cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure of a Model Transient Peroxide Intermediate of Peroxidases by ab Initio Methods

Peroxidases are oxidative metabolizing heme proteins that require hydrogen peroxide to be transformed to the catalytically active, compound I, species from the ferric resting state. Although a peroxide complex has been proposed as a key intermediate in this reaction, this intermediate is too transient to have thus far been definitively characterized. Results of previous molecular dynamics (MD) simulations of a peroxide complex with cytochrome C peroxidase (CCP) indicated that peroxide forms a stable complex and binds in a nonsymmetric, end-on mode in which the oxygen atoms systematically exchange places as ligands for the iron. These results provided support for a plausible pathway from the peroxide complex to compound I, involving the participation of nearby histidine and arginine residues. To further explore the reliability of this bonding description, we report here, for the first time, the use of ab initio methods to determine the optimized geometry and stability of a peroxide complex with a model hem...
An effective self-retaining retractor for anorectal procedures.

Abstract A self-retaining retractor technique is described for anorectal surgery eliminating many of the problems inherent in the commonly used instruments. It is particularly useful in endorectal pull-through procedures in which the exact level of anastamosis within the anorectal canal is of great importance.
Percutaneous intradiscal approach to the posterior annulus using a curved cannula and a flexible nucleotome – a technical note

Automated percutaneous lumbar diskectomy (APLD) is now a widely practiced treatment of herniated lumbar disks. To be effective, however, the herniated disk must still be contained by the annulus and posterior longitudinal ligament. Only 20% of herniated disks operated on are still contained. To increase the applicability of the percutaneous approach to lumbar disk disease, a more direct manipulation of the herniated disk is necessary. Our work with a tethered cannula demonstrates the feasibility of gaining access to a posterior annular rent with the posterolateral approach to the disk that avoids the epidural space and eliminates the major problem of epidural fibrosis. We have demonstrated that a flexible suction cutting device, the minimally traumatic flexible Nucleotome, can be placed through the curved cannula and directed through the annular rent into the region of the herniation. The design of the suction cutting device of the Nucleotome is such that it maximizes the safety of such a procedure. The b...
Double layering of a thermochemical plume in the upper mantle beneath Hawaii

Abstract According to classical plume theory, purely thermal upwellings rise through the mantle, pond in a thin layer beneath the lithosphere, and generate hotspot volcanism. Neglected by this theory, however, are the dynamical effects of compositional heterogeneity carried by mantle plumes even though this heterogeneity has been commonly identified in sources of hotspot magmas. Numerical models predict that a hot, compositionally heterogeneous mantle plume containing a denser eclogite component tends to pool at ∼ 300 – 410 km depth before rising to feed a shallower sublithospheric layer. This double-layered structure of a thermochemical plume is more consistent with seismic tomographic images at Hawaii than the classical plume model. The thermochemical structure as well as time dependence of plume material rising from the deeper into the shallower layer can further account for long-term fluctuations in volcanic activity and asymmetry in bathymetry, seismic structure, and magma chemistry across the hotspot track, as are observed.
Aromatic hydrogen bond in sequence-specific protein DNA recognition.

An aromatic hydrogen bond—an interaction between the π-electron cloud of an aromatic ring and a hydrogen-bond donor—can substitute for a conventional hydrogen bond in sequence-specific protein—DNA interactions and can contribute 0.5–1 kcal mol−1 to binding and 1–2 kcal mol−1 to specificity.
Effects of deprivation on smokers' mood during the operation of a complex computer simulation

Research has shown that smoking reduces mood fluctuation in smokers and deprivation of smoking leads to mood change. The purpose of this study was to assess the effects of three hours of deprivation and subsequent smoking on mood in smokers while operating a computer simulation of an air traffic controller's job in a 2 x 2 (Deprived vs. Nondeprived x Nicotine vs. Nicotine Free Cigarettes) factorial design. Subjects operated the simulation for two 20 minute periods, and after each period subjects smoked a nicotine or nicotine-free cigarette. Mood was assessed prior to operating the simulation and before and after each cigarette was smoked. Contrary to predictions, mood generally changed as a function of the procedure and not deprivation status or type of cigarette smoked.
Altering the Expression in Mice of Genes by Modifying Their 3′ Regions

Abstract Polymorphic differences altering expression of genes without changing their products probably underlie human quantitative traits affecting risks of serious diseases, but methods for investigating such quantitative differences in animals are limited. Accordingly, we have developed a procedure for changing the expression in mice of chosen genes over a 100-fold range while retaining their chromosomal location and transcriptional controls. To develop the procedure, we first dissected the effects in embryonic stem (ES) cells of elements within and downstream of the 3′ untranslated region (UTR) of a single copy transgene at the Hprt locus. As expected, protein expression varied with the steady-state level and half-life of the mRNA. The rank order of expression with various tested 3′ regions is the same in ES cells, and in cardiomyocytes and trophoblastocytes derived from them. In mice having two functionally different native genes with modified 3′UTRs, the desired expression was obtained.
Indicators of airborne fungal concentrations in urban homes: Understanding the conditions that affect indoor fungal exposures

Indoor fungal exposure can compromise respiratory health. Low-income urban areas are of concern because of high asthma and allergy rates and housing disrepair. Understanding the conditions that affect indoor fungal exposures is important for assessing health risks and for developing mitigation strategies. We examined the types and concentrations of airborne fungi inside and outside of homes in low-income areas of Syracuse, NY as well as the effect of snow cover on fungal levels. At 103 homes, air samples for viable fungi were collected, occupants were interviewed and homes were inspected for visible mold, musty odors, water problems and other factors. Multivariable logistic regression was used to relate high fungal levels to home conditions. Predominant indoor fungi included Cladosporium, Penicillium, Aspergillus, Alternaria and hyaline unknowns. Basidiomycetes and an uncommon genus Acrodontium were also found frequently due to analysis methods developed for this project. With snow cover, outdoor total fungal levels were depressed and indoor concentrations were three times higher than outdoor on average with a maximum of 29 times higher. Visible mold was related to elevated levels of Penicillium (OR 4.11 95% CI 1.37–14.0) and bacteria (OR 3.79 95% CI 1.41–11.2). Musty, moldy odors were associated with elevated concentrations of total fungi (OR 3.48 95% CI 1.13–11.6) and basidiomycetes. Cockroaches, an indicator of moisture, were associated with elevated levels of Penicillium (OR 3.66 95% CI 1.16–13.1) and Aspergillus (OR 4.36 95% CI 1.60–13.4). Increasing relative humidity was associated with higher concentrations of Penicillium, yeasts and basidiomycetes. Visible mold, musty odors, indoor humidity and cockroaches are modifiable factors that were important determinants of indoor fungal exposures. Indoor air investigators should interpret indoor:outdoor fungal ratios cautiously when snow cover is present.
Effect of sodium ion on the high-resolution melting of lambda DNA.

A series of high-resolution melting curves were obtained by the continuous direct-derivative method [Blake, R. D. & Lefoley, S. G. (1978) Biochim. Biophys. Acta518, 233–246] on lambda DNA (cI857S7 strain) under varying conditions of [Na+]. Examination of the denaturation patterns at close intervals of [Na+] indicates that frequent changes in mechanism occur below 0.04M Na+, while almost none occurs above 0.1M Na+. Changes at low [Na+] generally occur in an abrupt fashion, in most cases within a 3 mM change in [Na+], and in at least one case within 0.6 mM, indicating the balance between alternative mechanisms is frequently quite delicate. These changes involve segments of between 900 and 1500 or more base pairs in length and are therefore not insignificant. Changes at low [Na+] reflect a perturbation of the energetic balance between competing mechanisms by weakly screened long-range electrostatic forces. Some perturbation probably also arises from variations in the linear charge density of the double helix induced by the proximity of premelted loop segments; however, this contribution cannot be evaluated without a detailed denaturation map. At high [Na+] the mechanism of melting is more conserved, permitting the dependence of subtrasitional melting temperature tm(i) on [Na+] to be examined for almost all 34 ± 2 subtransitions. The G + C composition of segments responsible for each subtransition was determined by a quantitative spectral method. Analysis according to the Manning-Record expression [Manning, G. (1972) Biopolymers11, 937–949; Record, M. T., Jr., Anderson, C. F. & Lohman, T. M. (1978) Q. Rev. Biophysics11, 103–178] relating ΔHm and dtm(i)/d log[Na+] to the fraction of Na+ released during melting, appears to indicate almost 40% more Na+ is bound to the single-stranded G and/or C residues than to A and T residues. This is consistent with a much shorter mean axial spacing and higher charge density in the former, particularly single-stranded G residues, which have an extraordinary tendency to stack.
Of Normal Human Sympathies and Clear Consciences: Comments on Hyman Gross’s Crime and Punishment: A Concise Moral Critique

Contemporary criminal justice systems are extraordinarily unfair. Focusing on Hyman Gross’s Crimes and Punishment: A Concise Moral Critique, however, I identify ways in which scholarly criticisms of these criminal justice systems tend to miss their target. In particular, I argue against the assumption that in order to criticize these criminal justice systems we need to cast doubt on the very practice of blaming people and on the notion of desert, or that we need to reject wholesale retributive rationales for punishment. Quite the contrary: an important reason why contemporary criminal justice systems are unfair is that they punish many people undeservedly.
On transient performance improvement of adaptive control architectures

While adaptive control theory has been used in numerous applications to achieve given system stabilisation or command following criteria without excessive reliance on mathematical models, the ability to obtain a predictable transient performance is still an important problem – especially for applications to safety-critical systems and when there is no a-priori knowledge on upper bounds of existing system uncertainties. To address this problem, we present a new approach to improve the transient performance of adaptive control architectures. In particular, our approach is predicated on a novel controller architecture, which involves added terms in the update law entitled artificial basis functions. These terms are constructed through a gradient optimisation procedure to minimise the system error between an uncertain dynamical system and a given reference model during the learning phase of an adaptive controller. We provide a detailed stability analysis of the proposed approach, discuss the practical aspects...
Studies on interstitial cells in tissue culture. II. Steroid biosynthesis by a clonal line of rat testicular interstitial cells.

A stable, clonal, monolayer culture has been established from a transplantable tumor of the testicular interstitial cells of rat. The original culture contained 2 distinct cell types. An epithelial-type clone isolated from this culture secretes a high level of steroid hormones, is nearly diploid and is functionally stable through extended serial subcultures. The major steroids synthesized by this clone are 20α-hydroxypregn-4-en-3-one and progesterone. Androgenic steroids could not be detected in significant amounts. A second clone from the original culture was composed of a fibroblasttype cell and showed no steroidogenic capacity. (Endocrinology 82: 614, 1968)
Apical Orientation of the Microtubule Organizing Center and Associated γ-Tubulin during the Polarization of the Retinal Pigment Epithelium in Vivo

Simple epithelial cells express a morphological and functional polarity along their apical-to-basal axis. During the development of epithelia, a unique reorganization of microtubule arrays is thought to play a fundamental role in the establishment of cell polarity. To begin to understand this process in vivo, we have determined the distribution of gamma-tubulin within developing chicken retinal pigment epithelium (RPE). gamma-Tubulin is a recently discovered centrosomal protein that plays a role in nucleating microtubule growth from the centrosome. Although the RPE monolayer becomes established during embryonic Day 3, cell polarity gradually develops and matures over the next 10-13 days. Our studies reveal that gamma-tubulin is located in a distinct focus subjacent to the apical membrane by embryonic Day 3, the beginning of the polarization process. Using primary cell cultures, we examined the relationship between the establishment of junctional complexes and the reorganization of microtubule arrays. Despite the recovery of junctional complexes and a transepithelial electrical resistance, cultured cells failed to relocate gamma-tubulin foci to a position subjacent to the apical membrane. Rather, these foci remained in the juxtanuclear region. These data indicate that the rearrangement of unique, epithelial microtubule arrays requires more than cell-cell and cell-basement membrane interactions.
On-chip endothelial inflammatory phenotyping.

Atherogenesis is potentiated by metabolic abnormalities that contribute to a heightened state of systemic inflammation resulting in endothelial dysfunction. However, early functional changes in endothelium that signify an individual's level of risk are not directly assessed clinically to help guide therapeutic strategy. Moreover, the regulation of inflammation by local hemodynamics contributes to the non-random spatial distribution of atherosclerosis, but the mechanisms are difficult to delineate in vivo. We describe a lab-on-a-chip based approach to quantitatively assay metabolic perturbation of inflammatory events in human endothelial cells (EC) and monocytes under precise flow conditions. Standard methods of soft lithography are used to microfabricate vascular mimetic microfluidic chambers (VMMC), which are bound directly to cultured EC monolayers.1 These devices have the advantage of using small volumes of reagents while providing a platform for directly imaging the inflammatory events at the membrane of EC exposed to a well-defined shear field. We have successfully applied these devices to investigate cytokine-,2 lipid-3, 4 and RAGE-induced5 inflammation in human aortic EC (HAEC). Here we document the use of the VMMC to assay monocytic cell (THP-1) rolling and arrest on HAEC monolayers that are conditioned under differential shear characteristics and activated by the inflammatory cytokine TNF-α. Studies such as these are providing mechanistic insight into atherosusceptibility under metabolic risk factors.
Nested algebraic Bethe ansatz for open GL(N) spin chains with projected K-matrices

Abstract We consider an open spin chain model with GL ( N ) bulk symmetry that is broken to GL ( M ) × GL ( N − M ) by the boundary, which is a generalization of a model arising in string/gauge theory. We prove the integrability of this model by constructing the corresponding commuting transfer matrix. This construction uses operator-valued “projected” K-matrices. We solve this model for general values of N and M using the nested algebraic Bethe ansatz approach, despite the fact that the K-matrices are not diagonal. The key to obtaining this solution is an identity based on a certain factorization property of the reduced K-matrices into products of R-matrices. Numerical evidence suggests that the solution is complete.
Hobby-Eberly Telescope: instrumentation and current performance

The Hobby-Eberly Telescope (HET) is a revolutionary large telescope of 9.2 meter aperture, located in West Texas at McDonald Observatory. HET has been constructed by a consortium of US and German universities for about $16M. First light was obtained on December 11, 1996, HET was dedicated on October 8, 1997, and early scientific operations started on October 8, 1999. The HET operates with a fixed segmented primary and has a tracker which moves the four-mirror corrector and prime focus instrument package to track the sidereal and non-sidereal motions of objects. Here we describe the current performance of the HET relative to its goals. The first phase of HET instrumentation includes three facility instruments: the Low Resolution Spectrograph (LRS) which is in operation, the High Resolution Spectrograph (HRS), which will be commissioned in the summer, and the Medium Resolution Spectrograph (MRS), which is under construction. The other instrument currently in use is the Upgraded Fiber-Optic Echelle (UFOE), which provides medium resolution spectra via a fiber feed from the prime focus. This instrument is primarily a test-bed for fiber observations, and will evolve into a medium resolution J-band spectrograph following the delivery of a camera and detector upgrade (J-CAM), this spring. A J-band extension to the LRS (LRS-J) is also under development, aimed at providing multi-object spectroscopic coverage to 1.35 microns. The instruments are described in detail with predicted performance estimates.
Four newSalmonella serotypes isolated in curacao

The following newSalmonella serotypes were found in Curacao: a) 4225-53-4,5,12: g, m, s—from the stool of a two months old child affected with gastroenteritis. b) 4624-53 and 4638-53-6,7: z4,z24—from the water of a school cistern and from the stool of an adult male affected with diarrhea and fever. c) 4626-53-28: d-1,7—from the stool of a five weeks old child affected with diarrhea and fever. d) 4693-53-38: r-1,6—from the stool of a normal adult food handler. *** DIRECT SUPPORT *** A1365006 00004
The evidence for odd KΣN parity

Recently, Tripp, Watson and Feero-Luzzi have presented experimental evidence for odd KΣN parity, using a general method suggested by the author. The measurements involve the interference between the K-+p→π+Σ amplitudes produced fromD3/2and S12/ K-+P states in the neighborhood of the 1520 MeV resonance. However, it is not clear to what extent the parity conclusion depends on the particular forms of the amplitudes assumed by Tripp, Watson, and Perro-Luzzi. In order to clarify the situation we list the basic assumptions needed, and analyse the data without assuming definite forms for theS andD wave amplitudes. This analysis supports the conclusion of odd KΣN parity.
Mega2: validated data-reformatting for linkage and association analyses

In a typical study of the genetics of a complex human disease, many different analysis programs are used, to test for linkage and association. This requires extensive and careful data reformatting, as many of these analysis programs use differing input formats. Writing scripts to facilitate this can be tedious, time-consuming, and error-prone. To address these issues, the open source Mega2 data reformatting program provides validated and tested data conversions from several commonly-used input formats to many output formats. Mega2, the Manipulation Environment for Genetic Analysis, facilitates the creation of analysis-ready datasets from data gathered as part of a genetic study. It transparently allows users to process genetic data for family-based or case/control studies accurately and efficiently. In addition to data validation checks, Mega2 provides analysis setup capabilities for a broad choice of commonly-used genetic analysis programs. First released in 2000, Mega2 has recently been significantly improved in a number of ways. We have rewritten it in C++ and have reduced its memory requirements. Mega2 now can read input files in LINKAGE, PLINK, and VCF/BCF formats, as well as its own specialized annotated format. It supports conversion to many commonly-used formats including SOLAR, PLINK, Merlin, Mendel, SimWalk2, Cranefoot, IQLS, FBAT, MORGAN, BEAGLE, Eigenstrat, Structure, and PLINK/SEQ. When controlled by a batch file, Mega2 can be used non-interactively in data reformatting pipelines. Support for genetic data from several other species besides humans has been added. By providing tested and validated data reformatting, Mega2 facilitates more accurate and extensive analyses of genetic data, avoiding the need to write, debug, and maintain one’s own custom data reformatting scripts. Mega2 is freely available at https://watson.hgen.pitt.edu/register/ .
Habitat Characteristics in the Core Breeding Range of the Swainson's Warbler

I investigated the physiognomic and floristic characteristics of Swainson's Warbler ( Limnoth- lypis swainsonii) territories at five localities within its core breeding range in Arkansas, Mississippi, Louisiana, and Florida. The warbler attained its greatest abundance (10-20 territorial males/km 2 ) in floodplain forest char- acterized by small (,25 cm dbh) trees (ca 620-820 stems/ha) and understory thickets of saplings, vines, and shrubs (ca 35,000-48,000 small woody stems/ha). Territories in mature forest typically were associated with disturbance gaps. Canopy height, basal area, and floristics appear to be relatively unimportant factors in habitat selection, provided that understory requirements are met, which explains the warbler's occurrence in regenerating clearcuts as well as in relic tracts of old growth forest. Giant cane ( Arundinaria gigantea), hypothesized to be an essential habitat requisite along the northern periphery of its breeding range, was sparse or absent in the prime breeding locations surveyed in this study. Selective thinning and clearcutting are viable habitat manage- ment techniques for the Swainson's Warbler. Received 28 August 2001, accepted 28 February 2002. The success of management programs for Nearctic-Neotropic migratory birds ultimately will depend upon a thorough understanding of the fundamental habitat requirements of breeding and wintering populations. This un- derstanding typically is acquired in incremen-
Chromosome integrity at a double-strand break requires exonuclease 1 and MRX

The continuity of duplex DNA is generally considered a prerequisite for chromosome continuity. However, as previously shown in yeast as well as human cells, the introduction of a double-strand break (DSB) does not generate a chromosome break (CRB) in yeast or human cells. The transition from DSB to CRB was found to be under limited control by the tethering function of the RAD50/MRE11/XRS2 (MRX) complex. Using a system for differential fluorescent marking of both sides of an endonuclease-induced DSB in single cells, we found that nearly all DSBs are converted to CRBs in cells lacking both exonuclease 1 (EXO1) activity and MRX complex. Thus, it appears that some feature of exonuclease processing or resection at a DSB is critical for maintaining broken chromosome ends in close proximity. In addition, we discovered a thermal sensitive (cold) component to CRB formation in an MRX mutant that has implications for chromosome end mobility and/or end-processing.
Stimulation of NTS activates NMDA and non-NMDA receptors in rat cardiac vagal neurons in the nucleus ambiguus

While it is widely accepted that tonic and reflex changes in cardiac vagal activity play significant roles in cardiovascular function, little is known about the synaptic pathways in the brainstem responsible for the control of cardiac vagal neurons in the nucleus ambiguus (NA). In this study, we identified the principal post-synaptic receptors activated in cardiac vagal neurons upon stimulation of the nucleus tractus solitarius (NTS). Cardiac vagal neurons were identified by the presence of a retrograde fluorescent tracer and were visualized in rat brainstem slices. Perforated patch clamp techniques were used to record post-synaptic currents. NTS stimulation activated glutamatergic currents in cardiac vagal neurons with a typical delay of 8-18 ms. Post-synaptic responses were separated into NMDA and non-NMDA components using D-2-amino-5-phophonovalerate (AP5) and 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX), respectively. In conclusion, this study characterizes a monosynaptic glutamatergic pathway from NTS that activates NMDA and kainate/AMPA post-synaptic receptors in cardiac vagal neurons.
The complex association of health insurance and maternal health services in the context of a premium exemption for pregnant women: a case study in Northern Ghana

BACKGROUND: Health insurance premium exemptions for pregnant women are a strategy to increase coverage of maternal health services in sub-Saharan countries. We examine health insurance registration among pregnant women before or after the introduction of a premium exemption and test whether registration increases utilization of maternal health services. METHODS: Data were drawn from a retrospective cohort study of 1641 women having given birth between January 2008 and August 2010 in two impoverished districts of Northern Ghana. Among those 1411 became pregnant after premium exemption was adopted in July 2008. We compared registration rates before and after the exemption. We used logistic regressions to measure the association between insurance registration and receipt of essential maternal health interventions in the context of the premium exemption. We tested whether this association varied across levels of the health system [e.g. hospitals and health centres (HCs) vs community health compounds (CHC)]. RESULTS: Health insurance registration increased significantly among pregnant women after adoption of the premium exemption. Coverage of clinical and diagnostic services was high but antenatal care (ANC) clients received only partial counselling about safe motherhood (e.g. pregnancy-related danger signs). Three out of four clients who sought ANC in hospitals and HCs delivered at a health facility vs. slightly more than 50% among clients of CHC. In hospitals and HCs National Health Insurance Scheme (NHIS) registration was associated with higher quality of services. In CHCs NHIS registrants received fewer diagnostic tests were less extensively counselled about safe motherhood and were less likely to be vaccinated against tetanus toxoid than non-registered clients. Among CHCs clients being a NHIS registrant was however associated with an increased likelihood of delivering at a health facility. CONCLUSIONS: In the context of premium exemptions association of health insurance with use of maternal health services and quality of services received depends on place where pregnant women seek ANC. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine (c) The Author 2013; all rights reserved.
Validation of a Model to Predict Perioperative Mortality from Lung Cancer Resection in the Elderly

Rationale: Surgical resection is the mainstay therapy for localized non–small cell lung cancer (NSCLC), yet elderly patients are less likely to be treated due to concerns about morbidity and mortality related to surgery.Objectives: To validate and refine a clinical model to predict 30-day perioperative mortality (POM) in elderly patients undergoing curative resection for lung cancer.Methods: We identified 14,297 patients aged 65 years and older with stage I, II, or IIIA NCSLC from the Surveillance, Epidemiology, and End-Results Registry linked to Medicare claims. We used logistic regression analysis to identify independent risk factors for POM and to validate and refine a previously derived prediction model.Measurements and Main Results: Overall, POM was 4.6% (95% confidence interval, 4.2–4.9%). Multiple regression analysis revealed that greater age, male sex, resections of multiple lobes, advanced stage, greater tumor size, and certain comorbidities were associated with increased risk for POM. These risk...
Surface Evaluation of 6H-SiC after Doping by Diffusion

Doping by diffusion of aluminum into 6H-SiC has been carried out in the temperature range of 1800-2100°C. Aluminum carbide (Al 4C 3) is thought to be one of the best candidates for a p-type diffusion source material. A thin layer graphite mask was developed to protect the wafer surface from deteriorating by sublimation/epigrowth during high temperature diffusion. High-resolution optical microscope (HROM) and atomic force microscopy (AFM) were employed to evaluate the surface morphology of the diffused samples. The protective mask significantly decreased the surface roughness. In addition, secondary ion mass spectroscopy (SIMS) was used to identify the influence of the thin graphite mask on the diffusion properties in SiC. There were no significant differences in doping profiles in the samples with and without the graphite mask.
Numerical techniques for assessing reliability and performance of gracefully degrading computer systems

Gracefully degrading systems represent a cost effective alternative to the massively redundant fault-tolerant computing systems. Assessing the effectiveness of these systems requires combined reliability and performance measures such as computational availability, performability and accumulated reward. This paper compares, for the first time, two numerical algorithms used for assessing the complementary distribution of the accumulated reward and the expected accumulated reward, respectively. Both methods are employed for analyzing a multiprocessor server. The first one, based on Laplace transforms, numerical evaluation of eigenvalues, and analytical and numerical inversion of the Laplace transforms, gives accurate results for low values of the accumulated reward. However, instability of the numerical inversion routine negatively affects the results when the accumulated reward approaches the maximum attainable performance of the system. The second method, which relies on randomization, proves to be insensitive to the performance level reached by the system. This approach is used to analyze the impact of the fault/error coverage probability, spare processing units, repair, and performance degradation on the expected accumulated reward of the server. We conclude that the randomization based method is a more accurate approach for assessing the reliability and performance of gracefully degrading systems.
A Model for the Critical Height for Dislocation Annihilation and Recombination in GaN Columns Deposited by Patterned Growth

In order to reduce vertical leakage in III-nitride detectors, we have grown a patterned array of hexagonal GaN columns on masked heteroepitaxial GaN template layers using a-plane sapphire substrates. In addition to eliminating cracking, we have found that for GaN columns tens of microns in diameter and several microns high, the dislocation density is also significantly reduced. We have developed a simple closed-form analytical model for predicting the critical column height for the onset of the reduction in the dislocation density. Among the predictions of this model is that the critical column height for the onset of dislocation density reduction is proportional to the product of column width and the grain size of the GaN film.
Reply to Dr. McNabb-Baltar's letter

Dear Sir, We thank the interest shown in our manuscript by Dr. McNabb-Baltar and agree that identification of risk factors for infectious complications in patients with inflammatory bowel disease (IBD) is an important area of research.1 We agree with Dr. McNabb-Baltar that structural determinants of infection related hospitalizations are important to examine. Patients over the age of 65 years were at the highest risk of infection among the different age groups. The vast majority (90%) …
Fundamental performance limitations via entropy estimates with hidden Markov models

This paper is concerned with entropy based fundamental limitation results for the disturbance rejection problem in a scalar dynamical system. We propose a hidden Markov model (HMM) framework for entropy calculations. Using methods from ergodic theory, we obtain explicit entropy bounds for both the classical Bode problem (with linear dynamics) as well as certain cases of nonlinear dynamics. An important message of this paper is that the limitations are due to fundamental issues pertaining to estimation as opposed to the stabilization control problem.
ARMA modeling and phase reconstruction of multidimensional non-Gaussian processes using cumulants

A statistical multidimensional sequence, generated by a non-Gaussian process, passes through a linear space-invariant (perhaps ARMA) model and colored Gaussian noise is added at the output. Given output cumulants, algorithms are derived for the nonparametric reconstruction of the system's phase as well as for the parametric identification of the ARMA model, which can be noncausal or have nonseparable denominator. >
Expression of the pRb-Binding Regions of E1A Enables Efficient Transformation of Primary Epithelial Cells by v- src

Primary cultures of rat embryo fibroblasts have been shown to be resistant to transformation by dominant oncogenes such as v-src. We sought to determine if similar resistance is displayed by primary epithelial cells, and, if so, whether an immortalizing oncogene such as E1A could enhance transformation of primary epithelial cells by v-src. Transformation of primary rat epithelial cells by v-src was synergistically enhanced when E1A expression plasmids were cotransfected with a v-src expression plasmid. Foci were more numerous and observed earlier (9 to 14 days) with E1A plus v-src than with v-src alone (18 to 28 days). This cotransformation ability was abrogated by deletions in CR1 or CR2 of E1A, which encode the binding regions for the pRb family and are responsible for E1A-mediated cell cycle activation. Mutations in the p300 binding site or the second exon, which abolish immortalization, did not affect v-src cooperation, in contrast to ras and adenovirus E1B. While kinase activation was required for growth in soft agar, differential activation of Src kinase did not correlate with transformation efficiency. Cell morphology and actin structures were not dramatically impacted by E1A expression; thus, hypertransformation, as previously described for ras cotransformation, was not observed with v-src and second-exon mutants of E1A. However, growth rates for cells expressing both E1A and v-Src were higher than those for cells expressing only v-Src. These results suggest that functions involved in cell cycle activation encoded by E1A first exon can enhance v-src transformation of primary epithelial cells.
Probing Ribosomal Structure and Function: Analyses with rRNA and Protein Mutants

The recent development of new genetic systems for the construction of rRNA and ribosomal protein mutants in Escherichia coli has facilitated both structural and functional analyses of these molecules. Mutations in ribosomal proteins resulting in antibiotic resistance or alterations in the accuracy of translation can now be interpreted in structural terms while the consequences for ribosome structure of alterations in rRNA have been visualized directly for the first time by cryo-electron-microscopic techniques. This chapter reviews the recent developments that the author's have made in this area. They describe some of the recent applications of this strain and its potential for further analysis of rRNA function. The acceptance of the base-pairing model of enhancer action has led to the conclusion that all downstream box (DB) elements enhance translation by the same mechanism and has prompted the identification of DB elements by 16S rRNA sequence complementarity alone. Dihydrouridine (D) is one of the most common posttranscriptional modifications found in bacterial and eukaryal tRNAs, where it is believed to allow conformational flexibility in the loop regions of tRNAs that are involved in tertiary interactions. The development of an E. coli strain that permits the expression of pure populations of mutant rRNAs has greatly facilitated genetic, functional, and structural analyses of rRNA.
Points of Care in Using Statistics in Method Comparison Studies

As clinical chemists and laboratory scientists, we are often concerned when personnel who have little laboratory training begin to perform laboratory tests, such as in point-of-care applications. It may be easy to perform such tests today with modern analytical systems, but there still are things that could go wrong. We hope that some kind of quality system is used to check that everything is working okay with point-of-care analyses. Imagine how statisticians might feel about the powerful statistics programs that are now in our hands. It is so easy to key-in a set of data and calculate a wide variety of statistics—regardless what those statistics are or what they mean. There also is a need to check that things are done correctly in the statistical analyses we perform in our laboratories. In this issue of the Journal, Stockl et al. (1) provide an interesting discussion of linear regression techniques in method comparison studies, pointing out that the quality of the data may be more important than the quality of the regression technique (e.g., ordinary linear regression vs Deming regression vs Passing-Bablock regression). In this Journal, the standard method for analyzing the data from a method comparison experiment has been to prepare a “comparison plot” that shows the test method results on the y -axis and the comparative method results on the x -axis, and then to calculate regression statistics to determine the best line of fit for the data. Different regression techniques may be appropriate, depending on the characteristics of the data—particularly the analytical range that is covered relative to the test values that are critical for medical applications. Elsewhere in the literature (2), there is a movement to discourage the use of regression analysis altogether and replace it with a simple graphical presentation of method comparison data in the …
A RISC/UNIX[ 1] Workstation Second Stage Trigger

Recent advances in reduced-instruction-set computer (RISC) workstations have greatly altered the economics of processing power available for experiments. In addition, VME interfaces available for many of these workstations make it possible to use them in experiment front ends for filtering and compressing data. Such a second-stage trigger has been implemented at LAMPF (Clinton P. Anderson Meson Physics Facility) using a commercially available workstation and VME interface. The implementation is described, and measurements of data transfer speeds are presented. >
Nonprofit Organizations and Public Policy

Private, nonprofit organizations constitute a growing portion of the United States economy that has, until recently, escaped significant attention by many scholars interested in public policy. The papers in this symposium address four types of interactions between nonprofits and public policymakers—service provision and program implementation, policy advocacy, public policies toward nonprofits, and public/private partnerships. In addition, many private nonprofit organizations produce public goods that can supplement or substitute for government action.
DNA repair in antibody somatic hypermutation

Somatic hypermutation (SHM) underlies the generation of a diverse repertoire of high-affinity antibodies. It is effected by a two-step process: (i) DNA lesions initiated by activation-induced cytidine deaminase (AID), and (ii) lesion repair by the combined intervention of DNA replication and repair factors that include mismatch repair (MMR) proteins and translesion DNA synthesis (TLS) polymerases. AID and TLS polymerases that are crucial to SHM, namely polymerase (pol) θ, pol ζ and pol η, are induced in B cells by the stimuli that are required to trigger this process: B-cell receptor crosslinking and CD40 engagement by CD154. These polymerases, together with MMR proteins and other DNA replication and repair factors, could assemble to form a multimolecular complex (‘mutasome') at the site of DNA lesions. Molecular interactions in the mutasome would result in a ‘polymerase switch', that is, the substitution of the high-fidelity replicative pol δ and pol e with the TLS pol θ, pol η, Rev1, pol ζ and, perhaps, pol ι, which are error-prone and crucially insert mismatches or mutations while repairing DNA lesions. Here, we place these concepts in the context of the existing in vivo and in vitro findings, and discuss an integrated mechanistic model of SHM.
Modernization and Gender Equality: A Response to Adams and Orloff

Julia Adams and Ann Shola Orloff's insightful critical perspective in the first issue of this journal makes several important points about the relationship between modernization and gender equality. We agree with Adams and Orloff that—despite strong claims to the contrary (e.g., Young 2003)—modernization tends to be conducive to gender equality. And we also agree that the classic versions of modernization theory were inadequate. The basic insight that economic and technological development tends to bring coherent patterns of social and political change holds up well in the light of a large body of recent evidence; but previous models of modernization were mechanical and linear, and they omitted cultural factors that cannot be ignored. We join forces with Adams and Orloff in striving to develop a more adequate concept of modernization, recognizing that understanding ongoing processes of socioeconomic change is a long-term task that will need input from many perspectives.
"Delayed" prophylactic anticoagulation: a study of results and complications in 2,012 total hip arthroplasties.

Prophylactic anticoagulation with sodium warfarin was used after 1,950 of 2,012 consecutive total hip arthroplasties, beginning on the fifth postoperative day. No anticoagulative was used after the remaining procedures. The rate of fatal pulmonary embolism in the group treated with anticoagulants was 0.05 per cent, and in the group not treated with anticoagulants, 3.4 per cent. There were nineteen serious bleeding problems in the anticoagulated group, six of which necessitated surgery. There were also two deep infections associated with wound hematomas which resolved satisfactorily with treatment. There were no fatal complications resulting from anticoagulation.
Comparison of electrical characteristics of barbed-plate and wire-plate precipitators

Differences in electrical characteristics of barbed plate-to-plate and wire-plate precipitators are presented in terms of measured current-voltage curves and spatial distributions of current at the collection plate. Data are obtained in a 61.0 cm by 61.0 cm by 15.2 cm laboratory precipitator operating at Reynolds and electrohydrodynamic numbers typical of industrial precipitators. Results show that a barbed plate-to-plate precipitator produces more uniform distributions of current along the collector plates than exist in a conventional wire-plate precipitator. >
Dynamic representation of eye position in the parieto-occipital sulcus.

Dynamic representation of eye position in the parieto-occipital sulcus. Area V6A, on the anterior bank of the parieto-occipital sulcus of the monkey brain, contains neurons sensitive both to visual...
Qualification of Temper Bead Welding by an Alternative Hardness Testing Approach

In 2004, ASME Section IX added maximum hardness essential variables for temper bead procedure qualification when impact testing is not specified or required by the applicable book section. The assumption with specifying a maximum hardness criterion is that high hardness after temper bead welding indicates inadequate tempering. As discussed in PVP2013-97793 [2], imposing a maximum hardness criterion for temper bead qualification can actually lead to acceptance of a heat affected zone (HAZ) microstructure with less than optimum impact properties. In fact, depending on the weld HAZ microstructure the impact properties can vary widely from very low to very high at the same hardness. This paper describes an alternative hardness test protocol for temper bead procedure qualification. Rather than using a single maximum hardness acceptance threshold, this new test protocol characterizes the base material response to temper bead welding by determining the maximum achievable hardness with a bead-on-plate test and with a hardness calculation. Research shows that a high hardness in the HAZ prior to depositing the tempering weld layers provides the optimum microstructure for achieving desired HAZ impact properties. With proper tempering the HAZ hardness is reduced below the maximum achievable hardness. Temper bead procedure acceptance is thus determined by the drop in HAZ hardness after depositing the temper bead weld layers. Application of this new hardness test protocol for temper bead qualification is proposed as an alternative to a single maximum hardness acceptance criterion.Copyright © 2015 by ASME
More Time, More Work: How Time Limits Bias Estimates of Project Duration and Scope

We propose that time limits systematically bias predictions of workers’ completion times, even when the limits are uninformative and cannot affect worker’s behavior. We show evidence for this bias in controlled laboratory studies and in a field survey. We find that longer time limits contribute to a misperception that the task involves more work, even for experienced managers making estimates in a familiar setting. This scope and duration bias has important behavioral implications, including an excessive preference for flat fee compensation contracts over contracts based on time spent working.
Iridium( iii )-bis(imidazolinyl)phenyl catalysts for enantioselective C–H functionalization with ethyl diazoacetate

The intermolecular enantioselective C–H functionalization with acceptor-only metallocarbenes is reported using a new family of Ir(III)-bis(imidazolinyl)phenyl catalysts, developed based on the interplay of experimental and computational insights. The reaction is tolerant of a variety of diazoacetate precursors and is found to be heavily influenced by the steric and electronic properties of the substrate. Phthalan and dihydrofuran derivatives are functionalized in good yields and excellent enantioselectivities.
Neuronal NOS contributes to biphasic autoregulatory response during enhanced TGF activity.

To assess the afferent arteriolar autoregulatory response during increased activity of the tubuloglomerular feedback (TGF) mechanism and to delineate the contribution of neuronal nitric oxide synth...
Dyslipidemia in women with diabetes

Older reports of greater diabetes-associated increment in cardiovascular disease in women compared with men are confirmed in the recent reports of the Strong Heart Study of Native Americans. In that study, a greater apoprotein B level was seen in diabetic women, in keeping with a greater triglyceride, very low density lipoprotein C (VLDL-C), and lower high density lipoprotein C (HDL-C) level compared to men in previous studies. Greater total and low density lipoprotein (LDL) cholesterol levels may be seen as well. Lipoprotein abnormalities in diabetic women also predict the development of significant albuminuria in diabetic women compared with men and the development of diabetes itself which is a problem. Therapeutic interventions involving walking, triple drug therapy, and postmenopausal estrogen all offer promise. Major cardiovascular prevention trials have shown benefits in diabetic subjects but also have not differentiated response by gender. Such studies are greatly needed because of the greater degree of dyslipidemia and cardiovascular risk in diabetic women.