cssi/SciSciGPT-SciSciNet huggingface dataset:
National exposure measurements for decisions to protect public health from environmental exposures

Abstract Protecting public health from environmental exposures requires four steps: detection of exposures known or expected to cause disease, assessment of health risk from exposure, implementation of an exposure intervention, and assurance that the exposure intervention is effective. To prioritize efforts in these four areas one must consider the size of the population affected, the seriousness of health effects, and the availability of cost-effective exposure interventions. Population exposure data is critical to each of these steps for protecting health. Biomonitoring data for the US population is now available to assist public health scientists and physicians in preventing disease from environmental exposures, and it complements that available for levels of chemicals in environmental media. The Second National Report on Human Exposure to Environmental Chemicals provides for the US population serum, blood and urine levels for 116 environmental chemicals over the years 1999 and 2000, with separate analyses by age, sex, and race/ethnicity. This national exposure information identifies which chemicals get into Americans in measurable quantities; determines whether exposure levels are higher among population subgroups; determines how many Americans have levels of chemicals above recognized health threshold levels (for chemicals with such threshold levels); establishes reference ranges that define general population exposure so unusual exposures can be recognized; assesses the effectiveness of public health efforts to reduce population exposure to selected chemicals; and tracks over time trends in US population exposure. Blood lead measurements in the population were important in identifying lead in gasoline as a significant source of human lead exposure and documenting the reduction in blood lead levels in the population as a result of removing lead from gasoline and other products in the United States. Serum cotinine levels in the early 1990s found more widespread exposure to environmental tobacco smoke (ETS) in the United States than previously thought and additional measurements in 1999 and 2000 documented major declines in exposure to ETS as a result of public health actions in the 1990s. A new biomonitoring assessment of the exposure of the US population will be released every 2 years as the “National Report on Human Exposure to Environmental Chemicals.” These reports will include the current 116 chemicals and new chemicals added to monitor priority exposures of the population.
Attitudes, beliefs, and barriers related to milk consumption in older, low-income women.

Abstract Objective To determine attitudes, beliefs, and barriers related to adequate milk consumption in low-income women ages ≥ 60 years. Methods Nine focus groups were conducted with a convenience sample of 59 women at congregate meal sites in a metropolitan area. Grounded in Social Cognitive Theory, focus group questions were used to explore personal, behavioral, and environmental factors associated with milk consumption. Results Key response themes indicated a positive attitude for the taste of milk (except for low-fat), a primary belief that milk was important for bones and health, and a primary barrier of gastrointestinal side effects. Conclusions and Implications Knowledge regarding the benefits of milk and the dislike of its taste were not the primary reason for the lack of consumption. Instead, gastrointestinal side effects seemed to be the major barrier to adequate consumption. Future nutrition campaigns should test strategies for lactose intolerance management when communicating with low-income older women.
A computational framework for variable selection in multivariate regression

Stepwise variable selection procedures are computationally inexpensive methods for constructing useful regression models for a single dependent variable. At each step a variable is entered into or deleted from the current model, based on the criterion of minimizing the error sum of squares (SSE). When there is more than one dependent variable, the situation is more complex. In this article we propose variable selection criteria for multivariate regression which generalize the univariate SSE criterion. Specifically, we suggest minimizing some function of the estimated error covariance matrix: the trace, the determinant, or the largest eigenvalue. The computations associated with these criteria may be burdensome. We develop a computational framework based on the use of the SWEEP operator which greatly reduces these calculations for stepwise variable selection in multivariate regression.
4-Cyano-1-methyl-pyridinium nitrate.

The title mol­ecular salt, C7H7N2+·NO3−, displays an inter­penetrating sheet structure parallel to a with each sheet containing nearly coplanar cations and anions, each ion being bis­ected by a crystallographic mirror plane. C—H⋯O hydrogen bonds involving both ring and methyl H atoms in addition to cation–cation C—H⋯N hydrogen bonds (ring H to cyano N) serve to link the sheets together. In each set of parallel layers, the cations and anions stack with short distances of 3.094 (2) (between aligned nitrate N and pyridine N atoms) and 3.057 (2) A (between a nitrate O atom and the ring centroid). This motif is strikingly similar to the one that features in the isomeric salt 2-cyano-1-methyl­pyridinium nitrate.
The Fate of Trichohyalin SEQUENTIAL POST-TRANSLATIONAL MODIFICATIONS BY PEPTIDYL-ARGININE DEIMINASE AND TRANSGLUTAMINASES

Trichohyalin (THH) is a major structural protein of the inner root sheath cells and medulla layer of the hair follicle and, to a lesser extent, of other specialized epithelia. THH is a high molecular weight insoluble α-helix-rich protein that forms rigid structures as a result of postsynthetic modifications by two Ca2+-dependent enzymes, transglutaminases (TGases) (protein cross-linking) and peptidyl-arginine deiminase (conversion of arginines to citrullines with loss of organized structure). The modified THH is thought to serve as a keratin intermediate filament matrix protein and/or as a constituent of the cell envelope. In this paper, we have explored in vitro the order of processing of THH to fulfill these functions, using an expressed truncated, more soluble form THH-8. THH-8 is a complete substrate for three known TGases expressed in epithelia, but the kinetic efficiency with TGase 3 is by far the greatest. Following maximal conversion of its arginines to citrullines, THH-8 is cross-linked even more efficiently by TGase 3, using most glutamines partially and all lysines. In addition, we show that insoluble aggregates of THH-8 or native pig tongue THH can be solubilized following peptidyl-arginine deiminase modification. Together, these data suggest an in vivo model in which THH located in insoluble cytoplasmic droplets is first modified by peptidyl-arginine deiminase which denatures it and makes it more soluble. This renders it available for efficient cross-linking by TGase 3 to form highly cross-linked rigid structures in the cells. This temporal order of reaction is supported by the observation that THH is expressed in hair follicle cells before the TGase 3 enzyme.
PrBa0.5Sr0.5Co2O5+δ layered perovskite cathode for intermediate temperature solid oxide fuel cells

Abstract Layered perovskite oxides have ordered A-cations localizing oxygen vacancies, and may potentially improve oxygen ion diffusivity and surface exchange coefficient. The A-site-ordered layered perovskite PrBa0.5Sr0.5Co2O5+δ (PBSC) was evaluated as new cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs). The material was characterized using electrochemical impedance spectroscopy in a symmetrical cell system (PBSC/Ce0.9Sm0.1O1.9 (SDC)/PBSC), exhibiting excellent performance in the intermediate temperature range of 500–700 °C. An area-specific-resistance (ASR) of 0.23 Ω cm2 was achieved at 650 °C for cathode polarization. The low activation energy (Ea) 124 kJ mol−1 is comparable to that of La0.8Sr0.2CoO3−δ. A laboratory-scaled SDC-based tri-layer cell of Ni-SDC/SDC/PBSC was tested in intermediate temperature conditions of 550 to 700 °C. A maximum power density of 1045 mW cm−2 was achieved at 700 °C. The interfacial polarization resistance is as low as 0.285, 0.145, 0.09 and 0.05 Ω cm2 at 550, 600, 650 and 700 °C, respectively. Layered perovskite PBSC shows promising performance as cathode material for IT-SOFCs.
Effect of gender, dose, and time on 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT)-induced hepatotoxicity in Fischer 344 rats

1. The thiazolidinedione ring present in drugs available for type II diabetes can contribute to hepatic injury. Another thiazolidinedione ring-containing compound, 3-(3,5-dichlorophenyl)-2,4-thiazoli-dinedione (DCPT), produces liver damage in rats. Accordingly, the effects of gender, dose, and time on DCPT hepatotoxicity were therefore evaluated. 2. Male rats were more sensitive to DCPT (0.4-1.0 mmol kg(-1) by intraperitoneal administration) as shown by increased serum alanine aminotransferase levels and altered hepatic morphology 24 h post-dosing. Effects in both genders were dose dependent. In males, DCPT (0.6 mmol kg(-1)) produced elevations in alanine aminotransferases and changes in liver sections 3 h after dosing that progressively worsened up to 12 h. DCPT-induced renal effects were mild. 3. It is concluded that male rats are more susceptible to DCPT hepatotoxicity and that damage occurs rapidly. DCPT primarily affects the liver and can be a useful compound to investigate the role of the thiazolidinedione ring in hepatic injury. However, the gender dependency and rapid onset of DCPT hepatotoxicity require further investigation.
An epidemiologic study of a psychiatric liaison service

An epidemiologic study of 308 consultations revealed substantial differences in referral rates related to the demographic, clinical, and programmatic characteristics of patients and services. Actual liaison was associated with substantially increased referral rates across all age groups. Female patients appeared to have differentially benefited by liaison activities in terms of obtaining appropriate psychiatric intervention. Across all services studied (medicine, neurology, surgery, and obstetrics/gynecology), consultation appeared mainly directed at establishing a specific psychiatric diagnosis and treatment. Markedly different patterns of emotional disturbance were noted across different medical disease categories (e.g., cancer, chronic renal disease).
Bronchopulmonary dysplasia: A new look at an old problem

Abstract William Northway Jr. first described bronchopulmonary dysplasia (BPD) in 1967. Even with the many advances in the care of neonatal respiratory diseases BPD has remained a problem, but the gestational age of most affected infants has gradually lowered. Some therapies have been tried and abandoned or remain unproven. BPD in the extremely immature population follows a different pathology than originally described. There appears to be a disruption in lung development. The mechanisms of injury are similar (oxygen toxicity, ventilator-induced injury), with new evidence of perinatal inflammation playing a role. Preventing or minimizing lung injury beyond surfactant may be possible with high frequency oscillatory ventilation or the newer modes of tidal volume ventilation but remains unproven. Avoidance of mechanical ventilation and treatment with only continuous positive airway pressure holds promise. This article is an overview of current knowledge.
A novel approach for modeling concentration polarization in crossflow membrane filtration based on the equivalence of osmotic pressure model and filtration theory

A theoretical model for prediction of permeate flux during crossflow membrane filtration of rigid hard spherical solute particles is developed. The model utilizes the equivalence of the hydrodynamic and thermodynamic principles governing the equilibrium in a concentration polarization layer. A combination of the two approaches yields an analytical expression for the permeate flux. The model predicts the local variation of permeate flux in a filtration channel, as well as provides a simple expression for the channel-averaged flux. A criterion for the formation of a filter cake is presented and is used to predict the downstream position in the filtration channel where cake layer build-up initiates. The predictions of permeate flux using the model compare remarkably well with a detailed numerical solution of the convective diffusion equation coupled with the osmotic pressure model. Based on the model, a novel graphical technique for prediction of the local permeate flux in a crossflow filtration channel has also been presented.
Population limitation and the wolves of Isle Royale

Population regulation for gray wolves in Isle Royale National Park, Michigan, was examined in 1987–1995 when wolves were in chronic decline following a crash of the population in 1981–1982. Canine parvovirus (CPV-2) was probably influential during the crash, but it disappeared by the late 1980s. High mortality abruptly ceased after 1988, but low recruitment in the absence of disease and obvious shortage of food prevented recovery of the wolf population. In 1983–1995, with a comparable number of moose ≥10 years old as potential prey, wolves were only half as numerous as in 1959–1980. A simulation of annual fluctuations in effective population size ( N e ) for wolves on Isle Royale suggests that their genetic heterozygosity has declined ca. 13% with each generation and ca. 80% in the 50-year history of this population. Inbreeding depression and stochastic demographic variation both remain possible explanations for recent low recruitment.
Commentary: What does immunology have to do with brain development and psychopathology?--a commentary on O'Connor et al. (2014).

In the past, we have typically regarded the ‘immune system’ as a complex set of cellular and molecular processes that protect us against pathogens, from viruses to parasitic worms. It is now clear that the cellular and molecular processes that make up our ‘immune system’ are also crucial to normal brain development and play a role in the pathoaetiology of many mental and physical disorders. In their Annual Research Review, O'Connor, Moynihan and Caserta (2014) provide a useful introduction to this emerging area of science that is highly relevant to our field and is a natural outgrowth of their earlier and ongoing work in psychoneuroimmunology. However, their review goes well beyond these seminal findings. While work in developmental psychoneuroimmunology engenders a good deal of excitement among academic researchers, the ‘promise’ of the field clearly remains greater than the ‘deliverables’, in terms of any direct effect on patient care. This commentary looks at the implication of these findings for clinical practice and where future research efforts should be expended.
Definitizable Extensions of Positive Symmetric Operators in a Krein Space

The Friedrichs extension and the Krein extension of a positive operator in a Krein space are characterized in terms of their spectral functions in a Krein space.
Microstructure Evolution of a Metastable CrMnN Austenitic Stainless Steel during Compression Deformation

Microstructural evolution of a metastable 18Cr12Mn0.55N austenitic stainless steel during compression deformation was investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM observation showed the occurrence of deformation-induced phase transformation and atypical deformation twin, the deformation-induced phase cannot be identified as austenite or martensite. XRD test showed that the amount of deformation-induced phase is less than the detectable limit of XRD.
Tellurium-labeled fatty-acid analogs: relationship of heteroatom position to myocardial kinetics.

To determine the effects of tellurium-heteroatom position on myocardial fatty-acid kinetics, a series of tellurium Te 123m-labeled heptadecanoic-acid analogs (123mTe-THDA) were evaluated in dogs. The left-anterior descending coronary artery was partially occluded, and 123mTe-THDA labeled at either the 5, 6, 9, 10, 11, 12 or 13 position from the carboxyl group was administered intravenously. In 24 dogs, the 123mTe activity in the ischemic and normal zones was monitored continuously for 3 h using miniature radiation detectors. There were no significant differences between the ischemic- and normal-wall 123mTe clearance rates for any of the compounds. There was minimal fractional 3-h myocardial clearance for the 123mTe-THDA labeled at the 5, 6, and 9 position (range of means, 0.02–0.05). There was significant clearance of 123mTe-THDA labeled at the 11, 12, and 13 position (range of means, 0.37–0.44). The myocardial clearance of the 123mTe-THDA labeled at the 10 position was intermediate between the two extremes. Thus, as the 123mTe heteroatom is placed further from the carboxyl portion of the molecule, there is a progressive increase in the myocardial clearance. Selection of the heteroatom position should depend on whether initial fatty-acid distribution or subsequent clearance rates are being studied.
Surface waves generated by a line load on a half-space with depth-dependent properties

Abstract The reciprocity theorem of elastodynamics is used in this paper to determine the surface waves that are radiated from a time-harmonic line load applied at the surface of a solid body, whose elastic moduli and mass density depend on the distance from the surface. In a high-frequency approximation, the surface wave velocity and expressions for the displacement and stresses of free surface waves are employed in the reciprocity theorem. The general expressions for the surface wave radiated by the oscillating line load, together with a virtual free surface wave, when employed in the reciprocity theorem, yield relatively simple expressions for the amplitude factor of the radiated surface wave. Results show the amplitude factor as a function of the wavenumber.
Single-Snapshot File System Analysis

Metadata snapshots are a common method for gaining insight into file systems due to their small size and relative ease of acquisition. Since they are static, most researchers have used them for relatively simple analyses such as file size distributions and age of files. We hypothesize that it is possible to gain much richer insights into file system and user behavior by clustering features in metadata snapshots and comparing the entropy within clusters to the entropy within natural partitions such as directory hierarchies. We discuss several different methods for gaining deeper insights into metadata snapshots, and show a small proof of concept using data from Los Alamos National Laboratories. In our initial work, we see evidence that it is possible to identify user locality information, traditionally the purview of dynamic traces, using a single static snapshot.
Periodontal treatment of excessive gingival display

Excessive gingival display upon smile is usually considered esthetically displeasing. Based on the etiology, this condition can be treated with orthodontics alone or with an interdisciplinary approach including other dental specialists. This article focuses on periodontal methods that can be used to improve the "gingival smile" when it is caused by altered passive eruption and vertical maxillary excess. The anatomy of the normal periodontium, the concept of the biologic width, the etiologies, and diagnoses of excessive gingival display are discussed and surgical techniques are described.
The Import of the Original Bradley's Regress(es)

Much of the recent metaphysical literature on the problem of the relational unity of complexes leaves the impression that Bradley (or some Bradleyan argument) has uncovered a serious problem to be addressed. The problem is thought to be particularly challenging for trope theorists and realists about universals. In truth, there has been little clarity about the nature and import of the original Bradley’s regress arguments. In this paper, I offer a careful analysis and reconstruction of the arguments in Bradley’s Appearance and Reality (1893). The analysis reveals that no less than three regress arguments against relations can be found. I show that none of them are compelling. I argue that, as a result, it is a serious misstep for philosophers today to offer metaphysical theses based on the unchallenged assumption that Bradley has established his regress result. I further analyze the underpinnings of the Bradley problem as it is frequently cast in contemporary literature and show that they rely on certain confusions and biases, which once brought to light, make current Bradley-inspired arguments against relations unconvincing.
MIGRATION VELOCITIES OF BUBBLE-DEFECT CONFIGURATIONS IN NUCLEAR FUELS.

Abstract When a bubble, pinned on either a dislocation or a grain boundary, reaches the critical size for continued migration, it can create either a trailing dipole or a tube of grain boundary through continued interaction with the pinning defect. The continued interaction significantly reduces the migration velocities of bubbles with less than about twice the critical radius. The velocities of spherical bubbles migrating under typical UO 2 and UC fuel-element conditions are presented. The results indicate that while volume diffusion plays an insignificant role for bubble migration in UO 2 , it is the dominant mechanism in UC. For bubble migration in UO 2 , results are presented for both spherical and lenticular bubbles. The lenticular shape results in somewhat higher migration velocities.
Distribution of immunoreactive dynorphin in the central nervous system of the rat

A widespread distribution of immunoreactive dynorphin (ir-Dyn) in rat brain and spinal cord was demonstrated by means of a highly specific radioimmunoassay. The highest concentrations of ir-Dyn (greater than 399 pg/mg protein) were found in hypothalamic nuclei, i.e. the premamillary, anterior hypothalamic and dorsomedial nuclei and median eminence. Relatively high concentrations of ir-Dyn (between 320 and 399 pg/mg protein) were found in other hypothalamic nuclei such as the medial and lateral preoptic, perifornical, suprachiasmatic, ventromedial nuclei and in the medulla oblongata in the area postrema and in the nucleus of the solitary tract (commissural part). Moderate levels of ir-Dyn (between 140 and 320 pg/mg protein) were found in most diencephalic areas other than the hypothalamic nuclei and further nuclei in the medulla oblongata, in the mesencephalon, pons and spinal cord. Low to moderate levels of ir-Dyn were found in the telencephalon, with lowest levels (less than 140 pg/mg protein) found in the cerebral cortex, olfactory bulb, dorsal septal nucleus, medial amygdaloid nucleus, caudate-putamen, superior collicle, cerebellum and certain areas of the reticular formation.
Mutant p53 exhibits trivial effects on mitochondrial functions which can be reactivated by ellipticine in lymphoma cells

Increasing evidence has shown that a fraction of the wild-type (wt) form of the tumor suppressor p53, can translocate to mitochondria due to genotoxic stress. The mitochondrial targets of wt p53 have also been studied. However, whether mutant p53, which exists in 50% of human cancers, translocates to mitochondria and affects mitochondrial functions is unclear. In this study, we used doxorubicin, a chemotherapeutic drug, to treat five human lymphoma cell lines with wt, mutant or deficient in p53, to induce p53 activation and mitochondrial translocation. Our results demonstrated that mutant p53, like wt p53, was induced upon doxorubicin treatment. Similarly, a fraction of mutant p53 also translocated to mitochondria. However, Complex I and II activities in the mitochondria were compromised only in wt p53-bearing cells after doxorubicin treatment, but not in mutant p53-bearing cells. Similarly, doxorubicin treatment caused greater cell death only in wt p53-bearing cells, but not in mutant p53-bearing cells. When p53 deficient Ramos cells were transfected with mutant p53 (249S), the cells showed resistance to doxorubicin-induced cell death and decreases in complex activities. To reactivate mutant p53 and reverse chemoresistance, ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole) was used to treat mutant p53 cells. Ellipticine enhanced p53 mitochondrial translocation, decreased Complex I activity, and sensitized p53 mutant cells to doxorubicin-induced apoptosis. In summary, our studies suggest that mutations in p53 may not hinder p53’s mitochondrial translocation, but impair its effects on mitochondrial functions. Therefore, restoring mutant p53 by ellipticine may sensitize these cells to chemotherapy.
An Examination of the Role of Perceptions in Neighborhood Research.

Accumulating research demonstrates that both archival indicators and residents' self-reports of neighborhood conditions are useful predictors of a variety of physical health, mental health, substance use, criminal, and educational outcomes. Although studies have shown these two types of measures are often related, no research has systematically examined their relationship. With a sample of Mexican Americans, this study examined this relationship and demographic factors that might account for variations of residents' perceptions of their neighborhoods. Results showed that country of birth, social class, family structure, and gender moderated relations between archival variables and adults' perceptions of danger. Thus using information from both archival data and self-reports should improve the ability of neighborhood researchers to understand individual differences in responses to neighborhood conditions. © 2009 Wiley Periodicals, Inc.
A Linear-Discontinuous Spatial Differencing Scheme forSnRadiative Transfer Calculations

Various types of linear-discontinuous spatial differencing schemes have been developed for theSn(discrete-ordinates) equations approximating the linear Boltzmann transport equation. It has been shown through an asymptotic analysis that the 1D slab-geometry lumped linear-discontinuous scheme not only goes over to a convergent and robust differencing of the diffusion equation in the monoenergetic thick diffusion limit, but it also yields the correct interior solution, even when boundary layers are left unresolved by the spatial mesh. In the present work we generalize this scheme to obtain a 1D slab-geometry lumped linear-discontinuous scheme for the nonlinear radiative transfer equation and the associated material temperature equation. We present a full nonlinear energy-dependent asymptotic analysis of the behavior of this scheme in the thick equilibrium-diffusion limit. We find that this scheme goes over to a convergent and robust differencing of the equilibrium-diffusion equation on the interior of the mesh, but it does not yield the exact interior solution when boundary layers are left unresolved by the spatial mesh. Nevertheless, the interior solution obtained with spatially unresolved boundary layers is always well behaved and fairly accurate. Computational results are presented which test the predictions of our asymptotic analysis and demonstrate the efficiency of our solution technique.
Spontaneous-Fission-Isomer Excitation Energies from Threshold Measurements

A modification to an evaporation model employed in the analysis of isomer excitation functions is presented. Isomer excitation energies deduced from the modified model are shown to be in quantitative agreement with those obtained from a more sophisticated analysis.
Learning to smell danger: acquired associative representation of threat in the olfactory cortex

Neuroscience research over the past few decades has reached a strong consensus that the amygdala plays a key role in emotion processing. However, many questions remain unanswered, especially concerning emotion perception. Based on mnemonic theories of olfactory perception and in light of the highly associative nature of olfactory cortical processing, here I propose a sensory cortical model of olfactory threat perception (i.e., sensory-cortex-based threat perception): the olfactory cortex stores threat codes as acquired associative representations (AARs) formed via aversive life experiences, thereby enabling encoding of threat cues during sensory processing. Rodent and human research in olfactory aversive conditioning was reviewed, indicating learning-induced plasticity in the amygdala and the olfactory piriform cortex. In addition, as aversive learning becomes consolidated in the amygdala, the associative olfactory (piriform) cortex may undergo (long-term) plastic changes, resulting in modified neural response patterns that underpin threat AARs. This proposal thus brings forward a sensory cortical pathway to threat processing (in addition to amygdala-based processes), potentially accounting for an alternative mechanism underlying the pathophysiology of anxiety and depression.
The dependence of a protein solution structure on the quality of the input NMR data. Application of the double-iterated Kalman filter technique to oxytocin

The determination of a three-dimensional protein structure in solution from twodimensional NMR NOE distance data has been attempted in recent years by a variety of computational methods. In particular, the distance geometry algorithm (1, 2) has been extensively used (3~2-3 d), as well as a minimization of dihedral angles only, using a variable target function (4)) simulated annealing (5)) restrained molecular dynamics (6)) systematic conformational search ( 7-9)) and Monte Carlo simulations (IO). However, problems arise in all of these approaches. Recently, there have been increased efforts in defining the limitations and computational characteristics of the algorithms. Results on BPTI and on several peptides ( 11) indicate that some implementations of the distance geometry technique can generate incorrect extended structures, and sample only a small region of conformational space. Moreover, recent distance geometry calculations of Neutrophil peptide 5 (12) further reveal the sampling limitations of the algorithms used. We have recently developed a different methodology for protein structure determination, namely the double-iterated Kalman filter (DIKF) technique ( 13, 14), which addresses some of these problems by quantifying an upper bound on the set of atomic positions that are compatible with the data. This method enables both a structure determination and a definitive estimate of its uncertainty, and thus provides significant additional knowledge and insight on those regions of the protein which correspond to nonunique conformations, e.g., for the Zuc repressor headpiece (15). In general, it is of importance that any study of a protein solution structure from NMR NOE data is accompanied by an investigation of the dependence of the final structure on the quality of the input distance data. This consists primarily of a controlled application of the technique to a small molecule of a known structure with data sets of varying quantity and quality. The variables tested are: ( 1) abundance of the input data; (2) precision of the input data; and (3) the computation time, or the number of double-iterated cycles. The precision and accuracy of the results are recorded as a function of these variables. It is the purpose of this Note to offer a validation of the DIKF algorithm for protein structure determination by an application to the crystal structure of oxytocin. The approach has already proven successful in an NMR solution structure determination of a larger protein, i.e., the lac repressor headpiece (13-1.5),
The separation and amino acid analysis of collagen crosslinks on an extended basic ion-exchange column.

Abstract The major reducible crosslinks found in collagen were separated and analyzed on an extended basic amino acid analyzer column. Reaction with ninhydrin allows the direct analysis of collagen crosslinks, including hydroxyaldol-histidine, a naturally occurring, nonreducible crosslink. In addition to known crosslinks, direct amino acid analysis of tissue hydrolysates reveals the presence of an unknown, ninhydrin-reactive component, in both NaB 3 H 4 -reduced and unreduced collagenous tissues. Initial fractionation of hydrolysates on a Bio-Gel P-2 gel filtration column provides partial separaton of amino acids and crosslinks and enables more direct analysis of the crosslinks present in the samples, as well as detecting potential new crosslinks. The results also show that, prior to NaB 3 H 4 reduction, substantial amounts of known crosslinks are normally present in bovine skin and bone.
Structuring in community policing: Institutionalizing innovative change

Throughout the 20th century, police reform efforts have almost universally focused on changing employee behavior. Historically, studies of the human dynamics of organizations offer compelling evidence that organizational structure is a major determinant of employee behavior. Previous attempts to introduce innovative change in police organizations have failed to endure primarily because it has not been well understood by police executives that supportive structural changes are essential to institutionalizing behavioral change. Suggestions are given for the types of behavior-shaping structural changes that will maximize the probability of institutionalizing community policing as an integral part of routine police management and operations.
International Election Monitoring: The African Experience

Democracy in Africa, as elsewhere, is in someiing of a crisis. This has prompted an agonizing reappraisal of the role elections play in the consolidation of democracy and, in particular, of the contribution of independent election observers to that process. This article assesses critically the performance of election monitors within the context of broader international efforts to promote democratic norms in Africa. It explores the evolution and operationalization of the practice, identifies and evaluates the functions undertaken, and analyses the deficiencies revealed in the light of current crstiques. It concludes with some prescriptions as to how the process might be improved and the credibility of monitoring restored. DEMOCRACY IN AFRICA, AS ELSEWHERE, is in something of a crisis. The extravagant expectations of the early 1 990s have been only partially realized. Even in Benin, Mali and Zambia, the signal successes recorded earlier have not been sustained. This has prompted an agonizing reappraisal of the role elections play in the consolidation of democracy and, related to this, the contribution to that process of independent election observers from elsewhere in Africa and overseas. Yet, despite mounting criticism, the demand for international election monitoring remains strong. What, then, can be done to improve its performance, and perhaps restore its prestige?
Microwave image reconstruction from 3-D fields coupled to 2-D parameter estimation

An efficient Gauss-Newton iterative imaging technique utilizing a three-dimensional (3-D) field solution coupled to a two-dimensional (2-D) parameter estimation scheme (3-D/2-D) is presented for microwave tomographic imaging in medical applications. While electromagnetic wave propagation is described fully by a 3-D vector field, a 3-D scalar model has been applied to improve the efficiency of the iterative reconstruction process with apparently limited reduction in accuracy. In addition, the image recovery has been restricted to 2-D but is generalizable to three dimensions. Image artifacts related primarily to 3-D effects are reduced when compared with results from an entirely two- dimensional inversion (2-D/2-D). Important advances in terms of improving algorithmic efficiency include use of a block solver for computing the field solutions and application of the dual mesh scheme and adjoint approach for Jacobian construction. Methods which enhance the image quality such as the log-magnitude/unwrapped phase minimization were also applied. Results obtained from synthetic measurement data show that the new 3-D/2-D algorithm consistently outperforms its 2-D/2-D counterpart in terms of reducing the effective imaging slice thickness in both permittivity and conductivity images over a range of inclusion sizes and background medium contrasts.
Population genetics of trinucleotide repeat polymorphisms

Trinucleotide repeats at five disease loci (DM, DRPLA, HD, SBMA and SCA1) were surveyed in phenotypically normal individuals from three continental populations. This is the first analysis to examine the population dynamics of these five disease-related trinucleotide repeats in the same individuals from worldwide populations. Roughly half of all alleles observed at each locus are shared between all continental groups. For three loci, disease prevalence in each population corresponds with the number of alleles in the upper tail of the allele-size distribution. The allele-size distributions of African, Asian and Caucasian groups show a high degree of variation, and gene diversity estimates for trinucleotide repeat loci exceed estimates derived from dinucleotide or tetranucleotide repeats. Analyses that compared infinite alleles and stepwise mutation models suggest that normal variation at trinucleotide loci is not generated by stepwise mutation alone. Trees constructed for subpopulations using trinucleotide repeat loci show accurate continental clustering. Interpopulation genetic distance estimates show remarkable similarity to distance estimates produced from tetranucleotide repeats or nuclear restriction site polymorphisms. This finding is especially noteworthy in light of the fact that trinucleotide repeat polymorphisms at these loci can cause disease, while restriction site and tetranucleotide polymorphisms appear to be selectively neutral. In contrast, genetic distance estimates from trinucleotide loci are poorly correlated with genetic distance estimates from mitochondrial sequence data.
Case study: Systemic complications following absolute alcohol embolisation of scalp arteriovenous malformation

Alcohol ablation is an accepted technique for the management of arteriovenous malformations. It is preferred due to the unique property of absolute alcohol to cause complete ablation and prevention of revascularisation. However, this technique is associated with multiple complications which may lead to patient morbidity. Here the case is presented of a female patient with scalp arteriovenous malformation who underwent alcohol ablation and developed supraventricular arrhythmia accompanied with haemodynamic instability and intravascular haemolysis in the postoperative period.
Target-Site Search of DNA-Binding Proteins

Gene regulatory proteins find their target sites on DNA remarkably fast; the experimental binding constant for lac repressor is three orders of magnitude higher than predicted by free diffusion alone. It has been proposed that nonspecific binding aids the search by allowing proteins to slide and hop along DNA. We develop a reaction-diffusion theory of protein translocation that accounts for transport both on and off the strand and incorporates the physical conformation of DNA. For linear DNA modeled as a wormlike chain, the distribution of hops available to a protein exhibits long, power-law tails. As a result, the long-time displacement along the strand is superdiffusive. Our analysis predicts effective superdiffusion coefficients for given nonspecific binding and unbinding rate parameters. Translocation rates experience a maximum with salt concentration (i.e., binding rate constant), which has been verified experimentally. Simulated protein trajectories on DNA (see figure) agree with our theoretical predictions of superdiffusive transport. Our analytical theory allows us to predict the binding and unbinding rate parameters that optimize the protein translocation rate and the efficiency of the search. Finally, we use our theory to predict rates of target site localization under various experimental conditions.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Renal Cell Carcinoma: Dynamic Contrast-enhanced MR Imaging for Differentiation of Tumor Subtypes—Correlation with Pathologic Findings

Purpose: To retrospectively evaluate whether the enhancement patterns of pathologically proved clear cell, papillary, and chromophobe renal cell carcinomas (RCCs) measured on clinical dynamic contrast agent–enhanced magnetic resonance (MR) images permit accurate diagnosis of RCC subtype. Materials and Methods: This study was Institutional Review Board approved and HIPAA compliant; informed consent was waived. One hundred twelve patients (76 men, 36 women; age range, 25–88 years; mean age, 58.1 years) underwent MR imaging of 113 renal masses (mean diameter, 5.4 cm) with pathologic diagnoses of clear cell (n = 75), papillary (n = 28), or chromophobe (n = 10) RCC. A 1.5-T clinical MR protocol was used before and after (corticomedullary and nephrographic phases) intravenous administration of contrast agent. Region-of-interest measurements within tumor and uninvolved renal cortex were used to calculate percentage signal intensity change and tumor-to-cortex enhancement index. Subtype groups were compared by usi...
A comparison of the resources used in advanced cancer care between two different strong opioids: an analysis of naturalistic practice in the UK.

ABSTRACTObjective: To assess the resource implications of using strong opioids in patients with advanced cancer in the UK, based on naturalistic practice, in order to develop the evidence base supporting better management.Design and setting: A modelling study performed from the perspective of the UK’s National Health Service (NHS).Study participants and interventions: A data set was created from the DIN-link database comprising 986 patients with advanced cancer who were prescribed either 12-hourly sustained release morphine (SR morphine; MST Continuous) (n = 784) or transdermal fentanyl (Durogesic) (n = 202) as their first strong opioid between 1st January 1998 and 30th September 2000 and died during that period.Methods: Palliative care-related resource use data were obtained from the DIN-link database. Unit costs at 2000/2001 prices were applied to the resource use values to determine the mean NHS cost of palliative care from the start of treatment until death.Results: Patients initially treated with tra...
Latin American immigrants in Indianapolis: Perceptions of prejudice and discrimination

The article focuses on immigrants’ interactions with the Indiana natives, with emphasis in the city of Indianapolis and its suburbs. More specifically, this study aims at providing an understanding of the experiences of Latin American immigrants with special attention to perceptions of prejudice and discrimination and to feelings of social exclusion. A substantial proportion of Latin American immigrants interviewed indicated that they considered Indiana natives to be prejudiced and that they had personally experienced discrimination. The study reveals specific examples of discrimination experienced by the immigrants at the work place, in housing, in stores, restaurants and by various service providers. The results of the study demonstrate the relevance of the normative and power resource theories to explain prejudice and discrimination.
Hybrid poplar ( Populus ssp.) selections for arid and semi-arid intermountain regions of the western United States

The rapid growth rates of hybrid poplar (Populus spp.) enable rotations of 3–6 years for biofuels or 10–15 years to obtain merchantable timber, but many clones are susceptible to nutrient deficiencies when grown in alkaline soils. A 1995 Oregon study demonstrated that clone OP-367 (P. deltoides × P. nigra) was the only clone tested that performed well on alkaline soils. Tests in Colorado and New Mexico confirmed the adaptation of this clone. A multi-clonal trial was established in 2003 at Farmington, New Mexico and Ontario, Oregon in order to screen a larger number of clones for adaptability to alkaline soils. Trees were planted at 1.5 × 1.5 m spacing and irrigated by surface drip irrigation. Diameter at breast height (DBH) and tree height were recorded annually (2003–2006); wood volumes (WVol) and total aboveground biomass (TAB) were calculated from these measurements. Of the 25 clones tested, 19 were common to both sites. Mean height was greater at the Ontario site through the first 3 years (2003–2005). By the end of four seasons, the tallest Farmington entry was OP-367 at 9.4 m with 177 Mg ha−1 TAB while the tallest Ontario entry was Malheur-3 at 8.9 m with 195 Mg ha−1 TAB and several other clones had statistically similar production. Given the growth and productivity range at these two sites, it is difficult to make generalizations across wide areas, but it appears feasible to identify clones suited to alkaline soils in arid and semi-arid regions.
Sterol and fatty acid regulatory pathways in a Giardia lamblia-derived promoter: evidence for SREBP as an ancient transcription factor.

The sterol regulatory element binding-proteins (SREBPs) are transcription factors that regulate the genes of lipid metabolism. Cholesterol and unsaturated fatty acids regulate SREBPs. Giardia lamblia (GL) is an intestinal para- site and one of the earliest derived members within the eukaryotic lineage. GLs exist as trophozoites and cysts. Growth in cholesterol depletion induces transcription of cyst-wall protein (CWP) genes that are upregulated during encystation. The hypothesis was investigated that SREBP- like pathways have a role in cwp gene transcription. Chinese hamster ovary cells were transfected with a cwp-2 promoter reporter construct. Incubation with cholesterol or oleate re- duced cwp-2 mediated gene transcription to about half of the control. Incubation in sterol-depleted media, or in the presence of either an inhibitor of intracellular cholesterol movement or inhibitor of cholesterol synthesis, increased gene expression up to 3-fold. Overexpression of SREBPs increased reporter gene activity 2.5-fold. In the absence of functional SREBPs, cwp-2 was not regulated by cholesterol. Footprint analysis of cwp-2 reveals three novel binding sites for mammalian SREBPs with no homologies in other spe- cies or humans. The data show that SREBP binds to and can modulate transcription of a regulatory element from an ancient eukaryote and suggest the existence of an SREBP
Ultrananocrystalline diamond film as an optimal cell interface for biomedical applications

Surfaces of materials that promote cell adhesion, proliferation, and growth are critical for new generation of implantable biomedical devices. These films should be able to coat complex geometrical shapes very conformally, with smooth surfaces to produce hermetic bioinert protective coatings, or to provide surfaces for cell grafting through appropriate functionalization. Upon performing a survey of desirable properties such as chemical inertness, low friction coefficient, high wear resistance, and a high Young's modulus, diamond films emerge as very attractive candidates for coatings for biomedical devices. A promising novel material is ultrananocrystalline diamond (UNCD) in thin film form, since UNCD possesses the desirable properties of diamond and can be deposited as a very smooth, conformal coating using chemical vapor deposition. In this paper, we compared cell adhesion, proliferation, and growth on UNCD films, silicon, and platinum films substrates using different cell lines. Our results showed that UNCD films exhibited superior characteristics including cell number, total cell area, and cell spreading. The results could be attributed to the nanostructured nature or a combination of nanostructure/surface chemistry of UNCD, which provides a high surface energy, hence promoting adhesion between the receptors on the cell surface and the UNCD films.