cssi/SciSciGPT-SciSciNet huggingface dataset:
Ethics and Science: An Introduction

Preface 1. Introduction and overview 2. Ethical concepts and theories 3. Science and its norms 4. Research ethics I: misconduct and the responsible conduct of research 5. Research ethics II: science involving humans 6. Research ethics III: science involving animals 7. The science of ethics 8. Transition: from ethics to politics and policy 9. Science and politics I: policy for science 10. Science and politics II: science for policy 11. Science and ideational culture 12. Science applied: ethics and engineering Appendix: influential ethics codes and declarations Works cited Index.
The Neural Basis of Language Faculties

Language encompasses an extremely diverse set of phenomena, ranging from perceiving speech sounds, through representing concepts and constructing meaning, to reasoning about the thoughts and intentions of others. Research on the cognitive neuroscience of these processes over the past 150 years has shown that they involve the collaborative efforts of a broadly distributed neural network, including the four cortical lobes in both hemispheres, the cerebellum, and subcortical regions. Mapping the specific subcomponent processes to particular brain regions has been somewhat problematic; however, great advances toward this goal have been made in the past decade, primarily due to advancing methods for studying the brain. Such advances have resulted in more precise characterizations of the computations performed by neural regions underpinning language, often revealing overlap with more general memory and control processes. This chapter summarizes contemporary research on the neurobiology of language at two levels: representation and processing. Descriptions of methodological advances and limitations, and contemporary applications of these advances to research on individual differences in comprehension abilities and in bilingualism, are also discussed herein. Keywords: language; cognitive neuroscience; bilingualism; semantics; syntax; discourse processing; individual differences
Radar reflectivity calibration using differential propagation phase measurement

estimated from power measurements. Comparison of the direct estimate of propagation phase (F m ) measurement, which is unaffected by absolute calibration of the radar system, with the estimated propagation phase (F e ) from power measurements is the basis for the calibration method. Polarization measurements such as reflectivity (Z ), differential reflectivity (ZDR), and differential propagation phase (FDP) are sensitive to drop size distribution (DSD) and mean drop shape. It is important to devise a calibration technique relatively unperturbed by changes in DSD and drop shape. Statistical fluctuation in F e is derived to estimate the accuracy of the calibration procedure, raindrop shape, and attenuation. The proposed method is applied for calibrating reflectivity measurements of the National Center for Atmospheric Research (NCAR) S-band polarization radar (S-Pol) in midlatitude, subtropical, and tropical rain events. INDEX TERMS: 3354 Meteorology and Atmospheric Dynamics: Precipitation (1854); 3360 Meteorology and Atmospheric Dynamics: Remote sensing; 3394 Meteorology and Atmospheric Dynamics: Instruments and techniques; 6904 Radio Science: Atmospheric propagation; 6969 Radio Science: Remote sensing; KEYWORDS: polarization radar calibration, reflectivity, differential reflectivity, differential phase, raindrop size distribution
Morphology and electrophysiological properties of immunocytochemically identified rat dopamine neurons recorded in vitro

In vitro intracellular recordings were made from neurons in the rat midbrain slice. Two neuronal types could be distinguished in dopamine-containing (DA) midbrain regions based on electrophysiological criteria. One neuron type exhibited short duration action potentials (less than 1.5 msec), could fire at high frequencies (greater than 10 Hz), and exhibited either phasic or burst firing patterns. This neuron did not exhibit tyrosine hydroxylase immunoreactivity. A second neuronal type exhibited a unique set of electrophysiological properties, which included (1) a spontaneous pacemaker-like depolarizing potential, (2) a highly regular firing pattern, (3) long duration (greater than 2 msec) action potentials, and (4) a high (i.e., depolarized) spike threshold. This neuron was consistently double labeled using intracellular staining and immunocytochemical localization of the catecholamine-specific enzyme tyrosine hydroxylase, and thus represented the DA neuronal type. Midbrain DA neurons stained with Lucifer yellow could be separated into 3 classes based on their location and morphology: (1) fusiform neurons with laterally projecting dendrites in the dorsal substantia nigra zona compacta region, (2) multipolar cells with laterally and ventrally projecting dendrites in the ventral substantia nigra zona compacta, and (3) neurons with fusiform and multipolar somata and radially projecting dendrites in the ventral tegmental area. The dendrites also exhibited spine-like protrusions and ended with specialized forked processes. Spontaneously firing DA cells recorded in vitro had a number of distinguishing electrophysiological characteristics in common with those of DA neurons recorded in vivo, such as the presence of a slow depolarizing potential driving spike activity and a characteristic depolarized spike threshold (approximately-36 mV). However, in contrast to that found in vivo, the DA cells characterized here exhibited substantially higher input resistances and fired spontaneously in a very regular pacemaker pattern. Burst firing was not observed. Spike activity was apparently dependent on 4 depolarizing events: (1) a voltage-dependent TTX-sensitive slow depolarization, (2) a cobalt-sensitive low threshold depolarization that was activated during the rebound from brief membrane hyperpolarizations, (3) high threshold dendritic calcium spikes which gave rise to the spike afterhyperpolarization, and (4) a high threshold initial segment sodium spike. These depolarizations were modulated by several processes, including a 4-aminopyridine-insensitive delayed repolarization, an instantaneous and time-dependent anomalous rectifier, and an afterhyperpolarization. Although low threshold depolarizations and rebound action potentials could be triggered by the membrane repolarization following small membrane hyperpolarizations, comparatively larger hyperpolarizations attenuated this rebound activation, thereby suppressing anodal break excitation.(ABSTRACT TRUNCATED AT 400 WORDS)
Evidence for a Reductive Pathway for the Anaerobic Metabolism of Benzoate

Evidence is presented for a reductive pathway for the anaerobic metabolism of benzoate by Rhodopseudomonas palustris.
Temporal pattern of de novo lipogenesis in the postprandial state in healthy men

BACKGROUND Recent data suggest that hepatic de novo lipogenesis (DNL) is elevated in the fed state compared with the fasting state, but the rate at which lipogenesis can increase with meal consumption is currently unknown. OBJECTIVE The objective was to quantify the diurnal pattern of lipogenesis after 2 consecutive mixed meals were fed to healthy men (n = 8). DESIGN A liquid diet was administered after a 12-h fast. During the fasting and postprandial periods, serum insulin, glucose, triacylglycerol, and nonesterified fatty acid concentrations were measured, and rates of DNL were quantified via intravenous infusion of [1-(13)C] sodium acetate and mass isotopomer distribution analysis. RESULTS The temporal pattern of postprandial lipogenesis was similar in all subjects. Lipogenesis rose significantly from 4.7 +/- 3.3% at fasting, peaked at 18.2 +/- 7.1% after meal 1 (P = 0.003 compared with fasting), rose further to 23.1 +/- 8.9% after meal 2 (P = 0.01 for difference between meals), and then decreased toward baseline (P < 0.001). Lipogenesis peaked 4.2 h after the meals; lipoprotein-triacylglycerol concentrations peaked sooner, 2.0 h after the meals (P < 0.02). Maximum postprandial DNL ranged from 10.3% to 37.5%. Peak insulin concentrations after meal 1 correlated with peak DNL (R = 0.838, P = 0.037), although the leanest subjects had some of the highest rates of postprandial DNL. CONCLUSION These data confirm the acute stimulation of DNL after meals in healthy subjects and validate the contribution of this pathway to elevations in triacylglycerol concentration.
Defined by Her Dying, Not Her Death: The Guardian ad Litem's View of Schiavo

One of the most controversial legal and political events in the death of Theresa Marie Schiavo was the passage, by the Florida Legislature, of what become known as "Terri's Law," allowing the Florida Governor to replace her feeding and hydration tube, and requiring the appointment of a special guardian ad litem who reported to the Governor and the courts. In this article, that appointed guardian ad litem shares distinctive experiences and observations about artificial nutrition and hydration and about other related circumstances in Ms. Schiavo's case.
Altered Cerebral Perfusion in Executive, Affective, and Motor Networks During Adolescent Depression

Objective Although substantial literature has reported regional cerebral blood flow (rCBF) abnormalities in adults with depression, these studies commonly necessitated the injection of radioisotopes into subjects. The recent development of arterial spin labeling (ASL), however, allows noninvasive measurements of rCBF. Currently, no published ASL studies have examined cerebral perfusion in adolescents with depression. Thus, the aim of the present study was to examine baseline cerebral perfusion in adolescent depression using a newly developed ASL technique: pseudocontinuous arterial spin labeling (PCASL). Method A total of 25 medication-naive adolescents (13–17 years of age) diagnosed with major depressive disorder (MDD) and 26 well-matched control subjects underwent functional magnetic resonance imaging. Baseline rCBF was measured via a novel PCASL method that optimizes tagging efficiency. Results Voxel-based whole brain analyses revealed significant frontal, limbic, paralimbic, and cingulate hypoperfusion in the group with depression ( p p p Conclusions Adolescents with depression and healthy adolescents appear to differ on rCBF in executive, affective, and motor networks. Dysfunction in these regions may contribute to the cognitive, emotional, and psychomotor symptoms commonly present in adolescent depression. These findings point to possible biomarkers for adolescent depression that could inform early interventions and treatments, and establishes a methodology for using PCASL to noninvasively measure rCBF in clinical and healthy adolescent populations.
Spontaneous occurrence of a synchronous hermaphrodite in the banded killifish, Fundulus diaphanus (Lesueur)

An intersex specimen of the banded killifish, Fundulus diaphanus, was encountered during the analysis of the annual gametogenic cycle of this species. The simultaneous presence of mature spermatozoa and ova suggests that the potential for self-fertilization existed in this fish. The spontaneous occurrence of this intersex individual, although a rare event, indicates the potential for the development of the synchronous hermaphroditic condition under natural environmental conditions in this normally gonochoristic species.
Feynman-diagram models of fermion daughter regge trajectories

Some Feynman-diagram models of Regge poles are used to study daughter trajectories of fermions in backward pion-nucleon scattering. Both the simple model with bare propagators and a generalized model that includes propagator self-energy insertions are considered. It is found that, in the simple model, the first daughter is a fixed (as a function of the squared momentum transfer $u$) double pole in the complex $J$ plane. When self-energy corrections to the propagator are included, the fixed double pole breaks up into a moving daughter trajectory and a moving companion trajectory. It is found that away from $u=0$, the daughter and companion trajectories get mixed up in a complicated and model-dependent manner.
Targeting the COX-2 Pathway to Improve Therapeutic Response in the Obese Breast Cancer Patient Population

Multiple studies have demonstrated that obesity is associated with a worse outcome for all breast cancer subtypes and that obese breast cancer patients do not respond as well as normal weight patients to aromatase inhibitor treatment and chemotherapy. While a number of mechanisms have been proposed to explain this link, recent studies have provided evidence that elevated local cyclooxygenase-2 (COX-2) expression and the resulting increase in prostaglandin E2 (PGE2) production may play an important role. COX-2 upregulation in breast tumors is associated with a poor prognosis, a connection generally attributed to PGE2's direct effects on apoptosis and invasion as well as its stimulation of pre-adipocyte aromatase expression and subsequent estrogen production. Research in this area has provided a strong foundation for the hypothesis that COX-2 signaling is involved in the obesity-breast cancer link, and further study regarding the role of COX-2 in this link is warranted.
On lattices of varieties of restriction semigroups

The left restriction semigroups have arisen in a number of contexts, one being as the abstract characterization of semigroups of partial maps, another as the ‘weakly left E-ample’ semigroups of the ‘York school’, and, more recently as a variety of unary semigroups defined by a set of simple identities. We initiate a study of the lattice of varieties of such semigroups and, in parallel, of their two-sided versions, the restriction semigroups. Although at the very bottom of the respective lattices the behaviour is akin to that of varieties of inverse semigroups, more interesting features are soon found in the minimal varieties that do not consist of semilattices of monoids, associated with certain ‘forbidden’ semigroups. There are two such in the one-sided case, three in the two-sided case. Also of interest in the one-sided case are the varieties consisting of unions of monoids, far indeed from any analogue for inverse semigroups. In a sequel, the author will show, in the two-sided case, that some rather surprising behavior is observed at the next ‘level’ of the lattice of varieties.
Fibroblast growth regulatory factor inhibits DNA synthesis in BALB/c 3T3 cells by arresting in G1

Abstract A cell surface macromolecular component from quiescent BALB/c 3T3 mouse cells (designated fibroblast growth regulatory factor, FGRF) inhibits DNA synthesis and cell division in growing 3T3 cells. Addition of FGRF to synchronized populations of growing 3T3 cells in the late G1 or early S phase did not inhibit DNA synthesis in the immediate S phase. However, a significant inhibition was observed in the S phase of the next round of cell cycle. Cells exposed to the regulatory factor in late S/early G2 or early G1 showed reduced DNA synthesis in the upcoming S phase; the late S/early G2 cells were more sensitive to inhibition than the cells in the G1. Further, the regulatory factor delayed the progression of G 0 G 1 -arrested cells into the next S phase. These results suggest that the physiological effect of FGRF is to arrest cells in early G1, thus preventing their entry into a new round of cell cycle. In contrast to untransformed 3T3 cells, mouse cells transformed by SV40 were not subjected to growth-arrest by the regulatory factor, although the transformed cells contain active FGRF that inhibits DNA synthesis in growing 3T3 cells.
Optical properties and band structure of III–V compounds and alloys

Abstract A brief review of selected band structure calculations pertinent to III–V compounds and alloys is given and a simplified representation of alloy band structures is developed. Then measurement techniques and selected examples of these measurements are given for various types of band structure. Absorption, luminescence, and modulated reflectance measurements are discussed for the direct band gap; absorption, modulated absorption, luminescence measurements for the indirect gap; and modulated absorption measurements for subsidiary conduction bands.
Evolution of haplodiploidy: models for inbred and outbred systems.

Several new models are proposed for the evolution of haplodiploidy. Each of these models is evaluated for its ability to explain (1) special problems associated with transition to haplodiploidy from a population of diplodiploid progenitors, (2) current patterns of population structure in haplodiploid and related species, and (3) the evolution of genetic systems similar but not identical to haplodiploid systems. Of the new models, three are based on special conditions associated with inbreeding. Close inbreeding provides for the automatic effects of reduced problems in expressing recessives, lowered differences in gain from heterozygosity (to produce both heterotic effects and a greater variety of offspring) between haploid and diploid males, effective protection of haploids from direct competition with diploids, and a mechanism for the spread of haplodiploidy through gains derived from increased ability to control sex ratio. These models differ in the context where gain from sex ratio control is expressed. Pathways for the evolution of haplodiploidy in outbreeding populations are also discussed. Females who parthenogenetically produce haploid males have high genetic relatedness to their sons. If the sperm of these males is used to make both sons and daughters, i.e., through matings with diplodiploid females, there may be a net gain for haplodiploids. Another outbreeding model, modified from S. W. Brown (1964, Genetics 49, 797-817), deals with selection for females producing haploid males in populations where there are driving sex chromosomes. Biases created by drive in sex ratio may allow haplodiploid females to be the only effective producers of males in the population. Several of the new models explain the whole range of haplodiploid and related adaptations and provide predictions that appear to be more consistent with the known structure of contemporary populations than those available in current models.
The effect of periradicular endodontic pathosis on the apical region of adjacent implants

Implants have become standard for dentate individuals. A potential problem to consider is implant lesions from microbial contamination; these may occur if there is not careful diagnosis and treatment planning. A factor of concern during treatment planning is the pulpal and periradicular condition of teeth adjacent to the implant site. Periradicular pathosis may jeopardize the implant. Therefore, if endodontic pathosis is identified, root canal treatment or extraction should be initiated before implant placement to prevent microbial contamination of the implant during healing. In reviewing clinical cases, the authors found several that illustrated problems with adjacent teeth that contributed to inflammation surrounding the implant.
Investigation of pyrolysis residues of poly(amino acids) using matrix assisted laser desorption ionization-time of flight-mass spectrometry

Abstract Matrix assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) has been used to analyze the pyrolysis products of poly(proline), poly(phenylalanine), poly(leucine) and methionine enkephalin-Arg-Phe oligopeptide. Each was individually pyrolyzed in a quartz tube in the temperature range of 245–285 °C using a nitrogen atmosphere. After pyrolysis, the residue in the pyrolysis tube was removed and analyzed by MALDI-TOF-MS. Based on a difference of 18 mass units between the major peaks from the original peptides and the pyrolysis residues, cyclic oligomers were postulated. Digestion of the pyrolysis residues with cyanogen bromide, which selectively cleaves methionine-containing peptides, was used to substantiate the presence of cyclic product in the pyrolyzates.
Direct gas-chromatographic resolution of dl-myo-inositol 1-phosphate and other sugar enantiomers as simple derivatives on a chiral capillary column

Abstract A commercially available, chiral stationary-phase was used to separate sugar enantiomers. Derivatives commonly used for the gas chromatography of carbohydrates were employed. The most generally useful was found to be the per(heptafluorobutanoyl) derivative, in which form d - and l -arabinose, fucose, xylose, mannose, and chiro-inositol were well resolved. The d and l enantiomers of glucose were best separated as 6-O-trimethylsilyl-α-glucofuranose 1,2:3,5-bis(methaneboronate). dl -myo-Inositol 1-phosphate was well resolved as the 2,3,4,5,6-penta-O-(trimethylsilyl)-1-dimethylphosphate. Other derivatives were less well resolved, and some sugar enantiomers could not be separated by the means used.
Studies on Thyroglobulin-Specific Suppressor T Cell Function in Autoimmune Thyroid Disease*

T cell regulation of the generation of thyroglobulin plaque-forming cells (Tg PFC) and protein A plaque-forming cells (Prot A PFC) was investigated using lymphocytes from patients with autoimmune thyroid disease. T and B cell mixed cultures (T-B MC) were carried out without mitogenic or antigenic stimulation to identify physiological T cell effects in the system. Tg PFC were found in 8 (44‥) of 18 patients who had high titers of thyroglobulin antibody in their sera. Tg-specific and nonspecific immunoregulation by T cells from patients and normal subjects was studied using B cells from these eight patients in the T-B MC system. Remarkably lower values of Tg PFC induction compared to Prot A PFC induction were found after T cell addition. Normal T cells inhibited Tg PFC induction, but patient T cells did not, while the same extent of helper effects were found on Prot A PFC induction by the addition of patient and normal T cells. Irradiation (1500 rads) of T cells from patients and normal subjects significant...
T-CUP: A New High-Pressure Apparatus for X-ray Studies

T-cup is a miniature 6-8 multianvil apparatus designed to fit in a 250 ton hydraulic press, and modified to provide x-ray access. When used with eight 10 cm tungsten carbide cubes with 2mm truncation, it has reached internal pressures of 22 GPa, and can be heated to at least 1500°C. It is a work in progress.
Semiparametric model for the dichotomized functional outcome after stroke: The Northern Manhattan Study

The Northern Manhattan Study (NOMAS) is a prospective, population-based study. One of the goals of NOMAS is to characterize the functional status of stroke survivors over time after stroke. Based on generalized estimating equation models, previous parametric analysis showed that functional status declines over time and the trajectories of decline are different depending on insurance status. The two trends of functional status may not be linear, which motivates our semiparametric modeling. In this paper, we model the time trend nonparametrically, the associated covariates parametrically and an interaction term between the nonparametric time trend and a covariate. We consider both kernel weighted local polynomial-based and regression spline-based approaches for solving the semiparametric model, and propose a statistic to test for the interaction term. To evaluate the performance of the parametric model in the case of model misspecification, we study the bias and efficiency of the estimators from misspecified parametric models. We find that when the adjusted covariates are independent of the time, and the link function is identity, the estimators for those covariates are asymptotically unbiased, even if the time trend is misspecified. In general, however, under other conditions and nonidentity link, the misspecified parametric estimators are biased and less efficient even when they are unbiased. We compute the ARE and also conduct simulation studies and compare power for testing the adjusted covariate when the time trend is modeled parametrically versus nonparametrically. In the simulation studies, we observe significant gain in power of those semiparametric model-based estimators compared to the parametric model-based estimators in the cases when the time trend is nonlinear.
Predictors of coping with pain in mothers and their children with sickle cell syndrome.

ABSTRACT Objective This study examined predictors of strategies used to cope with pain in children with sickle cell disease and their mothers. Method Disease severity, socioeconomic status, child adjustment and adaptive behavior, maternal psychopathology, and family functioning were examined in 55 mother-child dyads to determine the predictive potential of these factors on engagement and disengagement coping. Results While controlling for socioeconomic status and psychopathology in the mothers, 15% of the variance in engagement coping was predicted by family adaptability. Disengagement coping was predicted by internalizing symptoms exhibited by the child, including a negative and pessimistic attributional style, which accounted for nearly one fifth of the variance. Finally, mothers who reported more active strategies for coping with their child's pain were more likely to endorse greater use of techniques to prevent and effectively manage pain in their children. Conclusions Neither coping strategy was predicted by severity of disease presentation in the children, suggesting the importance of psychosocial factors in adapting to childhood chronic illness and that severity of disease may not necessarily be a marker for families at risk for adjustment difficulties. Findings were interpreted to support a systemic family model in promoting active and adaptive engagement coping in caretakers of children with sickle cell syndrome.
DNA topoisomerase II is required at the time of mitosis in yeast

We have constructed five new temperature-sensitive DNA topoisomerase II mutations and have analyzed their physiological consequences in yeast. Several lines of evidence suggest that the activity of topoisomerase II is required specifically at the time of miosis. First, top2 mutations cause dramatic lethality at the restrictive temperature, but only if the mutant cells are actively traversing the cell cycle. Second, temperature-shift experiments with synchronized cultures show that the onset of inviability coincides with the time of mitosis. Third, fluorescence microscopy reveals that the normal progression of mitosis is disturbed in mutant cells at the restrictive temperature. Finally, inviability at the restrictive temperature is prevented by nocodazole, an inhibitor of tubulin polymerization that prevents formation of the mitotic spindle. These results are consistent with the hypothesis that the essential function of topoisomerase II is to allow the separation of intertwined chromosomal DNA molecules during mitosis.
A real-time electrical impedance based technique to measure invasion of endothelial cell monolayer by cancer cells.

Metastatic dissemination of malignant cells requires degradation of basement membrane, attachment of tumor cells to vascular endothelium, retraction of endothelial junctions and finally invasion and migration of tumor cells through the endothelial layer to enter the bloodstream as a means of transport to distant sites in the host1-3. Once in the circulatory system, cancer cells adhere to capillary walls and extravasate to the surrounding tissue to form metastatic tumors4,5. The various components of tumor cell-endothelial cell interaction can be replicated in vitro by challenging a monolayer of human umbilical vein endothelial cells (HUVEC) with cancer cells. Studies performed with electron and phase-contrast microscopy suggest that the in vitro sequence of events fairly represent the in vivo metastatic process6. Here, we describe an electrical-impedance based technique that monitors and quantifies in real-time the invasion of endothelial cells by malignant tumor cells. Giaever and Keese first described a technique for measuring fluctuations in impedance when a population of cells grow on the surface of electrodes7,8. The xCELLigence instrument, manufactured by Roche, utilizes a similar technique to measure changes in electrical impedance as cells attach and spread in a culture dish covered with a gold microelectrode array that covers approximately 80% of the area on the bottom of a well. As cells attach and spread on the electrode surface, it leads to an increase in electrical impedance9-12. The impedance is displayed as a dimensionless parameter termed cell-index, which is directly proportional to the total area of tissue-culture well that is covered by cells. Hence, the cell-index can be used to monitor cell adhesion, spreading, morphology and cell density. The invasion assay described in this article is based on changes in electrical impedance at the electrode/cell interphase, as a population of malignant cells invade through a HUVEC monolayer (Figure 1). The disruption of endothelial junctions, retraction of endothelial monolayer and replacement by tumor cells lead to large changes in impedance. These changes directly correlate with the invasive capacity of tumor cells, i.e., invasion by highly aggressive cells lead to large changes in cell impedance and vice versa. This technique provides a two-fold advantage over existing methods of measuring invasion, such as boyden chamber and matrigel assays: 1) the endothelial cell-tumor cell interaction more closely mimics the in vivo process, and 2) the data is obtained in real-time and is more easily quantifiable, as opposed to end-point analysis for other methods.
Evidence for changing positions of GABA neurons in the developing rat dentate gyrus.

In recent studies, we demonstrated a distinct change in the distribution of glutamate decarboxylase 67 (GAD67) mRNA-containing neurons within the rat dentate gyrus from embryonic day 20 (E20) to postnatal day 15 (PN15) (Dupuy and Houser, J Comp Neurol 1997;389:402–418). We also observed a similar changing pattern for cells with birthdates of many of the mature GAD-containing neurons in the dentate gyrus (Dupuy and Houser, J Comp Neurol 1997;389:402–418). These observations suggested that some early-appearing GABA neurons within the developing molecular layer of the dentate gyrus may gradually alter their positions to become the mature GABAergic cells along the inner border of the granule cell layer. The goal of the present study was to provide additional evidence for our hypothesis by demonstrating the spatial relationships between GAD-containing neurons and granule cells at progressively older ages during development. In this study, immunohistochemical or in situ hybridization methods for the localization of GAD67 or its mRNA were combined with bromodeoxyuridine birthdating techniques that labeled early-generated granule cells with birthdates on E17. At E20, GAD67-containing neurons were located above the granule cell layer that contained E17 birthdated granule cells. During the first two postnatal weeks, both GAD67 mRNA-containing neurons and early-born granule cells were primarily concentrated within the granule cell layer. Double-labeled neurons were rarely observed, and this suggests that these two groups are separate populations. By PN15-PN30, most GAD67 mRNA-containing neurons were distributed along the base of the granule cell layer, significantly below the E17 birthdated granule cells. These findings support our new hypothesis that mature GABA neurons along the inner border of the granule cell layer reach their positions by migrating or translocating through the developing granule cell layer. Hippocampus 1999;9:186–199. © 1999 Wiley-Liss, Inc.
Morphometric Changes in the Rat Optic Nerve Following Short-term Intermittent Elevations in Intraocular Pressure

PURPOSE. Intraocular pressure (IOP) fluctuations may occur in patients with glaucoma, but how these fluctuations affect axonal populations in the optic nerve and other structures in the eye has been difficult to assess. This study developed a rat model to evaluate the effect of intermittent controlled elevations in IOP on the morphology of the rat optic nerve. METHODS. IOP was transiently elevated for 1 hour on each of 6 days a week over 6 weeks with an adjustable vascular loop around the right topically anesthetized eye of Sprague-Dawley rats. IOP was measured by pneumatonometer before, immediately after, and at the end of 1 hour of treatment with ligature. Globes and optic nerve segments were prepared for histology and morphometry. RESULTS. Mean baseline IOP of 14.9 1.8 mm Hg increased to 35.3 2.6 mm Hg (P 0.001) during 1-hour treatments and returned to 15.0 2.2 mm Hg (P 0.84) 1 hour after completion. The contralateral untreated eyes had a mean IOP of 14.2 1.9 mm Hg at baseline and 14.6 1.9 mm Hg at the end of treatment. Nerve fiber layer thinning (22%‐25%) corresponded with a decrease (7%‐10%) in soma number in the ganglion cell layer. Optic nerves displayed axonal degeneration with a modest axon loss of 6% and increased expression of glial acidic fibrillary protein in astrocytes. CONCLUSIONS. Controlled daily 1-hour IOP elevations can be performed with an adjustable vascular loop in rats. After only 6 weeks, intermittent elevations in IOP produce changes in optic nerve consistent with early degeneration reported in chronic models of glaucoma. (Invest Ophthalmol Vis Sci. 2010; 51:6431‐6440) DOI:10.1167/iovs.10-5212
Regioselective synthesis of 6-amino- and 6-amido-6-deoxypullulans

Hydrophobically modified polysaccharides that contain amine and amide groups possess valuable features for drug delivery and other applications. These chemical groups are known to play a fundamental role in the biological activity of important polysaccharides. Pullulan is known for its non-toxicity and biocompatibility, therefore, we have applied the versatile Staudinger reaction for the synthesis of regioselectively substituted pullulan derivatives containing amine or amide groups with promise for biomedical applications. The synthesis began with the regioselective bromination of pullulan at C-6 with N-bromosuccinimide and triphenylphosphine, providing 6-bromo-6-deoxy-pullulan, which is soluble in a range of organic solvents and therefore is a dynamic intermediate for the synthesis of other pullulan derivatives. Azide displacement of bromide from 6-bromo-6-deoxy-pullulan esters yielded the corresponding 6-azido-6-deoxy-pullulan esters. Staudinger reduction of these azides efficiently and chemoselectively afforded the corresponding amino- or amidopullulans.
Methodological considerations in forecasting Saudi Arabian economic growth

Abstract The author surveys a number of factors responsible for Saudi Arabian economic growth and concludes that, contrary to popular belief, the petroleum sectors have had more than just a short-run transitory stimulating impact on the domestic economy. It appears that changes in the level of exports (and resulting government expenditures) have a number of impacts on the non-oil sector of the economy which take some time for their full effect to be felt. Government expenditures have become somewhat independent of current oil exports, so the current oil glut and falling revenues for Saudi Arabia are not likely to be translated into slower non-oil income growth.
The Effect of Crystallographic Imperfections on the Photoluminescence of ZnO Thin Films

ZnO thin films were synthesized by radio-frequency (RF) magnetron sputtering of high purity ZnO solid targets on sapphire substrates. Depositions were carried out at selected temperatures between 293 K and 1173 K, and post-deposition annealing was performed at 1173 K for 3 min. in an O 2 atmosphere. Samples for electron microscopy investigations were prepared by lift-out technique in a multi-beam FIB/SEM instrument. The ZnO thin films show generally uniform thickness (about 1µm), determined by transmission electron microscopy (TEM) imaging. Irrespective of the deposition temperature, the ZnO thin films are polycrystalline, with individual grains exhibiting columnar morphology with the long axis oriented perpendicular to the ZnO/sapphire interface. The grain size varies with the deposition temperature, and a direct correlation between grain size and photoluminescence has been observed. Analyses performed using low-temperature photoluminescence spectroscopy measurements at 12 K revealed luminescence peaks at 3.361, 3.317, 3.218 and 3.115 eV. The intensity of the luminescence peak at 3.317 eV decreased with increasing deposition temperature. The films deposited at lower temperatures also exhibited a higher density of stacking faults as observed from the atomic resolution TEM. The crystallographic imperfections/photoluminescence relationship is not clear. The purpose of this study is to quantify the observed crystallographic imperfections and understand their effect on the photoluminescence of undoped ZnO thin films deposited on sapphire substrates.
Simulation of particle size distribution in an aggregation-breakup process

A study is made to examine the dependence of the steady-state PSD (Particle Size Distribution) on its initial distribution and the possible existence of multiple steady-state PSDs. Estimates are also computed for the time required for different initial PSDs to reach steady state in a batch flocculation
A comparison of tripolar concentric ring electrode and spline laplacians on a four-layer concentric spherical model

We have simulated a four-layer concentric spherical head model. We calculated the spline and tripolar Laplacian estimates and compared them to the analytical Laplacian on the spherical surface. In the simulations we used five different dipole groups and two electrode configurations. The comparison shows that the tripolar Laplacian has higher correlation coefficient to the analytical Laplacian in the electrode configurations tested (19, standard 10/20 locations and 64 electrodes).
Stock reaction to dividend savings of convertible preferred calls: Free cash flow or price pressure effects?

Abstract Calls of in-the-money convertible preferred stock typically induce dividend savings for the firm, since preferred dividends exceed common stock dividends. Prior research finds that these savings are negatively related to stock returns at call announcement and argues that the market expects managers to abuse the increased free cash flow. This paper finds that dividend savings are closely related to call size, suggesting other explanations. Larger calls experience a more negative announcement reaction. Consistent with temporary liquidity effects, there is a price reversal during the conversion period, which is greater for larger calls.
Ion-exchange chromatography of sulfur amino acids on a single-column amino acid analyzer.

Abstract Examination of the extent of production of the ninhydrin-colored derivative, Ruhemann's purple, under automated conditions of a single-column amino acid analyzer by several classes of sulfur-containing amino acids revealed a wide variation in the color factors relative to leucine. These ranged from 0.02 for the methyl ester of cysteine to 2.19 for D-homocystine. Color yields obtained by the manual ninhydrin reaction are generally lower than the corresponding values obtained on the amino acid analyzer. The elution positions ranged from 5.12 min for cysteic acid to 84.9 min for l -cystine dimethyl ester. The observed behavior of these compounds in the ninhydrin reaction is rationalized in terms of structural and electronic factors which they exhibit in reacting with ninhydrin to form the visible dye. Such an analysis should make it possible to predict ninhydrin color factors, and possibly also elution times, of structurally related compounds.
Greedy dirty models: A new algorithm for multiple sparse regression

This paper considers the recovery of multiple sparse vectors, with partially shared supports, from a small number of noisy linear measurements of each. It has recently been shown that it is possible to lower the sample complexity of recovery, for all levels of support sharing, by using a “dirty model”: a super-position of sparse and group-sparse modeling approaches; this is based on convex optimization.
Pharmacokinetics of WR-1065 in mouse tissue following treatment with WR-2721.

Abstract Levels of reduced glutathione (GSH) and N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065) were measured in tissues of Balb/c mouse bearing EMT 6 tumors at time intervals ranging from 5 min to 48 hr after i.v. injection of S-2-(3-aminopropylamino)ethyl phosphorothioate (WR-2721) at 500 mg per kg. In all tissues examined (liver, kidney, lung, heart, muscle, brain, tumor, spleen, and salivary gland), maximal WR-1065 levels occurred 5–15 min after injection, with levels in liver, kidney, lung, and salivary gland exceeding one μmole per gm. The post-maximum decline in WR-1065 varied markedly with tissue, lung exhibiting a 6-fold drop by 30 min and salivary gland falling only 1596 after 3 hr. In a mouse treated with carbon-14 labeled WR-2721 it was found after 15 min that WR-1065 accounted for over half of the total drug in all tissues except tumor, where it accounted for a third of the total drug. There was no evidence that GSH levels were substantially altered by WR-2721 treatment. The results provide the first direct evidence supporting the widely held view that WR-2721 treatment results in intracellular WR-1065 and they demonstrate that high levels of WR-1065 occur very soon after i.v. injection.
Stochastic petri nets modeling using spn

This paper introduces SPN@, a tool for the graphical modeling of intricate dynamics scenarios relevant to safety, reliability, and availability. Implemented in SPN@ is a novel concept of aging tokens, enhancing colored stochastic Petri net formalism, and providing a visual and practical means for assessing complex dynamic scenarios. The examples provided serve to indicate a wide range of practical applications of SPN@, including a classical problem of shared load, repairable system with parallel tasks, and modeling of a system that undergoes both preventive and corrective maintenance with the associated consideration of risk trade offs
Internet-Based Medical Education

The Internet is revolutionizing medical education and medical practice by enabling teachers and students to utilize and integrate many forms of data in ways that cannot be done via classic textbooks. In cardiovascular medicine, dynamic images are essential for understanding cardiac function, coronary anatomy, and myocardial perfusion, as well as for learning cardiovascular pathophysiology and the typical and atypical presentations of disease states. Cardiosource, an educational Web site developed by the American College of Cardiology, illustrates the ways in which the Internet is being used to improve medical education and practice.
Quenching of Lattice Vacancies in Pure Silver

Quenching data on 99.999% pure silver gives the energy required to form a lattice vacancy to be 1.10\ifmmode\pm\else\textpm\fi{}0.04 ev. In addition, the data of Simmons and Balluffi (who obtained the vacancy concentration in equilibrium near the melting temperature) together with present data give the resistivity increase per atomic percent vacancies to be 1.3\ifmmode\pm\else\textpm\fi{}0.7 micro ohm cm.
Targeted delivery of therapeutics to endothelium

The endothelium is a target for therapeutic and diagnostic interventions in a plethora of human disease conditions including ischemia, inflammation, edema, oxidative stress, thrombosis and hemorrhage, and metabolic and oncological diseases. Unfortunately, drugs have no affinity to the endothelium, thereby limiting the localization, timing, specificity, safety, and effectiveness of therapeutic interventions. Molecular determinants on the surface of resting and pathologically altered endothelial cells, including cell adhesion molecules, peptidases, and receptors involved in endocytosis, can be used for drug delivery to the endothelial surface and into intracellular compartments. Drug delivery platforms such as protein conjugates, recombinant fusion constructs, targeted liposomes, and stealth polymer carriers have been designed to target drugs and imaging agents to these determinants. We review endothelial target determinants and drug delivery systems, describe parameters that control the binding of drug carriers to the endothelium, and provide examples of the endothelial targeting of therapeutic enzymes designed for the treatment of acute vascular disorders including ischemia, oxidative stress, inflammation, and thrombosis.
Studies on the Biochemistry and Fine Structure of Silica Shell Formation in Diatoms. Chemical Composition of Navicula pelliculosa during Silicon-Starvation Synchrony

Changes are reported in total cellular organic carbon, nucleic acids, proteins, carbohydrates, lipids and chlorophylls during the course of silicon-starvation synchrony of Navicula pelliculosa. All constituents increased at the same rate, relative to cell number, for 30 hours of exponential growth during which silicon was depleted from the medium. Increase in cell number then stopped, but net synthesis of most components continued for a further 5 to 7 hours before ceasing. Deoxyribonucleic acids and lipids accumulated throughout the 14 hour silicon-starvation period. When silicon was resupplied, lipid synthesis ceased and organic carbon and carbohydrates decreased slightly. Net synthesis remained low during the 4 hour silicon uptake period but was resumed at higher rates as cell number began to rise. In cultures transferred to the dark 1 hour prior to readdition of silicon, total carbon, carbohydrates, and lipids decreased markedly during silicon uptake and cell separation. This was due in part to conversion of protein which maintained the protein level of the dark cells close to that of cells kept in the light. Mechanisms by which silicon starvation and reintroduction of silicon might affect rates of cellular synthesis are discussed.
Overwintering of thrips (Thysanoptera: Thripidae) in North Carolina

Based on field cage studies, Frankliniella occidentalis (Pergande) successfully overwintered and reproduced during the winter months in North Carolina. A field survey for thrips vectors of tomato spotted wilt virus (TSWV) was conducted during the winter and spring of 1990–1991 and 1991–1992 in North Carolina. Plant, litter, and soil samples were collected from three geographically distinct regions in North Carolina. Plant samples included 51 wild host species and five winter crops. Three species of TSWV vectors, Frankliniella fusca (Hinds), F. occidentalis , and Thrips tabaci Lindeman, were collected from plant samples. F. fusca was the most abundant TSWV vector in plant samples and was collected from 30 wild host species and five winter crops. Few F. occidentalis and T. tabaci were collected from plant samples. T. tabaci was the most abundant vector collected from litter samples, and F. occidentalis was the second most abundant. Very few thrips were recovered from soil samples. Terebrantia thrips larvae were collected from 28 wild host species, five winter crops, and litter samples. In addition to TSWV vectors, 23 thrips species in the family Thripidae and 1 species in the family Merothripidae were collected from wild hosts, winter crops, or litter samples. The highest number of thrips species were observed in litter samples.
Attachment and Shell Integrity Affects the Vulnerability of Zebra Mussels (Dreissena polymorpha) to Predation

ABSTRACT We investigated the relationship between prey condition and predation vulnerability in the zebra mussel (Dreissena polymorpha). In aquarium experiments with rusty crayfish (Orconectes rusticus), a known predator of the zebra mussel, both removal of the zebra mussels from their substrata and damage to their shells significantly increased their vulnerability to predation. This result was corroborated in open-water trials in Douglas Lake, Michigan, USA. The effect of shell damage on predation of the mussels was less pronounced in the lake than in the laboratory, probably owing to the presence in the lake of alternative prey items for predators. In the lake trials, there was a significant negative correlation between predation and the distance the samples were set from the shoreline. Although zebra mussels can be important food items for molluscivore predators, their vulnerability to predators which use chemical cues such as rusty crayfish appears to be directly related to the integrity of the mussel...