cssi/SciSciGPT-SciSciNet huggingface dataset:
A METHOD OF INEXACT STEEPEST DESCENT FOR SYSTEMS OF LINEAR EQUATIONS

Al~tract---Our approach combines the method of inexact steepest descent with the method of contractor directions to obtain an algorithm for solving systems of linear equations. In order to enhance the scope of applicability, we consider an iterative method with variable step-size iterations. We prove the convergence and given an error estimate for our method. The algorithm is well-suited for parallel computation. In fact, for systems with m equations and n unknowns, each iteration may be computed in parallel time O(log m + log n), on an EREW PRAM with O (mn ) processors. The well-known method of steepest descent can also be applied to solve systems of linear algebraic equations. However, in practice, it is usually impossible to carry out the steepest descent computations exactly, e.g. due to the floating point arithmetic error. For this reason, we introduce a method of inexact steepest descent, or a gradient type method, with a variable step-size. Our method incorporates Altman's method of contractor directions [1, 2] together with some of the ideas from Ref. [3]. It is an iterative method with backtracking whose individual iteration steps can be computed with a high degree of parallelism. Moreover, the method of contractor directions allows for an additional level of parallel computation in that the computations for backtracking may be performed simultaneously. The method may be applied to systems of equations where m, the number of equations, is not equal to n, the number of unknowns.
Ultrastructural changes associated with pheromone production in the sex pheromone gland of Diatraea saccharalis

Abstract An ultrastructural study of the sex pheromone gland of female adult sugarcane borers suggests that pheromone is not produced during the first 2 hr after emergence but reaches a peak 48 hr after emergence. The sex pheromone gland is composed of two cell types and a number of structural changes observed to occur in the cells of the sex pheromone gland prior to pheromone production are described.
Stability of linear multivariable feedback systems

The stability of linear time-invariant multivariable feedback systems is studied from their open-loop transfer function matrices. It is shown that the stability of a multivariable feedback system depends on the determinant of the loop-difference matrix (det(I + G 1 G 2 )) and the characteristic polynomials of its open-loop transfer function matrices. The controllability and observability properties of the feedback system are considered. Hence the stability conditions insure the stability at the output terminals as well as at the state variables of the system. These conditions can be easily checked by using Nyquist plot, the root locus technique, or the Routh-Hurwitz criterion.
Laplacian-Isoparametric Grid Generation Scheme

An alternative to the commonly employed Laplacian grid generation scheme for finite element problems is developed. The procedure is based upon a local quadratic isoparametric transformation. The proposed isoparametric generation scheme overcomes the one serious defect of the commonly used Laplacian scheme, i.e., the inability to significantly utilize boundary curvature information and boundary node point spacing information when locating interior nodes. In addition, a generalized generation scheme is given that includes the Laplacian and isoparametric schemes as special cases of a family of generation schemes; this family is defined by a parameter with a range of zero (Laplacian grid) to one (isoparametric grid). Examples are given which compare grids generated for various values of the parameter.
The dangers of black-and-white conservation.

The world is a complex place. To simplify this complexity, people often reduce it to simple either–or choices— black or white, do or don’t, yes or no, winners or losers, nature or nurture, and so on. Even our computer systems are based on binary logic. Conservationists are people, so we tend to do this too. Case in point: protected areas. Protected areas have long been the cornerstone of conservation, both nationally and internationally. Many of the areas we aim to protect exist as remnants of natural habitat in highly fragmented landscapes or are carved out of larger areas that are rapidly being eroded by human actions. The protected areas—parks, nature reserves, wildlife refuges, wilderness areas—are often viewed as “islands” of nature surrounded by an inimical matrix with little conservation value. Decades ago, ecologists provided a scientific foundation for this view in the theory of island biogeography, which likened nature reserves to oceanic islands and explained their species richness and rates of biodiversity loss in terms of the size and isolation of the reserves. Even though we know that reserves and protected areas are not really islands and the surrounding landscape is not really the same as an ocean, this binary view—that areas are either protected and have conservation value or they are not and they do not—continues to hold sway over a good deal of thinking in conservation and resource management. Another case in point: the benefits of nature. Conservation is ultimately founded on the values that people and societies place on nature. These values, too, have tended to be viewed simplistically, contrasting the aesthetic, spiritual, and ethical benefits of conserving nature and biodiversity with the more pragmatic and economic benefits of protection. This distinction is not new—many Nature Conservancy preserves, for example, were created based on their beauty or an ethical responsibility to protect remnant populations of rare plants and animals, and the U. S. National Wildlife Refuge System was established largely to manage populations of game species for recre-
Nanoscratch studies of uncoated and coated ceramic matrix composite materials

Ceramics and cermets (ceramic matrix composites) are commonly used for various structural and tribological applications. Pullout of phases at high loads in a composite can be an issue and can be alleviated using a hard overcoat. In this study, nanoscratch and nanoindentation experiments on a SiC composite impregnated with graphite were carried out using a depth-sensing nanoindenter. Additional indentation studies on the graphite phase were carried out to examine whether it becomes fractured or dislodges readily. Additionally, experiments were carried out to study scratch performance and nanohardness of a hard overcoat and its ability to protect SiC composite phases underneath. We find that a hard overcoat adequately protects the substrate underneath. Finally, nanoscratch and nanoindentation experiments were performed on pure SiC as well as commonly used manufactured carbon-carbon graphite. It is found that SiC exhibits the highest scratch resistance and carbon graphite the least.
Meta-analysis of sentinel lymph node positivity in thin melanoma (≤1 mm)

BACKGROUND: Despite the lack of an established survival benefit of sentinel lymph node (SLN) biopsy, this technique has been increasingly applied in the staging of thin (≤1 mm) melanoma patients, without clear evidence to support this recommendation. The authors performed a meta-analysis to estimate the risk, potential predictors, and outcome of SLN positivity in this group of patients. METHODS: MEDLINE, EMBASE, and Cochrane databases were searched for rates of SLN positivity in patients with thin melanoma. The methodologic quality of included studies was assessed using the Methodological Index for Non-Randomized Studies criteria. Heterogeneity was assessed using the Cochran Q statistic, and publication bias was examined through funnel plot and the Begg and Mazumdar method. Overall SLN positivity in thin melanoma patients was estimated using the DerSimonial-Laird random effect method. RESULTS: Thirty-four studies comprising 3651 patients met inclusion criteria. The pooled SLN positivity rate was 5.6%. Significant heterogeneity among studies was detected (P = .005). There was no statistical evidence of publication bias (P = .21). Eighteen studies reported select clinical and histopathologic data limited to SLN-positive patients (n = 113). Among the tumors from these patients, 6.1% were ulcerated, 31.5% demonstrated regression, and 47.5% were Clark level IV/V. Only 4 melanoma-related deaths were reported. CONCLUSIONS: Relatively few patients with thin melanoma have a positive SLN. To the authors' knowledge, there are no clinical or histopathologic criteria that can reliably identify thin melanoma patients who might benefit from this intervention. Given the increasing diagnosis of thin melanoma, in addition to the cost and potential morbidity of this procedure, alternative strategies to identify patients at risk for lymph node disease are needed. Cancer 2009. © 2008 American Cancer Society.
Long-Term Developmental Outcomes of Prenatal Cocaine Exposure

The developmental outcomes of prenatal cocaine/polydrug exposure were evaluated using a multivariate research design that controlled for the possible confounding variables of age, sex, socioeconomi...
Environmental oxygen tension affects phenotype in cultured bone marrow-derived macrophages.

This study tested the hypothesis that the unique phenotype of alveolar macrophages (AM) is maintained through adaptation to the relatively high oxygen partial pressure (Po2) of the lung, through mo...
Impact of a Pharmacist on Compliance With Hospital Core Measures.

Purpose:The role of a pharmacist in achieving compliance with hospital core measures is described.Summary:Core measures for hospitals, also known as quality measures, were introduced by the Department of Health and Human Services as an initiative to improve health care through accountability and public disclosure. Hospitals receive financial incentives for compliance with these core measures, but most importantly, these measures ensure that evidence-based therapy is consistently provided to each patient. If a core measure is not met, documentation must be provided to ensure that there is not a failure to meet the measure. Pharmacists were granted the authority to provide core measure documentation in 2007. There are a total of 44 core measures, 22 (50%) of which are medication related and can be documented by a pharmacist. Over a 5-year period, clinical pharmacists have recorded 1281 interventions for core measure documentation. In an analysis of a 1-year period of charts with missing core measure documen...
Processing Wearable Sensor Data to Optimize Deep-Brain Stimulation

Our study suggests that a sensor-based technique might be an important adjunct to existing clinical measures to improve the management of patients undergoing Parkinson's control therapy via deep-brain stimulation. In the future, clinicians could gather accelerometer data for approximately one week before and after outpatient visits for deep-brain stimulation adjustments. An expert system could then merge clinical observations and results of the accelerometer data analyses to recommend optimal settings. Physicians would decide how to apply these recommendations as one option for the clinical management of motor symptoms, including adjustments in medication intake as well as changes in settings for deep-brain stimulation.
Epidemiology of respiratory viruses in children admitted to an infant/toddler unit

This study examined the prevalence of common respiratory viruses in an infant/toddler cohort tested as part of a comprehensive strategy to prevent nosocomial respiratory virus transmission and measured the unrecognized reservoir of viruses in children without common respiratory virus symptoms.
Trade boom and wage inequality: evidence from Ugandan districts

The process of economic integration over the past two decades has been accompanied by expanding skilled wage premia—a key measure of wage inequality—in most countries. This was also the case for Ugandan wage employees during the 1990s, a period of abrupt trade opening, market reforms and improved relations with neighbouring Kenya. As in other unskilled labour abundant countries, this is a surprising result in light of the standard Heckscher–Ohlin (H–O) framework. By using a novel district-level analysis, I find that in fact increased trade reduced wage inequality in line with the H–O predictions. During the 1990s districts more exposed to the trade boom experienced a rise in wage premia 2.8 percentage points lower relative to less-exposed districts. On the other hand, the intensification of domestic trade across districts and the increase in average education were associated with increased wage premia during the period of analysis.
Role of c-Jun N-terminal Kinase in the Regulation of Vascular Tone

The c-Jun N-terminal kinases (JNKs) belong to the mitogen-activated protein kinases superfamily, which play an important role in the pathogenesis of cardiovascular and metabolic diseases. However, it is still unclear whether JNK participates in the regulation of vascular tone. We investigated the effect of JNK inhibitors on vascular reactivity in aortic rings in organ bath and on angiotensin (Ang) II-induced pressor responses in vivo in Sprague-Dawley (SD) rats. In aortic rings from SD rats, KCl, norepinephrine (NE), Ang II, or endothelin 1 (ET)-1 induced a dose-dependent vasoconstriction. Preincubation with the JNK inhibitor SP600125 (20 μmol/L) slightly inhibited KCl-induced vasoconstriction (Emax: —19%) and markedly inhibited vasoconstriction to NE (—42%), Ang II (—54%), and ET-1 (—42%). SP600125 induced a dose-dependent relaxation in the NE-preconstricted aortic rings (—54%) but exerted minimal relaxation in the KCI-preconstriction rings. To exclude the nonspecific effect of SP600125, we performed add...
A NN algorithm for Boolean satisfiability problems

Satisfiability (SAT) refers to the task of finding a truth assignment that makes an arbitrary Boolean expression true. This paper compares a neural network algorithm (NNSAT) with GSAT, a greedy algorithm for solving satisfiability problems. GSAT can solve problem instances that are difficult for traditional satisfiability algorithms. Results suggest that NNSAT scales better as the number of variables increase, solving at least as many hard SAT problems.
Suppression of cryptic intragenic transcripts is required for embryonic stem cell self-renewal.

Recent discoveries of histone demethylases have shown that the dynamic regulation of histone methylation is important in differentiation and development. A paper in this issue of The EMBO Journal demonstrates that an H3K4me3 demethylase, KDM5B, is required for the regulation of self‐renewal and pluripotency of embryonic stem (ES) cells by removing intragenic H3K4me3 and repressing cryptic transcription.
Time-optimal commands with specified fuel usage for controlling flexible structures

We provide a mathematical justification for time-optimal and fuel-efficient controllers based on Pontryagin's minimum principle. We demonstrate that some symmetry properties of time-optimal commands, that are known to hold for undamped flexible structures, remain valid in the presence of fuel constraints. We also outline a procedure for designing robust time-optimal commands with specified fuel.
Of gods, glyphs and kings: divinity and rulership among the Classic Maya

The ANTIQUITY prize-winning article in the last volume addressed writing, its varying nature and role in early states. Now that the decipherment of Maya writing is well advanced, we can know more of the records of kingship. From them we may discern the concepts and beliefs that defined the authority of these holy lords, as we seek the source of the power of rulers like ‘Sun-faced Snake Jaguar’.
Natural language and natural selection

Many people have argued that the evolution of the human language faculty cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of as-yet unknown laws of growth and form. Others have argued that a biological specialization for grammar is incompatible with every tenet of Darwinian theory – that it shows no genetic variation, could not exist in any intermediate forms, confers no selective advantage, and would require more evolutionary time and genomic space than is available. We examine these arguments and show that they depend on inaccurate assumptions about biology or language or both. Evolutionary theory offers clear criteria for when a trait should be attributed to natural selection: complex design for some function, and the absence of alternative processes capable of explaining such complexity. Human language meets these criteria: Grammar is a complex mechanism tailored to the transmission of propositional structures through a serial interface. Autonomous and arbitrary grammatical phenomena have been offered as counterexamples to the position that language is an adaptation, but this reasoning is unsound: Communication protocols depend on arbitrary conventions that are adaptive as long as they are shared. Consequently, language acquisition in the child should systematically differ from language evolution in the species, and attempts to analogize them are misleading. Reviewing other arguments and data, we conclude that there is every reason to believe that a specialization for grammar evolved by a conventional neo-Darwinian process.
Intrayear Household Income Dynamics and Adolescent School Behavior

Economic life for most American households is quite dynamic. Such income instability is an understudied aspect of households’ economic contexts that may have distinct consequences for children. We examine the empirical relationship between household income instability, as measured by intrayear income change, and adolescent school behavior outcomes using a nationally representative sample of households with adolescents from the Survey of Income and Program Participation 2004 panel. We find an unfavorable relationship between income instability and adolescent school behaviors after controlling for income level and a large set of child and family characteristics. Income instability is associated with a lower likelihood of adolescents being highly engaged in school across the income spectrum and predicts adolescent expulsions and suspensions, particularly among low-income, older, and racial minority adolescents.
Microarray data analysis with PCA in a DBMS

Microarray data sets contain expression levels of thousands of genes. The statistical analysis of such data sets is typically performed outside a DBMS with statistical packages or mathematical libraries. In this work, we focus on analyzing them inside the DBMS. This is a difficult problem because microarray data sets have high dimensionality, but small size. First, due to DBMS limitations on a maximum number of columns per table, the data set has to be pivoted and transformed before analysis. More importantly, the correlation matrix on tens of thousands of genes has millions of values. While most high dimensional data sets can be analyzed with the classical PCA method, small, but high dimensional, data sets can only be analyzed with Singular Value Decomposition (SVD). We adapt the Householder tridiagonalization and QR factorization numerical methods to solve SVD inside the DBMS. Since these mathematical methods require many matrix operations, which are hard to express in SQL, query optimizations and efficient UDFs are developed to get good performance. Our proposed techniques achieve processing times comparable with those from the R package, a well-known statistical tool. We experimentally show our methods scale well with high dimensionality.
Phosphodiesterase 1A Modulates Cystogenesis in Zebrafish

Substantial evidence indicates the importance of elevated cAMP in polycystic kidney disease (PKD). Accumulation of cAMP in cystic tissues may be, in part, caused by enhanced adenylyl cyclase activity, but inhibition of cAMP degradation by phosphodiesterases (PDE) likely has an important role, because cAMP is inactivated much faster than it is synthesized. PDE1 is the only PDE family activated by Ca2+, which is reduced in PKD cells. To assess the contribution of the PDE1A subfamily to renal cyst formation, we examined the expression and function of PDE1A in zebrafish. We identified two splice isoforms with alternative starts corresponding to human PDE1A1 and PDE1A4. Expression of the two isoforms varied in embryos and adult tissues, and both isoforms hydrolyzed cAMP with Ca2+/calmodulin dependence. Depletion of PDE1A in zebrafish embryos using splice- and translation-blocking morpholinos (MOs) caused pronephric cysts, hydrocephalus, and body curvature. Human PDE1A RNA and the PKA inhibitors, H89 and Rp-cAMPS, partially rescued phenotypes of pde1a morphants. Additionally, MO depletion of PDE1A aggravated phenotypes in pkd2 morphants, causing more severe body curvature, and human PDE1A RNA partially rescued pkd2 morphant phenotypes, pronephric cysts, hydrocephalus, and body curvature. Together, these data indicate the integral role of PDE1A and cAMP signaling in renal development and cystogenesis, imply that PDE1A activity is altered downstream of polycystin-2, and suggest that PDE1A is a viable drug target for PKD.
Polynomially Hyponormal Operators

A survey of the theory of k-hyponormal operators starts with the construction of a polynomially hyponorrnal operator which is not subnormal. This is achieved via a natural dictionary between positive functionals on specific convex cones of polynomials and linear bounded operators acting on a Hilbert space, with a distinguished cyclic vector. The class of unilateral weighted shifts provides an optimal framework for studying k-hyponormality. Non-trivial links with the theory of Toeplitz operators on Hardy space are also exposed in detail. A good selection of intriguing open problems, with precise references to prior works and partial solutions, is offered.
Predictive Sampling of Rare Conformational Events in Aqueous Solution: Designing a Generalized Orthogonal Space Tempering Method.

In aqueous solution, solute conformational transitions are governed by intimate interplays of the fluctuations of solute–solute, solute–water, and water–water interactions. To promote molecular fluctuations to enhance sampling of essential conformational changes, a common strategy is to construct an expanded Hamiltonian through a series of Hamiltonian perturbations and thereby broaden the distribution of certain interactions of focus. Due to a lack of active sampling of configuration response to Hamiltonian transitions, it is challenging for common expanded Hamiltonian methods to robustly explore solvent mediated rare conformational events. The orthogonal space sampling (OSS) scheme, as exemplified by the orthogonal space random walk and orthogonal space tempering methods, provides a general framework for synchronous acceleration of slow configuration responses. To more effectively sample conformational transitions in aqueous solution, in this work, we devised a generalized orthogonal space tempering (gOS...
Chaos, Stochasticity, and Stability of a Nonlinear Oscillator with Control Part II: Simulation

In this first part on analysis of the title problem, we consider a structural model with a nonlinear soft spring of the Duffing type subjected to a deterministic harmonic force. A linear feedback control system with time delay is provided to suppress structural oscillations. The nonlinear control structural problem is formulated in a three-dimensional first order system with perturbation on the harmonic force, structural damping and control force. Based on the exact solution of the unperturbed simple but strongly nonlinear two-dimensional system the global stability of the degenerated system is examined. The global chaotic behavior of the perturbed three dimensional full system is then analyzed using the well known Melnikov function. An analytic criterion for chaos is found. The key engineering problem of control efficiency for linear and nonlinear systems is evaluated through an amplitude reduction ratio for both regular and chaotic oscillations. All digital simulated solutions are presented in part II of our study.
A diabetes problem solving support group: issues, process and preliminary outcomes

This report covers the development, process and outcomes of a yearlong diabetes problem solving support group. Using the task-centered group work model, the participants developed the skills for solving problems of a psychosocial nature. Issues, such as the formation of the group, the roles of facilitators and members, group process, results, and implications for practice, are discussed.
Normal modes of a coupled ice-shelf/sub-ice-shelf cavity system

Ice shelves and ice tongues are dynamically coupled to their cavities. Here we compute normal modes (eigenfrequencies and eigenfunctions) of this coupled system using a thin-plate approximation for the ice shelf and potential water flow in the ice-shelf cavity. Our results show that normal modes depend not only on the ice-shelf parameters (length, thickness, Young’s modulus, etc.) but also on the cavity depth. The dominant eigenmodes are higher for ice shelves floating over deeper cavities; they are also higher for shorter ice shelves and ice tongues (<50 km long). The higheigenfrequency eigenmodes are primarily controlled by the ice flexure and have similar periods to sea swell. These results suggest that both long ocean waves with periods of 100–400 s and shorter sea swell with periods of 10–20 s can have strong impacts on relatively short ice shelves and ice tongues by exciting oscillations with their eigenfrequencies, which can lead to iceberg calving and, in some circumstances, ice-shelf disintegration.
Dressing for Style in the Mutual Fund Industry

We define benchmark drift based on changes in a fund's beta relative to its self-promoted benchmark, calculated from the portfolio holdings of both the fund and benchmark. Benchmark drift has a strong adverse impact on mutual fund flows, even when funds beat the benchmark. Moreover, controlling benchmark drift plays a larger role in portfolio risk management than tournament-style behavior. Both external and internal governance mechanisms work to control benchmark drift: funds with greater institutional investment and those in larger fund families demonstrate less benchmark drift and take stronger steps to reduce it once it occurs.
Mass Spectrometry for Paper-Based Immunoassays: Toward On-Demand Diagnosis

Current analytical methods, either point-of-care or centralized detection, are not able to meet recent demands of patient-friendly testing and increased reliability of results. Here, we describe a two-point separation on-demand diagnostic strategy based on a paper-based mass spectrometry immunoassay platform that adopts stable and cleavable ionic probes as mass reporter; these probes make possible sensitive, interruptible, storable, and restorable on-demand detection. In addition, a new touch paper spray method was developed for on-chip, sensitive, and cost-effective analyte detection. This concept is successfully demonstrated via (i) the detection of Plasmodium falciparum histidine-rich protein 2 antigen and (ii) multiplexed and simultaneous detection of cancer antigen 125 and carcinoembryonic antigen.
Small vertebral cross-sectional area and tall intervertebral disc in adolescent idiopathic scoliosis

When compared to boys, girls have smaller vertebral cross-sectional area, which conveys a greater spinal flexibility, and a higher prevalence of adolescent idiopathic scoliosis. To test the hypothesis that small vertebral cross-sectional area and tall intervertebral disc height are structural characteristics of patients with adolescent idiopathic scoliosis. Using multiplanar imaging techniques, measures of vertebral cross-sectional area, vertebral height and intervertebral disc height in the lumbar spine were obtained in 35 pairs of girls and 11 pairs of boys with and without adolescent idiopathic scoliosis of the thoracic spine matched for age, height and weight. Compared to adolescents without spinal deformity, girls and boys with adolescent idiopathic scoliosis had, on average, 9.8% (6.68 ± 0.81 vs. 7.40 ± 0.99 cm2; P = 0.0007) and 13.9% (8.22 ± 0.84 vs. 9.55 ± 1.61 cm2; P = 0.009) smaller vertebral cross-sectional dimensions, respectively. Additionally, patients with adolescent idiopathic scoliosis had significantly greater values for intervertebral disc heights (9.06 ± 0.85 vs. 7.31 ± 0.62 mm and 9.09 ± 0.87 vs. 7.61 ± 1.00 mm for girls and boys respectively; both P ≤ 0.011). Multiple regression analysis indicated that the presence of scoliosis was negatively associated with vertebral cross-sectional area and positively with intervertebral disc height, independent of sex, age and body mass index. We provide new evidence that girls and boys with adolescent idiopathic scoliosis have significantly smaller vertebral cross-sectional area and taller intervertebral disc heights – two major structural determinants that influence trunk flexibility. With appropriate validation, these findings may have implications for the identification of children at the highest risk for developing scoliosis.
Four Cases of Metastases to the Penis and a Review of the Literature

Penile metastases are rare and usually are secondary to other genitourinary primaries. Approximately 200 cases have been reported. Survival for more than 1 year is unusual, and multiple metastases have been present in all autopsied cases. Occasional survival longer than 5 years has occurred with surgical excision, suggesting the possibility of cure for those patients in whom control of the primary has been achieved and who show no other clinical metastatic lesions.
Murine T-cell heterogeneity

Immunoregulatory lymphoid cells that mature under the influence of the thymus gland (T cells) have been implicated to a major extent in the induction or at least the perpetuation of malignant neoplasms in man. Those T cells are thought to inactivate, suppress, or neutralize the normally occurring tumoricidal effector cells and thereby facilitate the unchecked growth of the neoplasm; the term "suppressor T cells" is therefore used to denote their individual activity. This concept implies that there is a balance between the effector cells and the suppressor cells in healthy subjects and that perhaps enrichment and activation of those cells involved in the defense against neoplastic growth, and specific depletion and elimination of those cells involved in suppression or inactivation of the former in patients with malignant diseases, may provide new modalities in cancer immunotherapy. Most of the studies that form the basis of this concept have been derived in animal models, particularly the mouse. The existence of cell-surface markers which have been used as phenotypic tools has provided the knowledge that distinct subpopulations of lymphoid cells do exist. The phenotypic characterization of lymphoid cells involved in functionally dinstinct immunologic events has been the object of intensive investigation. Therefore, the purpose of this paper is to briefly document our current knowledge of the functional heterogeneity that exists in murine T cells based on the differential expression of these cell-surface markers.
Retrovirus envelope domain at 1.7 angstrom resolution.

We report the crystal structure of an extraviral segment of a retrovirus envelope protein, the Moloney murine leukemia virus (MoMuLV) transmembrane (TM) subunit. This segment, which comprises a region of the MoMuLVTM protein analogous to that contained within the X-ray crystal structure of low-pH converted influenza hemagglutinin, contains a trimeric coiled coil, with a hydrophobic cluster at its base and a strand that packs in an antiparallel orientation against the coiled coil. This structure gives the first high-resolution insight into the retrovirus surface and serves as a model for a wide range of viral fusion proteins; key residues in this structure are conserved among C- and D-type retroviruses and the filovirus ebola.
Countering network-level denial of information attacks using information visualization

We are besieged with information every day, our inboxes overflow with spam and our search queries return a great deal of irrelevant information. In most cases there is no malicious intent, just simply too much information. However, if we consider active malicious entities, the picture darkens. Denial of information (DoI) attacks assail the human through their computer system and manifest themselves as attacks that target the human's perceptual, cognitive and motor capabilities. By exploiting these capabilities, attackers reduce our ability to acquire and act upon desired information. Even if a traditional denial of service attack against a machine is not possible, the human utilizing the machine may still succumb to DoI attack. When successful, DoI attacks actively alter our decision making, often without our knowledge. In this dissertation, we address the problem of countering DoI attacks. We begin by presenting a taxonomy and framework of DoI attacks and countermeasures to add structure to the problem space. We then closely examine the use of information visualization as a countermeasure. Information visualization is a powerful technique that taps into the high bandwidth visual recognition capability of the human and is well suited to resist DoI attack. Unfortunately, most information visualization systems are designed without a clear emphasis on protecting the human from malicious activity. To address this issue we present a general framework for information visualization system security analysis. We then delve deeply into countering DoI in the network security domain using carefully crafted information visualization techniques to build a DoI attack resistant security visualization system. By creating such a system, we raise the bar on adversaries who now must cope with visualization enhanced humans in addition to traditional automated intrusion detection systems and text-based analysis tools. We conclude with a human-centric evaluation to demonstrate our system's effectiveness.
ALUMINUM DAMAGE SIMULATION IN HIGH-VELOCITY IMPACT

Plates of 6.55 mm-thick Al-5456 were damaged by impacting them with thin circular flyers of Mylar or Kapton at velocities between 1.8 and 10 mm/μs. Flyers were accelerated by the plasma generated by an aluminum foil rapidly vaporized by Joule heating. Recovered specimens were sectioned and photomicrographed. Simulations were performed using a one-dimensional wave-propagation code. The Mie-Gruneisen/expansion equation of state was used for compression; in tension a damage-softening model allowed spherical voids to nucleate and grow. For the lower velocities, observed spall thicknesses are in good agreement with computed values. At higher velocities, the amount of void damage in the highly disintegrated specimens appears to be consistent with the calculations.
Rheological behavior of silver nanowire conductive inks during screen printing

The rheological behavior of silver nanowire (AgNW) suspensions adapted for screen printing inks was investigated. Aqueous silver nanowire inks consisting of AgNW (length of 30 μm, and diameter of 40 and 90 nm), dispersant and binder were formulated. The effect of AgNW content on the rheological behavior of the ink and the build-up of ink structure after screen printing were examined as they depend on applied shear and temperature. Rheological measurements under conditions that mimic the screen printing process were done to assess viscoelastic properties induced by flow alignment of the wires and the subsequent recovery of the low shear structure. The Stretched Exponential model (SEmo) was used to model the recovery process after screen printing to obtain the characteristic time of the recovery or build-up process. The characteristic time was determined at several temperatures to obtain the activation energy of recovery. The domination of Brownian motion or non-Brownian motion behavior can be characterized by a Peclet number, which is the ratio of shear rate to the rotational diffusion coefficient. The Peclet number and the dimensionless concentration of wires were used to assess the recovery mechanism. The steady viscosity at low and high shear rates was also treated by an activation energy analysis.
Diversity of Human Clock Genotypes and Consequences

The molecular clock consists of a number of genes that form transcriptional and posttranscriptional feedback loops, which function together to generate circadian oscillations that give rise to circadian rhythms of our behavioral and physiological processes. Genetic variations in these clock genes have been shown to be associated with phenotypic effects in a repertoire of biological processes, such as diurnal preference, sleep, metabolism, mood regulation, addiction, and fertility. Consistently, rodent models carrying mutations in clock genes also demonstrate similar phenotypes. Taken together, these studies suggest that human clock-gene variants contribute to the phenotypic differences observed in various behavioral and physiological processes, although to validate this requires further characterization of the molecular consequences of these polymorphisms. Investigating the diversity of human genotypes and the phenotypic effects of these genetic variations shall advance our understanding of the function of the circadian clock and how we can employ the clock to improve our overall health.
Closing the Loop between Nodding Syndrome and Onchocerca Infection

We thank Spencer et al. for their interest in our study [1] and for the additional information about how the cases in Tanzania may differ from those with nodding syndrome in South Sudan and Uganda. As they point out, the epidemiological association between nodding syndrome and Onchocerca volvulus infection seems strong. Additional studies also show a strong association between O. volvulus infection and epilepsy in general (reviewed in [2]). However, due to the lack of evidence for direct invasion of the central nervous system by the O.
Barriers and facilitators to HPV vaccination among rural Alabama adolescents and their caregivers.

Abstract Introduction Half of all new human papillomavirus (HPV) infections occur in adolescents and young adults, and this population has poor HPV vaccination rates. Rural areas of the U.S. have high rates of HPV-related diseases and low vaccination rates as well. The purpose of this study was to determine the perceived barriers and facilitators to HPV vaccination among adolescents and their caregivers in rural south Alabama. Methods Vaccinated and non-vaccinated adolescents ages 11–18 years old and primary caregivers were recruited from three rural counties in south Alabama. Participants completed individual interviews to discuss perceived barriers to vaccination and factors influencing their decision to vaccinate. Discussion groups were held to determine potential solutions to barriers elucidated from the interviews. Interview and discussion group transcripts were analyzed, and themes were identified. Results Approximately 62.5% of adolescents had not initiated the HPV vaccine series. Of those adolescents who started the vaccine series (n = 9, 37.5%), about half completed it (n = 5). Few participants in this study reported speaking with their health care provider (HCP) about the vaccine in the past year. Lack of information about the vaccine, its side effects, and no HCP recommendation were common barriers cited by non-vaccinators. Facilitators to vaccination included cancer prevention, discussion with HCP, and peer testimonials. Potential solutions to barriers were also discussed. Conclusions Proposed strategies to increase HPV vaccination were similar between vaccinated and non-vaccinated groups. Education about HPV and the HPV vaccine is needed throughout these rural south Alabama communities to ensure informed decisions are made about vaccination and to increase vaccination rates.
International Political Authority: Nuclear Nonproliferation and the IAEA in the 1990s

The International Atomic Energy Agency (IAEA) has acquired the power to issues rules and commands on nuclear nonproliferation with which states expect they must comply. They comply when it defines “nonproliferation,” defines its implementation in “safeguards,” and judges state compliance with international nonproliferation treaties. I argue international organizations acquire political authority when they successfully overcome persistent barriers to international cooperation created by persistent policy and behavioral uncertainty to supply the collective outcomes demanded by states. The power of “authority” accounts for variation in the state-international organization relationship not explained by alternative theories. I find evidence of the demand for and supply of international political authority at the IAEA, which evolved from a limited agent at the end of the Cold War to become an international nuclear authority.
History of Tribology and its Industrial Significance

THE definitive and complete early history of tribology has been, written by (1979). He wisely focused on authors and events that have withstood the test of scientific and technological relevance. Some examples in his writing display the ingenuity of man in such items as support-pivots for the gates of ancient cities, the axles of chariots and wagons, and various articles of war. These items may seem mundane to us but they were vital for survival at the time. Friction was a major concern of that day because motive power was supplied largely by people or animals.
Symmetry Is the sine qua non of Shape

Three-dimensional (3D) shape has been studied for centuries despite the absence of a commonly accepted definition of this property. The absence of a useful definition has been a major obstacle in making progress towards understanding the mechanisms that are responsible for the perception of shape. Today, in the absence of the needed new definition, there is no consensus about whether shapes are, or can be, perceived veridically. This chapter reviews the main definitions of shape in use before our new definition was formulated, calling attention to their shortcomings. It then describes our new definition, which is based on the assumption that 3D shape is based on 3D geometrical self-similarities (3D symmetries) of an object, rather than on similarities of an object with respect to other objects. We explain the new definition by discussing the invariants of three types of symmetry groups in 3D and then derive the invariants of the perspective projection from a 3D space to a 2D image. In our definition, the invariants of 3D symmetries serve as the basis for describing the 3D shapes, and the invariants of perspective projections are essential for recovering 3D shapes from one or more 2D images. We conclude by discussing several implications of this new definition which makes it clear: (i) that the veridicality of shape perception is no longer only an empirical concept—the new definition provides a principled theory of when and how the veridicality of shape can be achieved; (ii) how shape constancy applies to non-rigid objects; (iii) that there are informative, but objective, shape priors that do not have to be learned from objects or updated on the basis of experience: these priors are the object’s symmetries and (iv) that what had loomed as a controversy between view-invariant and view-dependent shape perception has been resolved.
Modeling Political Conflict Dynamics In a Two-Party System

A nonlinear dynamic model is constructed for the purpose of exploring the interaction between two conflicting political parties attempting to capture a share of the independent vote and prevail in elections or decisions. Party members influence the decisions to collaborate or not, either through their insistence on remaining polarized in the name of the party’s purity or by making moves toward the political center that may concede some points in the interest of ending stalemates. The model allows exploration of the evolution in time of outcomes of such political confrontations – a joint (legislative or allocative) decision or continued conflict. We focus on the example of American two-party politics as party members contend with a sizeable proportion of the electorate that is unaffiliated (independent) and “up for grabs” through persuasive arguments of either party. Many contextual factors affecting the conflict episodes are captured in the arguments that people utilize to persuade their peers to either toe the party line or move to the center to enable joint decision making. Recent protracted political confrontations and the ensuing stalemate over decisions having to be made in a timely manner (such as federal budgets) drive interest in this area of conflict where both parties could benefit from a tool for exploring various likely scenarios, to prepare strategies for resolution.
Identification, Discrimination, and Retention of Visual Stimuli

Publisher Summary This chapter focuses on identification, discrimination, and retention of visual stimuli. There are two basic procedures for studying perception in man or monkeys, and with appropriate modifications, these procedures are also useful for studying memory. Discrimination tasks should require little description because discrimination learning tasks have been so widely used in primate research. Depending on which factors are kept constant and within the organism's capacity and which are systematically varied, perception and memory can be studied in the same paradigmatic way by means of identification and discrimination procedures. Judgmental processes are assumed to depend upon the adaptation level (AL) or internal norm for the stimulus dimension being judged. Performance on matching-to-sample and discrimination tasks can be improved if the animal attends to excess information that makes the stimuli more distinctive. This implies visual search and broadening of attention. Weighting the contributions of various classes of stimuli, past, present, focal, background is, thus, equivalent to narrowing and expanding attention, spatially and temporally.
Ethnicity and Food Stamp program participation: effect upon dietary intakes of low-income mothers served by a north Florida family practice center.

Abstract Ethnic differences in self-reported dietary intake between blacks and whites (participants and nonparticipants in the Food Stamp program) were studied in a group of 102 low-income mothers presenting themselves for treatment at an urban family practice center. The study population included 51 whites, of whom 21 were participants in the Food Stamp program, and 51 blacks, of whom 29 were Food Stamp program participants. The mean age of white and black mothers was approximately 29 years. Mean numbers of children per family were 2.1 for whites and 2.82 for blacks. Food and nutrient intake data were collected using a 24-hour recall and a food frequency questionnaire. Mean intakes of calcium, iron, riboflavin, and thiamin were found to be less than the RDAs for both groups. Whites additionally had mean intakes of vitamin A and niacin that fell below the RDAs. Blacks had significantly higher mean intakes of niacin and protein and a significantly higher 24-hour mean intake of soft drinks than whites. Being a member of the black race was positively associated with consumption of chicken, hot dogs, collard/mustard greens, and white rice. Being a member of the white race was positively associated with consumption of broccoli, potatoes, and whole wheat bread. Among participants in the Food Stamp program, mean intakes of protein, niacin, and soft drinks were significantly higher for blacks than for whites. This study suggests that ethnic differences in food preferences do exist but that those preferences do not translate into major differences in daily reported nutrient intakes. J Am Diet Assoc 88:1081, 1988.
Formalized Number Theory

In the preface to Principia Mathematica, it is stated that “what were formerly taken, tacitly or explicitly, as axioms, are either unnecessary or demonstrable” .1 In this spirit, we shall in this chapter define the natural numbers as the finite cardinals, and derive Peano’s Postulates from an Axiom of Infinity. We then establish those results about natural numbers and recursive functions which we need in order to establish the incompleteness results in Chapter 7.