortcomings of classical test models are considered first. Second, current item response models for the analysis of dichotomously scored item response data are introduced. Estimation of model parameters, assessment of model fit, and available software, are described next. Finally, applications of item response theory IRT models to test development, item bias, equating, and computer-adaptive testing are briefly described. Keywords: item response theory; latent trait theory; item characteristic functions; test characteristic functions; item and test information functions; test development; identification of item bias; test score equating; computer-adaptive testing
Decentralized Coordinate-Descent Data Detection and Precoding for Massive MU-MIMO

Massive multiuser (MU) multiple-input multiple-output (MIMO) promises significant improvements in spectral efficiency compared to small-scale MIMO. Typical massive MU-MIMO base-station (BS) designs rely on centralized linear data detectors and precoders which entail excessively high complexity, interconnect data rates, and chip input/output (I/O) bandwidth when executed on a single computing fabric. To resolve these complexity and bandwidth bottlenecks, we propose new decentralized algorithms for data detection and precoding that use coordinate descent. Our methods parallelize computations across multiple computing fabrics, while minimizing interconnect and I/O bandwidth. The proposed decentralized algorithms achieve near-optimal error-rate performance and multi-Gbps throughput at sub-1 ms latency when implemented on a multi-GPU cluster with half-precision floating-point arithmetic.
Correlator beamforming for multipath mitigation in high-fidelity GNSS monitoring applications

Safety and security critical global navigation satellite system (GNSS) applications ensure system integrity by performing long-term monitoring to quantify and characterize GNSS signal anomalies. Multipath significantly hinders these high-fidelity signal quality monitoring applications. Besides multipath limiting antennas and sophisticated receiver signal processing, any remaining multipath is currently removed by antenna siting and azimuth/elevation masking. As urban development around airports and monitoring installations continues, these solutions may not suffice and more aggressive but cost-effective mitigation technologies are needed. This article explores the application of correlator beamforming as a potential solution. Unlike traditional multielement beamforming that requires a separate receiver front-end for each antenna element, correlator beamforming time multiplexes the received signals and performs beamforming as part of receiver correlation processing. This article shows that the multipath mitigation performance of correlator beamforming significantly exceeds a geodetic antenna and approaches that of traditional multi-element beamforming. The results presented are relevant for all GNSS monitoring applications.
Present bias and financial behavior

Present bias is an important term in the theory of self‐control in behavioral finance. Empirical research finds that present bias is associated with undesirable spending, borrowing, and saving behaviors. Unlike previous research that focuses on one domain of financial behavior, the purpose of this study is to examine associations between present bias and a set of financial behaviors in various domains: spending, borrowing, saving, and money management. With data from a national urban sample in China, results show that some behavioral patterns are consistent with theoretical predictions that present biased consumers are more likely to spend in the present and less likely to save for the future. The findings have implications for further research on present bias and help researchers better understand this important concept. The results are also informative for financial planners to better serve their clients. Full Text Available Here: https://doi.org/10.1002/cfp2.1048
Police legitimacy in Trinidad and Tobago: resident perceptions in a high-crime community

Violent crime in Trinidad and Tobago has increased over the last two decades, yet the police have been largely unsuccessful in reducing violence. Between 1999 and 2016, the murder rate increased by...
Inverse Scattering with Non-Over-Determined Data

It is proved that the scattering amplitude A(β,α 0 , k 0 ), known for all β ∈ S2, where S2 is the unit sphere in ℝ3, and fixed α 0 ∈ S2 and k 0 > 0, determines uniquely the surface S of the obstacle D and the boundary condition on S. The boundary condition on S is assumed to be the Dirichlet, or Neumann, or the impedance one. The uniqueness theorems for the solution of multidimensional inverse scattering problems with non-over-determined data was not known for many decades. Such theorems are presented in this paper.
Rods and Rings: Soft Subdivision Planner for R^3 x S^2.

We consider path planning for a rigid spatial robot moving amidst polyhedral obstacles. Our robot is either a rod or a ring. Being axially-symmetric, their configuration space is R^3 x S^2 with 5 degrees of freedom (DOF). Correct, complete and practical path planning for such robots is a long standing challenge in robotics. While the rod is one of the most widely studied spatial robots in path planning, the ring seems to be new, and a rare example of a non-simply-connected robot. This work provides rigorous and complete algorithms for these robots with theoretical guarantees. We implemented the algorithms in our open-source Core Library. Experiments show that they are practical, achieving near real-time performance. We compared our planner to state-of-the-art sampling planners in OMPL. Our subdivision path planner is based on the twin foundations of \epsilon-exactness and soft predicates. Correct implementation is relatively easy. The technical innovations include subdivision atlases for S^2, introduction of \Sigma_2 representations for footprints, and extensions of our feature-based technique for "opening up the blackbox of collision detection".
Controlling group and phase velocities in bidirectional mode-locked fiber lasers

A bidirectional mode-locked fiber laser producing two correlated frequency combs of the same repetition rate is demonstrated. The intensity dependence of pulse and phase velocities are measured simultaneously. As expected, the phase delay is determined by the linear and nonlinear indices of refraction. The nonlinear Kerr effect contribution to the pulse velocity is dwarfed by a contribution from saturable gain dynamics.
The evolution of regime imaginaries on the Chinese Internet

This study examines popular perceptions about the ruling state on the Chinese Internet before and along the state’s project of ‘online public opinion guidance.’ We chose two historical moments from...
Beyond the Bile Duct: Advanced IR Endoscopic Interventions Involving the Gastrointestinal, Genitourinary, and Musculoskeletal Systems

Endoscopy is a technique used by interventional radiology (IR) in only a few centers throughout the United States. When used by IR, endoscopy is most well-known for its role in the treatment of hepatobiliary disease. However, its use with relation to pathology involving the gastrointestinal, genitourinary, and musculoskeletal systems is gaining momentum among IR. The purpose of this article is to demonstrate the potential benefits of IR endoscopy in nonbiliary intervention. A literature review, not requiring IRB approval, was performed via PubMed and Ovid Medline databases using the search terms "interventional radiology-operated endoscopy," "interventional endoscopy," "interventional radiology," "genitourinary," and "gastrointestinal." Literature describing IR endoscopy involving the gastrointestinal, genitourinary, and musculoskeletal systems were identified and described. Nine peer-reviewed articles were identified. While few studies were identified, a general theme suggesting a synergistic relationship between IR and endoscopy was noted. More studies are needed to better understand the role of endoscopy as a technique in the IR suite.
The power-law distribution of agricultural land size*

ABSTRACTPower-law distributions explain a variety of natural and man-made processes spanning various disciplines including economics and finance. This paper demonstrates that the distribution of ag...
Impact of Market Concentration on Employment and Wages: a Look at the Insurance Industry

The falling share of labor in national income is a global concern. This study examined the impact of changes in market concentration ratios in the insurance industry on employment, the share of wages, sales (premiums), and annual wages. Panel data were analyzed for the period 2001 to 2012 for the life, property, and health insurance industries, available from the Bureau of Economic Analysis, Bureau of Labor Statistics, and SNL Financial Analysis database. Using a fixed effects model, we found that higher market concentration was associated with lower employment in the industry and a lower share of wages. However, there was no statistically significant association between concentration and average annual wage. Moreover, there was evidence that market concentration is positively associated with higher total sales (premiums received by the companies). Thus, we conclude that lower employment is not driven by the poor economic performance of the industry.
Enhancing Biometric-Capsule-based Authentication and Facial Recognition via Deep Learning

In recent years, developers have used the proliferation of biometric sensors in smart devices, along with recent advances in deep learning, to implement an array of biometrics-based authentication systems. Though these systems demonstrate remarkable performance and have seen wide acceptance, they present unique and pressing security and privacy concerns. One proposed method which addresses these concerns is the elegant, fusion-based BioCapsule method. The BioCapsule method is provably secure, privacy-preserving, cancellable and flexible in its secure feature fusion design. In this work, we extend BioCapsule to face-based recognition. Moreover, we incorporate state-of-art deep learning techniques into a BioCapsule-based facial authentication system to further enhance secure recognition accuracy. We compare the performance of an underlying recognition system to the performance of the BioCapsule-embedded system in order to demonstrate the minimal effects of the BioCapsule scheme on underlying system performance. We also demonstrate that the BioCapsule scheme outperforms or performs as well as many other proposed secure biometric techniques.
Synthesis and Thermal Rearrangements of 4-Allyl-4-arylcyclobutenones

The synthesis and thermolysis of 4-allyl-4-arylcyclobutenones are detailed. Allylcyclobutenones were prepared through the trapping of the cyclobutenonium cation generated by treatment of 4-hydroxycyclobutenones with Lewis acids. A study of the nucleophilic trapping revealed the following mechanistic highlights: the most likely intermediate is the cyclobutenonium cation, the regioselectivity of the allylation reaction is dictated by attack at the site most suited to stabilize the cation, and the rate of allylation is dependent on carbocation formation. Thermolysis of 4-allyl-4-arylcyclobutenones made possible a study of the competitive [2 + 2] cycloaddition and 6π electrocyclization. A judicious choice of substituents allows some control of the selectivity between the two pathways. The substituents control this selectivity through a combination of imposed electronics in the dienylketene intermediate, the relative ketenophilicity of the 4-position substituent, and the relative contortion substituents in th...
Enantioselective synthesis of the carbacephem antibiotic loracarbef via Mitsunobu and Dieckmann cyclization from an unnatural amino acid

The nucleus of the carbacephem antibiotic loracarbef was synthesized in a highly efficient and enantioselective fashion from 2S,3S-2-amino-3-hydroxy-6-heptenoic acid (AHHA), which was derived from enzyme-catalyzed condensation of glycine and 4-pentenaldehyde. The bicyclic framework of this compound was established through sequential Mitsunobu reaction and aldol condensations.
Multi-SNP mediation intersection-union test.

SUMMARY Tens of thousands of reproducibly identified GWAS (Genome-Wide Association Studies) variants, with the vast majority falling in non-coding regions resulting in no eventual protein products, call urgently for mechanistic interpretations. Although numerous methods exist, there are few, if any methods, for simultaneously testing the mediation effects of multiple correlated SNPs via some mediator (e.g. the expression of a gene in the neighborhood) on phenotypic outcome. We propose multi-SNP mediation intersection-union test (SMUT) to fill in this methodological gap. Our extensive simulations demonstrate the validity of SMUT as well as substantial, up to 92%, power gains over alternative methods. In addition, SMUT confirmed known mediators in a real dataset of Finns for plasma adiponectin level, which were missed by many alternative methods. We believe SMUT will become a useful tool to generate mechanistic hypotheses underlying GWAS variants, facilitating functional follow-up. AVAILABILITY AND IMPLEMENTATION The R package SMUT is publicly available from CRAN at https://CRAN.R-project.org/package=SMUT. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Conformational properties of asymmetrically substituted mono-, di- and trisulfides: solid and liquid phase Raman spectra

Abstract The Raman spectra of diallyl trisulfide, allyl methyl sulfide, allyl methyl disulfide and allyl methyl trisulfide in the liquid and solid states are interpreted in terms of their conformational behavior. In both the liquid and solid states, the allyl moieties in all molecules are in a gauche conformation in which the sulfur atoms and the terminal vinyl carbons form a dihedral angle of between 105° and 120°. For diallyl trisulfide and allyl methyl trisulfide in both the liquid and solid states, only a near- cis SS rotational conformer exists with a CSSS dihedral angle of approximately 25°. Furthermore, the rotational isomerism of both SS bonds of these molecules is the same. For allyl methyl disulfide in the solid and liquid phases only the gauche SS conformer exists, with a CSSC dihedral angle of approximately 70°. In the liquid state, two CS rotational conformers occur in each of the four molecules examined. The gauche conformer corresponds to a CCSC (allyl methyl sulfide) or CCSS (allyl methyl disulfide, allyl methyl trisulfide and diallyl trisulfide) dihedral angle of 70°, while the trans conformer corresponds to a CCSC or CCSS dihedral angle of 180°. For allyl methyl sulfide in the solid state only the trans CS conformer exists, while for allyl methyl disulfide and diallyl trisulfide only the gauche CS conformers exist in the solid phase. For allyl methyl trisulfide in the solid state both CS conformers exist, with the gauche CS conformer being more stable. We suggest that the gauche CS conformers for the di- and trisulfide systems are stabilized by attractive 1,4 C··S interactions analogous to those proposed for other sulfur containing molecules (H.E. Van Wart, L.L. Shipman and H.A. Scheraga, J. Phys. Chem., 79 (1975) 1428; ibid., 79 (1975) 1436.)
First General Synthesis of (p-Nitroaryl)diarylmethanes via Vicarious Nucleophilic Substitution of Hydrogen

A general regiospecific method for the synthesis of (p-nitroaryl)diarylmethanes has been developed starting from diarylmethanols and 2- and/or 3-substituted nitrobenzenes. This utilizes the quantitative condensation between benzotriazole and diarylmethanols under acidic catalysis and in the presence of perfluorocarbon fluids, followed by vicarious nucleophilic substitution of the resulting diarylmethylbenzotriazoles upon nitrobenzenes in moderate to high yield. Oxidative nucleophilic substitution of hydrogen is observed as a side process. These vicarious nucleophilic substitutions complement Friedel−Crafts reactions for the synthesis of triarylmethanes.
The GRE over the entire range of scores lacks predictive ability for PhD outcomes in the biomedical sciences.

The association between GRE scores and academic success in graduate programs is currently of national interest. GRE scores are often assumed to be predictive of student success in graduate school. However, we found no such association in admission data from Vanderbilt’s Initiative for Maximizing Student Diversity (IMSD), which recruited historically underrepresented students for graduate study in the biomedical sciences at Vanderbilt University spanning a wide range of GRE scores. This study avoids the typical biases of most GRE investigations of performance where primarily high-achievers on the GRE were admitted. GRE scores, while collected at admission, were not used or consulted for admission decisions and comprise the full range of percentiles, from 1% to 91%. We report on the 32 students recruited to the Vanderbilt IMSD from 2007–2011, of which 28 completed the PhD to date. While the data set is not large, the predictive trends between GRE and long-term graduate outcomes (publications, first author publications, time to degree, predoctoral fellowship awards, and faculty evaluations) are remarkably null and there is sufficient precision to rule out even mild relationships between GRE and these outcomes. Career outcomes are encouraging; many students are in postdocs, and the rest are in regular stage-appropriate career environments for such a cohort, including tenure track faculty, biotech and entrepreneurship careers.
Photoreduction of 1,2-Dichloroalkanes and 1,2-Dichloroalkenes by Tetrakis(diphenyl phosphato)dimolybdenum(II,II)

The quadruply bonded metal-metal complex Mo 2 [O 2 P(OC 6 H 5 ) 2 ] 4 reduces 1,2-dichloroalkanes and 1,2-dichloroalkenes upon its irradiation with visible light (λ exc ≥495 nm). The inorganic product of the photochemistry in all cases is the Mo II Mo III mixed-valence binuclear complex Mo 2 [O 2 P(OC 6 H 5 ) 2 ] 4 + , which has been structurally characterized. Green prismatic crystals of the tetrafluoroborate salt are triclinic with a PI space group
Selection, Linkage, and Population Structure Interact To Shape Genetic Variation Among Threespine Stickleback Genomes.

The outcome of selection on genetic variation depends on the geographic organization of individuals and populations as well as the organization of loci within the genome. Spatially variable selection between marine and freshwater habitats has had a significant and heterogeneous impact on patterns of genetic variation across the genome of threespine stickleback fish. When marine stickleback invade freshwater habitats, more than a quarter of the genome can respond to divergent selection, even in as little as 50 years. This process largely uses standing genetic variation that can be found ubiquitously at low frequency in marine populations, can be millions of years old, and is likely maintained by significant bidirectional gene flow. Here, we combine population genomic data of marine and freshwater stickleback from Cook Inlet, Alaska, with genetic maps of stickleback fish derived from those same populations to examine how linkage to loci under selection affects genetic variation across the stickleback genome. Divergent selection has had opposing effects on linked genetic variation on chromosomes from marine and freshwater stickleback populations: near loci under selection, marine chromosomes are depauperate of variation, while these same regions among freshwater genomes are the most genetically diverse. Forward genetic simulations recapitulate this pattern when different selective environments also differ in population structure. Lastly, dense genetic maps demonstrate that the interaction between selection and population structure may impact large stretches of the stickleback genome. These findings advance our understanding of how the structuring of populations across geography influences the outcomes of selection, and how the recombination landscape broadens the genomic reach of selection.
Organo-Transition Metal Compounds Containing Perfluorinated Ligands

Publisher Summary This chapter discusses the effect of α-fluorine substituents on the structure and reactivity of organic ligands bound to transition-metal centers, with particular emphasis on recent chemistry of octafluorocycloocta-1,3,5,7-tetraene (OFCOT). The chemistry of transition-metal compounds containing hydrocarbon ligands continues to be intensively explored. The most common kinds of compounds are those with metal–carbon σ bonds and metal–olefin bonds. The physical properties and chemical reactivity of transition-metal compounds containing trifluoromethyl ligands are surveyed. Complexes of cyclic perfluoroolefins are also quite common. In contrast to their hydrocarbon analogues, many unsaturated fluorocarbons react with anionic transition-metal nucleophiles to yield products arising from the net displacement of fluoride ion. The fluorocarbon complexes are notably different in their chemical properties as compared to their hydrocarbon analogues. The regio- and stereochemistry of phosphine attack were unambiguously defined by a single-crystal X-ray diffraction study. The enhanced reactivity of the indenyl complexes of the transition metals toward ligand substitution, compared to their cyclopentadienyl analogues, is due to a slippage of the indenyl ligand from η5 to an η3 bonding mode, thus making the metal center coordinatively unsaturated. Further contrasting reactivity is observed using t-butylisocyanide (t-BuNC) as the exogenous ligand. No photochemical rearrangements or transannular ring closure chemistry were observed with the corresponding cyclopentadienyl analogues. Additional chromatography allowed for the isolation of minor amounts of a second isomeric complex that could not be totally separated from the major isomer.
Drosophila species learn dialects through communal living

Many species are able to share information about their environment by communicating through auditory, visual, and olfactory cues. In Drosophila melanogaster, exposure to parasitoid wasps leads to a decline in egg laying, and exposed females communicate this threat to naive flies, which also depress egg laying. We find that species across the genus Drosophila respond to wasps by egg laying reduction, activate cleaved caspase in oocytes, and communicate the presence of wasps to naive individuals. Communication within a species and between closely related species is efficient, while more distantly related species exhibit partial communication. Remarkably, partial communication between some species is enhanced after a cohabitation period that requires exchange of visual and olfactory signals. This interspecies “dialect learning” requires neuronal cAMP signaling in the mushroom body, suggesting neuronal plasticity facilitates dialect learning and memory. These observations establish Drosophila as genetic models for interspecies social communication and evolution of dialects.
Evaluation of Amino Substituents as Nucleofugal Controllers of Regioselectivity and as Chelate Modulators of Stereoselectivity in Squarate Ester Cascades

The tandem addition of an alkenyllithium reagent and a 2-lithioallylamine to squarate esters has been systematically examined. The effect of the sequencing of this twofold addition has been investigated. The extent to which the amino group is eliminated was found to be dependent on the structural features of the companion nucleophile. Also assessed was the comparative ease with which the amino and methoxy groups experience competitive β-elimination from the highly reactive, medium-ring dianionic intermediates. Attempts were made to curtail the level of competing 1,4-addition, and success was achieved by increasing the effective size of the O-alkyl groups in the squarate ester. The highly stereocontrolled transformations described represent a notably direct means for producing highly fused polycyclic compounds. Mechanistic considerations surrounding these reactions, which are characterized by an impressive enhancement of molecular scaffolding, are discussed.
Preparation of substituted semicarbazides from corresponding amines and hydrazines via phenyl carbamates

Abstract A simple synthetic procedure for the conversion of amines and hydrazines into substituted semicarbazides was developed. The initial condensation between the desired amine and phenyl chloroformate into phenyl carbamate is followed by the addition of hydrazine under basic conditions. The reaction is tolerable to a variety of functional groups, with mild conditions and high percent yields.
Calcium and Strontium Hexaluminates: NMR Evidence that “Pentacoordinate” Cation Sites Are Four-Coordinated

We report new, high-resolution solid state 27Al NMR data for two members of the magnetoplumbite group of structures, strontium hexaluminate (SrAl12O19, “SA6”) and calcium hexaluminate (CaAl12O19, “CA6,” synthetic hibonite), acquired at 14.1 and 18.8 T fields. The high-field data allow, for the first time, the accurate observation of the NMR signal from the Al(2) sites, which have been previously described as “pentacoordinate” but which appear instead to be very distorted tetrahedra, which give rise to 27Al isotropic chemical shifts of about 57 ppm and nuclear quadrupolar coupling constants of about 21 MHz. This finding is fully consistent with “split-atom” refinements of these crystal structures, in which the most probable position of the Al atom is displaced away from the average trigonal pyramidal site center, along the crystallographic 3-fold axis. The NMR data also demonstrate, however, that the “splitting” is the result of static, not dynamical, disorder among these sites.
A direct route to acylhydroquinones from α-keto acids and α-carboxamido acids

Abstract The reaction of quinones with in situ generated acyl- or carboxamido radicals provides a direct route to the synthesis of acylhydroquinones not accessible by the photochemical reaction of quinones with aldehydes.
Hydrothermal Descriptive Chemistry and Single Crystal Structure Determination of Cesium and Rubidium Thorium Fluorides

Two new cesium thorium fluorides and three new rubidium thorium fluorides have been synthesized hydrothermally and structurally characterized. The structures of two polymorphs of CsTh3F13 are described in space group P6/ mmm with a = 8.2608(14) and c = 8.6519(17) and space group Pmc21 with a = 8.1830(16), b = 7.5780(15), and c = 8.6244(17). The analogous orthorhombic compound RbTh3F13, with a = 8.1805(16), b = 7.4378(15), and c = 8.6594(17) in space group Pmc21, is also reported. Two other rubidium thorium fluorides are also described: RbTh2F9 crystallizes in the space group Pnma where a = 8.9101(18), b = 11.829(2), and c = 7.4048(15), and Rb7Th6F31 crystallizes in the space group R3 where a = 15.609(2) and c = 10.823(2). Comparison of these materials was made on the basis of their structures and synthesis conditions. The formation of these species in hydrothermal fluids appears to be dependent upon the concentration of the alkali fluoride mineralizer solution and, thus, the ratio of alkali ions to thorium in the system.
Heterogeneous reactions important in atmospheric ozone depletion: a theoretical perspective.

Theoretical studies of the mechanisms of several heterogeneous reactions involving ClONO2, H2O, HCl, HBr, and H2SO4 important in atmospheric ozone depletion are described, focused primarily on reactions on aqueous aerosol surfaces. Among the insights obtained is the active chemical participation of the surface water molecules in several of these reactions. The general methodology adopted allows reduction of these complex chemical problems to meaningful model systems amenable to quantum chemical calculations.
Anchoring of actin to the plasma membrane enables tension production in the fission yeast cytokinetic ring.

This computational study of partially anchored cytokinetic rings predicts ~30-fold increased constriction rates, agreeing with experiments in cell ghosts and in support of a ring tension mechanism ...
Synthesis of homoallylic alcohols via palladium-catalyzed three-component coupling of an arylboronic acid with allenes and aldehydes.

Racemic homoallylic alcohols have been synthesized by palladium-catalyzed three-component coupling of an arylboronic acid, an allene, and an aldehyde.