cssi/SciSciGPT-SciSciNet huggingface dataset:
H/sub infinity /-minimum error state estimation of linear stationary processes

A state estimator is derived which minimizes the H/sub infinity /-norm of the estimation error power spectrum matrix. Two approaches are presented. The first achieves the optimal estimator in the frequency domain by finding the filter transfer function matrix that leads to an equalizing solution. The second approach establishes a duality between the problem of H/sub infinity /-filtering and the problem of unconstrained input H/sub infinity /-optimal regulation. Using this duality, previously published results for the latter regulation problem are applied which lead to an optimal filter that possess the structure of the corresponding Kalman filter. The two approaches usually lead to different results. They are compared by a simple example which also demonstrates a clear advantage of the H/sub infinity /-estimate over the conventional l/sub 2/-estimate. >
EFFECT OF MAGNETIC FIELD ON IRON WHISKER GROWTH

Single crystal iron whiskers grow in alignment with field lines when subjected to magnetic field during growth process
Estrogen Receptor β Isoform-Specific Induction of Transforming Growth Factor β-Inducible Early Gene-1 in Human Osteoblast Cells: An Essential Role for the Activation Function 1 Domain

The estrogen receptors (ER) α and β are important ligand-mediated transcription factors known to play significant biological roles in numerous tissues including bone. Despite the high homology shared by these receptors, recent studies have suggested that their function is largely unique. Although these receptors have been studied in detail for more than a decade, little data exist concerning the mechanisms by which these two proteins regulate distinct sets of genes. Using the TGFβ-inducible early gene-1 (TIEG) as a model, we demonstrate that TIEG is rapidly induced in response to estrogen in osteoblasts by ERβ, but not ERα. We have identified the regulatory elements utilized by ERβ and have demonstrated that ERβ recruits steroid receptor coactivator (SRC)1 and SRC2 to this regulatory region. Additionally, deletion of the ERβ-activation function 1 (AF1) domain drastically decreases the estrogen induction of TIEG. Through the use of chimeric receptors, we have demonstrated that the AF1 domain of ERβ is responsible for recruiting SRC1 and SRC2 and inducing the expression of TIEG in osteoblasts. Finally, SRC1, but not SRC2, is essential for TIEG induction by ERβ. Overall, these data demonstrate that the estrogen induction of TIEG is ERβ specific and that the AF1 domain of ERβ confers this specificity. Finally, a novel and important role for ERβ’s AF1 is implicated in the recruitment of specific coactivators, suggesting that the AF1 may play a significant role in conferring the differences in regulation of gene expression by these two receptors.
Continuum percolation in an interacting system: Exact solution of the Percus-Yevick equation for connectivity in liquids.

The general role of interparticle interactions is considered for percolation problems in liquids. With the aid of a diagrammatic formulation of the Percus-Yevick approximation, we analyze the dependence of connectedness (percolation) on correlation (interaction). This idea is illustrated by the analytical solution of the Percus-Yevick equation for a model of percolation in liquids, revealing that excluded volume (for example) may either enhance or suppress percolation.
The Local Environment of Cu+ in Cu-Y Zeolite And Its Relationship to the Synthesis of Dimethyl Carbonate

Cu-exchanged Y zeolite was investigated in order to determine the location of the copper cations relative to the zeolite framework and to determine which Cu cations are active for the oxidative carbonylation of methanol to dimethyl carbonate (DMC). Cu−Y zeolite was prepared by vapor-phase exchange of H−Y with CuCl. The oxidation state, local coordination, and bond distances of Al and Cu were determined using Al K-edge and Cu K-edge X-ray absorption spectroscopy (XAS). Complimentary information was obtained by H2 temperature-programmed reduction and by in-situ infrared spectroscopy. Cu−Y has a Cu/Al ratio of unity and very little occluded CuCl. The average Al−O and Al−Cu bond distances are 1.67 A and 2.79 A, respectively, and the average Cu−O and Cu−Si(Al) bond distances are 1.99 A and 3.13 A, respectively. All of the Cu exchanged is present as Cu+ in sites I‘, II, and III‘. Cu−Y is active for the oxidative carbonylation of methanol, and at low reactant contact time produces DMC as the primary product. Wit...
Personal Moral Norms and Attitudes Toward Endangered Species Policies on Private Land

Research across multiple disciplines has shown that personal moral norms can play an important role in shaping individuals' attitudes and behaviour. Despite this, we know relatively little about patterns of support among landowners for either a personal moral norm favouring a strong, 'intrinsic' right of private ownership, or a moral duty to prevent extinction. In addition, we know even less about the ability of such norms to predict attitudes toward species protection on private lands, especially for non-charismatic species with few qualities that typically generate positive attitudes for conservation. Results from a mail survey of central Indiana landowners suggest broad support for a personal moral norm favouring a strong, 'intrinsic' right of ownership as well as a personal moral norm to prevent extinction, and that these norms are better predictors of attitudes toward endangered species policies than partisan identification, identification as an environmentalist, strong religious beliefs, or several other demographic factors. The results suggest that those seeking to influence landowner attitudes toward species protection policies should pay closer attention to the influence of these personal moral norms.
Mycotic dermatitis in a black ratsnake

Summary: A mycotic dermatitis in a black ratsnake (Elaphe obsoleta) was described. The snake has been in captivity since June 1978. The lesions were in the form of dull and roughened scales. They expanded and coalesced to involve several areas of the body. Mycological examination of the scales revealed fungus infection. The isolate was identified as Monilia sitophila. The lesions were cured satisfactory with Panalog® and Tinavet®. Zusammenfassung: Eine Hautmykose bei einer schwarzen Rattenschlange (Elaphe obsoleta) wird beschrieben. Die Schlange befand sich seit Juni 1978 in Gefangenschaft. Die Hautveranderungen bestanden aus matten Herden mit rauher Schuppung. Sie dehnten sich weiter aus und konfluierten, wobei ein groserer Teil des Korpers einbezogen wurde. Durch mykologische Untersuchungen der Schuppen konnte eine Pilzinfektion festgestellt werden. Der isolierte Pilz wurde als Monilia sitophila identifiziert. Die Hautveranderungen wurden mit Panalog® und Tinavet® befriedigend ausgeheilt.
A general concurrent algorithm for plasma particle-in-cell simulation codes

Abstract We have developed a new algorithm for implementing plasma particle-in-cell (PIC) simulation codes on concurrent processors with distributed memory. This algorithm, named the general concurrent PIC algorithm (GCPIC), has been used to implement an electrostatic PIC code on the 32-node JPL Mark III Hypercube parallel computer. To decompose a PIC code using the GCPIC algorithm, the physical domain of the particle simulation is divided into sub-domains, equal in number to the number of processors, such that all sub-domains have roughly equal numbers of particles. For problems with non-uniform particle densities, these sub-domains will be of unequal physical size. Each processor is assigned a sub-domain and is responsible for updating the particles in its sub-domain. This algorithm has led to a very efficient parallel implementation of a well-benchmarked 1-dimensional PIC code. The dominant portion of the code, updating the particle positions and velocities, is nearly 100% efficient when the number of particles is increased linearly with the number of hypercube processors used so that the number of particles per processor is constant. For example, the increase in time spent updating particles in going from a problem with 11,264 particles run on 1 processor to 360,448 particles on 32 processors was only 3% (parallel efficiency of 97%). Although implemented on a hypercube concurrent computer, this algorithm should also be efficient for PIC codes on other parallel architectures and for large PIC codes on sequential computers where part of the data must reside on external disks.
A 32 nm High-k Metal Gate SRAM With Adaptive Dynamic Stability Enhancement for Low-Voltage Operation

SRAM scaling faces increasing challenges in meeting power, performance, and density requirements as Moore's law continues to drive CMOS technology scaling. Due to process variation, SRAM bitcell design margin continues to shrink in scaled technologies and conventional SRAM is no longer able to fully realize the benefits of scaling. Smart and adaptive assist circuits can improve design margins while satisfying SRAM power and performance requirements in scaled technologies. VCC scaling is especially important to meet increasingly stringent power constraints [1]. Circuit techniques proposed in recent years enable SRAM V CC scaling by expanding read and write margins [2–6]. However, the improved design margins for SRAM V CC scaling are often achieved with significant design overhead, e.g., additional power supply [4], increased circuit complexity [5], and testing overheads required for die-by-die programming [6].
Effect of synthetic juvenile hormone on ovarian diapause of Culex pipiens mosquitoes.

Hormonal control of ovarian diapause in Culex pipiens was studied to determine whether synthetic hormones may be employed against natural populations to disrupt hibernation. As in previous studies, ovarian follicles of C. pipiens reared at a 16-hr (long) photophase were larger than were follicles from mosquitoes reared at an 8-hr (short) photophase. Ovarian follicles of allatectomized C. pipiens reared at a long photophase were smaller than those of long-photophase nonallatectomized mosquitoes and the same size as those of short-photophase non-allatectomized mosquitoes. Oral as well as topical treatment with synthetic juvenile hormone resulted in growth of such small follicles. These observations suggest that ovarian diapause of C. pipiens is controlled by the corpora allata and that hibernation may be disrupted by feeding synthetic juvenile hormone.
Efficient Estimation and Inferences for Varying-Coefficient Models

Abstract This article deals with statistical inferences based on the varying-coefficient models proposed by Hastie and Tibshirani. Local polynomial regression techniques are used to estimate coefficient functions, and the asymptotic normality of the resulting estimators is established. The standard error formulas for estimated coefficients are derived and are empirically tested. A goodness-of-fit test technique, based on a nonparametric maximum likelihood ratio type of test, is also proposed to detect whether certain coefficient functions in a varying-coefficient model are constant or whether any covariates are statistically significant in the model. The null distribution of the test is estimated by a conditional bootstrap method. Our estimation techniques involve solving hundreds of local likelihood equations. To reduce the computational burden, a one-step Newton-Raphson estimator is proposed and implemented. The resulting one-step procedure is shown to save computational cost on an order of tens with no...
ROP payload detection using speculative code execution

The prevalence of code injection attacks has led to the wide adoption of exploit mitigations based on nonexecutable memory pages. In turn, attackers are increasingly relying on return-oriented programming (ROP) to bypass these protections. At the same time, existing detection techniques based on shellcode identification are oblivious to this new breed of exploits, since attack vectors may not contain binary code anymore. In this paper, we present a detection method for the identification of ROP payloads in arbitrary data such as network traffic or process memory buffers. Our technique speculatively drives the execution of code that already exists in the address space of a targeted process according to the scanned input data, and identifies the execution of valid ROP code at runtime. Our experimental evaluation demonstrates that our prototype implementation can detect a broad range of ROP exploits against Windows applications without false positives, while it can be easily integrated into existing defenses based on shell-code detection.
Estimating number of fiber directions per voxel for ICA DTI tractography

Recently, we have shown that Independent Component Analysis (ICA) can be used to recover up to three distinct fiber directions per voxel by using diffusion MRI data with 25 gradient directions. One prerequisite of our ICA approach is that the number of fiber directions per voxel be known. In this paper, we present a method to extract voxels with zero to three fiber directions and classify them accordingly using diffusion MRI data. The approach relies on the SPM segmented white matter images as well as diffusion anisotropic values per voxel. K-means segmentation and constrained non-linear optimization techniques are used to classify voxels into one to three fiber directions. The diffusion model for optimization is based on the hierarchy of diffusion characteristics. The method is tested with a healthy human subject. It is observed that the fiber maps are consistent with the underlying brain anatomy.
The Brigham integrated computing system (BICS): advanced clinical systems in an academic hospital environment

The Brigham integrated computing system (BICS) provides nearly all clinical, administrative, and financial computing services to Brigham and Women’s Hospital, an academic tertiary-care hospital in Boston. The BICS clinical information system includes a very wide range of data and applications, including results review, longitudinal medical records, provider order entry, critical pathway management, operating-room dynamic scheduling, criticalevent detection and altering, dynamic coverage lists, automated inpatient sumaries, and an online reference library. BICS design emphasizes direct physician interaction and extensive clinical decision support. Impact studies have demonstrated significant value of the system in preventing adverse events and in saving costs, particularly for medications. © 1999 Elsevier Science Ireland Ltd. All rights reserved.
Method for extracting camera operations in order to describe subscenes in video sequences

Numerous attempts have been made to detect scene changes in video sequences and to treat scenes as units, to allow handling of very large amounts of video data. But less attention has been given to the structure of scenes themselves. In this study, we define a `sub-scene' as a structural component of a scene in terms of camera operations. In other words, sub-scenes are subsets of scenes, and consist of successive frames in which the movements of the contents are almost identical. The advantage of sub-dividing scenes into sub-scenes is that it gives added power to description of objects and motion information. In order to describe sub-scenes, the estimation of camera operations need not be very accurate, but it must be resistant to noise. The technique proposed in this paper for extracting camera operations, which processes more than two frames at a time by using a 2D spatio-temporal image, meets the above requirement. It is also faster than conventional frame-by-frame analysis. The results of experiments indicate that the technique is both feasible and useful.
Non-equivalent roles for the first and second zinc fingers of protein kinase Cdelta. Effect of their mutation on phorbol ester-induced translocation in NIH 3T3 cells.

Classical and novel protein kinase C (PKC) isozymes contain two, so-called cysteine-rich zinc finger domains that represent the binding sites for phorbol esters and the diacylglycerols. X-ray crystallographic, mutational, and modeling studies are providing detailed understanding of the interactions between the phorbol esters and individual PKC zinc fingers. In the present study, we explore the roles of the individual zinc fingers in the context of the intact enzyme. Our approach was to mutate either the first, the second, or both zinc fingers of PKCδ, to express the mutated enzyme in NIH 3T3 cells, and to monitor the effect of the mutations on the dose-response curve for translocation induced by phorbol 12-myristate 13-acetate. The introduced mutations change into glycine the consensus proline in the phorbol ester binding loop of the zinc finger; in the isolated zinc finger, this mutation causes a 125-fold decrease in phorbol ester binding affinity. We observed that mutation in the first zinc finger caused almost no shift in the dose-response curve for translocation; mutation in the second zinc finger caused a 21-fold shift, whereas mutation in both zinc fingers caused a 138-fold shift. We conclude that the zinc fingers in the intact PKC are not equivalent and that the second zinc finger plays the predominant role in translocation of protein kinase Cδ in response to phorbol 12-myristate 13-acetate. Our findings have important implications for the understanding and design of PKC inhibitors targeted to the zinc finger domains.
SPARC (secreted protein acidic and rich in cysteine) regulates endothelial cell shape and barrier function.

Abstract SPARC (secreted protein acidic and rich in cysteine) can be selectively expressed by the endothelium in response to certain types of injury and induces rounding in adherent endothelial cells in vitro. To determine whether SPARC might influence endothelial permeability, we studied the effect of exogenous SPARC on the movement of 14C-labeled bovine serum albumin across postconfluent bovine pulmonary artery endothelial cells. SPARC increased (P or = 0.5 microgram/ml. At a fixed dose (15 micrograms/ml), exposure times > or = 1 h augmented (P < 0.005) albumin flux by 1.3- to 3.6-fold; this increase was blocked by anti-SPARC antibodies but not by inhibition of protein synthesis. Barrier dysfunction was not associated with loss of cell viability. Monolayers exposed to SPARC exhibited a rounded morphology and intercellular gaps. Prior stabilization of F-actin with phallicidin protected against the changes in barrier function (P = 0.0001) that were otherwise induced by SPARC. Bovine aortic and retinal microvascular endothelia also responded to SPARC. We propose that SPARC regulates endothelial barrier function through F-actin-dependent changes in cell shape, coincident with the appearance of intercellular gaps, that provide a paracellular pathway for extravasation of macromolecules.
A model for a self-adapting filter

This paper deals with a system which detects unknown, randomly occurring signals which are imbedded in Gaussian noise. A model for the system is set forth and analyzed using methods derived from probability theory. The system uses a variable threshold characteristic. Approximations are given for the mean and variance of the threshold at equilibrium, as a function of the signal-to-noise ratio, the a priori probabilities of signal occurrence, and the rate of decay of the threshold.
Widening Educational Disparities in Premature Death Rates in Twenty Six States in the United States, 1993–2007

Background Eliminating socioeconomic disparities in health is an overarching goal of the U.S. Healthy People decennial initiatives. We present recent trends in mortality by education among working-aged populations. Methods and Findings Age-standardized death rates and their average annual percent change for all-cause and five major causes (cancer, heart disease, stroke, diabetes, and accidents) were calculated from 1993 through 2007 for individuals aged 25–64 years by educational attainment as a marker of socioeconomic status, using national vital registration data for 26 states with consistent educational information on the death certificates. Rate ratios and rate differences were used to assess disparities (≤12 versus ≥16 years of education) for 1993 through 2007. From 1993 through 2007, relative educational disparities in all-cause mortality continued to increase among working-aged men and women in the U.S., due to larger decreases of mortality rates among the most educated coupled with smaller decreases or even worsening trends in the less educated. For example, the rate ratios of all-cause mortality increased from 2.5 (95% confidence interval (CI), 2.4–2.6) in 1993 to 3.6 (95% CI, 3.5–3.7) in 2007 in men and from 1.9 (95% CI, 1.8–2.0) to 3.0 (95% CI, 2.9–3.1) in women. Generally, the rate differences (per 100,000 persons) of all-cause mortality increased from 415.5 (95% CI, 399.1–431.9) in 1993 to 472.7 (95% CI, 460.2–485.2) in 2007 in men and from 165.4 (95% CI, 154.5–176.2) to 256.2 (95% CI, 248.3–264.2) in women. Disparity patterns varied largely across the five specific causes considered in this study, with the largest increases of relative disparities for accidents, especially in women. Conclusions Relative educational differentials in mortality continued to widen among men and women despite emphasis on reducing disparities in the U.S. Healthy People decennial initiatives.
Regulation of oncogene-induced cell cycle exit and senescence by chromatin modifiers

Oncogene activation leads to dramatic changes in numerous biological pathways controlling cellular division, and results in the initiation of a transcriptional program that promotes transformation. Conversely, it also triggers an irreversible cell cycle exit called cellular senescence, which allows the organism to counteract the potentially detrimental uncontrolled proliferation of damaged cells. Therefore, a tight transcriptional control is required at the onset of oncogenic signal, coordinating both positive and negative regulation of gene expression. Not surprisingly, numerous chromatin modifiers contribute to the cellular response to oncogenic stress. While these chromatin modifiers were initially thought of as mere mediators of the cellular response to oncogenic stress, recent studies have uncovered a direct and specific regulation of chromatin modifiers by oncogenic signals. We review here the diverse functions of chromatin modifiers in the cellular response to oncogenic stress, and discuss the implications of these findings on the regulation of cell cycle progression and proliferation by activated oncogenes.
Immunochemical localization of proteins in the intestinal mucosa of children with diarrhea

Chronic diarrhea in children is a common and often frustrating problem confronting allergists, pediatricians, and gastroenterologists. We know very little about the mechanism and immunology of this problem. This study used an immunoperoxidase staining technique to evaluate the small bowel biopsy specimens of 15 children with chronic diarrhea. Ten children had diarrhea related to a specific food ingestion, and five had prolonged diarrhea without identification of an offending food. The new finding was the deposition of stain beneath the mucosal cells in the area of the basement membrane of the small bowel mucosa. Anti-IgG and anti-bovine serum albumin (BSA) were the antibody reagents most often associated with the detection of tissue deposits. Deposits of stain were found when the inflammatory system was active as determined by the presence of increased numbers of inflammatory walls in the mucosa.
Psychological state and mood effects of steroidal chemosignals in women and men.

Abstract We tested the hypothesis that isolated steroids, claimed to act like pheromones, affect human psychological state or mood. In the first experiment, we established that two steroids, Δ4,16-androstadien-3-one and 1,3,5(10)16-estratetraen-3-ol, modulated emotional states within 6 min of exposure. In men and women, neither steroid had specific effects on states of alertness or negative-confused mood. However, both steroids increased positive stimulated mood state in women but decreased it in men. These psychological findings do not parallel the reported sexually specific effects of these two steroids on the surface potential activity of putative vomeronasal epithelium. In a second experiment on women, we replicated that Δ4,16-androstadien-3-one modulated their general mood state, even when women were not aware of its odor and gave identical olfactory descriptions for the steroid and the control carrier solutions. In this within-subjects, repeated-measures experiment, androstadienone prevented the deterioration in general mood which occurred during exposure to the clove oil carrier solution in the laboratory environment. Thus, androstadienone appears to modulate affect, rather than releasing stereotyped behaviors or emotions. It is premature to call these steroids human pheromones. They are nonetheless psychologically potent, mandating future work delineating their function—i.e., whether these steroids are communicative chemosignals, context specific, or related to unconscious associations. In light of these modulatory effects and the complexity of human behavior, the function of chemosignals and pheromonal systems in a variety of species may need to be expanded to include the concept of modulators, as well as the traditional releasers, primers, and signaling compounds.
Calculations on the effect of methylation on the electrostatic stability of the B- and Z-conformers of DNA.

The three-dimensional Poisson–Boltzmann equation for the distribution of counterion charge density around double-helical DNA has been solved for solutions of .01M, .10M, and .20M monovalent salt. The polymers, poly[d(CpGp)] and poly[d(m5CpGp)], were studied in the B- and the Z-conformations. The effect of methylation on the relative stabilities of these conformers in solutions of different ionic strengths is known to favor the Z-form. Accumulation of charge density around the B- and the Z-conformers is compared in detail. The relative electrostatic stabilities of the B- and Z-conformers in .01M, .10M, and .20M solutions are compared and discussed in terms of the ion–DNA interactions and the self-energy of the structured ionic environment. The ion–DNA interaction energies, termed “phosphate screening,” monotonically decrease with ionic strength and are consistent with a B-to-Z conformation change induced in either polymer by increased electrolyte concentration. However, these calculated energies alone do not account for the fact that the ionic strength at the midpoint of the transition of the methylated polymer is substantially lower than that of its unmethylated analogues. The phosphate screening effect is counterbalanced by changes in the self-energy required for the creation of the structured counterion environment. This self-energy of the electrolyte environment monotonically increases with ionic strength. Methylation-induced shifts in the overall conformational equilibria depend on the relative changes of these competing effects. Increasing salt concentration is calcualted to favor the Z-conformer. The effect of methylation, lowering the ionic strength of the transition midpoint, is proposed to originate in minor structural changes in the Z-form of the polymer, making the groove more accessible to counterions in the G(3′ – 5′)C region. This allows a redistribution of counterion density and a lowering of the self-energy of the ionic environment, conferring added stability to the Z-conformation, as indicated by calculations of relative entropies. The experimentally observed temperature dependence of the B-to-Z transition, however, cannot be explained without assuming the release of bound water. Maps of the calculated three-dimensional structure at the counterion distribution near the surface of these molecules in both the B- and the Z-forms are also presented.
Energy structure in the axial channelling of 30 keV protons through gold

Abstract Structure which appears in energy analysed spectra for the transmission of 30 keV protons through a thin crystal of gold is ascribed to selection of discrete channelling orbits for the [110] axial channel.
Time decays of donor-bound excitons in GaAs under pressure-induced Γ - X crossover

We report on photoluminescence time decays of excitons bound to donors in high-purity, n-type GaAs at He temperatures and high hydrostatic pressures (up to 80 kbar), for both direct (P\ensuremath{\lesssim}41.3 kbar) and indirect band gaps. Measured lifetimes for direct donor-exciton states (${D}_{\ensuremath{\Gamma}}^{+}$,X) are uniformly fast, being \ensuremath{\lesssim}1 nsec, and correspond to either the exciton formation or radiative decay times. For indirect donor-exciton states (${D}_{X}^{0}$,X), the observed lifetimes are much longer (20--100 nsec), increase with pressure, and reflect a combination of nonradiative Auger decay and band-structure-dependent natural radiative decay. The considerable difference observed between the donor lifetimes over the range of pressures inducing the \ensuremath{\Gamma}-X transition illustrates the importance of band structure for shallow, bound states in multivalley semiconductors.
Writing Scientific Biography

Much writing on scientific biography focuses on the legitimacy and utility of this genre. In contrast, this essay discusses a variety of genre conventions and imperatives which continue to exert a powerful influence on the selection of biographical subjects, and to control the plot and structure of the ensuing biographies. These imperatives include the following: the plot templates of the Bildungsroman (the realistic novel of individual self-development), the life trajectories of Weberian ideal types, and the functional elements and personae of the folkloric tale of the “hero’s quest.” The essay discusses the nature and application of these genre conventions in some detail, with the conclusion that biography, however useful, exerts a powerfully distorting influence on the image of how most science gets done.
Test–retest stability of neuropsychological testing and individual differences in variability in schizophrenia outpatients

The accurate measurement of neurocognitive function requires stable and reliable instruments. These assessments are critically important as correlates, predictors, and outcome measures of psychopathology, neuropathology, and treatment. Particularly, in studies that evaluate the impact of treatments on neurocognitive function, it is essential that their reliability as repeated measures be quantified. In an attempt to measure within- and between-subject variance on a battery of neuropsychological tests commonly used in schizophrenia research, baseline measures were administered twice, approximately 10 weeks apart, to 54 stable outpatients with schizophrenia or schizoaffective disorder. Instruments were judged for their stability, and individuals were assessed for individual differences in test-retest variability. The majority of the instruments administered were highly stable. Group means for several tests showed improvement on retest, which may indicate a practice effect, although many tests did not reach our criteria for "change." Of 962 test scores, 21 (2%) showed significant change. Most subjects were stable, with only 7% of subjects accounting for 38% of significant test-retest changes. Results indicate that the instruments assessed have sufficient reliability and stability to be used as repeated measures in clinical trials and that a small number of patients may have instability of performance as an individual characteristic.
Multiple fractal dimensions in snow

Abstract Here we analyze fields of snowfall as delineated by weather radar data. By applying box counting we obtain a spectrum of fractal dimensions that range from about 1.80 to about 1.30. Thus our results suggest that snow exhibits multiple fractal dimensions which are substantially higher than the fractal dimensions that have been found in rain.
Injection frequency and anatomic outcomes 1 year following conversion to aflibercept in patients with neovascular age-related macular degeneration.

Background/Aim To evaluate the clinical, anatomic and functional effects of conversion to aflibercept following ranibizumab and/or bevacizumab in patients with neovascular age-related macular degeneration (AMD). Methods A retrospective review of patients with neovascular AMD treated with intravitreal ranibizumab and/or bevacizumab who were switched to aflibercept was performed. The primary outcome was change in injection frequency in the year following the change. Secondary outcomes included change in central macular thickness (CMT) at 6 months and 1 year, presence of intraretinal and subretinal fluid at 6 months and visual acuity at 1 year. Results A total of 109 eyes with neovascular AMD were switched to aflibercept and met inclusion criteria. Overall, aflibercept injection frequency was unchanged with patients receiving 7.4 antivascular endothelial growth factor (VEGF) injections the year prior to conversion compared with 7.2 aflibercept injections in the year following (p=0.47). However, the change to aflibercept was associated with improvement in CMT from 324 to 295 μm (p=0.0001) at 6 months and 299 μm (p=0.0047) at 1 year. There was no effect on visual acuity at 1 year. In a subgroup analysis, patients who had received ≥10 anti-VEGF injections in the year prior had fewer injections (11.1 to 8.4, p Conclusions In our population, switching to aflibercept therapy was not associated with a change in injection frequency nor improved visual acuity, but was associated with improved CMT at 6 months and 1 year. In patients who received at least 10 anti-VEGF injections in the year prior, transitioning to aflibercept was associated with a reduced injection frequency and CMT, suggesting potential cost savings in this population.
The Perception of Pain in Others: How Gender, Race, and Age Influence Pain Expectations

Abstract Sex, race/ethnic, and age differences in pain have been reported in clinical and experimental research. Gender role expectations have partly explained the variability in sex differences in pain, and the Gender Role Expectations of Pain questionnaire (GREP) was developed to measure sex-related stereotypic attributions about pain. It is hypothesized that similar expectations exist for age- and race-related pain decisions. This study investigated new measures of race/ethnic- and age-related stereotypic attributions of pain sensitivity and willingness to report pain, and examined the psychometric properties of a modified GREP. Participants completed the Race/Ethnicity Expectations of Pain questionnaire, Age Expectations of Pain questionnaire, and modified GREP. Results revealed a 3-factor solution to the race/ethnicity questionnaire and a 2-factor solution to the age questionnaire, consistent with theoretical construction of the items. Results revealed a 4-factor solution to the modified GREP that differed from the original GREP and theoretical construction of the items. Participants' pain-related stereotypic attributions differed across racial/ethnic, age, and gender groups. These findings provide psychometric support for the measures examined herein and suggest that stereotypic attributions of pain in others differ across demographic categories. Future work can refine the measures and examine whether select demographic variables influence pain perception, assessment, and/or treatment. Perspective The findings suggest that one's expectations of the pain experience of another person are influenced by the stereotypes one has about different genders, races, and ages. The 3 pain expectation measures investigated in the current study could be used in future work examining biases in pain assessment and treatment.
An unusual case of hyperphosphatemia in a vitamin D-deficient patient with tuberculosis

Vitamin D deficiency is associated with several alterations in mineral metabolism [1]. Initially, the development of secondary hyperparathyroidism maintains normal circulating 1,25-dihydroxyvitamin D (1,25-vitamin D) and serum calcium values, but both these values decrease in advanced vitamin D deficiency. Serum phosphorus values usually decrease because of secondary hyperparathyroidism, but rarely are serum phosphorus values high [1]. The rare variant of hyperphosphatemia with vitamin D deficiency has been attributed to an acquired pseudohypoparathyroidism type II resulting from hypocalcemia and/or receptor desensitization from chronically elevated parathyroid hormone (PTH) values [1, 2]. The paradigm for phosphate regulation changed dramatically with the discovery of bone-derived hormone fibroblast growth factor 23 (FGF23), which allows bone to interact with other organ systems involved in the regulation of mineral homeostasis. FGF23 inhibits production of 1, 25-vitamin D, renal phosphate reabsorption and secretion of PTH [3]. In turn, 1,25-vitamin D and phosphate stimulate FGF23 production. We present a case of intermittent hyperphosphatemia associated with severe vitamin D deficiency in which 25-hydroxyvitamin D (25-vitamin D) and 1,25-vitamin D were markedly decreased in the absence of impaired renal function. In contrast to previous reports of pseudohypoparathyroidism with severe vitamin D deficiency, hypocalcemia was absent and the PTH value was normal. We hypothesize that an abnormal FGF23 response may have played a role in the hyperphosphatemia observed in this patient.
Epidermal Growth Factor Produces Inotropic and Chronotropic Effects in Rat Hearts by Increasing Cyclic AMP Accumulation

Previously we have shown that epidermal growth factor (EGF) stimulates cardiac adenylyl cyclase and increases cAMP accumulation in the rat heart (Nair et al., Biochem. J. 264, 563-571, 1989). Moreover, we have shown that the stimulation of adenylyl cyclase by EGF in heart is mediated via activation of the stimulatory GTP binding regulatory protein Gs alpha (Nair et al., J. Biol. Chem. 265, 21317-21322, 1990). Since cAMP increases the beating rate of hearts, studies were performed to investigate the effects of EGF on mechanical function of the heart and the role of cAMP in mediating the cardiac effects of EGF. In isolated perfused rat hearts EGF (15 nM) decreased perfusion pressure, increased ventricular contractility and heart rate in a manner similar to that observed with the beta-adrenergic receptor agonist isoproterenol (10 nM). In the presence of the adenosine A1 receptor agonist (-)-N6-(R-phenylisopropyl)-adenosine (PIA, 100 nM) which via activation of the inhibitory GTP binding protein Gi inhibits adenylyl cyclase, the effects of EGF on cAMP accumulation in the heart were markedly attenuated. PIA also decreased the ability of EGF and isoproterenol to alter cardiac contractility and beating rate. However, PIA did not attenuate the increase in heart rate and contractility induced by the alpha-adrenergic agonist phenylephrine which does not stimulate cAMP accumulation in the heart. These data suggest that EGF alters cardiac function by increasing cellular cAMP accumulation.
THE RECOVERY OF TRANSMISSIVITY IN PASSIVE IRON WIRES AS A MODEL OF RECOVERY PROCESSES IN IRRITABLE LIVING SYSTEMS : PART I.

1. Passive iron (steel) wires, when activated after prolonged immersion in nitric acid of 55 to 90 per cent concentration (volumes per cent of HNO(3), specific gravity 1.42) revert spontaneously to the passive state, after a temporary reaction which is transmitted rapidly over the whole length of wire. The duration of this reaction at any region decreases rapidly with increase in the concentration above a certain critical limit of 52 to 54 per cent. In weaker acid (50 per cent and lower) the reaction continues uninterruptedly until all the metal is dissolved. 2. Immediately after this automatic repassivation the wire fails to transmit activation through more than a short distance (1 to 2 cm.); if left undisturbed in the acid it recovers by degrees its power of transmission (as measured by the distance traveled by an activation wave), at first slowly, then more rapidly; eventually, after an interval varying with the concentration of acid and the temperature, the activation wave is transmitted through an indefinite distance as before. 3. The return of complete transmissivity in 55 per cent acid occupies less than a minute (at 20 degrees ); in stronger acid it is more gradual, requiring in 90 per cent acid 20 minutes or more. This "complete recovery time" is nearly proportional to the excess of concentration of acid above the limiting value of 53 to 54 per cent. 4. In a given solution of acid the rate of recovery exhibits a temperature coefficient closely similar to that of most chemical reactions at this temperature (3-20 degrees ), and also to that of the rate of recovery (refractory period) of irritable living tissues after stimulation (Q(10) = about 3). 5. Two definite phases are distinguishable in the recovery process: (1) the redeposition of the continuous passivating surface layer (of oxide or oxygen compound); and (2) the progressive change of the newly passivated wire from the state of incomplete to that of complete transmissivity. The former phase is of brief duration and is indicated by a sudden change in the electrical potential of the wire, from that of active to that of passive iron; this phase is succeeded by the second and more prolonged period during which the passivating layer undergoes the progressive alteration associated with the recovery of transmissivity. This alteration appears to consist in a progressive thinning of the passivating film until a minimal thickness of (probably 1 molecule) is attained. Further thinning is prevented by local electrochemical oxidation. 6. The phenomena of partial or limited transmission during the second phase of the recovery process show a close correspondence with the phenomena of conduction with decrement in irritable living tissues such as nerve. Other analogies with the behavior of irritable tissues (threshold phenomena, distinction between "local" and "propagated" effects, summation, effects resembling electrotonus) are described.
Complementary resources and cooperative research: a model of research joint ventures among competitors

We present a model of research joint ventures in which if firms have highly complementary skills and resources then they prefer to cooperate in areas where the technology is highly appropriable, as in applied research. The model also indicates that large firms have a greater incentive to cooperate because they are better positioned to capture the benefits of a research venture. These findings seem to explain why cooperative research among rival firms in Japan has been applied rather than basic and conducted frequently among large companies. But firms prefer as small a partner as possible to limit the sharing of research results, creating a tension that may make cooperative efforts among rivals difficult to manage. For this reason, cooperation with organizations, such as universities or nonprofit institutions, may be a viable alternative for firms looking for complementary skills and resources.
The impact of combat trauma across the family life cycle: Clinical considerations

Clinical experience and research with veterans of the Second World War and subsequent military conflicts have demonstrated the longstanding nature of combat-related post-traumatic stress disorder and the reverberating effects upon the families of traumatized individuals. The consequences of combat trauma during various stages of family life are discussed. Specifically, the impact upon (a) courtship and mate selection, (b) marriage, (c) childbirth and childrearing, (d) marriage in mid-life, (e) children leaving home, and (f) retirement in late life are reviewed. Finally, clinical considerations for the practice of family psychotherapy in this area are presented.
Insurance coverage for experimental technologies

Prologue: As health care costs continue their upward spiral, insurers attempt to rein in the amounts they cover. One way of doing this is to cut spending for procedures, devices, and drugs that are considered “experimental.” In this paper the authors argue that had insurers, including Medicare, not paid the costs associated with “unproven” technologies in the past, many of the innovations for which American medicine is lauded might not have come to pass. Insurers' reluctance to foot the bill could curtail the development of new technologies and threaten our health care system's ability to keep up the pace of helpful innovations. This paper contains a specific policy proposal for all stakeholders—payers, providers, government, and patients—to bear some responsibility to ensure that this does not occur. Earl Steinberg is vice-president of Health Technology Associates in Washington, D.C., and is codirector of its Outcomes Studies Group. He is a professor of medicine at the Johns Hopkins School of Medicine an...
A Biologically Motivated Solution to the Cocktail Party Problem

We present a new approach to the cocktail party problem that uses a cortronic artificial neural network architecture (Hecht-Nielsen, 1998) as the front end of a speech processing system. Our approach is novel in three important respects. First, our method assumes and exploits detailed knowledge of the signals we wish to attend to in the cocktail party environment. Second, our goal is to provide preprocessing in advance of a pattern recognition system rather than to separate one or more of the mixed sources explicitly. Third, the neural network model we employ is more biologically feasible than are most other approaches to the cocktail party problem. Although the focus here is on the cocktail party problem, the method presented in this study can be applied to other areas of information processing.
The Structure and Activity of Pt‐Co Alloys as Oxygen Reduction Electrocatalysts

This paper reports on carbon-supported Pt-Co (3:1 atom ratio) catalysts prepared in both acid and alkaline aqueous media, followed by heat-treatments to promote alloy formation. both preparations began with a commercial 10% Pt-on-carbon catalyst, with Pt particle sizes of 15--30 {Angstrom}. Significantly greater alloying was observed in the catalyst prepared in the acid medium. X-ray diffraction studies of the acid-prepared catalyst demonstrated lattice parameters tending away from Pt (3.927 {Angstrom}) and forward that for Pt{sub 3}Co (3.831 {Angstrom}), greatly increased particle sizes, and significant ordering evidenced by the presence of super-lattice reflections. In all cases, catalysts prepared in the alkaline medium were alloyed to a lesser extent, were of moderately increased particle size, and gave no indication of alloy ordering. Activity testing under phosphoric acid fuel cell conditions demonstrated that the most highly alloyed catalysts were not significantly more active than pure Pt catalyst of comparable crystallite size. Loss of cobalt in the phosphoric acid environment was the lowest in catalysts which were the most alloyed, and were the Pt{sub 3}Co ordered phase was present.
C3-4: Primary Care Physician Efficiency in Handling Patient Secure Email and the Impact on Patient Communication and Access

Background/Aims All Kaiser Permanente regions have implemented secure email functionality. Regional policies, workflows, and provider best practices have been established regarding secure email encounters with patients. This Phase I study explores effective practices of primary care physicians (PCPs) handling email traffic with patients, provides evidence regarding current secure email workflow and volumes, and estimates physician workloads related to daily secure email encounters with patients.