cssi/SciSciGPT-SciSciNet huggingface dataset:
A mesh independence principle for perturbed Newton-like methods and their discretizations

In this manuscript we study perturbed Newton-like methods for the solution of nonlinear operator equations in a Banach space and their discretized versions in connection with the mesh independence principle. This principle asserts that the behavior of the discretized process is asymptotically the same as that for the original iteration and consequently, the number of steps required by the two processes to converge to within a given tolerance is essentially the same. So far this result has been proved by others using Newton’s method for certain classes of boundary value problems and even more generally by considering a Lipschitz uniform discretization. In some of our earlier papers we extend these results to include Newton-like methods under more general conditions. However, all previous results assume that the iterates can be computed exactly. This is not true in general. That is why we use perturbed Newton-like methods and even more general conditions. Our results, on the one hand, extend, and on the other hand, make more practical and applicable all previous results.
Highly Transparent Glasses

Absorption and scattering processes which limit the transparency of amorphous solids are reviewed with emphasis on highly transparent glasses for optical fiber communication. The following topics are briefly discussed: absorption by electronic transitions (intrinsic, and by defects, impurities and free carriers), absorption by lattice vibrations (intrinsic and by impurities) and attenuation by scattering (Rayleigh, Mie, Brillouin and Raman).
Effects of fuel content and density on the smoldering characteristics of cellulose and hemicellulose

Abstract Smoldering combustion in wildland fires poses hazards for both ecosystems and humans by destroying biomass, transitioning to flaming combustion, and releasing significant quantities of pollution. Understanding the parameters that control smoldering is necessary to help predict and potentially mitigate these hazards. A challenge in identifying these parameters is the wide variety of biomasses which occur in nature. The objective of this study is to identify the effects of density and fuel concentration on the smoldering characteristics of cellulose and hemicellulose mixtures. These fuels were considered because they are some of the major organic constituents within biomass. To this end, downward smoldering propagation velocities were measured for 50%, 75%, and 100% cellulose content at densities varying from 170 to 400 kg/m3. The horizontal smoldering propagation velocities and temperature distributions were also determined for loosely packed samples ranging from 100% to 0% cellulose (with residual hemicellulose). Additionally, horizontal smoldering propagation velocities were determined for systematically varied ratios of cellulose (50–100%) and densities (200–400 kg/m3). The fuel was burned in an insulated reactor box. An infrared camera measured the horizontal propagation velocity, and thermocouples measured the downward propagation. A one-dimensional reactive porous media model with reduced chemistry was used to identify key processes causing the observed sensitivities. At constant packing density, the propagation velocity increased as cellulose content decreased because of decreased heat release with increased cellulose content and the earlier onset of hemicellulose pyrolysis. The propagation velocity decreased with respect to packing density when the fuel content was constant because of reduced oxygen diffusion. The propagation velocity increased with cellulose content when the fuel was loosely packed because of the decreasing density.
Prevoicing and prenasalization in Russian initial plosives

Abstract This study investigated the production of prevoiced initial plosives in Russian, including examining (i) how closure voicing varies depending on consonantal place, vocal context and speaker gender and (ii) whether Russian speakers rely on prenasalization to produce vocal fold vibration in initial closures, which is one of the mechanisms of reducing supraglottal pressure during oral occlusion. The study analyzed acoustic and airflow data from large samples of speakers and stimulus items, which made it possible to examine group-level patterns. Results for prevoicing duration revealed an effect of consonantal posteriority and adjacent vowel height. Shorter durations were seen in velars than bilabials or dentals and in tokens with high vowels (especially in male speech). Prevoiced tokens also showed higher levels of nasal flow than voiceless plosives during the initial part of closure. Nasal flow levels were lower in bilabials than dentals or velars and were not affected by vowel context. Speaker gender influenced voiceless tokens only. Towards the end of closure, voiced and voiceless tokens demonstrated comparable nasal flow levels. These results provide new insights into prevoicing in Russian and the link between prevoicing and prenasalization.
Quantifying the Optimal Structure of the Autism Phenotype: A Comprehensive Comparison of Dimensional, Categorical, and Hybrid Models

Objective The two primary—seemingly contradictory—strategies for classifying child psychiatric syndromes are categorical and dimensional; conceptual ambiguities appear to be greatest for polythetic syndromes such as autism spectrum disorder (ASD). Recently, a compelling alternative has emerged that integrates both categorical and dimensional approaches (ie, a hybrid model), thanks to the increasing sophistication of analytic procedures. This study aimed to quantify the optimal phenotypic structure of ASD by comprehensively comparing categorical, dimensional, and hybrid models. Method The sample comprised 3,825 youth, who were consecutive referrals to a university developmental disabilities or child psychiatric outpatient clinic. Caregivers completed the Child and Adolescent Symptom Inventory−4R (CASI-4R), which includes an ASD symptom rating scale. A series of latent class analyses, exploratory and confirmatory factor analyses, and factor mixture analyses was conducted. Replication analyses were conducted in an independent sample (N = 2,503) of children referred for outpatient evaluation. Results Based on comparison of 44 different models, results indicated that the ASD symptom phenotype is best conceptualized as multidimensional versus a categorical or categorical−dimensional hybrid construct. ASD symptoms were best characterized as falling along three dimensions (ie, social interaction, communication, and repetitive behavior) on the CASI-4R. Conclusion Findings reveal an optimal structure with which to characterize the ASD phenotype using a single, parent-report measure, supporting the presence of multiple correlated symptom dimensions that traverse formal diagnostic boundaries and quantify the heterogeneity of ASD. These findings inform understanding of how neurodevelopmental disorders can extend beyond discrete categories of development and represent continuously distributed traits across the range of human behaviors.
Assessment of the androgen receptor (AR) activity score versus AR expression in muscle invasive bladder cancer (MIBC).

463Background: Previous studies have demonstrated that a considerable proportion of BCs express androgen receptor (AR), and that AR might drive tumor growth. The RNA-based AR activity score is a no...
Honor, Oath, and Office

This contribution to the Culverhouse School of Law's Capstone Lawyer magazine is a short introduction to a larger, ongoing project on oaths and the Constitution. That project seeks to examine the relationship between oaths and constitutional interpretation, and to argue for the revival of honor, suitably revised, as an essential virtue in citizenship and office-holding. The focus here is on the intimate connection between the concepts and institutions that I call the "troika": office, honor, and the oath. Office is best thought of not simply in terms of power, and with the officer viewed merely as any individual who happens to exercise a power-wielding office at a given moment. Instead, the key feature of office is duty, and the officer is defined as much by the limits on his or her power as by its exercise. Honor is the institution that connects the officer to his or her office. Properly understood, it has both internal and external aspects and involves more than the love of fame. Honor is the desire to be thought well of by those whose opinion ought to count, and the desire to *deserve* to be thought well of by that honor group. This "quality of character," as Sharon Krause puts it, this "ambitious desire to live up to one's code and to be publicly recognized for doing so," is essential if office-holders are to fulfill the duties of their office with virtue and excellence. And it provides the office-holder with a valuable sense of energy and agency. The character of the men and women who occupy offices thus remains an essential element of our political and constitutional order. In our constitutional system, the device that ties individual honor to the ostensibly "impersonal" office is the oath. The oath is a linchpin that connects the individual to the office and the office-holder to the commitment to act honorably. It is imperfect, and in contemporary society both honor and oath require substantial rethinking and revivification to function properly. But the oath is not unimportant and is no mere empty ritual. Taken together, this troika of institutions--office, honor, and oath--encourage the sound and faithful performance of one's duties in a democratic constitutional republic. Thinking about the troika shifts our focus from power to duty, and from substance and doctrine to character and virtue. It helps us to see that a "government of laws and not of men" is and must be powerfully and ineluctably personal. Comments on the larger project are emphatically welcome. I note that the subject of the oath, and of the importance of duty and character in office-holding, has given rise to a growing literature that is well worth exploring.
Video-rate volumetric neuronal imaging using 3D targeted illumination

Fast volumetric microscopy is required to monitor large-scale neural ensembles with high spatio-temporal resolution. Widefield fluorescence microscopy can image large 2D fields of view at high resolution and speed while remaining simple and costeffective. A focal sweep add-on can further extend the capacity of widefield microscopy by enabling extended-depth-of-field (EDOF) imaging, but suffers from an inability to reject out-of-focus fluorescence background. Here, by using a digital micromirror device to target only in-focus sample features, we perform EDOF imaging with greatly enhanced contrast and signal-to-noise ratio, while reducing the light dosage delivered to the sample. Image quality is further improved by the application of a robust deconvolution algorithm. We demonstrate the advantages of our technique for in vivo calcium imaging in the mouse brain.
Exact solution of multiangle quantum many-body collective neutrino-flavor oscillations

I study the flavor evolution of a dense neutrino gas by considering vacuum contributions, matter effects, and neutrino self-interactions. Assuming a system of two flavors in a uniform matter background, the time evolution of the many-body system in discretized momentum space is computed. The multiangle neutrino-neutrino interactions are treated exactly and compared to both the single-angle approximation and mean-field calculations. The monoenergetic two-neutrino beam scenario is solved analytically. I proceed to solve flavor oscillations for monoenergetic cubic lattices and quadratic lattices of two energy levels. In addition I study various configurations of 12, 16, and 20 neutrinos. I find that when all neutrinos are initially of the same flavor, all methods agree. When both flavors are present, I find collective oscillations and flavor equilibration develop in the many-body treatment but not in the mean-field method. This difference persists in dense matter with tiny mixing angle and it can be ascribed to non-negligible flavor polarization correlations being present. Entanglement entropy is significant in all such cases. The relevance for supernovae or neutron stars mergers is contingent upon the value of the normalization volume $V$ and the large $N$ dependence of the timescale associated with oscillations. In future work, I intend study this dependence using larger lattices and also include antineutrinos.
Inherited Moderate Factor X Deficiency Presenting as Cardiac Tamponade.

Factor X deficiency is a rare bleeding disorder that varies in the severity of its clinical manifestations. The symptoms of this disorder can occur at any age, although most severe cases appear in childhood. The rarity of this condition has not allowed for the establishment of evidence‐based management guidelines, and thus, individuals afflicted with factor X deficiency are treated based on limited literature and the opinions of clinicians with extensive experience. In this case report, we discuss a unique presentation of a 38-year-old male who was found to have cardiac tamponade as a result of his newly diagnosed inherited moderate factor X deficiency. This was discovered by obtaining a factor X activity assay and confirmed with genetic testing which demonstrated a missense variant on the factor X gene on chromosome 13. His management involved correction of his factor X deficiency with fresh frozen plasma, a pericardiocentesis, and placement of a pericardial window. He has been asymptomatic and without hemorrhagic episodes for the 10 months following his discharge.
Immobilized RGD concentration and proteolytic degradation synergistically enhance vascular sprouting within hydrogel scaffolds of varying modulus.

AbstractInsufficient vascularization limits the volume and complexity of engineered tissue. The formation of new blood vessels (neovascularization) is regulated by a complex interplay of cellular i...
Statistical reliability analysis for a most dangerous occupation: Roman emperor

Popular culture associates the lives of Roman emperors with luxury, cruelty, and debauchery, sometimes rightfully so. One missing attribute in this list is, surprisingly, that this mighty office was most dangerous for its holder. Of the 69 rulers of the unified Roman Empire, from Augustus (d. 14 CE) to Theodosius (d. 395 CE), 62% suffered violent death. This has been known for a while, if not quantitatively at least qualitatively. What is not known, however, and has never been examined is the time-to-violent-death of Roman emperors. This work adopts the statistical tools of survival data analysis to an unlikely population, Roman emperors, and it examines a particular event in their rule, not unlike the focus of reliability engineering, but instead of their time-to-failure, their time-to-violent-death. We investigate the temporal signature of this seemingly haphazardous stochastic process that is the violent death of a Roman emperor, and we examine whether there is some structure underlying the randomness in this process or not. Nonparametric and parametric results show that: (i) emperors faced a significantly high risk of violent death in the first year of their rule, which is reminiscent of infant mortality in reliability engineering; (ii) their risk of violent death further increased after 12 years, which is reminiscent of wear-out period in reliability engineering; (iii) their failure rate displayed a bathtub-like curve, similar to that of a host of mechanical engineering items and electronic components. Results also showed that the stochastic process underlying the violent deaths of emperors is remarkably well captured by a (mixture) Weibull distribution. We discuss the interpretation and possible reasons for this uncanny result, and we propose a number of fruitful venues for future work to help better understand the deeper etiology of the spectacle of regicide of Roman emperors.
Structures and functions of the thyroid gland

Abstract The thyroid gland is the largest purely endocrine gland in the body. It is located in the anterior neck and has a butterfly-like shape. It curves across the anterior surface of the trachea and is slightly inferior to the larynx. This gland regulates basal body metabolism via the various hormones that it releases. The thyroid is also involved in gluconeogenesis, protein synthesis, glycogenolysis, lipogenesis, and thermogenesis. The parathyroid glands are embedded in the posterior surface of the lateral lobes of the thyroid gland and aid in calcium homeostasis.
Engineering Disciplinary Interests by Gender and Parental Level of Education

This research category work-in-progress paper uses cross-sectional data, collected in the fall of 2017, to understand first-generation and continuing-generation college students’ intended choice of an engineering major. Data for this analysis came from a large-scale survey of 3,711 first-year engineering students from 32 U.S. institutions of which 790 students identified as first-generation college students and 2,072 identified as having one or more parent(s) with a bachelor’s degree or higher (continuing-generation college students). A Welch’s t-test was used to examine the differences in engineering major selection between and within groups. Results from the within-group comparison show that men and women, who are first-generation college students, have similar disciplinary interest as reported in the ASEE Engineering by the Numbers. Most notably women first-generation college students were more likely to choose biomedical, chemical engineering, and other STEM-related degree compared to men first-generation college students. When analyzing the data by gender and examining college generation group differences, we found that women first-generation college students were more likely to choose, civil, computer, construction management, electrical engineering, computer science and, information technology compared to women in the other group. While men first-generation college students were more likely to choose construction management, electrical engineering compared to men in the other group. Enrollment trends of first-generation college students in engineering are difficult to determine, this study provides a first step towards understanding the fields that attract these students.
Patient-Adaptive Magnetic Resonance Oximetry: Comparison With Invasive Catheter Measurement of Blood Oxygen Saturation in Patients With Cardiovascular Disease.

BACKGROUND The current standard method to measure intracardiac oxygen (O2 ) saturation is by invasive catheterization. Accurate noninvasive blood O2 saturation by MRI could potentially reduce the duration and risk of invasive diagnostic procedures. PURPOSE To noninvasively determine blood oxygen saturation in the heart with MRI and compare the accuracy with catheter measurements. STUDY TYPE Prospective. SUBJECTS Thirty-two patients referred for right heart catheterization (RHC) and five healthy subjects. FIELD STRENGTH/SEQUENCE T2-prepared single-shot balanced steady-state free-precession at 1.5T. ASSESSMENT MR signals in venous and arterial blood, hematocrit, and arterial O2 saturation from a pulse oximeter were jointly processed to fit the Luz-Meiboom model and estimate blood O2 saturation in the right heart. Interstudy reproducibility was evaluated in volunteers and patients. Interobserver reproducibility among three readers was assessed using data from volunteers and 10 patients. Accuracy of MR oximetry was compared to RHC in all patients. STATISTICAL TESTS Coefficient of variation, intraclass correlation coefficient, Bland-Altman analysis, Pearson's correlation. RESULTS The coefficient of variation for interstudy reproducibility of O2 saturation was 2.6% on average in volunteers and 3.2% in patients. Interobserver reproducibility among three observers yielded intraclass correlation coefficients of 0.81 and 0.87 respectively for RV and MPA O2 saturation. O2 saturation (y = 0.85x + 0.13, R = 0.78) and (a-v)O2 difference (y = 0.71x + 0.90, R = 0.69) by MR and RHC were significantly correlated (N = 32, P < 0.05 in both cases) in patients. MR slightly overestimated O2 saturation compared to RHC with 2% ± 5% bias and limits of agreement between -7% and 12%. DATA CONCLUSION MR oximetry is repeatable and reproducible. Good agreement was shown between MR and catheter venous O2 saturation and (a-v)O2 difference in a cohort whose venous O2 ranged from abnormally low to high levels, with most values in the normal physiological range. LEVEL OF EVIDENCE 2. TECHNICAL EFFICACY STAGE 2.
What Is the Spatial Extent of a Bemisia tabaci Population

Effective pest management depends on basic knowledge about insect dispersal patterns and gene flow in agroecosystems. The globally invasive sweet potato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is considered a weak flier whose life history nonetheless predisposes it to frequent dispersal, but the scale over which populations exchange migrants, and should therefore be managed, is uncertain. In this review, we synthesize the emergent literature on B. tabaci population genetics to address the question: What spatial scales define B. tabaci populations? We find that within-species genetic differentiation among sites is often low, and evidence of population structuring by host plant or geography is rare. Heterozygote deficits prevail among populations, indicating that migrants from divergent populations are frequently sampled together. Overall, these results suggest that there is high ongoing gene flow over large spatial extents. However, genetic homogeneity typical of recently invading populations could obscure power to detect real isolation among populations. Genome-wide data collected systematically across space and time could distinguish signatures of invasion history from those of ongoing gene flow. Characterizing the spatial extent of B. tabaci populations could reveal whether insecticide rotations can be tailored to specific commodities or if coordination across linked commodities and regions is justified.
Relay Interactions Enable Remote Synchronization in Networks of Phase Oscillators

Remote synchronization describes a fascinating phenomenon where oscillators that are not directly connected via physical links evolve synchronously. This phenomenon is thought to be critical for distributed information processing in the mammalian brain, where long-range synchronization is empirically observed between neural populations belonging to spatially distant brain regions. Inspired by the growing belief that this phenomenon may be prompted by intermediate mediating brain regions, such as the thalamus , in this letter we derive a novel mechanism to achieve remote synchronization. This mechanism prescribes remotely synchronized oscillators to be stably connected to a cohesive relay in the network – a group of tightly connected oscillators mediating the distant ones. Remote synchronization unfolds whenever the stability of the subnetwork formed by relays and remotely synchronized oscillators is not affected by the rest of the oscillators. In accordance with our results, we find that remotely-synchronized cortico-thalamo-cortical circuits in the brain posses strong interconnection profiles. Finally, we demonstrate that the absence of cohesive relays prevents stable remote synchronization in a large class of cases, further validating our results.
Force redistribution during clathrin-mediated endocytosis revealed by new phase-separating force sensors

Forces exerted at the molecular level are central to countless processes in health and disease. However, measuring molecular forces remains difficult if not impossible using existing approaches. During clathrin-mediated endocytosis (CME), the plasma membrane is deformed into a vesicle by the forces produced by the actin cytoskeleton and transmitted to the membrane by a multi-protein coat. However, the actual forces required for endocytosis remain unknown. Here we present a new series of in vivo force sensors to measure the forces on the fission yeast HIP1R homologue End4p, a protein that links the endocytic membrane to the actin cytoskeleton. These new force sensors are based on calibrated coiled-coils that phase separate when they are under force. The measured forces on End4p are between 11 and 20 pN near the actin meshwork, between 10 and 11 pN near the clathrin lattice, and between 8 and 10 pN near the plasma membrane. Our results predict the participation of additional proteins to relay forces in different layers of the endocytic machinery during CME, and our approach points to a novel direction for in vivo force measurement.
1H NMR Studies of Genetic Variants and Point Mutants of Myoglobin: Modulation of Distal Steric Tilt of Bound Cyanide Ligand

The oxygen-binding sites in the hemoproteins myoglobin, Mb, and hemoglobin, Hb, are considered to have evolved to provide a preferential binding site for the bent geometry of a bound O2 molecule over the linear and perpendicular geometry of a bound CO (Dickerson and Geis, 1983). The preferential affinity of reduced heme iron for CO over O2 in model compounds is modulated in proteins by steric destabilization of the linear Fe-CO unit and stabilization of the bent Fe-OO unit by hydrogen bonding by distal residues (Springer et al., 1989). X-ray structures have demonstrated distorted Fe-CO units in heme proteins (Kuriyan et al., 1986), but the tilt is difficult to characterize quantitatively. While hydrogen-bonding can be inferred from X-ray data by the position of the relevant heteroatoms (Phillips, 1980), the direct observation of the proton requires neutron diffraction (Phillips and Schoenborn, 1981). Functional studies of natural genetic variants (i.e., elephant Mb with E7 His→Gin) (Romero-Herrera et al., 1981) and, more recently, the sperm whale point mutants expressed in E. coli using a synthesized gene (Springer et al., 1989), have generally confirmed the perturbations expected to follow from systematic variations of the E7 residue. However, the details of the stereochemistry in the heme pocket for these variants are not yet known.
Alignment of strategic priorities and performance: an integration of operations and strategic management perspectives

Abstract In theory, strategic priorities at the functional level align with and support business level strategies. Alignment of priorities is presumed to contribute to enhanced organizational performance, just as misalignment is expected to undermine performance. This study further develops and tests these theoretical conventions by examining the perceptions of general managers and manufacturing managers regarding manufacturing priorities of their business units. Based on a sample of matched pairs of manufacturing managers and general managers from 98 manufacturing plants, the hypotheses regarding the alignment–performance relationship are tested. Specifically, we tested whether the performance of the manufacturing unit is enhanced when general managers and manufacturing managers agree on strategic priorities. Furthermore, the influence of organizational factors on the relationship between alignment and performance of the manufacturing unit is studied. Results support our hypotheses that certain organizational variables moderate the relationship between alignment of priorities and manufacturing performance.
Public Employee Free Speech: The Policy Reasons for Rejecting a Per Se Rule Precluding Speech Rights

Public employees do not enjoy the same free speech rights under the First Amendment as do ordinary citizens. The Fourth Circuit Court of Appeals recently adopted a virtual per se rule precluding free speech rights for public employees while they are performing ordinary job duties. This Note argues that such a per se rule both lacks policy justification and, more importantly, would undermine the purposes of the First Amendment by impeding academic freedom and permitting viewpoint discrimination. Rejecting the per se rule best preserves the free speech rights of public employees and in turn allows them to speak freely about governmental operations—an especially important function of public employees, who are firsthand witnesses to government activities.
Approximating a Norm by a Polynomial

We prove that for any norm \(\Vert \cdot \Vert\) in the d-dimensional real vector space V and for any odd n > 0 there is a non-negative polynomial p(x), \(x \in V\) of degree 2n such that $$p^{1\over 2n}(x) \leq \Vert x\Vert \leq {n + d-1 \choose n}^{1 \over 2n} p^{1\over 2n}(x).$$ Corollaries and polynomial approximations of the Minkowski functional of a convex body are discussed.
Division Cycle of Myxococcus xanthus III. Kinetics of Cell Growth and Protein Synthesis

The kinetics of cell growth and protein synthesis during the division cycle of Myxococcus xanthus was determined. The distribution of cell size for both septated and nonseptated bacteria was obtained by direct measurement of the lengths of 8,000 cells. The Collins-Richmond equation was modified to consider bacterial growth in two phases: growth and division. From the derived equation, the growth rate of individual cells was computed as a function of size. Nondividing cells (growth phase) comprised 91% of the population and took up 87% of the time of the division cycle. The absolute and specific growth rates of nondividing cells were observed to increase continually throughout the growth phase; the growth rate of dividing cells could not be determined accurately by this technique because of changes in the geometry of cells between the time of septation and physical separation. The rate of protein synthesis during the division cycle was measured by pulselabeling an exponential-phase culture with radio-active valine or arginine and then preparing the cells for quantitative autoradiography. By measuring the size of individual cells as well as the number of grains, the rate of protein synthesis as a function of cell size was obtained. Nondividing cells showed an increase in both the absolute and specific rates of protein synthesis throughout the growth phase; the specific rate of protein synthesis for dividing cells was low when compared to growthphase cells. Cell growth and protein synthesis are compared to the previously reported kinetics of deoxyribonucleic acid and ribonucleic acid synthesis during the division cycle.
Natural inequalities: why some L-type Ca2+ channels work harder than others

### Introduction Voltage-gated L-type Ca2+ channels are expressed in the surface membrane of neurons and muscle cells ([Catterall, 2000][1]). There, they regulate multiple processes including excitability, contraction, gene expression, and memory storage. L-type Ca2+ channels are heteromeric
A generalized expression for the reliability of measures.

In certain situations it is important to obtain as many measures as possible, all presumably measuring the same function, for each of a group of persons. In general the number and source of the measures may vary from one member of the group to another. We take the mean of the measures for each person as the best estimate of the function for that person. The conventional formulas can not be used to determine the reliability of a set of means so obtained. A formula is developed which provides a unique estimate of the reliability of such a set of means. The formula is more general than some of the well-known reliability formulas, so that these formulas are shown to be special cases of the more general formula.
On the base-free measure of change proposed by Tucker, Damarin and Messick

Tucker, Damarin and Messick proposed a “base-free” measure of change which involves the computation of residual scores that are uncorrelated with true scores on the pretest. The present note discusses this change measure and demonstrates that, because of an incorrect derivation by the authors, properties they attribute toα (the coefficient for the regression of true scores from the second testing on true scores from the first testing) are, in fact, properties ofb, the ordinary regression coefficient. A correct derivation of the initial position—change correlation in terms ofα is obtained, and Tucker et al.'s discussion of the “law of initial values” is reconsidered.
Pain and depression in caregivers affected their perception of pain in stroke patients.

Abstract Objectives Informal caregivers often serve as proxy raters of Health-Related Quality of Life (HRQL) when patients cannot report on their own behalf. Caregiver depression has been associated with bias in proxy ratings, but few studies have examined the role of caregiver pain. The aim of this study was to determine if caregiver depressive symptoms and/or pain systematically affected patient–proxy agreement on patient HRQL after stroke. Study Design and Settings Secondary data analysis of 95 stroke patients and their caregivers (dyads) at 6 months poststroke. Caregiver depressive symptoms were measured by Center for Epidemiologic Studies Depression Rating Scale, and pain was measured using EQ-5D. Using multivariate regression, we examined the effect of caregiver depressive symptoms and pain on patient–proxy difference scores on Health Utilities Index 3 (HUI3) attributes and Short Form-36 domains of vitality and social functioning. Results Caregiver depressive symptoms and pain were associated with significant differences in patient–proxy scores on HUI3 pain (P Conclusion Presence of pain and depressive symptoms in caregivers can significantly affect perceptions of pain in stroke patients. Results suggest that caregivers with pain and/or depression may provide more biased proxy assessments of pain.
An analytic study of the power of popular quantitative-trait-locus mapping methods.

Comparison of the power of various statistical methods is an important issue in quantitative-trait-locus mapping analysis. One effective means is to compare the noncentrality parameters of various test statistics. Such comparisons have been conducted in the literature either by using computer simulations or by comparing approximations to the noncentrality parameters. While useful, these approaches are not accurate by nature and could generate erroneous conclusions. For the popular sibpair design, I compare the noncentrality parameters of four popular statistical methods, i.e., a variance components method, a regression-based method, a score statistic and a “robustified” score statistic. Assuming that marker map is fully informative, I show analytically that noncentrality parameters for these methods are in the following order, from the largest to the smallest, the variance components method, the score statistic method, the regression method and the “robustified” score statistic. I also show by using an example that such ordering can fail for family structures other than sibpairs.
Bioaccumulation and biomagnification of polybrominated diphenyl ethers in a food web of Lake Michigan

Polybrominated diphenyl ethers are hydrophobic chemicals and can biomagnify in food chains. Little is known about the biomagnification of PBDEs in the Lake Michigan food web. Plankton, Diporeia, lake whitefish, lake trout, and Chinook salmon were collected from Lake Michigan in 2006 between April and August. Fish liver and muscle and whole invertebrates were analyzed for six PBDEs (BDE-47, 99, 100, 153, 154, and 209). Carbon and nitrogen stable isotope ratios (δ13C and δ15N) were also quantified in order to establish the trophic structure of the food web. Geometric means of $$\sum\hbox{PBDE}$$ concentrations in fish ranged from 0.562 to 1.61 μg/g-lipid. BDE-209 concentrations ranged from 0.184 to 1.23 μg/g-lipid in all three fish species. $$\sum\hbox{BDE}{\text{-}}47$$ , 99, and 209 comprised 80–94% of $$\sum\hbox{PBDE}$$ molar concentration. Within each fish species, there were no significant differences in PBDE concentrations between liver and muscle. The highest concentration of BDE-209 (144 μg/g-lipid) was detected in Diporeia. Based on analysis of δ15N and PBDE concentrations, BDE-47 and 100 were found to biomagnify, whereas BDE-209 did not. A significant negative correlation between BDE-209 and trophic level was found in this food web. Biomagnification factors were also calculated and again BDE-47 and 100 biomagnified between food web members whereas BDE-209 did not. Diporeia could be one of the main dietary sources of BDE-209 for fish in Lake Michigan; BDE-47 and 100 biomagnified within this food chain; the concentration of BDE-209 decreased at higher trophic levels, suggesting partial uptake and/or biotransformation of BDE-209 in the Lake Michigan food web.
RESINVM3D: A 3D resistivity inversion package

We have developed an open source 3D, MATLAB based, resistivity inversion package. The forward solution to the governing partial differential equation is efficiently computed using a second-order finite volume discretization coupled with a preconditioned, biconjugate, stabilized gradient algorithm. Using the analytical solution to a potential field in a homogeneous half space, we evaluate the accuracy of our numerical forward solution and, subsequently, develop a source correction factor that reduces forward modeling errors associated with boundary effects and source electrode singularities. For the inversion algorithm we have implemented an inexact Gauss-Newton solver, with the model update being calculated using a preconditioned conjugate gradient algorithm. The inversion uses a combination of zero and first order Tikhonov regularization. Two synthetic examples demonstrate the usefulness of this code. The first example considers a surface resistivity survey with 3813 measurements. The discretized model s...
Vertebral bone marrow fat is positively associated with visceral fat and inversely associated with IGF-1 in obese women.

Recent studies have demonstrated an important physiologic link between bone and fat. Bone and fat cells arise from the same mesenchymal precursor cell within bone marrow, capable of differentiation into adipocytes or osteoblasts. Increased BMI appears to protect against osteoporosis. However, recent studies have suggested detrimental effects of visceral fat on bone health. Increased visceral fat may also be associated with decreased growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels which are important for maintenance of bone homeostasis. The purpose of our study was to assess the relationship between vertebral bone marrow fat and trabecular bone mineral density (BMD), abdominal fat depots, GH and IGF-1 in premenopausal women with obesity. We studied 47 premenopausal women of various BMI (range: 18–41 kg/m2, mean 30 ± 7 kg/m2) who underwent vertebral bone marrow fat measurement with proton magnetic resonance spectroscopy (1H-MRS), body composition, and trabecular BMD measurement with computed tomography (CT), and GH and IGF-1 levels. Women with high visceral fat had higher bone marrow fat than women with low visceral fat. There was a positive correlation between bone marrow fat and visceral fat, independent of BMD. There was an inverse association between vertebral bone marrow fat and trabecular BMD. Vertebral bone marrow fat was also inversely associated with IGF-1, independent of visceral fat. Our study showed that vertebral bone marrow fat is positively associated with visceral fat and inversely associated with IGF-1 and BMD. This suggests that the detrimental effect of visceral fat on bone health may be mediated in part by IGF-1 as an important regulator of the fat and bone lineage.
Physicochemical and Rheological Properties of Butter Made from Supercritically Fractionated Milk Fat

Abstract A milk fat fraction enriched with high melting triglyceride was extracted by using a continuous, pilot-scale supercritical CO 2 system and recombined into butter. Compared with market butter, the high melting butter had higher contents of unsaturated long-chain fatty acids, high melting triglycerides, and β-carotene; higher intensity of yellow color; and lower cholesterol content. At similar temperatures, the high melting butter exhibited higher solid fat contents, complex viscosities, and power law consistency indices for viscoelastic parameters, indicating that its behavior is more like that of solids. The viscoelastic properties of high melting butter at 32°C were comparable with those of market butter at 22°C. The high melting triglyceride butter revealed higher emulsion stability without oiling off at 34°C. Because of its stable behavior at high temperatures, the product also offers good potential for application in bakery, chocolate, and confectionery industries in which stability of fat is a desired characteristic. Water activities were lower for high melting triglyceride butter than for market butter at similar temperatures, which should enhance microbial stability as well. Lower cholesterol and saturated fatty acid contents should also make high melting butter more attractive to consumers.
Structural and Enzymatic Aspects of Rhodopsin Phosphorylation

Photoactivated rhodopsin (Rho∗) is phosphorylated near the C terminus at multiple sites, predominantly at Ser334, Ser338, and Ser343. We systematically examined the sites of phosphorylation upon flash activation of Rho in rod outer segment (ROS) homogenates. Addition of an inhibitory antibody against rhodopsin kinase (RK) lowered phosphorylation at Ser334, Ser338, and Ser343, without changing the ratio between phosphorylation sites. In contrast, no effect of protein kinase C was detected after stimulation (by a phorbol ester), inhibition (with H7), or reconstitution of protein kinase C with purified ROS membranes. The stoichiometry and the ratio between different phosphorylation sites in purified Rho were also reproduced using RK, purified to apparent homogeneity from ROS or from an insect cell expression system. Thus, we conclude that light-dependent phosphorylation of Rho is mediated primarily by RK. Depalmitoylation of Rho at Cys322 and Cys323 altered the conformation of the C terminus of Rho, as observed by phosphorylation by casein kinase I, but did not affect phosphorylation by RK. The sites of phosphorylation were influenced, however, by the presence of four conserved amino acids at the C terminus of Rho. The accumulation of phosphorylated Ser334 observed in vivo could result from slower dephosphorylation of this site as compared with dephosphorylation of Ser338 and Ser343. These data provide a molecular mechanism for the site-specific phosphorylation of Rho observed in vivo.
Interpretation of nonlinear steady state enzyme kinetics--cyclic and mathematical properties of cooperative, second-site and random pathway models

Abstract Nonlinear steady state kinetic patterns are frequently encountered in enzyme studies. Consequently, there is a need to develop procedures for systematically interpreting such data. This paper contributes to this development by identifying a common feature in nonlinear systems and by showing that quite different models commonly in use give very similar mathematical functions. Identical or similar cycles can result from quite different chemical events in enzyme mechanisms, cooperativity, second sites and random pathways. Such cycles can account for many of the observed nonlinear patterns, i.e., power functions, substrate activation and inhibition. Therefore nonlinear steady state kinetics generally requires the presence of a cycle(s) in the mechanism without specifying the underlying chemical events giving rise to that cycle(s). Rate equations for cooperative, second-site and random pathway models are derived and shown to yield virtually identical mathematical functions. Thus empirical equations composed of these functions can be used to represent nonlinear kinetic data without specifying the underlying chemical events.
Nutrition and feeding of yellow perch (Perca flavescens)

Yellow perch (Perca flavescens) have become one of the focal points in aquaculture in the Great Lakes region of the United States. In this paper, we reviewed existing information on nutrition of yellow perch and identified critical areas in need of development. Yellow perch are small at hatching (4–7 mm total length), and are difficult to feed. Zooplankton cultures remain the only viable means of mass propagation, but larvae can be trained to accept formulated feeds in ponds at the age of 30–45 days. Few nutritional requirements exist for yellow perch, thus there are no diets formulated specifically for this species. The current recommendations are use of feeds formulated for trout and salmon. Ongoing research efforts are underway that will improve our ability to feed yellow perch at all life history stages.
Autonomic nervous system balance and introversion

In a sample of 61 undergraduates, a measure of parasympathetic predominance in the autonomic system was associated with introversion as predicted by Lester (1974).
Literal Nyquist stability criterion for MIMO control systems

Nyquist stability criteria for multiple-input multiple output (MIMO) feedback systems are derived using a literal approach. In contrast to existing generalized Nyquist stability criteria, which involve the transfer function of the MIMO plant, the proposed literal approach allows the results to be expressed in terms of the poles and zeros of each of the elemental plants. Thus, explicit necessary and sufficient stability conditions for two-input and two-output and for three-input and three-output control systems are given. The results are illustrated in a flight control problem.
Metallurgical and electrical properties of alloyed Ni/AuGe films on n-type GaAs

Abstract An experimental study of the alloying characteristics of a composite thin-film structure which is often used as an ohmic contact to GaAs is presented. A AuGe layer of eutectic composition covered by a thin-film of Ni and deposited on n-type epitaxial GaAs is investigated in order to better understand the relationship between the alloying behavior and the electrical properties of the contact. The barrier energy ϕBn and the specific contact resistance of the Ni/AuGe/GaAs system is measured for a wide range of alloy temperatures and times. The metallurgical properties of the Ni/AuGe/GaAs system are obtained with Auger electron spectroscopy and scanning electron microscopy. Auger spectroscopy combined with in situ sputter etching is used to determine depth-composition profiles for all constituents of both as-deposited and alloyed Ni/AuGe/GaAs contacts. In samples heat-treated below the AuGe eutectic temperature, Ni is found to move rapidly through the intervening AuGe layer to collect at the GaAs interface, and the effective value of ϕBn rises to the value characteristic of Ni/GaAs Schottky diodes. For heat-treatment above the AuGe eutectic temperature, ohmic contact behavior is observed, and uniform alloyed contact surfaces are found to result from the presence of Ni at the GaAs interface. Ga outdiffusion and surface accumulation resulting from GaAs dissociation occurs for all alloy temperatures and times. The Ga outdiffusion appears to be characterized by a very low activation energy.
Two kinds of factor analysis

In descriptive factor analysis, the factor matrix is merely an alternate mode of expression of the meaning expressed by the correlation matrix. In inferential factor analysis, the factor matrix expresses material inferred from the correlation matrix but not contained in the correlation matrix. A major problem has been whether or not the latter type is possible. Granit's color cone study is interpreted as a factor study in the hope of showing that inferential factor analysis actually exists. It is argued that proof of these and other points in factor theory can be accomplished only by logical analysis.
Understanding the Use of Educational Technology among Faculty, Staff, and Students at a Medical University.

A college of health professions at a medical university located in the southeastern United States is striving to increase the use of educational technology among faculty, staff, and students. A strategic planning group was formed and charged with enhancing the use of educational technology within the college. In order to understand the current state of technology use, perceptions of technology, and training needs, surveys and focus groups were conducted. Based on the qualitative and quantitative data obtained, a conceptual model illustrating levels of technology use and factors that influence use was developed.