cssi/SciSciGPT-SciSciNet huggingface dataset:
Efficient regularized solution path algorithms with applications in machine learning and data mining

The topic of this dissertation is based on regularization methods and efficient solution path algorithms for machine learning and data mining. The first essay proposes the doubly regularized support vector machine (DrSVM) for classification. The DrSVM uses the elastic-net penalty, a mixture of the L2-norm and the L1-norm penalties. By doing so, the DrSVM performs automatic variable selection in a way similar to the L1-norm SVM. In addition, the DrSVM encourages highly correlated variables to be selected (or removed) together, which is called the grouping effect. It also develops efficient algorithms to compute the whole solution paths of the DrSVM. Based on the DrSVM, the second essay proposes the hybrid huberized support vector machine (HHSVM). The HHSVM uses the elastic-net penalty and the huberized hinge loss function. Similar to the DrSVM, the HHSVM performs automatic variable selection and has the grouping effect. However its computational cost is significantly reduced due to its loss function. The third essay proposes two models for image denoising. In this essay, the L1-norm of the pixel updates is used as the penalty. The L1-norm penalty has the advantage of changing only the noisy pixels, while leaving the non-noisy pixels untouched. Efficient algorithms are designed to compute entire solution paths of these L1-norm penalized models, which facilitate the selection of a balance between the "loss" and the "penalty." The last essay proposes a two-step kernel learning method based on the support vector regression (SVR) for financial time series forecasting. Given a number of candidate kernels, our method learns a sparse linear combination of these kernels so that the resulting kernel can be used to predict well on future data. The L1-norm regularization approach is used to achieve kernel learning. Since the regularization parameter must be carefully selected, to facilitate parameter tuning, we develop an efficient solution path algorithm that solves the optimal solutions for all possible values of the regularization parameter. Our kernel learning method is applied to forecast the S&P500 and the NASDAQ market indices and shows promising results.
The Problem of African Entrepreneurial Development

Future reductions in poverty in Sub-Saharan Africa will have to come from a significant expansion in private sector activity and substantial improvements in productivity. The capacity of the sector to bring about such changes will depend importantly on the ability of entrepreneurs to develop more effective business strategies, make profitable investments, and improve technologies in use. Unfortunately, as the development literature has so often pointed out, differences in the availability of entrepreneurial talent (both technical and managerial) and differences in the motivational mechanisms that drive entrepreneurs have been important causes of Africa’s relative stagnation, compared with other parts of the developing world. So where will the necessary entrepreneurial talent come from in Africa? What types of changes in motivational mechanisms and capacities will be needed to increase its effectiveness?
The Global Precipitation Measurement (GPM) Mission Status: Emphasis on Falling Snow Retrievals

Water is essential to our planet Earth. Retrievals of falling snow from space represent an important data set for understanding the Earth's atmospheric, hydrological, and energy cycles. Knowing when, where and how precipitation falls is crucial for understanding these linkages between the Earth's water and energy cycles and is classifying surface precipitation as frozen snow versus liquid rain. The Global Precipitation Measurement (GPM) Core Observatory spacecraft launched February 27, 2014, is the anchor to the GPM international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide “next-generation” precipitation products. GPM is a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA). Status and successes in terms of spacecraft, instruments, retrieval products, validation, and impacts for science and society will be presented with an emphasis on the falling snow products and comparison to CloudSat snow products.
The relationship between price and quality in durable product categories with private label brands

This paper aims to investigate price and objective-quality in durable product categories containing national and private-label (PL) brands.,Using data from consumer reports objective-test results of 14,476 durable products available in the US the authors identified product categories containing both national and PL brands; constructed relative price- and quality-indices for each category; calculated price and quality differentials for each category then modeled the relationship between them; estimated the price premium associated with national brands (NBs); and computed price–quality (PQ) correlations for each category. The authors also analyzed the same relationships using subjective brand-perception data collected from 240 consumers.,Overall the price of NBs in durable products was substantially higher than the price of PL brands despite there being little to no difference in quality levels overall, with the proportion of categories having higher PL quality nearly equaling that of categories having superior NB quality. Correlation between price and quality was moderate. Accuracy of consumer perceptions varied depending on the importance of brand in the purchase decisions for particular product categories.,This paper uses a large objective dataset spanning a period of more than eight years to assess price and quality for durable goods in categories offering PL brands. It addresses an under-studied area, that of PL brands for higher-priced, longer-lasting products. The findings contribute to an existing understanding of PLs, especially in the domain of durable-goods, as well as to the body of research in the area of PQ relationships. It also adds to our understanding of consumers’ perceptions of brand as a factor in durable product decisions and how the market aligns with those perceptions.
Biochemical and Physical Properties of Siderophores

The significance of iron as a nutrient and its role in biological processes have major consequences in areas of science ranging from geochemistry to human disease. Invading microorganisms exposed to circulating blood produce siderophores to compete for iron with the human transport protein transferrin; this constitutes one aspect of virulence and pathogenicity. This chapter focuses on the coordination chemistry of the remarkable compounds, where a lot of function is packed into small molecules. It summarizes our knowledge of siderophores, a remarkable group of microbial iron-binding molecules. The three broad groups of siderophores (catecholates, hydroxamates, and hydroxycarboxylates) are distinguished by the chemical structure of the metal-binding functionality. The chapter places emphasis on the function, stability, structure, and spectroscopy of siderophores. The basic biochemical and physical properties do much to explain the growing body of biomedical and biochemical science surrounding the siderophores and their iron transport functions.
Influence of Mesoscale and Macroscale Heterogeneities in Metals on Higher Harmonics Under Plastic Deformation

In nonlinear ultrasonic techniques, the material nonlinearity is observable in the ultrasonic signal through the generation of higher harmonics (HH). The HH generation, however, can be triggered by many sources. Any variation in the micro-, meso-, and macroscopic scales of the structure may collectively lead to HH generation. This paper presents a finite element approach with mesoscale heterogeneities explicitly modeled for the nonlinear wave propagation. The aim of this paper is to understand HH generation due to the non-mesoscale variation and non-uniform deformations introduced by the uniaxial tensile test. The study is divided into two parts: first, the effect of non-uniform plastic deformation resulted by geometrical variation of structures on HH is studied. The effect of non-uniformity due to mesoscale variations on HH is then analyzed. The numerical studies and predictions are crossly validated with nonlinear ultrasonic experiments and microscale imaging, including X-ray diffraction scanning. Numerical and experimental studies both indicate that non-uniform variations in different length scales affect the generation of both second- and third-harmonics and that both second- and third-harmonics acoustic nonlinearity parameters grow with the increase of plastic strain level. However, the third-harmonics acoustic nonlinearity coefficient is more sensitive when micro-, meso- and macrostructural variations exist.
Development of brain PET imaging agents: Strategies for imaging neuroinflammation in Alzheimer's disease

Neuroinflammation is thought to play a key role in the development and progression of neurodegenerative diseases such as Alzheimer's disease. Positron emission tomography (PET) is an in vivo imaging technique capable of studying the biochemical processes which provide the molecular basis of disease. PET imaging of neuroinflammation, which is characterized by the activation of glial cells in the central nervous system (CNS), has been traditionally studied using radiotracers targeting the translocator protein 18kDa (TSPO). However, limitations in the properties of PET radiotracers for imaging the TSPO has led to the search for alternative strategies for imaging neuroinflammation. The current review presents the current status of PET radiotracers for imaging the TSPO, and describes alternative biological targets that have gained interest for imaging of microglial activation over recent years. These include cannabinoid receptor type-2, cyclooxygenase-2, the P2X7 receptor, CSF1R and reactive oxygen species and some promising radiotracers for these targets. Although a lot of advances have been made in the field of imaging neuroinflammation, current radiotracers all target the pro-inflammatory (M1) phenotype of activated microglia, since the number of known biological targets specific for the anti-inflammatory (M2) phenotype, is still limited. In spite of these limitations, PET imaging studies comparing the temporal relationship between Aβ plaque formation, microglial activation, and the formation of tau-based neurofibrillary tangles would provide valuable information on the "neuroinflammatory hypothesis" of neurodegeneration. The development of a suitable radiotracer for imaging the anti-inflammatory, M2 microglia would represent a great advance in imaging neuroinflammation since this would allow for imaging of the dynamics of microglial activation in different diseases.
Application of the genetic algorithm for computer-aided design of VLSI layout

This research investigates the application of the Genetic Algorithm for four VLSI layout problems, Gate Matrix Layout, Partitioning, Standard Cell, and Macro Cell Placement. In permutation problems such as placement and gate matrix optimization, the traditional binary genetic operators cause conflicts, and hence cannot be applied without modifications. This research investigates various chromosomal representations and the genetic operators that eliminate such conflicts, and adapt the GA for efficient optimization of these CAD problems. The Standard Cell Placement algorithm uses three crossover operators, Order, PMX, and Cycle crossover, in order to manipulate the placement efficiently during the optimization process. The algorithm was tested against TimberWolf 3.3 on five industrial circuits consisting of 100 to 800 cells, and the performance was comparable. The Macro Cell Placement algorithm uses a bit matrix to represent various sizes, shapes and orientations of macro cells. For chromosomes having thousands of bits, the processing of a bit matrix during crossover is much faster than a linear bit string. The algorithm was used to place five MCNC benchmark circuits, and the complete layout including routing was obtained by interfacing the algorithm to the Berkeley CAD tools. The Gate Matrix algorithm uses a novel implementation of the GA in combination with beam search. The principles of beam search have been used in order to resolve the conflicts in the traditional GA, while simultaneously reducing the search space. The algorithm produces better results than simulated annealing and a graph theoretic approach on published netlists. The GA has been implemented for circuit partitioning with a significant improvement in result quality compared to the Fiduccia-Matthesis algorithm. It can optimize a cost function with multiple constraints. Separate algorithms have been developed for bipartitioning and multiway partitioning. The bipartitioning problem is represented as a binary chromosome. Efficient bit-mask operations perform crossover, mutation, and net cut evaluation 32 bits at a time, without unpacking. The multiway partitioning algorithm has a global view of the problem, and optimizes all the necessary partitions simultaneously. The algorithms were tested on the MCNC benchmark circuits, and the cut size obtained was lower than that for the conventional Fiduccia-Matthesis algorithm.
Serverless Workflows for Indexing Large Scientific Data

The use and reuse of scientific data is ultimately dependent on the ability to understand what those data represent, how they were captured, and how they can be used. In many ways, data are only as useful as the metadata available to describe them. Unfortunately, due to growing data volumes, large and distributed collaborations, and a desire to store data for long periods of time, scientific "data lakes" quickly become disorganized and lack the metadata necessary to be useful to researchers. New automated approaches are needed to derive metadata from scientific files and to use these metadata for organization and discovery. Here we describe one such system, Xtract, a service capable of processing vast collections of scientific files and automatically extracting metadata from diverse file types. Xtract relies on function as a service models to enable scalable metadata extraction by orchestrating the execution of many, short-running extractor functions. To reduce data transfer costs, Xtract can be configured to deploy extractors centrally or near to the data (i.e., at the edge). We present a prototype implementation of Xtract and demonstrate that it can derive metadata from a 7 TB scientific data repository.
Clinical recommendations made in dermatology publications are frequently not supported by adequate evidence.

Objectives: Absolute risk and cost-benefit analyses are necessary to guide clinical decision making. The purpose of this study was to evaluate whether clinical recommendations in dermatology public...
Proteomics-Based Characterization of the Effects of MMP14 on the Protein Content of Exosomes from Corneal Fibroblasts

Background Exosomes secreted by corneal fibroblasts contain matrix metalloproteinase (MMP) 14, which is known to influence pro-MMP2 accumulation on exosomes. Accordingly, we hypothesized that the enzymatic activity of MMP14 may alter the protein content of corneal fibroblast- secreted exosomes. Objective The aim of this study was to investigate the effects of MMP14 on the composition and biological activity of corneal fibroblast-derived exosomes. Methods Knock out of the catalytic domain (ΔExon4) of MMP14 in corneal fibroblasts was used to determine the effect of MMP14 expression on the characteristics of fibroblast-secreted exosomes. The amount of secreted proteins and their size distribution were measured using Nano Tracking Analysis. Proteins within exosomes from wild-type (WT) and ΔExon4-deficient fibroblasts were identified by liquid chromatography-tandem mass spectrometry (MS/MS) proteomics analysis. The proteolytic effects of MMP14 were evaluated in vitro via MS identification of eliminated proteins. The biological functions of MMP14-carrying exosomes were investigated via fusion to endothelial cells and flow cytometric assays. Results Exosomes isolated from WT and ΔExon4-deficient fibroblasts exhibited similar size distributions and morphologies, although WT fibroblasts secreted a greater amount of exosomes. The protein content, however, was higher in ΔExon4-deficient fibroblast-derived exosomes than in WT fibroblast-derived exosomes. Proteomics analysis revealed that WT-derived exosomes included proteins that regulated cell migration, and ΔExon4 fibroblast-derived exosomes contained additional proteins that were cleaved by MMP14. Conclusion Our findings suggest that MMP14 expression influences the protein composition of exosomes secreted by corneal fibroblasts, and through those biological components, MMP14 in corneal fibroblasts derived-exosomes may regulate corneal angiogenesis.
A knowledge-based organ dose prediction tool for brachytherapy treatment planning of patients with cervical cancer

Abstract Purpose The purpose of this study is to explore knowledge-based organ-at-risk dose estimation for intracavitary brachytherapy planning for cervical cancer. Using established external-beam knowledge-based dose-volume histogram (DVH) estimation methods, we sought to predict bladder, rectum, and sigmoid D2cc for tandem and ovoid treatments. Methods and materials A total of 136 patients with loco-regionally advanced cervical cancer treated with 456 (356:100 training:validation ratio) CT-based tandem and ovoid brachytherapy fractions were analyzed. Single fraction prescription doses were 5.5–8 Gy with dose criteria for the high-risk clinical target volume, bladder, rectum, and sigmoid. DVH estimations were obtained by subdividing training set organs-at-risk into high-risk clinical target volume boundary distance subvolumes and computing cohort-averaged differential DVHs. Full DVH estimation was then performed on the training and validation sets. Model performance was quantified by ΔD2cc = D2cc(actual)-D2cc(predicted) (mean and standard deviation). ΔD2cc between training and validation sets were compared with a Student's t test (p Results Training set deviations were bladder ΔD2cc = −0.04 ± 0.61 Gy, rectum ΔD2cc = 0.02 ± 0.57 Gy, and sigmoid ΔD2cc = −0.05 ± 0.52 Gy. Model predictions on validation set did not statistically differ: bladder ΔD2cc = −0.02 ± 0.46 Gy (p = 0.80), rectum ΔD2cc = −0.007 ± 0.47 Gy (p = 0.53), and sigmoid ΔD2cc = −0.07 ± 0.47 Gy (p = 0.70). The only significant categorical variable was the attending physician for bladder and rectum ΔD2cc. Conclusion A simple boundary distance-driven knowledge-based DVH estimation exhibited promising results in predicting critical brachytherapy dose metrics. Future work will examine the utility of these predictions for quality control and automated brachytherapy planning.
Understanding Dog Bites: The Important Role of Human Behavior

This research contributes to extant knowledge about dog bites by using police department bite incident data to explore three sets of potential correlates of bites: traits of the victim, traits of t...
Democratizing local government: What Malaysia can learn from Mexico and India

The Pakatan Harapan 2018 election manifesto had established commitments to strengthen the authority of local government, and to make local councils more accountable. This suggested that the local government elections would resume, after an absence of more than 60 years. While the Pakatan Harapan’s tenure as Malaysia’s ruling government was shortlived, their rise to power did put the local government back into the spotlight, as well as elevated the prospects of the resumption of local government elections in the country. There are a number of reasons that supports a more democratic and participatory approach to local government which has been highly hoped for in Malaysia. These include the view that it discourages public malfeasance and produces local officials that are more responsive to the needs of the citizens they serve. However, there are challenges that follow with the introduction of a more democratic form of local government, especially for countries that are attempting to transition from authoritarianism to a democracy at the national level, and contain a diverse multi-ethnic population of differing socio-economic backgrounds. In order to better understand what these challenges are and how they can be overcome, this study examines two case studies, Mexico and India. These two countries have shown some similarities to Malaysia, particularly with regards to regime-type and demographics. This study considers the evolving approach taken by these two countries on their local government, in terms of their structure and practices. It is proposed that the case studies could provide potential lessons for Malaysia. This study begins with a brief historical overview of the system of local government in Malaysia to present day. This is followed by a discussion of the uneven experiences of Mexico and India on the efforts to democratize their local governments. The findings from the examination of both the case studies reveal the manner for which the countries with an authoritarian past often undergo during a transitional period, whereby although the structures of local governance have become more democratic, local officials and citizens are remain trapped in the old authoritarian modes of behavior. Unless interventionist steps are taken, democratizing local government structures alone do not necessarily lead to greater citizen empowerment, especially for those from the more marginalized sections of society.
Biomechanics of Circumferential Cervical Fixation Using Posterior Facet Cages: A Cadaveric Study.

OBJECTIVE Anterior cervical discectomy and fusion (ACDF) is a common procedure for the treatment of cervical disease. Circumferential procedures are options for multilevel pathology. Potential complications of multilevel anterior procedures are dysphagia and pseudarthrosis, whereas potential complications of posterior surgery include development of cervical kyphosis and postoperative chronic neck pain. The addition of posterior cervical cages (PCCs) to multilevel ACDF is a minimally invasive option to perform circumferential fusion. This study evaluated the biomechanical performance of 3-level circumferential fusion with PCCs as supplemental fixation to anteriorly placed allografts, with and without anterior plate fixation. METHODS Nondestructive flexibility tests (1.5 Nm) performed on 6 cervical C2-7 cadaveric specimens intact and after discectomy (C3-6) in 3 instrumented conditions: allograft with anterior plate (G+P), PCC with allograft and plate (PCC+G+P), and PCC with allograft alone (PCC+G). Range of motion (ROM) data were analyzed using 1-way repeated-measures analysis of variance. RESULTS All instrumented conditions resulted in significantly reduced ROM at the 3 instrumented levels (C3-6) compared to intact spinal segments in flexion, extension, lateral bending, and axial rotation (p < 0.001). No significant difference in ROM was found between G+P and PCC+G+P conditions or between G+P and PCC+G conditions, indicating similar stability between these conditions in all directions of motion. CONCLUSION All instrumented conditions resulted in considerable reduction in ROM. The added reduction in ROM through the addition of PCCs did not reach statistical significance. Circumferential fusion with anterior allograft, without plate and with PCCs, has comparable stability to ACDF with allograft and plate.
Frequency of Withdrawal of Life-Sustaining Therapy for Perceived Poor Neurologic Prognosis.

To measure the frequency of withdrawal of life-sustaining therapy for perceived poor neurologic prognosis among decedents in hospitals of different sizes and teaching statuses. Design We performed a multicenter, retrospective cohort study. Setting Four large teaching hospitals, four affiliated small teaching hospitals, and nine affiliated nonteaching hospitals in the United States. Patients We included a sample of all adult inpatient decedents between August 2017 and August 2019. Measurements and main results We reviewed inpatient notes and categorized the immediately preceding circumstances as withdrawal of life-sustaining therapy for perceived poor neurologic prognosis, withdrawal of life-sustaining therapy for nonneurologic reasons, limitations or withholding of life support or resuscitation, cardiac death despite full treatment, or brain death. Of 2,100 patients, median age was 71 years (interquartile range, 60-81 yr), median hospital length of stay was 5 days (interquartile range, 2-11 d), and 1,326 (63%) were treated at four large teaching hospitals. Withdrawal of life-sustaining therapy for perceived poor neurologic prognosis occurred in 516 patients (25%) and was the sole contributing factor to death in 331 (15%). Withdrawal of life-sustaining therapy for perceived poor neurologic prognosis was common in all hospitals: 30% of deaths at large teaching hospitals, 19% of deaths in small teaching hospitals, and 15% of deaths at nonteaching hospitals. Withdrawal of life-sustaining therapy for perceived poor neurologic prognosis happened frequently across all hospital units. Withdrawal of life-sustaining therapy for perceived poor neurologic prognosis contributed to one in 12 deaths in patients without a primary neurologic diagnosis. After accounting for patient and hospital characteristics, significant between-hospital variability in the odds of withdrawal of life-sustaining therapy for perceived poor neurologic prognosis persisted. Conclusions A quarter of inpatient deaths in this cohort occurred after withdrawal of life-sustaining therapy for perceived poor neurologic prognosis. The rate of withdrawal of life-sustaining therapy for perceived poor neurologic prognosis occurred commonly in all type of hospital settings. We observed significant unexplained variation in the odds of withdrawal of life-sustaining therapy for perceived poor neurologic prognosis across participating hospitals.
“Multi-scale Analysis of Urban Spatial Structures acquired from OpenStreetMap”

We propose computationally feasible statistical algorithms for the automated assessment of isolation and integration of urban locations and neighborhoods by using maps acquired from the OpenStreetMap service. Integration and isolation defined by observing the properties of scale-dependent random walks on city street maps are not always opposites. While isolation worsens economic and social mobility prospects in sprawling metropolitan areas, some secluded places homing the wealthiest can be characterized as being in integrated isolation in the city.
A touch panel system for control applications

The use of finger-sensitive touch panels in association with computer-generated displays for control and monitoring of the Stanford linear accelerator is discussed. This control concept has proven to be very effective. The hardware and software aspects of the Touch Panel portion of the control system are described.
Multiple barriers to gene exchange in a field cricket hybrid zone

Data on patterns of variation within hybrid zones, combined with studies of life history, mate choice, and hybrid performance, allow estimates of the contribution of different pre-zygotic and post-zygotic barriers to reproductive isolation. We examine the role of behavioural barriers to gene exchange in the maintenance of a hybrid zone between North American field crickets Gryllus firmus and Gryllus pennsylvanicus. We consider these barriers in the context of previous studies that documented temporal and ecological isolation and a one-way post-mating incompatibility (i.e. G. firmus females do not produce offspring when they mate only with heterospecific males). Based on no-choice mating experiments in the laboratory, we demonstrate strong behavioural pre-mating barriers between the two species, but no apparent fecundity or fertility costs for G. firmus females when they mate with both conspecific and heterospecific males. Furthermore, we show that G. firmus females do not discriminate between hybrids and conspecifics, whereas G. pennsylvanicus females do. This observation could explain the asymmetric allele introgression observed in the hybrid zone. We also document a failure of heterospecific males to induce normal oviposition in G. firmus females, which may be due to rapid evolution of accessory gland proteins and may serve as an additional barrier to gene exchange. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 390–402.
Androgen treatment and recovery of function following recurrent laryngeal nerve injury in the rat.

Purpose: To investigate the effects of the androgen testosterone propionate (TP), on regeneration of the recurrent laryngeal nerve (RLN) after unilateral crush injury using assessment of vocal fold mobility (VFM) as a measure of behavioral recovery. Methods: 48 adult male rats underwent standardized crush injury of left RLN and received treatment in the form of 2 silastic capsules containing TP or controls receiving a blank capsule (untreated). Direct laryngoscopic assessment of vocal cord mobility was performed before, immediately following and 1, 2, 3, 4, 5 or 6 weeks post injury. Results: Treatment with TP enhanced the recovery of full VFM following crush injury of the RLN compared to controls. There was statistically significant improvement in VFM seen at the 1 and 2 week time points (p < 0.05). By 4 weeks TP-treated rats displayed a 100% recovery of VFM function, compared to only 50% by the control group. Conclusions: TP enhances RLN functional recovery following a crush injury, which further supports its potential general applicability as a therapeutic agent in peripheral nerve injury.
Role of laparoscopic stone surgery.

OBJECTIVES To define the role of laparoscopic stone surgery in current urologic practice. METHODS All cases of laparoscopic surgery for renal calculus disease performed at a single institution during a 2-year period were reviewed. A total of 449 stone-removing procedures were performed by one of us (D.G.A.) during this interval, of which 5 were laparoscopic (1.1%). Of the five laparoscopic procedures, three were pyelolithotomy/pyeloplasty, one was laparoscopic-assisted percutaneous nephrostolithotomy, and one was caliceal diverticular stone removal. RESULTS All 5 patients were rendered stone free, and no patient had perioperative complications. CONCLUSIONS A laparoscopic approach is rarely needed in patients requiring stone removal. However, it can be a safe and effective approach in the management of select patients with complex stone disease.
Intestinal mitochondrial calcium uptake during adaptation to dietary calcium restriction

In order to evaluate the role of mitochondrial calcium uptake in intestinal calcium absorption, the effect of adaptation to dietary calcium deficiency on the in vitro uptake of calcium by isolated duodenal mitochondria was studied. Experiments were performed utilizing 28-day-old cockerels which had received a diet adequate in vitamin D3 and phosphate and containing either 0.08% or 1.20% calcium. Mitochondrial 45Ca uptake from chicks deprived of dietary calcium was not significantly different from controls. These results suggest that increased calcium uptake by intestinal mitochondria is not crucial for adaptation to a low calcium diet.
A multiple group method of factoring the correlation matrix

There are a number of methods of factoring the correlation matrix which require the calculation of a table of residual correlations after each factor has been extracted. This is perhaps the most laborious part of factoring. The method to be described here avoids the computation of residuals after each factor has been computed. Since the method turns on the selection of a set of constellations or clusters of test vectors, it will be calleda multiple group method of factoring. The method can be used for extracting one factor at a time if that is desired but it will be considered here for the more interesting case in which a number of constellations are selected from the correlation matrix at the start. The result of this method of factoring is a factor matrixF which satisfies the fundamental relationFF'=R.
Development Of A Photonic Data Recorder

In conjunction with our implementation of photonic diagnostics on pulsed power accelerators at Sandia, we are developing a Photonic Data Recorder (PDR) which sweeps and records photon analog signals directly rather than converting photons to electrons and sweeping the electrons, as in a conventional oscilloscope or streak camera.
Sustainable and increased food production

Abstract In the next decades, Asian farmers—particularly rice growers—will collectively face the biggest challenge of their lives in trying to produce enough food for the very rapidly growing world populations dependent on them. For practitioners of the systems approach, primary attention must focus on how to help those farmers meet this challenge. Any narrow scientific or technical approach aimed just at providing productive and sustainable systems will not provide the answer to the complex question of how to make the very fundamental changes which are required. Scientists, particularly those at the international agricultural research centers such as IRRI and its national partners, accordingly must conceive of and carry out their research in a constantly broader framework. They must take into consideration the whole range of human problems that farmers face, problems which will differ substantially from region to region. Achieving real sustainability that not only produces enough food for the present, and protects the key assets for the future (i.e. water and particularly soil), but also does this without disrupting the age-old and usually healthy rhythms of rural life is indeed a mighty challenge. Although the adaptation of systems that scientists design to meet the needs of farmers in the thousands of different ecological and economic circumstances is a formidable challenge at the micro level, there is an even more daunting task still that requires the serious participation of scientists, i.e. devising country-specific strategies for attaining agricultural sustainability. Such strategies must address economic, political, environmental and social conditions and objectives. They can take many forms and be of varying sophistication, but must be based on a realistic analysis of such diverse aspects as trade, science, and demographics. Forming the partnerships that can facilitate the tough political decisions required from national leaders and international supporters must become one of the highest priorities of all those concerned with sustainable increases in food production.
Cholesteryl lignocerate hydrolysis in adrenoleukodystrophy.

Summary: Because cholesteryl esters with very long chain fatty acids accumulate in Schilder adrenoleukodystrophy, the ability of extracts of such fibroblasts to hydrolyze [14C]cholesteryl lignocerate was examined. Hydrolytic activity was detected at pH 3.0, and this activity was impaired by sulfhydryl inactivating agents. Cholesteryl lignocerate hydrolysis was deficient in cells from patients with cholesteryl ester storage disease or Wolman disease due to acid lipase deficiency, but was in the control range for adrenoleukodystrophy fibroblasts. This suggests that cholesteryl lignocerate hydrolysis can be carried out by acid lipase. Speculation: Deficiency of a specific lysosomal lipase is probably not the genetic defect in Schilder adrenoleukodystrophy. A defect in long chain fatty acid metabolism may be more likely.
Cooperation and Conflict within Groups: Bridging Intragroup and Intergroup Processes

Whereas intragroup processes and intergroup relations are often assumed to reflect discrete processes and cooperation and conflict to represent alternative outcomes, the present article focuses on intergroup dynamics within a shared group identity and challenges traditional views of cooperation and conflict primarily as the respective positive and negative outcomes of these dynamics. Drawing on the ideas, theories, and evidence presented in other articles in this volume, we (1) consider the dynamic tension between stability and change that exists within hierarchical groups; (2) discuss the different perspectives that advantaged and disadvantaged subgroups within a larger group have regarding this tension; (3) propose that cooperation and conflict should be viewed as developmental processes in the life of a group; (4) suggest that constructive resolution of conflict depends upon whether subgroups manage to satisfy the different needs of each group, and (5) conclude by discussing the personal, social, and policy implications of this perspective.
Growth inhibition, mitotic cycle time and cell number in chronically irradiated root meristems of Pisum

Abstract Seedlings of Pisum sativum were chronically irradiated with gamma rays from a Co60 source at daily exposure rates sufficient to produce growth inhibition. Exposure rates of 500 and 1000 r/day reduced root growth by the fourth day. In order to determine the factor(s) that might be responsible for the reduced growth rate, the following measurements were made: (1) the number of cells comprising the root meristem was determined daily for seven days, (2) the percentage of aberrant cells at anaphase was scored after three days exposure, and (3) the minimum mitotic cycle time for meristematic cells was established, also after three days of exposure. Cell counts showed an approximate reduction of 5, 25, and 45 per cent compared to control on the third day of exposure at rates of 250, 500 and 1000 r per day. The minimum mitotic cycle time was measured by producing a tetraploid cell population with colchicine and noting the span of time between the production of this population and its initial appearance in the subsequent mitosis. These measurements indicated no change in the minimum cycle time of the cells in the irradiated meristems as compared to the unirradiated controls. Analysis of cells at anaphase showed an increase in the number of cells with broken chromosomes with increased exposure rate. Therefore, the reduction in growth observed in irradiated seedlings was attributed to the loss of reproductive integrity not due to a general slowing down of the cells' division rate but rather to genetic loss and/or unbalance and mitotic arrest of meristematic cells.
Effects of polydispersity on confined homopolymer melts: A Monte Carlo study

New insight into the molecular scale details of polymer melts under confined conditions is obtained from the first dynamic Monte Carlo study incorporating polydispersity. While confinement effects on polymers have been widely explored, little work exists on the effects of polydispersity. This is surprising given the near universal presence of polydispersity in physical systems. To address this shortcoming, a new variation of on-lattice dynamic Monte Carlo simulation is used to provide an understanding of how polydispersity alters confinement effects on polymer melts. Polymer melts of varying polydispersity are simulated between two hard walls (surface interaction parameter, χs = 0) of variable spacing. As plate spacing decreases, polymer chains adopt conformations in which the end-to-end vector is parallel to the hard walls. However, polydisperse melts with the same length average molecular weight, Nw (which is analogous to the weight average molecular weight, Mw) show reduced orientation effects. Polydis...
Effect of androgens on plasma somatomedin-C/insulin-like growth factor I responses to growth hormone.

SUMMARY In search of the mechanism for the relatively high plasma somatomedin-C (Sm-C) concentrations in pubertal boys and girls, we have measured the plasma Sm-C responses to exogenous growth hormone (GH) in prepubertal hypopituitary boys before and after testosterone administration. Sm-C responses were determined in 5 hypopituitary boys (9–14 years of age) who were given two successive injections of GH (0·1 U/kg) 48 h apart. Eight days later, after administering 200 mg testosterone IM, their Sm-C responses to the same GH challenge were reassessed. There were no significant differences between the pre-testosterone Sm-C response to GH and the post-testosterone response, despite evidence for reductions in 24 h urinary nitrogen excretion and serum urea nitrogen concentrations in response to testosterone. The results provide no evidence that androgen augments the effect of GH to raise plasma Sm-C during puberty, or that androgen has a direct stimulatory effect on Sm-C production. By inference and from published reports, it appears more likely that a sex hormone-stimulated increase in GH secretion is responsible for the increased Sm-C observed during puberty.
Helper Th1 and Th2 cell responses following mucosal or systemic immunization with cholera toxin.

We have used the potent mucosal immunogen cholera toxin (CT) to assess antigen-specific CD4+ T-cell responses, including Th1- and Th2-type cells in mucosa-associated tissues, e.g. Peyer's patches (PP), and systemic tissue, e.g. spleen (SP), for their regulatory role in the induction of CT-specific B-cell antibody responses in the gastrointestinal (GI) tract as well as in systemic sites. The CT was given by either oral or intravenous (i.v.) routes and the mice orally immunized with CT exhibited brisk IgA anti-CT antibody responses in faecal extracts and elevated IgG anti-CT antibody responses in serum. Further, significant IgA anti-CT spot-forming cells (SFCs) were seen in lamina propria lymphocytes (LPLs) from mice orally immunized with CT. In contrast, i.v. immunization with CT induced IgM and IgG anti-CT SFC responses in SP, and serum anti-CT antibodies of these two isotypes; no anti-CT responses were induced in the GI tract after immunization by this route. The CD4+ T cells isolated from PP and SP of mice orally immunized with CT were stimulated in vitro with CT-B-coated latex microspheres for 1-6 days, and the induction of IL-2 and interferon gamma (IFN-gamma) (Th1-type) or IL-4 and IL-5 (Th2-type) producing SFCs were analysed by a cytokine-specific ELISPOT and cytokine-specific mRNA was detected by reverse transcriptase (RT)-PCR assays.(ABSTRACT TRUNCATED AT 250 WORDS)
The spectral evolution of classical gamma-ray bursts

Abstract Gamma ray burst spectral evolution is characterized by two trends: on time scales of ∼ 1 s the hardness and intensity rise and fall together, but there is hard-to-soft evolution within and between intensity spikes. The major issues in the study of spectral evolution are the universality of this characterization, and whether the observed broad-band spectra are truly broad-band or whether they consist of many short-lived narrow-band (e.g., black body) flares. We present results from techniques which sacrifice spectral resolution for temporal resolution.
Non-facial and non-verbal affective expression for appearance-constrained robots used in victim management

Non-facial and non-verbal methods of affective expression are essential for social interaction in appearance-constrained robots such as those used in search and rescue, law enforcement, and military applications. This research identified five main methods of non-facial and non-verbal affective expression (body movements, postures, orientation, color, and sound). Based on an extensive review of literature, prescriptive design recommendations were developed for the appropriate non-facial and non-verbal affective expression methods for three proximity zones of interest (intimate, personal, and social). These design recommendations serve as guidelines to add retroactively affective expression through software with minimal or no physical modification to a robot. A large-scale, complex human-robot interaction study was conducted to validate these design recommendations using 128 participants and four methods of evaluation. The study was conducted in a high-fidelity, confined-space simulated disaster site with all robot interactions performed in the dark. Statistically significant results indicated that participants felt the robots that exhibited affective expressions were more calming, friendly, and attentive, which improved the social human-robot interactions.
Influence of the pituitary gland on sodium conservation, plasma renin and renin substrate concentrations in the rat.

The responses of plasma renin and renin substrate concentrations to changes in dietary sodium intake have been investigated in normal and hypophysectomized rats. In the normal rat sodium deprivation for 13 days produced a striking increase in plasma renin concentration. However, unlike the response observed in other species, administration of 0.45 and 0.9 % sodium chloride in the drinking water failed to suppress the level of plasma renin below that observed in rats drinking 0.18% saline. No significant changes in plasma renin substrate concentration were induced by the various alterations in sodium intake. The changes observed in plasma renin concentration support the view that the renin-angiotensin system is involved in sodium conservation in the rat, perhaps in part via the stimulation of aldosterone secretion. In the hypophysectomized groups of animals similar changes in plasma renin concentration were observed in relation to changes in salt balance, indicating that the basic responsiveness of the sys...
Michaelis-Menten Kinetics at High Enzyme Concentrations

The total quasi-steady state approximation (tQSSA) for the irreversible Michaelis-Menten scheme is derived in a consistent manner. It is found that self-consistency of the initial transient guarantees the uniform validity of the tQSSA, but does not guarantee the validity of the linearization in the original derivation of Borghans et al. (1996, Bull. Math. Biol., 58, 43-63). Moreover, the present rederivation yielded the noteworthy result that the tQSSA is at least roughly valid for any substrate and enzyme concentrations. This reinforces and extends the original assertion that the parameter domain for which the tQSSA is valid overlaps the domain of validity of the standard quasi-steady state approximation and includes the limit of high enzyme concentrations. The criteria for the uniform validity of the original (linearized) tQSSA are corrected, and are used to derive approximate solutions that are uniformly valid in time. These approximations overlap and extend the domains of validity of the standard and reverse quasi-steady state approximations.
Future Directions in Overactive Bladder Treatment

Overactive bladder (OAB) remains a remarkably common urologic condition resulting in significant clinical and economic sequelae. Although likely underestimated, the overall prevalence of overactive bladder is projected to be between 15% and 38%. The mainstay of therapy for decades has revolved around anticholinergic pharmaceuticals. However, recent advances in bladder and urothelial physiology have dramatically expanded the treatment options available for OAB management. Herein we present an overview of several emerging options for OAB therapy and review the available literature regarding these therapies. Despite substantial investment into OAB treatment, we are witness to but the genesis of research on detrusor function and urothelial biology that will guide practitioner interventions in the coming decades. Immense opportunity exists for future evaluation of OAB pathophysiology to advance our knowledge regarding management of this multifactorial urologic disorder.