cssi/SciSciGPT-SciSciNet huggingface dataset:
Clearing Away Assumptions Through Philosophy and Research

This article illustrates one way in which philosophical inquiry and empirical research can be combined to illuminate processes like learning and social identification. Over the past 20 years, my empirical work in classrooms and communities has drawn on philosophical discussions about how knowledge is interconnected with social relationships and how we should conceptualize multiple levels of explanation. Both empirical research and philosophy can be done in various ways, and I offer no comprehensive account of how the two relate. I focus instead on one central goal of my work—to clear away assumptions that commonly limit our view of human activity and to offer alternative conceptualizations that open new pathways for thought and action. In pursuing this goal I have drawn on philosophical accounts of knowledge, identity and scientific explanation, as well as on philosophical methods for interrogating assumptions. My empirical analyses also provide philosophers useful cases to think with. Empirical research enriched by philosophical insights and methods can combine tools from both traditions to clear away unproductive assumptions and advance our understandings of the human world.
Olefin polymerization with Me4Cp–Amido complexes with electron-withdrawing groups

A series of Me 4 Cp-amido complexes ([η 5 ;η 1 -(Me 4 C 5 )SiMe 2 NR)TiCl 2 ; R = t-Bu, 1; C 6 H 5 , 2; C 6 F 5 , 3; SO 2 Ph, 4; or SO 2 Me, 5) were prepared and investigated for olefin polymerization in the presence of methylaluminoxane (MAO). X-ray crystallography of complexes 3 and 4 revealed very long Ti-N bonds relative to the bonds of 1. These complexes were employed for ethylene-styrene copolymerizations, styrene homopolymerizations, and propylene homopolymerizations in the presence of MAO. The productivities of the catalysts derived from 3-5 were much lower than the productivity of the catalyst derived from 1 for the propylene polymerizations and ethylene-styrene copolymerizations, whereas the styrene polymerization activities were much higher for the catalysts derived from 3-5 than for the catalyst derived from 1. The polymerization behavior of the catalysts derived from the metallocenes 3-5 were more reminiscent of monocyclopentadienyl titanocene Cp'TiX 3 /MAO catalysts than of CpATiX 2 /MAO catalysts such as 1 containing alkylamido ligands.
Detection of Flow Injection Analysis by Acousto-Optic Tunable Filter-Based Fluorimetry and Its Application in the Determination of Solvent Polarity

The instrumentation development of a fluorescence detector for flow injection analysis (FIA) based on an acousto-optic tunable filter (AOTF) is reported. The unique features of the AOTF-namely, its all-solid-state, compact, fast-scanning, and high-resolution characteristics-make it possible to develop the first fluorescence detector for FIA which is capable of recording the whole fluorescence spectrum with fine vibronic structure of the compound as it is flowing through the FIA detector. This capability, in turn, makes it possible to use this detector for the determination of the polarity of any sample by doping it with a small amount of pyrene and measuring the ratio of fluorescence intensities of band 1 and band 3. Because the sample in this case is flowing through the FIA instrument, it can be a mixture of two different solvents or surfactants by operating the FIA instrument under gradient condition. Polarity of any mixtures of solvents and surfactants can be simply, rapidly, and economically (in terms of the amount of samples and the time needed for measurements) determined.
A method for enforcing the solenoidal condition on magnetic field in numerical calculations

Abstract A method is proposed for enforcing the solenoidal condition V · B = 0 on the magnetic field B at all times during a transient numerical calculation. The method is based on the observation that Faraday's law for the time evolution of B can be cast into an alternative equivalent form which closely resembles the equations of incompressible hydrodynamics. In this alternative formulation, the solenoidal condition appears as a constraint that applies for all time, rather than just as an initial condition. The solenoidal condition may therefore be preserved during a transient calculation simply by basing the numerical scheme on the alternative formulation instead of the usual one. A possible numerical scheme is suggested which is analogous to the MAC method for incompressible fluid flow.
Stenosis severity effects for unbalanced simple-pulsatile bifurcation flow

Abstract A numerical finite-difference analysis is made of a plane simple-pulsatile flow past a symmetrical bifurcation which contains an asymmetrical smooth-contoured stenosis in the trunk. In essence, such a situation could represent a stenosed common carotid artery immediately upstream from the carotid junction. The flow is unbalanced; two-thirds of it exits or enters through the lower branch. The effect on various flow parameters of the stenosis itself and on changes in its severity is investigated by comparing the results for a severe stenosis, a mild stenosis, and no stenosis. The simple-pulsatile forcing function is specified in terms of an oscillatory and a steady Karman number. To obtain a significant amount of backflow, the oscillatory trunk Karman number is taken as 1000 compared to the steady value of 250. The frequency of oscillation is stipulated by a trunk Stokes number of 10π. The numerical procedures utilize the vorticity-transport version of the Navier-Stokes governing equations. A non-orthogonal coordinate transform allows the calculations to be made in a rectangular grid where the central difference expressions are easily applied. The results are presented in terms of both kinematic and kinetic parameters. The variation in the basic kinematic variables of stream function and vorticity is shown by temporal sequences of contour plots at times of peak flow and during the flow reversal stages as well as by several velocity vector plots. Kinetic results are given in terms of the temporal variation in shear stresses along boundaries. The peak shears are found to occur at the zenith of the stenosis at times of peak flow: the value for the severe stenosis is twice as large as that for the mild stenosis. The midline pressure distribution in the trunk and the centerline pressure distributions in the branches are also included.
Demonstration of nanometer-level active metrology for long-range interferometric displacement measurements

We report on the laboratory demonstration of an active linear metrology scheme using two separate lasers. In `active' metrology, the passive retroreflector in one arm of a typical heterodyne interferometer is replaced with an active optical transponder. The Transponder can dramatically boost the returned signal strength, thereby providing a way to perform metrology and pathlength control over long (> km) distances. Two Lightwave Electronics non-planar ring oscillator lasers at a wavelength of 1.319 micrometers were used as the Source and Transponder. The frequency of the Transponder is offset locked to the signal received from the Source using the Lightwave Laser Offset Locking Accessory, and the Transponder beam is sent back to the Source. The phases of the beat signals are measured locally at the Source and Transponder by appropriately demodulating the signal, and post-processed to determine displacement. In initial experiments, the standard deviation of the measurement errors was less than three nanometers.
The spectrum of hypopituitarism caused by PROP1 mutations

Mutations in the PROP1 gene are responsible for a high proportion of cases of multiple or combined anterior pituitary hormone deficiencies in humans. The physical and hormonal phenotypes of affected individuals are not uniform. The diagnosis is seldom considered during the first year of life. Growth failure is usually evident later in childhood. Deficiency of growth hormone (GH) tends to precede deficiency of thyroid-stimulating hormone (TSH). While most affected individuals fail to enter puberty without sex hormone replacement, some enter puberty but then develop pubertal arrest with a loss of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) responses to GnRH. Partial deficiency of corticotrophin (ACTH) is a late finding. Imaging of the pituitary may disclose either a small anterior pituitary gland or an intrapituitary mass. The mechanisms responsible for delayed loss of hormone production and the occasional overgrowth of the pituitary represent important areas for future research.
Sexual Selection and the Psychophysics of Female Choice

and Summary Evolutionary theories of female mate-choice tacitly assume a considerable ability of females to discriminate among potential mates on the basis of male epigamic differences. The general validity of this assumption is evaluated here through the application of comparative psychophysics. It is shown that perceptual or behavioral responses are typically logarithmic, rather than linear, functions of the stimulus intensity (the Weber-Fechner relationship). In general, then, ever-greater increments in absolute stimulus strength are required in order to elicit successive levels of discrimination. Through female choice, the mean value of a male epigamic trait increases in a population over evolutionary time. As this baseline increases, ever-greater absolute increments in the magnitude of the trait will be required in order for females to make successive discriminations among males. Thus, while male costs of producing stronger signals continue to rise, the corresponding benefits follow a diminishing returns function. This provides an inherent physiological check on the “runaway” selection process envisioned by Fisher (1930). Psychophysical theory also predicts that there should be a positive correlation between the mean value of a male epigamic trait in a species (or population) and the discriminatory acuity of females along the relevant stimulus intensity dimension. This prediction is testable via the comparative method. Sensory discrimination ability is here viewed not only as a product of natural selection but also as having important feedback influences upon the evolutionary process itself. Zusammenfassung 1 Es wird angenommen, das Partnerwahl durch das Weibchen eine Form sexueller Selektion ist, die zu extravaganten sekundaren Geschlechtsmerkmalen bei Mannchen fuhrt. 2 Die Hypothese erfordert, das Weibchen unter den verfugbaren Mannchen auf der Basis dieser Merkmale wahlen und das ihre Praferenz gerichtet ist. 3 Zu Beginn der Evolution eines solchen mannlichen Merkmals ist diese Unterscheidung relativ einfach. Je starker das Merkmal ausgebildet ist, desto schwieriger wird die Unterscheidung, und zwar wegen psychophysikalischer Beschrankungen des Unterscheidungsprozesses. Infolgedessen nimmt die Wirksamkeit der Partnerwahl durch die Weibchen allmahlich ab. 4 Die den Sinnessystemen von Tieren zugrundeliegende Physiologie besitzt damit eine bisher nicht erkannte Kontrollfunktion fur das von Fisher (1930) postulierte “Davonlaufen” (run-away) der sexuellen Selektion.
Flow field characterization of a jet and vortex actuator

An actuator, which produces several different flow fields that may be used for active flow control, is characterized in still air using flow visualization and velocity measurements. The primary actuator-induced flow fields are: free jets, wall jets, and vortex flows. The non-dimensional parameters governing these actuator-induced flows are developed. For the vortex-flow regime, the operational range of the actuator increases as it’s size decreases without a significant decrease in either the actuator induced velocity or vortex core size. The velocity scaling is developed for the vortex flow and suggests that the optimum actuator efficiency occurs at a Stokes number of approximately 7.9 for the range of parameters surveyed. In a turbulent, zero pressure gradient boundary layer, measurements made just downstream of the actuator (when operated in the vortex mode) indicate a vortical disturbance is generated in the boundary layer.
Defining Lactation Acuity to Improve Patient Safety and Outcomes

While substantial evidence exists identifying risks factors associated with premature weaning from breastfeeding, there are no previously published definitions of patient acuity in the lactation field. This article defines evidence-based levels of lactation acuity based on maternal and infant characteristics. Patient acuity, matching severity of illness to intensity of care required, is an important determinant of patient safety and outcomes. It is often used as part of a patient classification system to determine staffing needs and acceptable workloads in health care settings. As acuity increases, more resources, including more skilled clinicians, are needed to provide optimal care. Developing an evidence-based definition of lactation acuity can help to standardize terminology, more effectively distribute health care staff resources, encourage research to verify the validity and reliability of lactation acuity, and potentially improve breastfeeding initiation and duration rates.
Screening for adolescent depression in a pediatric emergency department.

Objectives: To describe the prevalence of depressive symptoms in adolescents presenting to the emergency department (ED) and to describe their demographics and outcomes compared with adolescents endorsing low levels of depressive symptoms. Methods: The Beck Depression Inventory–2nd edition (BDI-II) was used to screen all patients 13–19 years of age who presented to the ED during the period of study. The BDI-II is a 21-item self-report instrument used to measure the presence and severity of depressive symptoms in adolescents and adults. Demographics and clinical outcomes of screening-program participants were abstracted by chart review. Patients were categorized into one of four severity categories (minimal, mild, moderate, or severe) and one of three presenting complaint categories (medical, trauma, mental health). Results: Four hundred eighty-seven patients were approached, and 351(72%) completed the screening protocol. Participants endorsed minimal (n= 192, 55%), mild (n= 52, 15%), moderate (n= 41, 11%), or severe depressive symptoms (n= 66, 19%). Those with moderate or severe depressive symptoms were more likely to be hospitalized. Of patients completing the BDI-II, 72% with psychiatric, 12% with traumatic, and 19% with medical chief complaints endorsed either moderate or severe depressive symptoms. Conclusions: Depressive symptoms are prevalent in this screening sample, regardless of presenting complaint. A substantial proportion of patients with nonpsychiatric chief complaints endorsed moderate or severe depressive symptoms. A screening program might allow earlier identification and referral of patients at risk for depression.
On the scalability and capacity of planar wireless networks with omnidirectional antennas

An Erratum has been published for this article in Wireless Communications and Mobile Computing 2004; 4(4): 473. We extend the previously well-known results on the capacity of wireless networks and present the implications of our results on network scalability. In particular, we find bounds on the maximum achievable per-node end-to-end throughput, λe, and the maximum number of simultaneously successful wireless transmissions, Ntmax, under a more general network scenario than previously considered. Furthermore, in the derivation of our results, we make no restrictions on the mobility pattern of the nodes or on the number simultaneous transmissions and/or receptions that nodes are capable of maintaining. In our derivation, we analyze the effect of parameters such as the area of the network domain, A, the path loss exponent, γ, the processing gain, G, and the SINR threshold, β. Specifically, we prove the following results for a wireless network of N nodes that are equipped with omnidirectional antennas: (1) λe is Θ(1/N) under very general conditions. This result continues to hold even when the communication bandwidth is divided into sub-channels of smaller bandwidth. (2) Ntmax has an upper bound that does not depend on N, which is the simultaneous transmission capacity of the network domain, NtQ. For a circular network domain, NtQ is O(Amin{γ/2,1}) if γ≠2 and O(A/log(A)) if γ = 2. In addition, NtQ is O(γ2) and O(G/β). Moreover, lack of attenuation and lack of space are equivalent, where NtQ cannot exceed 1 + G/β. (3) As N ∞ a desired per-node end-to-end throughput is not achievable, unless the average number of hops between a source and a destination does not grow indefinitely with N, A grows with N and N is O(Amin{γ/2,1}) if γ≠2 and O(A/log(A)) if γ = 2. Copyright © 2004 John Wiley & Sons, Ltd.
Lattice instabilities and ferroelectricity in A ScO 3 perovskite alloys

The structural properties and lattice instabilities of perovskites in the $(\mathrm{T}\mathrm{h},\mathrm{P}\mathrm{b},\mathrm{B}\mathrm{i},\mathrm{Y}){\mathrm{ScO}}_{3}$ system are investigated by first-principles density-functional calculations with the linearized augmented plane-wave method. In all cases, Th is found to be tetravalent on the perovskite A site. The electronic structures have substantial Sc-O hybridization, as well as both Pb-O covalency, as is common in Pb based transition-metal perovskites, and significant hybridization of nominally unoccupied Th p and d states with O p states. The calculations show that the ideal cubic perovskite structure is highly unstable in $(\mathrm{T}\mathrm{h},\mathrm{P}\mathrm{b}){\mathrm{ScO}}_{3}.$ The dominant instability is against rotation of the ${\mathrm{ScO}}_{6}$ octahedra, as is common in perovskites with small A-site cations as defined by the perovskite tolerance factor. However, there are also substantial, though weaker, instabilities against ferroelectric distortions. These are characterized by large shifts of the A-site ions against the surrounding O, especially for the Th. The tetragonal ferroelectric state is favored over a rhombohedral state, and in addition a large tetragonal $c/a$ ratio is found. At least for a particular ordering of the A-site ions we find that the ferroelectric and rotational distortions coexist, yielding a monoclinic symmetry ferroelectric ground state with rotated octahedra and a large Th off-centering. Calculations are also reported for ${\mathrm{BiScO}}_{3}$ and ${\mathrm{YScO}}_{3}$ in the perovskite structure. Considering only ferroelectric instabilities, these compounds show somewhat different anisotropies but both favor large $c/a$ ratios when tetragonal. The instability against rotation of the ${\mathrm{ScO}}_{6}$ octahedra is similar in energy to the ferroelectric instability in ${\mathrm{BiScO}}_{3}$ and substantially stronger than the ferroelectric instability in ${\mathrm{YScO}}_{3}.$ Trends in the lattice instabilities of $A{\mathrm{ScO}}_{3}$ perovskites are discussed in terms of these results. Of the systems considered, the most likely to show a piezoelectrically active morphotropic phase boundary is ${\mathrm{Th}}_{(1\ensuremath{-}x)/2}{\mathrm{Bi}}_{x}{\mathrm{Pb}}_{(1\ensuremath{-}x)/2}{\mathrm{ScO}}_{3}.$ Implications for practical piezoelectric materials are discussed.
The effect of photodynamic therapy on squamous cell carcinoma in a murine model: Evaluation of time between intralesional injection to laser irradiation

Successful treatment of naturally occurring periocular squamous cell carcinoma (SCC) in horses with photodynamic therapy (PDT) has been performed by injecting residual tumor with verteporfin and applying laser irradiation immediately following injection. This study used a murine model to evaluate the influence of time between intralesional injection of verteporfin to laser irradiation on tumor growth inhibition with PDT. Mice were randomized into six groups (n=10/group). Each tumor was injected with either 0.1mg/cm(3) of verteporfin (Tx) or 5% dextrose in water (C). Tx and C groups 1, 2, and 3 were irradiated at 1, 30, and 180min after injection. Wilcoxon-rank sum test (P< or =0.05) was performed to determine the relative change in tumor volume (RCTV) between groups. Statistical significance was demonstrated between treatment groups. Although verteporfin-PDT treated mice in Tx1 and Tx2 demonstrated a lower RCTV compared to C1 and C2 mice, the differences were not statistically significant.
Learning to Read the Bible with Desire: Teaching the Eros of Exegesis in the Theological Classroom

. The article begins with two brief theoretical descriptions of a pedagogy of desire vis-a-vis the Christian Bible. The first of these is a poem; the second summarizes the conversation constituted by four quite different books: the Confessions by Augustine of Hippo, Freud & Philosophy by Paul Ricoeur, Pedagogy of the Oppressed by Paulo Freire, and The Ethnography of Reading edited by Jonathan Boyarin. There follows, then, a case in point: an account of my most recent effort to teach the eros of exegesis at Emmanuel College (Toronto), using the Song of Songs. This account includes discussion of the (pre)conception(s) of the (biblical) text that inform(s) this undertaking and of the practice of communal reading as a specific type of bodily activity and social experience. In conclusion, the question of evaluation is addressed. How does one learn to love – when, by, in, with, and under – reading the Bible?
Release of γ-aminobutyric acid from guinea pig myenteric plexus synaptosomes

A crude synaptosomal preparation obtained from myenteric plexus of guinea pig small intestine was used to study the release of [3H]GABA. GABA release was elevated in response to depolarizing agents when tested in normal Krebs but was depressed in a calcium-free medium. GABA was also noted to stimulate a release of [3H]ACh from the same preparation. These data support the possible role of GABA as an enteric neurotransmitter.
Nonlinear response of an initially buckled beam with 1: 1 internal resonance to sinusoidal excitation

The nonlinear response of an initially buckled beam in the neighborhood of 1:1 internal resonance is investigated analytically, numerically, and experimentally. The method of multiple time scales is applied to derive the equations in amplitudes and phase angles. Within a small range of the internal detuning parameter, the first mode; which is externally excited, is found to transfer energy to the second mode. Outside this region, the response is governed by a unimodal response of the first mode. Stability boundaries of the unimodal response are determined in terms of the excitation level, and internal and external detuning parameters. Boundaries separating unimodal from mixed mode responses are obtained in terms of the excitation and internal detuning parameters. Stationary and non-stationary solutions are found to coexist in the case of mixed mode response. For the case of non-stationary response, the modulation of the amplitude depends on the integration increment such that the motion can be periodically or chaotically modulated for a choice of different integration increments. The results obtained by multiple time scales are qualitatively compared with those obtained by numerical simulation of the original equations of motion and by experimental measurements. Both numerical integration and experimental results reveal the occurrence of multifurcation, escaping from one well to the other in an irregular manner. and chaotic motion.
Identification of prostaglandin E2 and leukotriene B4 in the synovial fluid of painful, dysfunctional temporomandibular joints

It has been hypothesized that prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) should be present in the synovial fluid of inflamed, dysfunctional temporomandibular joints. An assay to identify PGE2 and LTB4 and platelet-activating factor (PAF) was used, and a strong correlation between the levels of these lipid mediators of pain and inflammation and an index of clinical joint pathology was found.
Research on flexible automation and robotics for plant production at Rutgers University.

Abstract This is an overview of research activities in the areas of flexible automation and robotics (FAR) within controlled environment plant production systems (CEPPS) in the Department of Bioresource Engineering, Rutgers University. In the past thirty years, our CEPPS research has dealt with the topics including structures and energy, environmental monitoring and control, plant growing systems, operations research and decision support systems, flexible automation and robotics, and impact to natural (i.e. surrounding) environment. Computer and modeling/simulation techniques have been utilized extensively. Mechanized systems have been developed to substitute human's physical labor and maintain uniformity in production. Automation research has been directed towards adding, to the mechanized systems, the capabilities of perception, reasoning, communication, and task planning. Computers, because of their programmability, provide flexibility to automated systems, when incorporated with generic hardware devices. Robots are ideal hardware tools to be employed in flexible automation systems. Some technologies developed in our CEPPS research may be readily adaptable to Closed Bioregenerative Life Support Systems (CBLSS).
Representation and Spatial Analysis in Geographic Information Systems

A common—perhaps modal—representation of geography in spatial analysis and geographic information systems is native (unexamined) objects interacting based on simple distance and connectivity relationships within an empty Euclidean space. This is only one possibility among a large set of geographic representations that can support quantitative analysis. Through the vehicle of GIS, many researchers are adopting this representation without realizing its assumptions or its alternatives. Rather than locking researchers into a single representation, GIS could serve as a toolkit for estimating and exploring alternative geographic representations and their analytical possibilities. The article reviews geographic representations, their associated analytical possibilities and relevant computational tools in the combined spatial analysis and GIScience literatures. The discussion identifies several research and development frontiers, including analytical gaps in current GIS software.
Endotoxin stimulates endothelin-release in vivo and in vitro as determined by radioimmunoassay.

Abstract A marked increase in immunoreactive endothelin was observed in rat serum collected within 10–15 min after infusion of endotoxin. Endothelin level was 117 ± 11.5 pg/ml (mean ± S.E., N=4) in rats exposed to endotoxin as compared with undetectable levels (less than 2 pg/ml, N=4) in controls. We have also observed a significant stimulation of endothelin-release by endotoxin from cultured bovine transformed thoractic aortic endothelial cells at concentrations of endotoxin ranging between 0.1 and 10.0 ug/ml. Serum was indispensable for the stimulating effect of endotoxin, although serum itself did not show any effect at the concentration used (1%). These results suggest that endothelin plays an important role in mediation of pathophysiological responses caused by endotoxin. The levels of endothelin were measured by radioimmunoassay with high sensitivity.
Physiological amino acids in brain tissue of the lepismatids, Lepisma saccharina and Thermobia domestica (Insecta, Thysanura)

Abstract 1. The free (physiological) amino acid profile in the brain tissue of Lepisma saccharina and Thermobia domestica (Thysanura, Lepismatidae) was investigated. 2. Nitrogenous waste products (ammonia and urea) together constituted 28% of the total ninhydrinpositive compounds for both species. 3. GABA accounted for 3% of the total ninhydrin-positive compounds in the brain of L. saccharina , and T. domestica. 4. Glutamate comprised 7% of the total ninhydrin-positive compounds in the brain of L. saccharina , and 8% in T. domestica. 5. The most abundant amino acids were alanine, proline, arginine and taurine. 6. The possible role of amino acids as neurotransmitters and/or modulators of neurotransmitter activity is discussed as well as the comparative free amino acid composition of the brain tissues of various arthropod groups.
Luminaries in medicine: Richard Mead, James Gibbs, and solar and lunar effects on the human body in early modern England.

In early modern England, the medical effects of the sun and the moon had been traditionally explained by a vast symbolic system of "analogies, correspondences, and relations among apparently discrete elements in man and the universe," which had its conceptual origins in the works of Aristotle, Ptolemy, and Galen. The ultimate causes of planetary emanations had been considered "occult," an Aristotelian and early modern term utilized when distinguishing "qualities which were evident to the senses from those which were hidden." After the Restoration, many physicians attempted to rid the natural world of occult causes and to explain invisible forces like solar and lunar emanations via mechanical, chemical, and mathematical systems. To explain the medical effects of the luminaries, the English physicians Richard Mead (1673-1754) and James Gibbs (d. 1724) utilized iatromechanism, which regarded the body as a Cartesian machine, conforming in its functions to mechanical laws. Gibbs's and Mead's use of chemical and mechanical explanations illustrates the changed intellectual climate after the Restoration, which placed rationalistic, empirical, and "scientific" values above traditional academic medicine. However, the basis of Mead's and Gibb's theories were traditionally Galenic and based upon astrological medicine.
Variations of linewidth enhancement factor and linewidth as a function of laser geometry in (AlGa)As lasers

A quantitative analysis of the laser geometry dependence of the linewidth enhancement factor alpha and linewidth Delta f in GaAs/AlGaAs lasers is presented. Analytical expressions for the refractive index change and alpha are presented. Variations of alpha and Delta f depending on active layer thickness and laser length are estimated by using the expressions and previous experimental data of absorption spectra. Considering small variations in the reported experimental data depending on laser type, it is shown that the calculated values of alpha agree well with the experimental data. The magnitude of alpha decreases gradually with the decrease of active layer thickness and laser length. Since the change of active layer thickness affects only alpha , neglecting small variations of other terms in the linewidth expression, the reduction of active layer thickness is suggested to be a practical method for the reduction of linewidth. >
Beverage alcohol spending in Singapore: an empirical update.

Data on Singapore suggest strongly that consumer spending on imported and locally produced beverage alcohol was on the rise from 1986 through 1991 just as it had been from 1978 through 1986. Although not alarming in contrast to countries such as South Korea, the rise could signal an emerging problem with both public health and economic growth implications. In terms of economic growth, Singapore's continued economic success and its future plans require a highly skilled labor force, but skilled local workers are in very short supply. Continued rises in spending on beverage alcohol could pose a potential constraint to labor availability and therefore continued material progress. On the public health side, a rise in spending on beverage alcohol could lead to illness and accidents that cause chronic absenteeism, decrease on-the-job productivity, and lead to the permanent loss of valuable workers through alcohol-related motor car and other fatal accidents. A minimalist intervention strategy featuring education ...
Elevated Levels of PDGF α Receptors in Keloid Fibroblasts Contribute to an Enhanced Response to PDGF

Despite a number of studies, the etiology of keloids remains unknown. We have investigated the response of fibroblasts derived from keloid tissue and normal adult skin to platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and fibroblast growth factor (FGF). Keloid fibroblasts were more responsive in both chemotactic and mitogenic assays to all three isoforms of PDGF than fibroblasts from normal skin. No enhanced response of the cells to either EGF or FGF was detected. The enhanced PDGF response of keloid fibroblasts appears to be mediated by elevated levels of PDGF a receptors, which are 4–5 times higher than those in normal human skin fibroblasts.
A discussion format for computer ethics

This paper, describes a format and grading scheme for a discussion course in Computing Ethics. The teaching of ethics, particularly in a discussion format, can be somewhat problematic in a computer science department where courses tend to be technical and faculty tend to be more comfortable with material presented in a lecture and/or workshop format. Grading of discussion and papers can also be perceived as more difficult or, at least, less grounded in objective criteria. The following describes an approach that attempts to address those particular concerns. The course described was offered in the spring of 2003 when two sections were taught.
Stimulus control of behavioral inhibition in the preweanling rat

Previous studies demonstrate that 14-day-old rats reduce their emission of ultrasonic vocalizations and freeze when exposed to an unfamiliar adult male rat. This study sought to identify the stimulus characteristics of conspecific males that potentiate the display of behavioral inhibition. In Experiment 1, day 14 rats were isolated from the nest and exposed to either an unfamiliar prepubescent male rat or an unfamiliar adult male rat. Pups exposed to the unfamiliar adult male rat exhibited significantly elevated levels of freezing and reduced their emission of ultrasounds. In Experiment 2, pups were exposed to either a familiar or an unfamiliar adult male rat. Although several pups exposed to the familiar adult male rat exhibited freezing, pups tested with the unfamiliar adult rat showed a reliably higher duration of freezing and made fewer vocalizations. Results suggest that neither the unfamiliar factor nor cues associated with male adulthood are sufficient to account for the occurrence of behavioral inhibition when presented separately. However, the combination of unfamiliarity and adult male stimuli are highly potent stimulus features that elicit behavioral inhibition in preweanling rats.
Variation in the Constituents of Milk Under Arizona Conditions. III. Variation in Milk from Jersey, Guernsey, Holstein, and Mixed Herds

Summary (1)Total solids, serum solids, fat, and protein values were highest in winter and lowest in summer. (2)The milk from Jersey and Guernsey herds, containing 4.91 and 4.36 per cent fat, respectively, showed no definite trends in lactose content in relation to other constituents. The milk from the Holstein and mixed herds had a slightly lower lactose value during the summer, with an increase in the fall and winter months. (3)The serum solids content of milk from Holstein cows Was below 8.5 per cent during 6 months of the year. This decline occurred in summer and was accompanied by decreases in total solids, fat, and lactose. Serum solids content of the milk from Jersey, Guernsey, and mixed herds also averaged lowest in summer, but was still above the legal minimum, except for mixed herds, which had an average of 8.48 per cent serum solids in August. (4)The average chloride values were 0.152 for the Holstein herds, 0.134 for the mixed, 0.128 for the Guernsey, and 0.110 per cent for the Jersey herds. The chloride values were highest in summer and lowest in winter. (5)Cows on marginal rations and consequently not in good physical condition produced milk which is considered normal in composition and averaged only slightly lower in total solids, fat, and lactose, essentially the same in serum solids, and slightly higher in the protein content and in specific gravity. (6)Herd samples of milk representing one day's production may be abnormally low in serum solids but well above the minimum in fat.
A Gripping New Mechanism of Drug Resistance in HIV-1 Reverse Transcriptase

HIV-1 Reverse Transcriptase (RT) converts viral RNA into dsDNA that is integrated into the human genome. Nonnucleoside RT inhibitors (NNRTIs) are highly effective in the treatment and prevention of HIV. NNRTI resistance mutations arise from therapy, yet the mechanism(s) of how these mutations inhibit polymerization by RT is unclear. We examine the role of NNRTI on the dynamics between RT and its Template/Primer (T/P) substrate using a combination of molecular modeling, single-molecule and bulk fluorescence techniques and provide an unprecedented glimpse into the dynamics of RT-T/P interaction as well as the intramolecular conformation of RT itself while bound to its substrate. The data suggests a unique mechanism of resistance that is mediated by interplay between intramolecular conformational changes in RT and intermolecular dynamics of the RT-template/primer-dNTP complex.
Pregnancy outcomes after laparoscopic Roux-en-Y gastric bypass

Abstract Background Early reports described adverse perinatal outcomes of pregnancies after weight loss surgery (WLS), which subsequently raised concerns regarding safety. Our objective was to investigate, in a community-based, academic, tertiary care center, the safety of pregnancies after laparoscopic Roux-en-Y gastric bypass (LRYGB) and its potential effect on obesity-related perinatal complications. Methods The pregnancy outcomes of patients delivering infants after LRYGB at our institution were compared with those of control subjects (stratified by body mass index) who had not undergone WLS. The charts were retrospectively reviewed for demographics, delivery route, and perinatal complications. Results A total of 26 patients who delivered after LRYGB and 254 controls were identified. The mean interval from LRYGB to conception was 25.4 ± 13.0 months. In general, the perinatal complications in the LRYGB patients were similar to those in the nonobese controls and lower than in the obese and severe obese controls, although statistical significance was not noted for all complications. No spontaneous abortions or stillbirths occurred in the LRYGB patients. No LRYGB patients required intravenous nutrition or hydration. The overall incidence of cesarean section in the LRYGB patients was similar to that in the obese and severely obese controls but significantly greater than that in the nonobese controls. The complication rates were similar in pregnancies occurring "early" ( 18 mo) after LRYGB. Conclusion The results of our study have shown that pregnancy after LRYGB is safe, with an incidence of perinatal complications similar to that of nonobese patients, and lower than that of obese and severely obese patients, who had not undergone WLS. Larger studies are required to demonstrate statistically significant improvements in outcome in patients treated with WLS.
Choosing a cosolvent: Solubilization of naphthalene and cosolvent property

The addition of an organic cosolvent to water can increase the aqueous solubility of many hydrophobic organic compounds (HOCs). This work examines the correlations between the change of naphthalene solubility and various physicochemical properties of the cosolvent added to the system. Results show that the dielectric constant and surface tension do not correlate with the solubilization power of cosolvent toward naphthalene. The solubility parameter correlated well with increases in naphthalene solubility and therefore provides a convenient tool when screening cosolvents for their ability to enhance HOC solubility in various environmental engineering applications. Other properties investigated include the octanol/water partition coefficient, interfacial tension E{sub T}(30), viscosity, and hydrogen bonding capacities.
Factors associated with caregiver burden among caregivers of patients with cancer in a hospice setting

Abstract Purpose: Previous research has examined caregiver burden in the context of chronic illness, but little is known about this problem in hospice settings. The objective of this project was to identify factors associated with caregiver perceptions of burden among those caring for the terminally ill, with a long-term goal of better understanding the links between the level of burden and the risk of adverse medical and psychological outcomes. Our expectation was that certain groups (e.g., older women) would experience greater burden. Methods: We conducted a cross-sectional survey of primary caregivers in a hospice setting. Among 388 caregivers of patients with cancer admitted between October 1999 and September 2000, 200 (52%) agreed to participate. In-person interviews were conducted to ascertain data on the caregivers' socio-demographic characteristics, self-reported health status, support systems, religiosity, and amount of assistance they provided to their patients. Using this information, we also calculated a composite social network index, incorporating marital status, religious activities, contact with friends, and participation in community groups. Caregiver burden was measured using a 9-item subset of the Zarit burden inventory, and the summary scores were dichotomized at the upper quartile. Using logistic regression, unadjusted and adjusted analyses identified factors significantly associated with increased burden scores. Results: We found that increased caregiver burden was related to younger age (OR 1.49, CI 1.12–1.99), a worse score on the social network index (OR 1.43, CI 1.05–1.95), and the number of activities in which the caregivers themselves were restricted due to their caregiving responsibilities (OR 1.32, CI 1.11–1.58). Conclusions: Although several factors were associated with caregiver feelings of burden, the specific results we found were not anticipated. Future research should examine these factors, as well as others that might be more easily modifiable, when evaluating increased risk among caregivers.
Jet entrainment rate in air curtain of open refrigerated display cases

Experimental and computational methods are used to address those parameters that have significant effects on the amount of entrained (warm) air in an open refrigerated display case. These parameters are identified, quantified, and the rate of entrainment is expressed as a function of these parameters. It is found that the turbulence intensity, the shape of the mean velocity profile at the discharge air grill, and the Reynolds number are mainly responsible for the amount of entrained air in a display case. It is also concluded that lower Reynolds numbers will reduce the amount of the entrained air in the display case, however, the trade off will be higher temperature of the food products on shelves. Digital particle image velocimetry (DPIV) was used to map the entire mean velocity flowfield and the turbulence intensity. The laser doppler velocimetry technique was also used to verify the mean velocity and turbulence intensity measurements made by DPIV. The results indicated an excellent agreement between both methods. Parametric studies for the rate of entrainment of the outside air into the display case were performed using a computational fluid dynamics tool. The results indicate that lowering the Reynolds number of the air curtain reduces the entrainment rate. However, sufficiently high momentum should still exist to enforce the integrity of the air curtain structure.
Ethical analyses of institutional measures to increase health care worker influenza vaccination rates.

Abstract Health care worker (HCW) influenza vaccination rates are modest. This paper provides a detailed ethical analysis of the major options to increase HCW vaccination rates, comparing how major ethical theories would address the options. The main categories of interventions to raise rates include education, incentives, easy access, competition with rewards, assessment and feedback, declination, mandates with alternative infection control measures, and mandates with administrative action as consequences. The aforementioned interventions, except mandates, arouse little ethical controversy. However, these efforts are time and work intensive and rarely achieve vaccination rates higher than about 70%. The primary concerns voiced about mandates are loss of autonomy, injustice, lack of due process, and subsuming the individual for institutional ends. Proponents of mandates argue that they are ethical based on beneficence, non-maleficence, and duty. A number of professional associations support mandates. Arguments by analogy can be made by mandates for HCW vaccination against other diseases. The ethical systems used in the analyses include evolutionary ethics, utilitarianism, principalism (autonomy, beneficence, non-maleficence, and justice), Kantism, and altruism. Across these systems, the most commonly preferred options are easy access, assessment and feedback, declinations, and mandates with infection control measures as consequences for non-compliance. Given the ethical imperatives of non-maleficence and beneficence, the limited success of lower intensive interventions, and the need for putting patient safety ahead of HCW convenience, mandates with additional infection control measures as consequences for non-compliance are preferred. For those who opt out of vaccination due to conscience concerns, such mandates provide a means to remain employed but not put patient safety at risk.
A novel long term short interval physical activity regime improves body composition in mice

Exercise training (ET) and physical activity (PA) offer obvious health benefits in regular participants. In pre-clinical animal models, treadmills and running wheels are the models of choice for intervention studies using ET and PA. However, the frequency and duration necessary for positive effects on health are not completely understood. We investigated the impact of short duration voluntary wheel running on body composition in FVB × C57BL/6 F1 hybrid mice over 22 weeks. Mice were randomized and given access to voluntary wheel running (N = 6) or locked wheels (N = 5) for 1 hour per night during the dark cycle, 5 days per week. Average weekly running distance was generally cyclic in nature over the 22 weeks but did not change significantly from week to week, except for a difference between week 3 and week 9 (P = 0.05). Daily running distances ranged from 0.78 km to 1.45 km. Compared with non-runners, runners demonstrated significantly lower relative fat mass (9.98 ± 0.56% vs. 14.91 ± 1.47%, P = 0.0067) and significantly higher relative lean mass (79.18 ± 0.65% vs. 75.41 ± 1.28%, P = 0.019). No differences were observed with respect to glucose metabolism. Voluntary wheel running for one hour a day five days a week over a five month period improved body composition in young adult mice. This repetitive short interval exercise regime should be a useful model to investigate the effects of structured moderate intensity physical activity on physiological performance and chronic disease conditions in mice.
SnapShot: The hematopoietic stem cell niche.

The bone marrow microenvironment regulates hematopoietic stem cell (HSC) function and protects HSCs from exhaustion. Technological advances have expanded understanding of the microenvironment's structural and functional organization. Here, we describe three major HSC niche components: the endosteal zone, the vasculature, and hematopoietic progeny. Roles for the microenvironment in HSC mobilization and in malignancy are presented.