cssi/SciSciGPT-SciSciNet huggingface dataset:
Field Estimation using Robotic Swarms through Bayesian Regression and Mean-Field Feedback

Recent years have seen an increased interest in using mean-field density based modelling and control strategy for deploying robotic swarms. In this paper, we study how to dynamically deploy the robots subject to their physical constraints to efficiently measure and reconstruct certain unknown spatial field (e.g. the air pollution index over a city). Specifically, the evolution of the robots' density is modelled by mean-field partial differential equations (PDEs) which are uniquely determined by the robots' individual dynamics. Bayesian regression models are used to obtain predictions and return a variance function that represents the confidence of the prediction. We formulate a PDE constrained optimization problem based on this variance function to dynamically generate a reference density signal which guides the robots to uncertain areas to collect new data, and design mean-field feedback-based control laws such that the robots' density converges to this reference signal. We also show that the proposed feedback law is robust to density estimation errors in the sense of input-to-state stability. Simulations are included to verify the effectiveness of the algorithms.
Dynamic Representation of the Subjective Value of Information.

To improve future decisions, people should seek information based on the value of information (VOI), which depends on the current evidence and the reward structure of the upcoming decision. When additional evidence is supplied, people should update VOI to adjust subsequent information seeking, but the neurocognitive mechanisms of this updating process remain unknown. We used a modified beads task to examine how the VOI is represented and updated in the human brain of both sexes. We theoretically derived, and empirically verified, a normative prediction that the VOI depends on decision evidence and is biased by reward asymmetry. Using fMRI, we found that the subjective VOI is represented in right dorsolateral prefrontal cortex (DLPFC). Critically, this VOI representation was updated when additional evidence was supplied, showing that DLPFC dynamically tracks the up-to-date VOI over time. These results provide new insights into how humans adaptively seek information in the service of decision making. SIGNIFICANCE STATEMENT For adaptive decision making, people should seek information based on what they currently know and the extent to which additional information could improve the decision outcome, formalized as the value of information (VOI). Doing so requires dynamic updating of VOI according to outcome values and newly arriving evidence. We formalize these principles using a normative model and show that information seeking in people adheres to them. Using fMRI, we show that the underlying subjective VOI is represented in dorsolateral prefrontal cortex, and critically, that it is updated in real time according to newly arriving evidence. Our results reveal the computational and neural dynamics through which evidence and values are combined to inform constantly evolving information seeking decisions.
Mitochondrial Respiratory Chain Protein Co-Regulation in the Human Brain

Mitochondrial respiratory chain (RC) function requires the stochiometric interaction among dozens of proteins but their co-regulation has not been defined in the human brain. Here, using quantitative proteomics across three independent cohorts we systematically characterized the co-regulation patterns of mitochondrial RC proteins in the human dorsolateral prefrontal cortex (DLPFC). Whereas the abundance of RC protein subunits that physically assemble into stable complexes were correlated, indicating their co-regulation, RC assembly factors exhibited modest co-regulation. Within complex I, nuclear DNA-encoded subunits exhibited >2.5-times higher co-regulation than mitochondrial (mt)DNA-encoded subunits. Moreover, mtDNA copy number was unrelated to mtDNA-encoded subunits abundance, suggesting that mtDNA content is not limiting. Alzheimer’s disease (AD) brains exhibited reduced abundance of complex I RC subunits, an effect largely driven by a 2-4% overall lower mitochondrial protein content. These findings provide foundational knowledge to identify molecular mechanisms contributing to age- and disease-related erosion of mitochondrial function in the human brain.
Improved draft reference genome for the Glassy-winged Sharpshooter (Homalodisca vitripennis), a vector for Pierce's disease

Homalodisca vitripennis (Hemiptera: Cicadellidae), known as the glassy-winged sharpshooter, is a xylem feeding leafhopper and an important agricultural pest as a vector of Xylella fastidiosa, which causes Pierce's disease in grapes and a variety of other scorch diseases. The current H. vitripennis reference genome from the Baylor College of Medicine's i5k pilot project is a 1.4-Gb assembly with 110,000 scaffolds, which still has significant gaps making identification of genes difficult. To improve on this effort, we used a combination of Oxford Nanopore long-read sequencing technology combined with Illumina sequencing reads to generate a better assembly and first-pass annotation of the whole genome sequence of a wild-caught Californian (Tulare County) individual of H. vitripennis. The improved reference genome assembly for H. vitripennis is 1.93-Gb in length (21,254 scaffolds, N50 = 650 Mb, BUSCO completeness = 94.3%), with 33.06% of the genome masked as repetitive. In total, 108,762 gene models were predicted including 98,296 protein-coding genes and 10,466 tRNA genes. As an additional community resource, we identified 27 orthologous candidate genes of interest for future experimental work including phenotypic marker genes like white. Furthermore, as part of the assembly process, we generated four endosymbiont metagenome-assembled genomes, including a high-quality near complete 1.7-Mb Wolbachia sp. genome (1 scaffold, CheckM completeness = 99.4%). The improved genome assembly and annotation for H. vitripennis, curated set of candidate genes, and endosymbiont MAGs will be invaluable resources for future research of H. vitripennis.
On training targets for noise-robust voice activity detection

The task of voice activity detection (VAD) is an often required module in various speech processing, analysis and classification tasks. While state-of-the-art neural network based VADs can achieve great results, they often exceed computational budgets and real-time operating requirements. In this work, we propose a computationally efficient real-time VAD network that achieves state-of-the-art results on several public real recording datasets. We investigate different training targets for the VAD and show that using the segmental voice-to-noise ratio (VNR) is a better and more noise-robust training target than the clean speech level based VAD. We also show that multi-target training improves the performance further.
Multiscale IOU: A Metric for Evaluation of Salient Object Detection with Fine Structures

General-purpose object-detection algorithms often dismiss the fine structure of detected objects. This can be traced back to how their proposed regions are evaluated. Our goal is to renegotiate the trade-off between the generality of these algorithms and their coarse detections. In this work, we present a new metric that is a marriage of a popular evaluation metric, namely Intersection over Union (IoU), and a geometrical concept, called fractal dimension. We propose Multiscale IoU (MIoU) which allows comparison between the detected and ground-truth regions at multiple resolution levels. Through several reproducible examples, we show that MIoU is indeed sensitive to the fine boundary structures which are completely overlooked by IoU and f1-score. We further examine the overall reliability of MIoU by comparing its distribution with that of IoU on synthetic and real-world datasets of objects. We intend this work to re-initiate exploration of new evaluation methods for object-detection algorithms.
Dynein activation in vivo is regulated by the nucleotide states of its AAA3 domain

Summary Cytoplasmic dynein is activated by the dynactin complex, cargo adapters and LIS1 (Lissencephaly 1). How this process is regulated in vivo remains unclear. The dynein motor ring contains six AAA+ (ATPases associated with diverse cellular activities) domains. Here, we used the filamentous fungus Aspergillus nidulans to examine whether ATP hydrolysis at AAA3 regulates dynein activation in the context of other regulators. In fungal hyphae, early endosomes undergo dynein-mediated movement away from the microtubule plus ends near the hyphal tip. Dynein normally accumulates at the microtubule plus ends. The early endosomal adaptor Hook protein, together with dynactin, drives dynein activation to cause its relocation to the microtubule minus ends. This activation process depends on LIS1, but LIS1 tends to dissociate from dynein after its activation. In this study, we found that dynein containing a mutation-blocking ATP hydrolysis at AAA3 can undergo LIS1-independent activation, consistent with our genetic data that the same mutation suppresses the growth defect of the A. nidulans LIS1-deletion mutant. Our data also suggest that blocking AAA3 ATP hydrolysis allows dynein activation by dynactin without the early endosomal adaptor. As a consequence, dynein accumulates at microtubule minus ends whereas early endosomes stay near the plus ends. Dynein containing a mutation-blocking ATP binding at AAA3 largely depends on LIS1 for activation, but this mutation abnormally prevents LIS1 dissociation upon dynein activation. Together, our data suggest that the AAA3 ATPase cycle regulates the coordination between dynein activation and cargo binding as well as the dynamic dynein-LIS1 interaction.
Bottlenecks in Blockchain Consensus Protocols

Most of the Blockchain permissioned systems employ Byzantine fault-tolerance (BFT) consensus protocols to ensure that honest validators agree on the order for appending entries to their ledgers. In this paper, we study the performance and the scalability of prominent consensus protocols, namely PBFT, Tendermint, HotStuff, and Streamlet, both analytically via load formulas and practically via implementation and evaluation. Under identical conditions, we identify the bottlenecks of these consensus protocols and show that these protocols do not scale well as the number of validators increases. Our investigation points to the communication complexity as the culprit. Even when there is enough network bandwidth, the CPU cost of serialization and deserialization of the messages limits the throughput and increases the latency of the protocols. To alleviate the bottlenecks, the most useful techniques include reducing the communication complexity, rotating the hotspot of communications, and pipelining across consensus instances.
Structural variants are a major source of gene expression differences in humans and often affect multiple nearby genes.

Structural variants (SVs) are an important source of human genome diversity but their functional effects are not well understood. We mapped 61,668 SVs in 613 individuals with deep genome sequencing data from the GTEx project and measured their effects on gene expression. We estimate that common SVs are causal at 2.66% of eQTLs, which is a 10.5-fold enrichment relative to their abundance in the genome and consistent with prior work using smaller sample sizes. Duplications and deletions were the most impactful variant types, whereas the contribution of mobile element insertions was small (0.12% of eQTLs, 1.9-fold enriched). Multi-tissue analysis of expression effects revealed that gene-altering SVs show significantly more constitutive effects than other variant types, with 62.09% of coding SV-eQTLs active in all tissues with known eQTL activity compared to 23.08% of coding SNV- and indel-eQTLs, while noncoding SVs, SNVs and indels show broadly similar patterns. We also identified 539 rare SVs associated with nearby gene expression outliers. Of these, 62.34% are noncoding SVs that show strong effects on gene expression yet modest enrichment at known regulatory elements, demonstrating that rare noncoding SVs are a major source of gene expression differences but remain difficult to predict from current annotations. Both common and rare noncoding SVs often show strong regional effects on the expression of multiple genes: SV-eQTLs affect an average of 1.82 nearby genes compared to 1.09 genes affected by SNV- and indel-eQTLs, and 21.34% of rare expression-altering SVs show strong effects on 2-9 different genes. We also observe significant effects on rare gene expression changes extending 1 Mb from the SV. This provides a mechanism by which individual noncoding SVs may have strong or pleiotropic effects on phenotypic variation and disease.
Impact of Natal Kicks on Merger Rates and Spin-Orbit Misalignments of Black Hole-Neutron Star Mergers

The long wait for the detection of merging black hole -- neutron star (BH--NS) binaries is finally over with the announcement by the LIGO/Virgo/Kagra collaboration of GW200105 and GW200115. Remarkably, the primary of GW200115 has a negative spin projection onto the orbital angular momentum, with about $90\%$ probability. Merging BH--NS binaries are expected to form mainly through the evolution of massive binary stars in the field, since their dynamical formation in dense star clusters is strongly suppressed by mass segregation. In this paper, we carry out a systematic statistical study of the binary stars that evolve to form a BH--NS binary, considering different metallicities and taking into account the uncertainties on the natal kick distributions for BHs and NSs and on the common envelope phase of binary evolution. Under the assumption that the initial stellar spins are aligned with the binary angular momentum, we show that both large natal kicks ($\gtrsim 150\kms$) and high efficiencies for common envelope ejection are required to simultaneously explain the inferred high merger rates and the large spin-orbit misalignment of GW200115.
COVID-19 Contact Tracing and Privacy: A Longitudinal Study of Public Opinion

There is growing use of technology-enabled contact tracing, the process of identifying potentially infected COVID-19 patients by notifying all recent contacts of an infected person. Governments, technology companies, and research groups alike have been working towards releasing smartphone apps, using IoT devices, and distributing wearable technology to automatically track "close contacts" and identify prior contacts in the event an individual tests positive. However, there has been significant public discussion about the tensions between effective technology-based contact tracing and the privacy of individuals. To inform this discussion, we present the results of seven months of online surveys focused on contact tracing and privacy, each with 100 participants. Our first surveys were on April 1 and 3, before the first peak of the virus in the US, and we continued to conduct the surveys weekly for 10 weeks (through June), and then fortnightly through November, adding topical questions to reflect current discussions about contact tracing and COVID-19. Our results present the diversity of public opinion and can inform policy makers, technologists, researchers, and public health experts on whether and how to leverage technology to reduce the spread of COVID-19, while considering potential privacy concerns.
Energy Price Jumps, Fat Tails and Climate Policy

Many authors who have analyzed key energy prices, such as crude oil and natural gas, have found that these prices exhibit “fat tails”—the feature that large percentage changes occur far more often than would be predicted by a conventional model. These fat tails can arise either because of time-varying volatility or because of rapid, unexpected changes—also known as jumps. Addressing global climate change is likely to require broad-based deployment of new infrastructure. This new infrastructure is likely to be both costly to build and difficult to reverse—suggesting the deployment of new infrastructure is an example of “investment under uncertainty” [1]. In this context, a key concept is the “option value of waiting,” i.e., the potential gain in value that arises from waiting to learn more about the evolution of some key underlying stochastic ingredient, such as a commodity price or the cost of a carbon permit. We argue that this option value of waiting is likely to be increased by the presence of jumps. Assuming there is some urgency in undertaking these investments, the increase in option value of waiting is worrisome and motivates the deployment of a policy intervention that reduces this option value.
Self-supervised Longitudinal Neighbourhood Embedding

Longitudinal MRIs are often used to capture the gradual deterioration of brain structure and function caused by aging or neurological diseases. Analyzing this data via machine learning generally requires a large number of ground-truth labels, which are often missing or expensive to obtain. Reducing the need for labels, we propose a self-supervised strategy for representation learning named Longitudinal Neighborhood Embedding (LNE). Motivated by concepts in contrastive learning, LNE explicitly models the similarity between trajectory vectors across different subjects. We do so by building a graph in each training iteration defining neighborhoods in the latent space so that the progression direction of a subject follows the direction of its neighbors. This results in a smooth trajectory field that captures the global morphological change of the brain while maintaining the local continuity. We apply LNE to longitudinal T1w MRIs of two neuroimaging studies: a dataset composed of 274 healthy subjects, and Alzheimer’s Disease Neuroimaging Initiative (ADNI, \(N=632\)). The visualization of the smooth trajectory vector field and superior performance on downstream tasks demonstrate the strength of the proposed method over existing self-supervised methods in extracting information associated with normal aging and in revealing the impact of neurodegenerative disorders. The code is available at https://github.com/ouyangjiahong/longitudinal-neighbourhood-embedding.
Feedback Linearization for Quadrotors with a Learned Acceleration Error Model

This paper enhances the feedback linearization controller for multirotors with a learned acceleration error model and a thrust input delay mitigation model. Feedback linearization controllers are theoretically appealing but their performance suffers on real systems, where the true system does not match the known system model. We take a step in reducing these robustness issues by learning an acceleration error model, applying this model in the position controller, and further propagating it forward to the attitude controller. We show how this approach improves performance over the standard feedback linearization controller in the presence of unmodeled dynamics and repeatable external disturbances in both simulation and hardware experiments. We also show that our thrust control input delay model improves the step response on hardware systems.
Proterrence, rule illegitimacy, and the ban on tobacco smoke in Amsterdam's coffeeshops

This article examines the concept of proterrence: scaring people into doing something to stop others from doing something bad. This contrasts to deterrence, which involves threatening persons to not do something bad. The tobacco ban in Amsterdam coffeeshops and, more specifically, coffeeshop personnel’s reaction to it is used as the empirical vessel to examine proterrence. Proterrence permits examination of the interface between order maintenance and social control against a backdrop of perceived sanction illegitimacy. It also permits exploration of the process by which formal sanctions thread through informal mechanisms—where that threading is enforcement rather than consequence-based and where rule implementers face the brunt of the sanction that a third party violates. Data are based on in-depth fieldwork in Amsterdam coffeeshops. The wider applicability of proterrence is discussed.
Evaluation of a High Performance Fixed-Ratio Traction Drive

The results of a test program to evaluate a compact, high performance, fixed ratio traction drive are presented. This transmission, the Nasvytis Multiroller Traction Drive, is a fixed ratio, single stage planetary with two rows of stepped planet rollers. Two versions of the drive were parametrically tested back-to-back at speeds to 73,000 rpm and power levels to 180 kW (240 hp). Parametric tests were also conducted with the Nasvytis drive retrofitted to an automotive gas turbine engine. The drives exhibited good performance, with a nominal peak efficiency of 94 to 96 percent and a maximum speed loss due to creep of approximately 3.5 percent.
Emergency Equity: Access and Emergency Medical Services in San Francisco

In 2020, California required San Francisco to consider equity in access to resources such as housing, transportation, and emergency services as it re-opens its economy post-pandemic. Using a public dataset maintained by the San Francisco Fire Department of every call received related to emergency response from January 2003 to April 2021, we calculated the response times and distances to the closest of 48 fire stations and 14 local emergency rooms. We used logistic regression to determine the probability of meeting the averages of response time, distance from a fire station, and distance to an emergency room based on the median income bracket of a ZIP code based on IRS statement of income data. ZIP codes in the lowest bracket ($25,000-$50,000 annually) consistently had the lowest probability of meeting average response metrics. This was most notable for distances to emergency rooms, where calls from ZIP codes in the lowest income bracket had an 11.5% chance of being within the city’s average distance (1 mile) of an emergency room, while the next lowest probability (for the income bracket of $100,000-$200,000 annually) was 75.9%. As San Francisco considers equity as a part of California’s “Blueprint for a Safer Economy,” it should evaluate the distribution of access to emergency services. Funding Information: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Declaration of Interests: None declared.
Holographic symmetry algebras for gauge theory and gravity

All 4D gauge and gravitational theories in asymptotically flat spacetimes contain an infinite number of non-trivial symmetries. They can be succinctly characterized by generalized 2D currents acting on the celestial sphere. A complete classification of these symmetries and their algebras is an open problem. Here we construct two towers of such 2D currents from positive-helicity photons, gluons, or gravitons with integer conformal weights. These generate the symmetries associated to an infinite tower of conformally soft theorems. The current algebra commutators are explicitly derived from the poles in the OPE coefficients, and found to comprise a rich closed subalgebra of the complete symmetry algebra.
Impact of Media Celebrities on Geny Fashionistas in China

Based on prior research in which we identified four major sources of fashion information among Chinese women (fashion magazines, fashion advertising, celebrities, and the Internet), this study targeted young Chinese women with high interest in fashion (fashionistas) in an effort to determine which of the four was most influential. Subjects (n=388) were solicited through China’s largest publisher of fashion magazines and were from cities across China. Using an Internet survey, it was determined that celebrity influence was significantly greater (p<.000) than the other three purveyors of fashion information. The study has implications for international and Chinese marketers of fashion-forward products.
Mean Arterial Blood Pressure Correlates with Neurological Recovery after Human Spinal Cord Injury: Analysis of High Frequency Physiologic Data

Abstract Current guidelines for the care of patients with acute spinal cord injuries (SCIs) recommend maintaining mean arterial pressure (MAP) values of 85–90 mm Hg for 7 days after an acute SCI however, little evidence supports this recommendation. We sought to better inform the relationship between MAP values and neurological recovery. A computer system automatically collected and stored q1 min physiological data from intensive care unit monitors on patients with SCI over a 6-year period. Data for 100 patients with acute SCI were collected. 74 of these patients had American Spinal Injury Association Impairment Scale (AIS) grades determined by physical examination on admission and at time of hospital discharge. Average MAP values as well as the proportion of MAP values below thresholds were explored for values from 120 mm Hg to 40 mm Hg in 1 mm Hg increments; the relationship between these measures and outcome was explored at various time points up to 30 days from the time of injury. A total of 994,875 q...
Corticosteroids differentially regulate secretion of IL-6, IL-8, and G-CSF by a human bronchial epithelial cell line

Human airway epithelial cells play an active role in modulating airway inflammation by elaborating a variety of proinflammatory molecules, including cytokines. The purpose of this study was to define the role of corticosteroids in the regulation of cytokine gene transcription and secretion by human bronchial epithelial cells. In particular, we assessed whether dexamethasone was capable of inhibiting the tumor necrosis factor-alpha (TNF-alpha)-mediated secretion of interleukin-6 (IL-6), interleukin-8 (IL-8), and granulocyte colony-stimulating factor (G-CSF) by a human bronchial epithelial cell line (BEAS-2B). Stimulation with 20 ng/ml of TNF-alpha resulted in significant increases in secretion of immunoreactive IL-6, IL-8, and G-CSF that were maximal at 24 h. TNF-alpha-mediated IL-6, IL-8, and G-CSF secretion was concentration dependent and specific. In addition, stimulation with TNF-alpha resulted in significant increases in the quantity of IL-6, IL-8, and G-CSF mRNA as detected by reverse-transcription polymerase chain reaction. Dexamethasone preconditioning significantly inhibited both the secretion of immunoreactive IL-6 and the accumulation of IL-6 mRNA. Although dexamethasone appeared to reduce both the secretion of immunoreactive IL-8 and accumulation of IL-8 mRNA, the inhibitory effects did not reach statistical significance. Finally, dexamethasone did not inhibit either the secretion of immunoreactive G-CSF or the accumulation of G-CSF mRNA. In summary, our results suggest that corticosteroids have a differential effect on the regulation of cytokine secretion by human bronchial epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Total ischemic time: The correct focus of attention for optimal ST-segment elevation myocardial infarction care

Currently accepted standards for gauging quality of care in the treatment of ST-segment elevation myocardial infarction (STEMI) mainly focus on shortening the time to treatment after the patient arrives at the hospital. But this narrow focus fails to consider the substantial duration of myocardial ischemia that exists prior to hospital arrival, and the large number of deaths that occur during the pre-hospital period. The time from symptom onset until reperfusion occurs is one estimate of total ischemic time. Several experimental studies and now human clinical studies have confirmed that infarct size and mortality are strongly correlated with the total ischemic time, and much less so with its subintervals like door-to-balloon time. This review will discuss the importance of total ischemic time in STEMI.
The extragenital effects of diethylstilbestrol

Abstract During the past year, 100 patients receiving diethylstilbestrol for therapeutic reasons have been carefully observed and studied. All tests were controlled by performing them both before and after treatment. The observations reported relate to the effects of this drug on systems other than the reproductive organs. In general these extragenital effects duplicate those that have been found with the natural estrogens, and while many of these observations are of interest and invite further study, none of them can in any way be considered as representing toxic manifestations of diethylstilbestrol.
Evaluation of a wideband direction estimation algorithm for acoustic arrays

In this work we experimentally evaluate the performance of an acoustic target detection and direction estimation algorithm. The algorithm was developed by Nawab et. al. [1] for small microphone arrays. The accuracy of azimuth estimates for a single source and the ability to handle multiple sources was examined. Single source accuracy was measured as a function of input SNR and source types. The azimuth separartion required to resolve two sources and the maximum number of widely spread (in azimuth space) sources that can be resolved were measured as a function of input SNR. The usefulness of an output quality measure was experimentally tested.
SSN effects on tapered buffers

Higher frequency of operation, simultaneous switching of the output drivers and the parasitic inductance present at the pin-pad-package interface results in significant switching noise (SSN). The effect of SSN on overall buffer propagation delay, taper factor and transition time is discussed. Skewing the buffer output switching reduces SSN.
Pharmacokinetic Evaluation of para‐Aminosalicylic Acid Granules

Study Objective. To determine the bioavailability and renal elimination of para-aminosalicylic acid (PAS) and its inactive metabolite acetyl-para-aminosalicylic acid (AcPAS) from a new PAS formulation. Design. (a) Single-dose pharmacokinetic study in healthy volunteers; (b) Day-1 and day-8 pharmacokinetic comparison in patients with multidrug-resistant tuberculosis (MDR-TB). Setting. Referral hospital that specializes in the treatment of mycobacterial infections. Patients. (a) Twelve healthy male and female volunteers recruited by the investigators. Eleven subjects (92%) completed the study; one subject could not maintain venous access and was removed from the study, (b) Six sequential male and female patients receiving multidrug treatment for advanced MDR-TB. All patients completed the study. Interventions. (a) Volunteers received a single 4-g dose of enteric-coated PAS granules administered with food. Blood and urine samples were collected over 24 hours after the dose, (b) Patients received 4-g doses of enteric-coated PAS granules every 8 hours for 7 days as part of their treatment regimen. Blood samples were obtained at approximately 2,4, and 8 hours after the first dose on day 1 and the twenty-second dose on day 8. Measurements and Main Results. Concentrations of PAS and AcPAS were determined using high-performance liquid chromatography. The serum concentration-time curves from volunteers and patients showed sustained PAS concentrations, in contrast to immediate-release sodium PAS tablets. In the six patients with tuberculosis, day 8 concentrations were considerably higher than those on day 1, and all were sustained well above the PAS minimal inhibitory concentration for Mycobacterium tuberculosis. Conclusions. Para-aminosalicylic acid granules produce adequate serum concentrations and appear to be safe.
FDTD based numerical Green's function for S-parameter measurement in inverse scattering problems

We present a numerical Green's function that serves as the kernel for volume integral equation (VIE) in inverse scattering problems. The primary motivation for this research is to address the lack of full antenna modeling in the VIE when solving inverse scattering problems. The numerical Green's function introduced here directly links the total field in the object domain and the object's dielectric properties to the measured scattered S parameters in the presence of the antennas and a presumed imaging cavity.
Laryngeal adductor function in experimental models of recurrent laryngeal nerve injury.

Objectives/Hypothesis Most patients with unilateral vocal fold paralysis experience some degree of spontaneous reinnervation, which depends upon the type and severity of recurrent laryngeal nerve (RLN) injury. After partial recovery, the paretic vocal fold may or may not adduct adequately to allow glottic closure, which in turn affects phonatory and swallowing outcomes. This process was studied in a series of canine laryngeal nerve injury models.
Myofibrillar Protein Gelation: Viscoelastic Changes Related to Heating Procedures

Dynamic Theological properties were investigated during gelation of chicken myofibrillar protein as influenced by heating procedures, Thermal scan (1°C/min) of myofibril suspensions in 0.6M NaCl (pH 6.0) induced a major transition in storage modulus (G′, peak 48°C), preceded by a transition in protein-protein aggregation (46°C) and accompanied by a marked reduction in actomyosin solubility. Preheating at 50°C diminished the transition and resulted in increased final G′value. Isothermal heating produced complex, temperature-dependent Theological changes (G′and phase angles), particularly within 43–58°C. The rheological transitions of myofibrillar protein were probably related to kinetic changes during formation of elastic gel networks. Such Theological data on gel formation can help predict and control muscle food responses to specific thermal processes.
Development of an in silico model for human skin permeation based on a Franz cell skin permeability assay.

Abstract A multiple linear regression QSAR model was developed based on a set of 61 compounds with internally consistent permeability data measured across Franz cell. The data was normalized using a mean permeability value of a reference compound, 3-isobutyl-1-methylxanthine (IBMX). The QSAR model contained only five simple descriptors and had a correlation coefficient, r 2 of 0.77 between experimental and calculated values for skin permeability. The mean absolute error (MAE) was 0.3 for the entire set and the cross validation coefficient, q 2 was 0.71. The in silico skin permeability model was used as a filter for virtual libraries and to optimize skin permeation of specific compounds for several dermatology discovery projects.
Lysozyme crystal growth studied by atomic force microscopy

Abstract We have used atomic force microscopy to observe growing crystals of the protein lysozyme in their mother liquor. The images of the crystal surface show the time course of nucleation, spreading, and merging of two-dimensional islands to form successive layers of the crystal. Step velocities and two-dimensional nucleation rates were obtained. The formation of large macrosteps appears to be common on crystals growing at relatively low supersaturation.
The Viroporin Activity of the Minor Structural Proteins VP2 and VP3 Is Required for SV40 Propagation

For nonenveloped viruses such as Simian Virus 40, the mechanism used to translocate viral components across membranes is poorly understood. Previous results indicated that the minor structural proteins, VP2 and VP3, might act as membrane proteins during infection. Here, purified VP2 and VP3 were found to form pores in host cell membranes. To identify possible membrane domains, individual hydrophobic domains from VP2 and VP3 were expressed in a model protein and tested for their ability to integrate into membranes. Several domains from the late proteins supported endoplasmic reticulum membrane insertion as transmembrane domains. Mutations in VP2 and VP3 were engineered that inhibited membrane insertion and pore formation. When these mutations were introduced into the viral genome, viral propagation was inhibited. This comprehensive approach revealed that the viroporin activity of VP2 and VP3 was inhibited by targeted disruptions of individual hydrophobic domains and the loss of membrane disruption activity impaired viral infection.
Yeast recombination factor Rdh54 functionally interacts with the Rad51 recombinase and catalyzes Rad51 removal from DNA.

The Saccharomyces cerevisiae RDH54-encoded product, a member of the Swi2/Snf2 protein family, is needed for mitotic and meiotic interhomologue recombination and DNA repair. Previous biochemical studies employing Rdh54 purified from yeast cells have shown DNA-dependent ATP hydrolysis and DNA supercoiling by this protein, indicative of a DNA translocase function. Importantly, Rdh54 physically interacts with the Rad51 recombinase and promotes D-loop formation by the latter. Unfortunately, the low yield of Rdh54 from the yeast expression system has greatly hampered the progress on defining the functional interactions of this Swi2/Snf2-like factor with Rad51. Here we describe an E. coli expression system and purification scheme that together provide milligram quantities of nearly homogeneous Rdh54. Using this material, we demonstrate that Rdh54-mediated DNA supercoiling leads to transient DNA strand opening. Furthermore, at the expense of ATP hydrolysis, Rdh54 removes Rad51 from DNA. We furnish evidence that the Rad51 binding domain resides within the N terminus of Rdh54. Accordingly, N-terminal truncation mutants of Rdh54 that fail to bind Rad51 are also impaired for functional interactions with the latter. Interestingly, the rdh54 K352R mutation that ablates ATPase activity engenders a DNA repair defect even more severe than that seen in the rdh54Δ mutant. These results provide molecular information concerning the role of Rdh54 in homologous recombination and DNA repair, and they also demonstrate the functional significance of Rdh54·Rad51 complex formation. The Rdh54 expression and purification procedures described here should facilitate the functional dissection of this DNA recombination/repair factor.
The Path to Intractability: Time and the Entrenchment of Territorial Disputes

Why do territorial disputes become more difficult to resolve over time? Why are states often unable to resolve long-standing territorial disputes over land that is of little strategic or economic value? One explanation for territorial dispute entrenchment draws on changes in dispute perception. Specifically, as territorial disputes mature they undergo processes that increase the integrity of the disputed territory, clarify the definition of the territory's boundaries, and make it more difficult to find substitutes for the territory. Territorial dispute resolution is both stochastic and exogenous to the entrenchment process and thus impossible to predict. It is possible, however, to forecast ex ante the degree to which young territorial disputes are likely to resist resolution efforts in the future based on two variables: perceptions of a territory's integrity, boundaries, and value at the outset of the dispute, and physical constraints on expansion and settlement into the territory.
Solitude: A Central Motif in Thomas Merton's Life and Writings

ilence and solitude have important roles in the history of religions. From the solitaries of Upanishadic Hinduism and early Taoism to the initiates of Pythagorean wisdom and early Christian asceticism, seekers have attempted to reach ultimate goals by cultivating quiet and living in seclusion. This quest is frequently associated with those who follow the ways of the monk and the mystic. The life of the monk, with varying degrees of withdrawal from the world, and the path of the mystic, with silent meditation and ineffable experiences, characteristically require some physical isolation and reduction in speech. But monasticism and mysticism in their most profound forms manifest something far more interesting than the literal practice of silence and solitude: monks and mystics often understand solitude as the climate and silence as the language of liberation, enlightenment, or union with God. Silence and solitude then become sacred metaphors, often more than metaphors, to express the experience of ultimate transformation. The intimate relationship between silence and solitude in Thomas Merton's writings is one of the most striking themes in his work. "My only task is to be what I am," he wrote near the end of his life, "a man seeking God in silence and solitude, with deep respect for the demands and realities of his own vocation, and fully aware that others too are seeking the truth in their own way" (1973b:245). Silence and solitude, so central to Christian monasticism, had attracted Merton before he joined the Trappists in 1941, and his search for increasingly deeper silence and solitude remained a powerful force throughout his life; the explicit connection of these themes,
UV photoelectron spectra of group IV alkyl hydrides

Abstract We have had occasion to measure the photoelectron spectra of some heavy group IV alkyls and alkyl hydrides. Although the ionization potentials serve primarily as a body of information which is useful in investigating trends in reactivity for processes involving electron transfer [1], they also provide a pleasing example of the simplicity with which the language of molecular orbital theory can be used to explain trends in the energies and nature of the radical cation states of a series of chemically related molecules [2].
Education: Embed social awareness in science curricula

Separate ethics courses are not enough, argues Erin A. Cech. Understanding the public-welfare impacts of science and engineering is a core professional skill.
Computed Tomography-oriented Stereotactic System

A new and simple computed tomography (CT)-oriented stereotactic system that uses the basic principle of working in the CT plane of the target is described. The system consists of a movably mounted frame carrying an adjustable probe holder capable of sliding along the length of the frame and being inclined to any desired angle, together with an independently mounted head fixed system. The movably mounted frame and the sliding probe holder are adjusted in the CT plane of the target. The angle and the distance to which the probe holder should be adjusted for accurate probing can be obtained from a single scan image. The system can be used in any total body scanner with standard features. No special computer programming is necessary, and no calculations are needed. The operation of the system is described wit illustrative cases.
Materials problems in large scale production of hydrogen from water and in hydroge storage

Methods for the production of hydrogen from water are discussed with emphasis on thermochemical cycles. These consist of a series of reactions, performed at various temperatures up to about 1000°C, which by their nature involve some compounds that are aggressive toward containment materials. Experience with most such reactions is presently not available in the chemical industry, and a lack of knowledge is thus evident regarding corrosion-resistant materials. The most promising thermochemical cycles are described in terms of the aggressiveness of their reagents. Materials problems associated with the production of hydrogen by water electrolysis and hydrogen storage in the form of metallic hydrides are also reviewed.
Estrogen and urinary incontinence in women.

Abstract Objective: The purpose of this study was to review the efficacy of estrogen therapy for urinary incontinence by examining published trials and to review the epidemiologic and physiologic evidence for its action. Data Sources: Controlled and uncontrolled trials of estrogen therapy in the English literature were collected. Eight controlled and 14 uncontrolled trials were identified. Methods of Study Selection: Trials were selected if they were prospective. All types of estrogen treatment were included. All types of outcome measurements were included. Data Extraction and Synthesis: Trials were categorized by type of estrogen used; outcome variables (subjective improvement vs. objective urodynamic data); and cure/improvement rates. Conclusions: Published trials do not support estrogen replacement as efficacious therapy for stress urinary incontinence. It may be useful for incontinence associated with urgency and frequency. Adequately large controlled trials that evaluate estrogen replacement regimens used in the USA remain to be done.
Use of Streamwise Periodic Boundary Conditions for Problems in Heat and Mass Transfer

Fully developed periodic boundary conditions have frequently been employed to effect performance calculations for heat and mass exchange devices. In this paper a method is proposed, which is based on the use of primitive variables combined with the prescription of slip values. Either pressure difference or mass flow rate may be equivalently prescribed. Both constant wall temperature (Dirichlet) and constant heat flux (Neumann) conditions may be considered, as well as the intermediate linear (Robin) boundary condition. The example of an offset-fin plate-fin heat exchanger is used to illustrate the application of the procedure. The mathematical basis by which the method may be extended to the consideration of mass transfer problems with arbitrary boundary conditions, and associated continuity, momentum, and species sources and sinks is discussed.
Histopathology of the European chafer, Amphimallon majalis, infected with Bacillus popilliae☆

Abstract Third-instar larvae of the European chafer were challenged orally or by injection with spore suspensions of Bacillus popilliae. The pathogenesis was investigated by histological examination of larvae sacrificed at various exposure times. Spores germinated in the center of hemocytic capsules when injected and probably in the lumen of the anterior intestine when ingested. Following preliminary multiplication inside the basement membrane of the midgut, vegetative cells penetrated and continued to multiply in the hemolymph. Whether larvae were infected by ingestion or injection, the bacilli concentrated in connective tissue sheaths or in close association with hemocytes for sporulation.
Density-functional theory of classical systems

An exact density-functional theory is developed for nonuniform classical systems, expressing the free energy in terms of direct correlation functions. It is shown how this theory may be used in a practical fashion to remove several unjustified, although physically plausible, approximations made in earlier work. Further understanding of the approximations is obtained.
Thermogenic vent gas and gas hydrate in the Gulf of Mexico slope: Is gas hydrate decomposition significant?

Samples of vent gas and gas hydrate on the Gulf of Mexico slope were collected by research submersible (∼540 m water depth) and by piston coring (∼1060–1070 m water depth). Although gas hydrate that crops out is transiently unstable, the larger volume of structure II gas hydrate in the gulf is stable or increasing in volume because gas from the subsurface petroleum system is venting prolifically within the gas hydrate stability zone. Vent gas from gas hydrate shows no meaningful molecular evidence of gas hydrate decomposition. Gas hydrate fabrics, mainly vein fillings, are typical of ongoing crystallization. Once crystallized, most hydrocarbons are protected from bacteria within the crystal lattice of gas hydrate. A leaky petroleum system is proposed to be the main source of thermogenic greenhouse gases in the central gulf. Stable gas hydrate sequesters large volumes of greenhouse gases, suggesting that gas hydrate may not be a significant factor in models of climate change at present.
Magnetic and transport properties of the alloys

Magnetization and transport measurements have been performed to study the martensitic and pre-martensitic transitions for a series of ferromagnetic Heusler alloys. Both magnetization and resistivity measurements show a clear jump at the martensitic transition and a discontinuous slope change at the pre-martensitic transition. The characteristic temperatures correspond well with those derived from previous direct structural results from neutron scattering, electron microscopy and ultrasonic studies. The martensitic transition temperature decreases with increasing Mn concentration.