cssi/SciSciGPT-SciSciNet huggingface dataset:
Two conformers observed and characterized in isobutylbenzene.

The microwave spectrum of isobutylbenzene (2-methyl-1-phenylpropane) reveals the presence of two conformers that are characterized by their microwave spectra and by quantum chemical calculations. The more stable conformer has a gauche configuration of the C(phenyl)−C1−C2−H chain coupled with a ∼80° dihedral angle between the phenyl group and the C(phenyl)−C1−C2 plane with C1 symmetry. The less stable conformer has a plane of symmetry, Cs, with an anti configuration of the C(phenyl)−C1−C2−H chain coupled with a 90° dihedral angle between the phenyl group and the C(phenyl)−C1−C2 plane. The rotational constant values are 3070.9273(4) MHz, 736.01980(6) MHz, and 680.92889(6) MHz for the C1 species and 2500.780(8) MHz, 885.72743(10) MHz, and 770.42036(10) MHz for the Cs species. Quantum chemical calculations are in agreement with these structures and predict a relative energy between those two conformers of 0.4 kcal/mol.
Effect of PTTG on endogenous gene expression in HEK 293 cells

Pituitary tumor transforming gene (PTTG), also known as securin, is highly expressed in various tumors including pituitary, thyroid, colon, ovary, testis, lung, and breast. An overexpression of PTTG enhances cell proliferation, induces cellular transformation in vitro, and promotes tumor development in nude mice. PTTG also inhibits separation of sister chromatids leading to aneuploidy and genetic instability. A great amount of work has been undertaken to understand the biology of PTTG and its expression in various tumors. However, mechanisms by which PTTG mediates its tumorigenic function are not fully understood. To utilize this gene for cancer therapy, identification of the downstream signaling genes regulated by PTTG in mediation of its tumorigenic function is necessary. For this purpose, we expressed PTTG in human embryonic kidney (HEK293) cells that do not express PTTG and analyzed the downstream genes using microarray analysis. A total of 22,277 genes printed on an Affymetrix HG-U133A 2.0 GeneChip™ array were screened with labeled cRNA prepared from HEK293 cells infected with adenovirus vector expressing PTTG cDNA (AdPTTG cDNA) and compared with labeled cRNA prepared from HEK293 cells infected with control adenovirus (control Ad) or adenovirus vector expressing GFP (AdGFP). Out of 22,277 genes, 71 genes were down-regulated and 35 genes were up-regulated with an FDR corrected p-value of ≤ 0.05 and a fold change of ≥2. Most of the altered genes identified are involved in the cell cycle and cell apoptosis; a few are involved in mRNA processing and nitrogen metabolism. Most of the up-regulated genes belong to the histone protein family. PTTG is a well-studied oncogene for its role in tumorigenesis. In addition to its importance in regulation of the cell cycle, this gene has also been recently shown to play a role in the induction of cell apoptosis. The microarray analysis in the present study demonstrated that PTTG may induce apoptosis by down-regulation of oncogenes such as v-Jun and v-maf and up-regulation of the histone family of genes.
Aortic pulse wave velocity measurements with undersampled 4D flow‐sensitive MRI: comparison with 2D and algorithm determination

PURPOSE To compare pulse wave velocity (PWV) measurements obtained from radially undersampled 4D phase-contrast MRI (PC-MRI) with 2DPC measurements and to evaluate four PWV algorithms.
Effects of peer feedback on contribution: a field experiment in Wikipedia

One of the most significant challenges for many online communities is increasing members' contributions over time. Prior studies on peer feedback in online communities have suggested its impact on contribution, but have been limited by their correlational nature. In this paper, we conducted a field experiment on Wikipedia to test the effects of different feedback types (positive feedback, negative feedback, directive feedback, and social feedback) on members' contribution. Our results characterize the effects of different feedback types, and suggest trade-offs in the effects of feedback between the focal task and general motivation, as well as differences in how newcomers and experienced editors respond to peer feedback. This research provides insights into the mechanisms underlying peer feedback in online communities and practical guidance to design more effective peer feedback systems.
On the possibility of rational policy evaluation

Arrow proved the inconsistency of a set of reasonable looking conditions on a social decision rule. These conditions are stated and their rationale explained. It is argued that the blame for the inconsistency must lie with Arrow's Collective Rationality condition. Arrow's abstract problem is generalized and interpreted in terms of individual as well as collective decision-making. His conditions are revised so that (1) cardinal - even interpersonal - utility comparisons are allowed and (2) the Collective Rationality condition - which formulates the traditional conception of rational choice as maximizing choice - is weakened to its bare bones. The revised set of conditions is still inconsistent. Once again the culprit is the Collective Rationality condition, now drastically weakened: even the bare bones of Arrow's conception of rational choice as maximizing choice is untenable. An alternative conception is proposed.
Choosing a hospital and physician: Does the public really care about infection rates and being informed?

BACKGROUND: The American Medical Association (AMA) has defined six necessary components of an informed consent document: diagnosis, nature, purpose, risks, benefits of proposed and alternative treatment or procedure, and risks and benefits of no treatment or procedure. It remains unclear whether the general public's knowledge before entering the hospital setting is in fact “informed.” OBJECTIVES: To evaluate the public's knowledge of “informed consent,” healthcare-acquired infections (HAIs) and factors considered in choosing a hospital. METHODS: An inner-city university population was surveyed through convenience sampling utilizing yes/no and open-ended responses as well as an online survey representing a random population. RESULTS: Seventy-one percent of respondents identified all six of the AMA's criteria for informed consent to be information needed before signing the document. Thirty-five percent of respondents ranked a physician's procedure mortality rate to be most important. However, no respondent ranked a physician's infection rate to be the most important information. Variables of post-procedure well-being (pain, recovery time) were most important, and malpractice record and insurance coverage were least important. Eighty-five percent of respondents were aware of HAIs, and 81% knew the importance of hand hygiene. Only 17% of respondents felt there was a need to know infection rates prior to hospitalization. In fact, when choosing a hospital, infection rates ranked 10th in a list of 13 important factors, but were the number one reason consumers said they would leave a hospital system. Eighty-four percent of respondents were willing to pay additional money for infection control programs that were designed to allow them to take a pro active approach to their own care. CONCLUSIONS: Although there is an understanding of the components of an informed consent document, respondents did not identify infection rates to be important before signing a consent form or entering a hospital although they indicated they would leave a hospital system if the rates were high. These findings strongly suggest there is a critical need for consumer education about infection rates in light of state mandatory reporting program for HAIs.
Upper gastrointestinal hemorrhage after nonresponsive thoracic spine pain: a case report.

Objective This case study reports the findings of an upper gastrointestinal hemorrhage in a patient with thoracic spine pain reporting to a chiropractic clinic. The purpose of this article is to highlight the importance of identifying a patient's medication history as well as reviewing the signs and symptoms of gastrointestinal bleeding from a nonvariceal lesion.
Kant and the perfect duty to others not to lie

A great contempt for lies and liars is evident in all of Kant's writings on practical philosophy and theology. 1 Despite the frequency and the virulence with which lies and liars are condemned, how...
A mixed-mode crack analysis of rectilinear anisotropic solids using conservation laws of elasticity

A very simple and convenient method of analysis for studying two-dimensional mixed-mode crack problems in rectilinear anisotropic solids is presented. The analysis is formulated on the basis of conservation laws of anisotropic elasticity and of fundamental relationships in anisotropic fracture mechanics. The problem is reduced to a system of linear algebraic equations in mixed-mode stress intensity factors. One of the salient features of the present approach is that it can determine directly the mixed-mode stress intensity solutions from the conservation integrals evaluated along a path removed from the crack-tip region without the need of solving the corresponding complex near-field boundary value problem. Several examples with solutions available in the literature are solved to ensure the accuracy of the current analysis. This method is further demonstrated to be superior to other approaches in its numerical simplicity and computational efficiency. Solutions of more complicated and practical engineering problems dealing with the crack emanating from a circular hole in composites are presented also to illustrate the capacity of this method.
Generalized Hook and Content Numbers Identities—The Projective Case

The study of identities of hook pairs and of content pairs of partitions in is continued. For a strict partition ?= (?1??k) let?= (?1,? , ?k|?1? 1,? , ?k? 1) in the Frobenius notation. It is proved that for such partitions there are refinements of the identities in , and further identities exist which arise from half of each of the diagrams involved.
Structural manipulation of the frictional properties of linear polymers in single molecular layers

Manipulation of the frictional properties of self-assembled monolayers containing internal molecular scaffolding through subtle variations in the alkyl structure is demonstrated using atomic force microscopy. Photopolymerizable diacetylene groups are incorporated within the alkyl chains of the monolayer, resulting in noncovalent electronic interactions between diacetylene groups, in the unpolymerized form. Under these conditions, discrete transitions in the friction vs load curves are observed, indicating partial collapse of the monolayer at specific loads. Subsequent photopolymerization by UV irradiation results in covalent cross-linking between molecules and the creation of a linear conjugated polymer backbone. This significantly alters the frictional properties of the monolayers by inhibiting lateral displacement within the monolayer. The presence of domains due to the directionality of the polymer backbone leads to a corresponding directionality in the frictional properties of the assembly that is not...
Effect of Various Prelaying Levels of Dietary Calcium Upon Subsequent Performance in Chickens

Abstract INTRODUCTION CONSIDERABLE research has been reported concerning the calcium requirements for growth and bone development of chicks (Hart et al, 1930; Twing et al., 1965; Itoh and Hatano, 1964) and the effect of dietary calcium upon the productive performance of laying hens (Deobald et al., 1936; Petersen et al., 1960; Mehring and Titus, 1964). However, relatively few and often very conflicting investigations have been reported concerning the calcium requirements of pullets from eight weeks to the onset of egg production and concerning the effect of calcium levels during the developing period upon the subsequent production. Berg et al. (1947) fed .7, .9, and 3.0% calcium levels for 50 days prior to laying and found no effect upon egg production for the first three months of production. Berg et al. (1964) fed levels as low as .4% Ca and .3% P and found no effect upon productive performance. Young et al.…
On‐line reliability estimation for individual components using statistical degradation signal models

With very few exceptions, most contemporary reliability engineering methods are geared towards estimating a population characteristic(s) of a system, subsystem or component. The information so extracted is extremely valuable for manufacturers and others that deal with product in relatively large volumes. In contrast, end users are typically more interested in the behavior of a ‘particular’ component used in their system to arrive at optimal component replacement or maintenance strategies leading to improved system utilization, while reducing risk and maintenance costs. The traditional approach to addressing this need is to monitor the component through degradation signals and ‘classifying’ the state of a component into discrete classes, say ‘good’, ‘bad’ and ‘in-between’ categories. In the event, one can develop effective degradation signal forecasting models and precisely define component failure in the degradation signal space, then, one can move beyond the classification approach to a more vigorous reliability estimation and forecasting scheme for the individual unit. This paper demonstrates the feasibility of such an approach using ‘general’ polynomial regression models for degradation signal modeling. The proposed methods allow first-order autocorrelation in the residuals as well as weighted regression. Parametric bootstrap techniques are used for calculating confidence intervals for the estimated reliability. The proposed method is evaluated on a cutting tool monitoring problem. In particular, the method is used to monitor high-speed steel drill-bits used for drilling holes in stainless-steel metal plates. A second study involves modeling and forecasting fatigue-crack-growth data from the literature. The task involved estimating and forecasting the reliability of plates expected to fail due to fatigue-crack-growth. Both studies reveal very promising results. Copyright © 2002 John Wiley & Sons, Ltd.
A conceptual framework for organizational readiness to implement nutrition and physical activity programs in early childhood education settings.

Across multiple sectors, organizational readiness predicts the success of program implementation. However, the factors influencing readiness of early childhood education (ECE) organizations for implementation of new nutrition and physical activity programs is poorly understood. This study presents a new conceptual framework to measure organizational readiness to implement nutrition and physical activity programs in ECE centers serving children aged 0 to 5 years. The framework was validated for consensus on relevance and generalizability by conducting focus groups; the participants were managers (16 directors and 2 assistant directors) of ECE centers. The framework theorizes that it is necessary to have “collective readiness,” which takes into account such factors as resources, organizational operations, work culture, and the collective attitudes, motivation, beliefs, and intentions of ECE staff. Results of the focus groups demonstrated consensus on the relevance of proposed constructs across ECE settings. Including readiness measures during program planning and evaluation could inform implementation of ECE programs targeting nutrition and physical activity behaviors.
Nonanticipating Dynamical Model and Optimal Control

Abstract Suppose (Y,||), (Z,||) and (U,||) are Banach spaces and denote M(I,Y) the Banach space of all essentially bounded Bochner measurable functions from the interval I=[0,a] into Y. Assume y belongs to M(I,Y) and T is nonanticipating and Lipschitzian operation from an initial domain D(x,Y) into M(I,Z). For a given control function u in M(I,U), we will prove existence and uniqueness of the solution to the nonlinear dynamical model y′(t) = f(t,y(t),T(y)(t), u(t)) for almost all t in I. Will show, there exist an optimal control u in Q, compact subset of M(I, U) satisfying this dynamical system and optimizes the functional P(u) = ʂ t 0 g(t, y(t), T(y), u(t))dt .
Kinematical Problem in Spin-Wave Theory

A spin-1/2, nearest neighbor Heisenberg Hamiltonian acting on a periodic,d-dimensional lattice is considered. Multi-spin-wave solutions to the Schrodinger equation for a Heisenberg ferromagnet involve an unlimited superposition of spin-reversal operators at sites. This violates the physical restriction that no more than one excitation reside on any one site. This exclusion rule affects spin-wave interaction—the determination of these effects is called the kinematical problem. A general nonperturbative treatment that includes kinematical effects in spin-wave theory is developed along the following lines. Using the property of the Heisenberg Hamiltonian that it does not couple states obeying the single occupation condition at all sites with states that violate the single-occupancy condition at some sites, the unphysical multiply occupied states can be eliminated by a nonunitary transformation of the eigenvalue equation. An overcomplete Hamiltonian matrix is obtained that contains all the physical eigenvalues as a subset of its spectrum. Overcompleteness is shown to be a large part of the kinematical problem and several schemes to handle it are discussed. The remainder of the kinematical problem lies in the nonorthogonality of spin waves. It is shown that a new type of distribution, one that is neither Bose nor Fermi, correctly describes free spin-wave statistics at all temperatures. This formal but nonetheless complete solution to the overcompleteness aspect of the kinematical problem is then carried over,in toto, to the boson formulation of the spin Hamiltonian. Application to the calculation of the partition function and to thermal Green's functions is noted.
Very long-term aging of 52In–48Sn (at.%) solder joints on Cu-plated stainless steel substrates

Long-term metallurgical aging was studied in thermal switches comprised of 52In–48Sn (at.%) alloy solder plugs contained in Cu-plated stainless steel cylinders. These switches are locking devices designed so that, if overheated, a “fusible” alloy melts and allows the activation of a spring-loaded mechanism. The soldered assemblies studied ranged in age from about 24 to 28 years old at the time of this analysis. A concern has been the buildup of intermetallic compound (IMC) within the solder or at the solder/substrate interface, which could raise the switch operating temperature. In this work, the melting temperature of the aged solder alloy was slightly lower (116.3 ± 0.3 °C) than the expected value, 118.4 °C (245 °F), based on differential scanning calorimetry (DSC). The slight decrease in melting temperature range was caused by the diffusion of a small amount of Cu into the solder during processing and possibly during long-term service. The interfacial IMC layer was primarily Cu2In3Sn. The IMC thickness agreed with that predicted by growth kinetics determined in a previous study, assuming aging temperatures in the vicinity of room temperature. Differences in the IMC phase chemistries were found between earlier research, which employed bulk Cu substrates, and the present analyses with thin electroplated Cu substrates. Evidence was found for depletion of the thin Cu plating layer over time, as well as incorporation of Fe and Ni from the stainless steel into the IMC layer.
Random fields and the limit of their spectral densities: existence and bounds

Abstract For a sequence of discrete random fields indexed by an integer lattice of finite dimension that satisfy a weak linear dependence condition, have converging covariances, and (not necessarily continuous) spectral densities f ( l ) bounded between two positive constants, a limiting spectral density f bounded between two positive constants is obtained, along with a weak form of convergence of f ( l ) to f . Two examples are given that show this convergence seems to be the best one can get.
Theory of the tensile test

Abstract The phenomenology of the tensile test is re-examined with special attention to the influence of strain rate sensitivity of the flow stress. Explicit formulae are deduced for the measured variables of the test in terms of the phenomenological parameters of the material. The stability of the deformation is examined, and the growth of an inhomogeneity is described in the unstable deformation regime. The effect of elasticity of the specimen and the testing machine is investigated with special attention to relaxation tests.
Heat capacities (1 to 108 K) and linear thermal expansivities (1 to 300 K) of LuH 0.148 single crystals: Thermal relaxation effects and the pairing transition

Previous heat capacity (C{sub p}) and linear thermal expansivity ({alpha}) data for the hexagonal {alpha}-LuH{sub x} and LuD{sub x} [LuH(D){sub x}] single crystal alloys (x=0,h0.005,h0.053) [C. A. Swenson, Phys. Rev. B {bold 53}, 3680 (1996)] have been extended to LuH{sub 0.148}. A feature (a transition) near 170 K in {alpha} vs {ital T} for LuH{sub 0.053} crystals is much more pronounced for the present results, with the {ital c}-axis ({ital a}-axis) data showing an almost 40{percent} (30{percent}) decrease (increase) in {alpha} on cooling below 170 K. This transition, which was associated with the pairing of H along the {ital c} axis in next-nearest-neighbor tetrahedral sites on opposite sides of a lutetium ion, is not clearly defined, however, and, after a change in temperature, is characterized by isothermal drifts in the sample length with time constants which are very small at 175 K but increase to 100 h at 144 K. The migration energy associated with the temperature dependence of these time constants [0.26(3) eV] is approximately one-half that which is associated with high-temperature bulk diffusion. The conclusion is that pair breakup (pairing) does not occur (is not completed) at a unique transition temperature when the alloy is warmed (cooled), butmore » is a thermally activated process, with the equilibrium fraction of paired H increasing with decreasing temperature, to achieve a saturation concentration below 140 K. The approach to pairing equilibrium for T{lt}175hK is diffusion limited. {copyright} {ital 1999} {ital The American Physical Society}« less
The effect of medial thalamic lesions on emotionality, activity, and discrimination learning in the rat.

Abstract Three experiments were conducted to examine the effects of medial thalamic lesions on emotionality, open-field activity, and discrimination learning. The first study revealed that rats with large medial thalamic lesions are significantly less responsive to capture and to handling than are sham-operated rats. The second study failed to produce any significant differences in open-field activity. A third study revealed that rats with large medial thalamic lesions, and with both small anterior and posterior medial thalamic lesions are impaired on the acquistion of an appetitive visual-tactile discrimination task, with the deficit being greatest in the large lesion group. It was concluded that the medial thalamus plays a role in the neural mediation of certain emotional responses and is critical in the acquisition of complex appetitive tasks.
Transparent and flame retardant PMMA nanocomposites

Poly(methyl methacrylate) (PMMA) nanocomposites containing an organoclay and triphenyl phosphate (TPP) were prepared by solution blending using a PMMA solution in methyl methacrylate (MMA) solvent. Exfoliated nanostructures were shown by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The optical transmittance of the PMMA nanocomposites decreased with an increase in the clay content. The improvement in the thermal stability of the PMMA nanocomposites was greater in air than in nitrogen. Nanocomposite formation brought about reductions of the peak heat release rate (PHRR), as measured by cone calorimetry. The combination of the nanoclay and TPP brought about a further decrease in the PHRR and an increase in the average specific extinction area (ASEA, related to smoke production). Copyright © 2008 John Wiley & Sons, Ltd.
Health Care in Small Areas of Three Command Economies: What Do the Data Tell Us?

The present project assembles and analyzes health systems data for small areas in contiguous regions of East Germany, Czechoslovakia, and Poland in 1988. The data were collected and maintained by the Communist central governments of East Germany and Czechoslovakia, and by the voivodships in Poland during the command system era. Analyses of these regions are compared to contemporary data from U.S. regions. Instead of assuming a common goal for each region, the data are studied to ascertain whether they reflect an identifiable, de facto goal. The key findings are that coefficients of variation of health care resource availability are somewhat larger in the command systems; and coefficients of variation in mortality rates are smaller in two of the command systems, suggesting a de facto emphasis on health status equality. The U.S. regions' data appear to be more consistent with an implicit goal of regional health status maximization. Discussions explain the relationships between the alternative goals and sugg...
Metal-fill optical test structures for improved chemical mechanical polishing

This paper presents an iterative algorithm that merges the physical layout of a circuit with an optical test structure called a wire segment hologram. Wire segment holograms are geometrical patterns that resemble circuit wiring but are arranged to project an holographic image when illuminated with a light source whose wavelength is comparable to the feature size of the process under test. The quality of the projected image is strongly correlated with the fidelity of the fabrication process and therefore provides rapid, non-contact, dimensional metrology. We propose that the merged circuit/test structure is ideal for metal processing which suffers from high pattern dependence, such as chemical mechanical polishing. By changing the relative width, height and pitch of the merged diffractive elements, it is possible to generate test structures with a wide range of metal density. Thus, these test structures can perform the dual task of reducing pattern dependent defect formation and characterizing the dimensional fidelity of the fabrication process. Initial results are presented that indicate the merged circuit/test structures can resolve mask offset variations as small as 0.1 micrometer for a 2 micrometer wire width.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Multiplatform GPGPU implementation of the active contours without edges algorithm

An OpenCL implementation of the Active Contours Without Edges algorithm is presented. The proposed algorithm uses the General Purpose Computing on Graphics Processing Units (GPGPU) to accelerate the original model by parallelizing the two main steps of the segmentation process, the computation of the Signed Distance Function (SDF) and the evolution of the segmented curve. The proposed scheme for the computation of the SDF is based on the iterative construction of partial Voronoi diagrams of a reduced dimension and obtains the exact Euclidean distance in a time of order O(N/p), where N is the number of pixels and p the number of processors. With high resolution images the segmentation algorithm runs 10 times faster than its equivalent sequential implementation. This work is being done as an open source software that, being programmed in OpenCL, can be used in dierent platforms allowing a broad number of nal users and can be applied in dierent areas of computer vision, like medical imaging, tracking, robotics, etc. This work uses OpenGL to visualize the algorithm results in real time.
A subphrenic abscess in a previously healthy child

The presence of fever, grunting respirations, toxic appearance, and an infiltrate on a chest radiograph is consistent with the diagnosis of pneumonia in a 22-month-old child. We present a case in which the diagnosis of a subphrenic abscess was obscured by the absence of a typical history and physical findings and the presence of pulmonary infiltrates on chest radiographs. A 22-month-old boy with no significant medical history was well until 8 days before admission, when he presented with fever to 104°F. He was exposed to a nonspecific viral illness in the home 1 week before getting ill, and he had choked on a piece of bread a few weeks before the fever. There was no vomiting, diarrhea, or abdominal pain. There was no history of pica. Initially at physical examination his chest was clear, and a chest radiograph revealed bilateral hilar infiltrates. He started receiving amoxicillin and clavulanic acid, but there was no clinical response. The following day he was admitted to a community hospital for intravenous antibiotics. At the time of admission his temperature was 104°F, respiratory rate 32, blood pressure 90/50, and heart rate 120. He seemed toxic at physical examination, with grunting respirations. A chest radiograph demonstrated right upper lobe and right perihilar infiltrates and an elevated right hemidiaphragm. Laboratory studies revealed an elevated white blood cell count, 22 300/μL with 60% segmented neutrophiles and 16% bands. The hemoglobin was 9.8 g/dL, and …
Late-onset psychotic disorder, not otherwise specified : clinical and neuroimaging findings

Utilizing current neuroimaging technology, recent relC~rts suggest that in psychotic and mood disorders, particularly when these present in the elderly, there is a higher prevalence of cerebral atrophy~ ventricular enlargement, and white matter lesions (WML) compared with control subjects (Miller and Lesser 1988; Jeste et al !988b; Nasrallah et al 1989; Andreasen et al 1990; Coffey et al 1990; Breitner et al 1990; Lesser et al 1991; Miller et al 1991; Krull et al 1991). Although schizophrenic and mood disorders in the elderly have been studied, little attention has been given to the residual diagnosis of psychotic disorder, not otherwise specified (PDNOS) (American Psychiatric Association 1987). As part of a larger study of late-onset psychotic disorder, we now report the results of clinical and neuroimaging evaluations of patients diagnosed as having PDNOS, with symptom onset after the age of 45.
Growth Inhibition of Sporomusa ovata by Incorporation of Benzimidazole Bases into Cobamides

Phenolyl cobamides are unique members of a class of cobalt-containing cofactors that includes vitamin B12 (cobalamin). Cobamide cofactors facilitate diverse reactions in prokaryotes and eukaryotes. Phenolyl cobamides are structurally and chemically distinct from the more commonly used benzimidazolyl cobamides such as cobalamin, as the lower axial ligand is a phenolic group rather than a benzimidazole. The functional significance of this difference is not well understood. Here we show that in the bacterium Sporomusa ovata, the only organism known to synthesize phenolyl cobamides, several cobamide-dependent acetogenic metabolisms have a requirement or preference for phenolyl cobamides. The addition of benzimidazoles to S. ovata cultures results in a decrease in growth rate when grown on methanol, 3,4-dimethoxybenzoate, H2 plus CO2, or betaine. Suppression of native p-cresolyl cobamide synthesis and production of benzimidazolyl cobamides occur upon the addition of benzimidazoles, indicating that benzimidazolyl cobamides are not functionally equivalent to the phenolyl cobamide cofactors produced by S. ovata. We further show that S. ovata is capable of incorporating other phenolic compounds into cobamides that function in methanol metabolism. These results demonstrate that S. ovata can incorporate a wide range of compounds as cobamide lower ligands, despite its preference for phenolyl cobamides in the metabolism of certain energy substrates. To our knowledge, S. ovata is unique among cobamide-dependent organisms in its preferential utilization of phenolyl cobamides.
Role of NBC1 in apical and basolateral HCO3− permeabilities and transendothelial HCO3− fluxes in bovine corneal endothelium

Corneal transparency and hydration control are dependent on HCO3− transport properties of the corneal endothelium. Recent work (13) suggested the presence of an apical 1Na+-3HCO3− cotransporter (NB...
Boundary element analysis of non-planar three-dimensional cracks using complex variables

Abstract This paper reports new developments on the complex variables boundary element approach for solving three-dimensional problems of cracks in elastic media. These developments include implementation of higher order polynomial approximations for the boundary displacement discontinuities and more efficient analytical techniques for evaluation of integrals. The approach employs planar triangular boundary elements and is based on the integral representations written in a local coordinate system of an element. In-plane components of the fields involved in the representations are separated and arranged in certain complex combinations. The Cauchy–Pompeiu formula is used to reduce the integrals over the element to those over its contour and evaluate the latter integrals analytically. The system of linear algebraic equations to find the unknown boundary displacement discontinuities is set up via collocation. Several illustrative numerical examples involving a single (penny-shaped) crack and multiple (semi-cylindrical) cracks are presented.
Efficient Mutual Exclusion in Peer-to-Peer Systems

Due to the recent surge in the area of grid computing, there is an urgency to find efficient ways of protecting consistent and concurrent access to shared resources. Traditional peer-to-peer (P2P) applications such as Kazaa and Gnutella have been primarily used for sharing read-only files (such as mpegs and mp3s). This paper introduces two novel protocols, the End-to-End and Non End-to-End, for achieving mutual exclusion efficiently in dynamic P2P systems. The protocols are layered atop a distributed hash table (DHT), making them scalable and fault-tolerant. The burden of controlling access to the critical section is also evenly distributed among all the nodes in the network, making the protocols more distributed and easily adaptable to growing networks. Since the protocols are designed independent of any specific DHT implementation, they can be incorporated with any generic P2P DHT, depending on the application requirements. We present experiments comparing our implementations with existing mutual exclusion algorithms. The significant reduction in overall message overhead and better load-balancing mechanisms makes the proposed protocols very attractive in being used for current and future P2P and grid applications.
Program entanglement, feature interaction and the feature language extensions

One of the most difficult tasks in software development is that the programmer must implement a feature going through a laborious and error prone process of modifying the programs of other features. The programs of the different features entangle in the same reusable program units of the programming language, making them also difficult to be verified, maintained and reused. We show that if (C1) the features interact, (C2) they are executed by the same process and (C3) they are implemented in a programming language that requires the programmer to specify execution flows, program entanglement is inevitable and the problem cannot be solved by software design alone. Applications with interacting features are common including those that require exception handling. The feature language extensions (FLX) is a set of programming language constructs designed to enable the programmer to develop interacting features as separate and reusable program modules even though the features interact. The programmer uses FLX to specify non-procedural program units, organize the program units into reusable features and integrate features into executable feature packages. He develops a feature based on a model instead of the code of other features. FLX supports an automatic procedure to detect the interaction condition among features; the programmer then resolve the interaction in a feature package without changing feature code. FLX features and feature packages are reusable; the programmer may package different combinations of them and resolve their interactions differently to meet different user needs. An FLX to Java compiler has been implemented; our experience of using it has been very positive.
Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling

The Cretaceous/Tertiary (K/Pg) mass extinction has long been viewed as a pivotal event in mammalian evolutionary history, in which the extinction of non-avian dinosaurs allowed mammals to rapidly expand from small-bodied, generalized insectivores to a wide array of body sizes and ecological specializations. Many studies have used global- or continental-scale taxonomic databases to analyze this event on coarse temporal scales, but few studies have documented morphological diversity of mammalian paleocommunities on fine spatiotemporal scales in order to examine ecomorphological selectivity and ecospace filling across this critical transition. Focusing on well-sampled and temporally well-constrained mammalian faunas across the K/Pg boundary in northeastern Montana, I quantified dental-shape disparity and morphospace occupancy via landmark- and semilandmark-based geometric morphometrics and mean body size, body-size disparity, and body-size structure via body-mass estimates.My results reveal several key findings: (1) latest Cretaceous mammals, particularly metatherians and multituberculates, had a greater ecomorphological diversity than is generally appreciated, occupying regions of the morphospace that are interpreted as strict carnivory, plant-dominated omnivory, and herbivory; (2) the decline in dental-shape disparity and body-size disparity across the K/Pg boundary shows a pattern of constructive extinction selectivity against larger-bodied dietary specialists, particularly strict carnivores and taxa with plant-based diets, that suggests the kill mechanism was related to depressed primary productivity rather than a globally instantaneous event; (3) the ecomorphological recovery in the earliest Paleocene was fueled by immigrants, namely three multituberculate families (taeniolabidids, microcosmodontids, eucosmodontids) and to a lesser extent archaic ungulates; and (4) despite immediate increases in the taxonomic richness of eutherians, their much-celebrated post-K/Pg ecomorphological expansion had a slower start than is generally perceived and most likely only began 400,000 to 1 million years after the extinction event.
On Scalability of Proximity-Aware Peer-to-Peer Streaming

P2P (peer-to-peer) technology has proved itself an efficient and cost-effective solution to support large-scale multimedia streaming. Different from traditional P2P applications, the quality of P2P streaming is strictly determined by performance metrics such as streaming delay. To meet these requirements, previous studies resorted to intuitions and heuristics to construct peer selection solutions incorporating topology and proximity concerns. However, the impact of proximity-aware methodology and delay tolerance of peers on the scalability of P2P system remains an unanswered question. In this paper, we study this problem via an analytical approach. To address the challenge of incorporating Internet topology into P2P streaming analysis, we construct a H-sphere network model which maps the network topology from the space of discrete graph to the continuous geometric domain, meanwhile capturing the the power-law property of Internet. Based on this model, we analyze a series of peer selection methods by evaluating their performance via key scalability metrics. Our analytical observations are further verified via simulation on Internet topologies.
Triboelectric Interference in the ECG

Triboelectric noise resulting from motion in the patient vicinity has been observed to occasionally interfere with the ECG. Experiments were performed to verify the nature of the interference and to define the factors which enable this ever-present phenomenon to interfere with ECG acquisition. No instances have been observed that could not be corrected by good electrode placement technique. This study shows that currents produced during the generation or discharge of static electricity can be easily and accurately measured, and the technique used may be applicable to other areas of investigation.
Microstructural but not macrostructural disruption of white matter in women with chronic alcoholism.

The results of in vivo neuroimaging studies assessing whether and where brain white matter damage occurs in alcoholic women is controversial. To address this controversy, we examined regional white matter macrostructure and microstructure, the latter of which may be more sensitive to the detection of subtle fiber disruption than gross measures of size. Accordingly, we used conventional magnetic resonance imaging (MRI) to quantify regional callosal size and diffusion tensor imaging (DTI) to examine intravoxel coherence (fractional anisotropy, FA) and intervoxel coherence (C) of white matter of the genu and splenium of the corpus callosum and of the centrum semiovale in 12 detoxified alcoholic women and 18 control women. Additional analyses examined sex differences in FA and C in alcoholic women compared with alcoholic men. Despite absence of group differences in regional areas of callosal macrostructure, the alcoholic women had lower FA and C in genu and centrum semiovale than the control group of women. These measures also correlated with total lifetime consumption of alcohol and performance on a test of visual search in the alcoholic women. Sex comparisons revealed similar extents of FA abnormality in the genu and centrum semiovale in alcoholic men and women and differential effects in other DTI measures, with abnormalities present in splenium FA and C in the men and abnormalities present in centrum C in the women. These results provide in vivo evidence for disruption of white matter microstructure in alcoholic women not necessarily detectable with coarser measures of white matter mass and perhaps antedating its appearance.
Unifying Representations and Responses Perseverative Biases Arise From a Single Behavioral System

A dominant account of perseverative errors in early development contends that such errors reflect a failure to inhibit a prepotent response. This study investigated whether perseveration might also arise from a failure to inhibit a prepotent representation. Children watched as a toy was hidden at an A location, waited during a delay, and then watched the experimenter find the toy. After six observation-only A trials, the toy was hidden at a B location, and children were allowed to search for the toy. Two- and 4-year-olds' responses on the B trials were significantly biased toward A even though they had never overtly responded to this location. Thus, perseverative biases in early development can arise as a result of prepotent representations, demonstrating that the prepotent-response account is incomplete. We discuss three alternative interpretations of these results, including the possibility that representational and response-based biases reflect the operation of a single, integrated behavioral system.
Persistence of cognitive impairment in geriatric patients following antidepressant treatment: a randomized, double-blind clinical trial with nortriptyline and paroxetine

Cognitive dysfunction is common in older persons suffering from a major depression. However, the degree to which this dysfunction is reversible with successful treatment of the depression remains uncertain. The present study examined the effects that treatment (randomized double-blind design) with either an SSRI (paroxetine) or a tricyclic antidepressant (nortriptyline) had on cognition in older depressed patients. The patients' performance was compared to that of a group of normal controls of similar age and education. Patients and controls were administered measures of working memory, information-processing speed, episodic memory and attention five times over the course of a 12 week trial. At baseline, the patients performed more poorly than the elderly controls on all cognitive measures. While the patients' performance did improve over the course of their treatment, the magnitude of this improvement did not exceed that produced in the elderly controls by practice alone. The same pattern of results was evident in both intent-to-treat and responder analyses. Thus, there was no evidence that the depressed patients' cognitive performance normalized after response to antidepressant therapy. Neither the patients' age at onset nor their baseline level of cognitive functioning influenced the amount by which their performance improved over the 12 week trial. There was no difference between paroxetine and nortriptyline in the amount of cognitive change associated with treatment. The present results suggest that cognitive dysfunction persists in older depressed patients even after their mood disorder has responded to antidepressant medications.
Top predator control of plant biodiversity and productivity in an old‐field ecosystem

Predators can have strong indirect effects on plants by altering the way herbivores impact plants. Yet, many current evaluations of plant species diversity and ecosystem function ignore the effects of predators and focus directly on the plant trophic level. This report presents results of a 3-year field experiment in a temperate old-field ecosystem that excluded either predators, or predators and herbivores and evaluated the consequence of those manipulations on plant species diversity (richness and evenness) and plant productivity. Sustained predator and predator and herbivore exclusion resulted in lower plant species evenness and higher plant biomass production than control field plots representing the intact natural ecosystem. Predators had this diversity-enhancing effect on plants by causing herbivores to suppress the abundance of a competitively dominant plant species that offered herbivores a refuge from predation risk.
Analytical Solution for Normal Irrigation Distribution Parameters

The model most widely used to represent sprinkler irrigation distribution parameters is based on numerical solutions to the normal cumulative probability density function. For most practical irrigation design and management applications, numerical solutions are too laborious. One other study reported analytical approximations for several irrigation distribution parameters derived from the normal model. The estimation error resulting from these approximations were variable over the operational range of irrigation uniformity and irrigation adequacy and were quite high in some ranges. In this note, more accurate analytical approximations are presented for the distribution coefficient, the application efficiency, the water requirement efficiency, the deficiently irrigated volume, and the average deficit over the deficiently irrigated area. On average, over the entire operational range of irrigation uniformity and irrigation adequacy, the new approximations are about an order of magnitude more accurate than the previous approximations and introduce negligible error for most practical applications.