cssi/SciSciGPT-SciSciNet huggingface dataset:
Targeted Delivery of Gemcitabine to Pancreatic Adenocarcinoma Using Cetuximab as a Targeting Agent

One of the key challenges in anticancer therapy is the toxicity and poor bioavailability of the anticancer drugs. Nanotechnology can play a pivotal role by delivering drugs in a targeted fashion to the malignant cells that will reduce the systemic toxicity of the anticancer drug. In this report, we show a stepwise development of a nanoparticle-based targeted delivery system for in vitro and in vivo therapeutic application in pancreatic cancer. In the first part of the study, we have shown the fabrication and characterization of the delivery system containing gold nanoparticle as a delivery vehicle, cetuximab as a targeting agent, and gemcitabine as an anticancer drug for in vitro application. Nanoconjugate was first characterized physico-chemically. In vitro targeting efficacy, tested against three pancreatic cancer cell lines (PANC-1, AsPC-1, and MIA Paca2) with variable epidermal growth factor receptor (EGFR) expression, showed that gold uptake correlated with EGFR expression. In the second part, we showed the in vivo therapeutic efficacy of the targeted delivery system. Administration of this targeted delivery system resulted in significant inhibition of pancreatic tumor cell proliferation in vitro and orthotopic pancreatic tumor growth in vivo. Tumor progression was monitored noninvasively by measuring bioluminescence of the implanted tumor cells. Pharmacokinetic experiments along with the quantitation of gold both in vitro and in vivo further confirmed that the inhibition of tumor growth was due to targeted delivery. This strategy could be used as a generalized approach for the treatment of a variety of cancers characterized by overexpression of EGFR.
Effect of potassium and magnesium deficiency on the electrocardiogram and plasma electrolytes of pure-bred beagles☆

Abstract The effect of K+ or Mg++ deficiency, or both, upon the electrocardiogram and plasma electrolytes has been studied in young pure-bred beagle dogs maintained on selected diets for eight weeks. K+ deficiency, in addition to resulting in the known electrocardiographic changes, caused a rise in serum Mg++ and hypokalemia. Mg++ deficiency resulted in a peaking of the T wave similar to that seen in hyperkalemia, although serum K+ was normal. In doubly deficient dogs diphasic T waves developed with marked terminal inversions. In two Mg++ deficient dogs, maintained on the diet for an additional seven months, hypokalemia developed as well as changes in the electrocardiogram indistinguishable from those seen in doubly deficient animals.
Reaching At-Risk Students Through Music Education

Unfortunately, most discussions sur rounding at-risk students focus on remedying deficiencies in "basic skills, " often defined narrowly as English literacy and the ability to per form mathematical computations. However, music and the other arts play an important part in reaching and retaining at-risk secondary students.
Ideological Budgeting: The Influence of Political Philosophy on Public Policy

Influences of Ideology The Concept of Political Ideology Specific Ideologies: Nationalism, Communism, Socialism, Capitalism, Fascism, and Democracy Contemporary American Belief Systems Ideologies and Budget Policy Ideological Influences on Budget Outputs Rational versus Political Budgeting Bibliography Index
Mathematical Morphology in Multi-Dexel Representation

Mathematical morphology provides a set-theoretic approach for spatial structure analysis and is particularly useful for describing the spatial relationship between a tool under motion and the part surface. However, its usage in three-dimension has so far been limited in part due to its computational complexity. This paper presents a multi-dexel based computer implementation of morphology operations. Three dimensional objects (tools and parts) are represented as collections of dexels (depth elements) in multiple directions. Morphology operations such as dilation and erosion are then converted to a series of 1D set operations in each direction. We show that our definition of multi-dexel is formal and our implementation is complete. We present our implementation results on three morphological applications: AFM image simulation, noise removal in 3D mesh, and NC path generation.Copyright © 2009 by ASME
Segmenting full-length VBR video into shots for modeling with Markov-modulated gamma-based framework

All traffic models for MPEG-like encoded variable bit rate (VBR) video can be categorized into (i) data rate models (DRMs), and (ii) frame size models (FSMs). Almost all proposed VBR traffic models are DRMs. Since DRMs generate only data arrival rate, they are good for estimating average packet-loss and ATM buffer over-flowing probabilities, but fail to identify such details as percentage of frames affected. FSMs generate sizes of individual MPEG frames, and are good for studying frame loss rate in addition to data loss rate. Among three previously proposed FSMs: (i) one generates frame sizes for full-length movies without preserving GOP-periodicity; (ii) another generates frame sizes for full-length movies without preserving size-based video-segment transitions; and (iii) the third generates VBR video traffic for news videos from scene content description provided to it presupposing a proper segmentation. In this paper, we propose two segmentation techniques for VBR videos - (a) Equal Number of GOPs in all shot classes (ENG), and (b) Geometrically Increasing Interval Lengths for shot classes (GIIL). Each technique partitions the GOPs in the video into size-based shot classes. Frames in each class produce three data-sets one each for I-, B-, and P-type frames. Each of these data-sets can be modeled with an axis shifted Gamma distribution. Markov renewal processes model interclass transitions. We have used QQ plots to show visual similarity of model-generated VBR video data-sets with original data-set. Leaky-bucket simulation study has been used to show similarity of data and frame loss rates between model-generated videos and original video. Our study of frame-based VBR video revealed GIIL segmentation technique separates the I-, B-, and P- frames in well behaved shot classes whose statistical properties can be captured by Gamma-based models.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The binding of pyridoxamine 5-phosphate to alanine aminotransferase as measured by fluorescence spectroscopy

The interaction between pyridoxamine 5-phosphate and alanine aminotransferase (l-alanine:2-oxoglutarate aminotransferase, EC 2.6.1.2) was investigated by fluorescence spectroscopy. The cofactor bound to the catalytic site of the enzyme is subject to environmental perturbations which cause a blue shift of 17 mμ in the band position of the emission spectrum, a 10-fold decrease in the fluorescence yield and a uniform increase in the polarization of fluorescence values. An analysis of the results of polarization of fluorescence according to Perrin's equation indicates that pyridoxamine 5-phosphate has rotational flexibility when bound to the catalytic site of the enzyme alanine aminotransferase. Since the fluorescence properties of the cofactor are sensitive to conformational changes of the enzyme, it was possible to investigate the mechanism of inhibition by p-mercuribenzoate and obtain further information on the functional role of the reactive sulfhydryl groups of the enzyme alanine aminotransferase.
Codon bias evolution in Drosophila. Population genetics of mutation-selection drift

Although non-random patterns of synonymous codon usage are a prominent feature in the genomes of many organisms, the relatives roles of mutational biases and natural selection in maintaining codon bias remain a contentious issue. In some species, patterns of codon bias and empirical findings on the biology of translation suggest 'major codon preference', a balance among mutation pressure, genetic drift, and weak selection in favor of translationally superior codons. Population genetics theory makes testable predictions to distinguish such a model from a strictly mutational model of codon bias. Major codon preference predicts two fitness classes of synonymous DNA changes: 'preferred' mutations from non-major to major codons and 'unpreferred' changes in the opposite direction. An extension of current statistical methods is employed to reveal differences in the within and between species dynamics of preferred and unpreferred silent mutations in Drosophila simulans. In this lineage, codon bias appears to be maintained under roughly equal magnitudes of natural selection and genetic drift. In the sibling species, D. melanogaster, however, a reduction in N(e)s, the product of effective population size and selection coefficient, appears to have allowed a genome-wide reduction in codon bias.
Vitamin D status and concomitant autoimmunity in celiac disease.

Goals To determine whether patients with celiac disease and low vitamin D levels also have a higher prevalence of other autoimmune diseases (AD) as compared to patients with normal vitamin D levels.
Effect of In-Cylinder Liquid Fuel Films on Engine-Out Unburned Hydrocarbon Emissions for an SI Engine

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2011.
Cellular solutions for highly nonequilibrium directional solidification

We compute numerically the cellular shape expected for the directional solidification of CBr/sub 4/, at velocities far above the threshold for the Mullins-Sekerka instability. Our cell has a smooth tip plunging to a deep narrow channel which ends with a small liquid bubble. Our results are compared to the experimental findings of S. de Cheveigne, C. Guthmann, and M. M. Lebrun (J. Phys. (Paris) 47, 2095 (1986)).
The Effect of Potassium on the Occurrence of Petechial Hemorrhages in Renal Hypertensive Rabbits

Administration of extra potassium to rabbits with renal hypertension reduces the incidence and severity of petechial hemorrhages. It also enables the animals to sustain higher blood pressure levels. Potassium apparently protects the vascular system to some extent against the damage caused by hypertension.
Reactive atmosphere processing of oxides (Part II)

The application of the reactive atmosphere process (RAP) to rare-earth oxides to suppress OH− impurity introduction is extended to the reduction of the higher oxide. A marked difference in the action of H2 and CO is shown in the reduction of Tb4O7 to Tb2O3.
Cardiovascular effects of antiretroviral therapy and noninvasive assessments of cardiovascular disease in HIV infection.

The heart is frequently affected in patients with the acquired immune deficiency syndrome (AIDS). Although the introduction of potent antiretroviral therapy (ART) has produced a sharp decline in mortality and morbidity in HIV-infected patients, the use of ART is associated with the development of peripheral insulin resistance, dyslipidemia, and lipodystrophy. These abnormalities are also associated with coronary artery disease, and numerous reports of myocardial infarction in young HIV-infected patients have raised concerns of premature coronary disease in this population. A comprehensive review of the epidemiology of coronary artery disease is given. In recent years, several noninvasive methods to detect early development of atherosclerosis have been evaluated. Two noninvasive techniques using ultrasound have emerged as valid methods to detect early development of atherosclerosis: intima-media thickness and endothelial dysfunction assessed by the measurement of flow-mediated brachial artery dilatation. Multicenter, randomized trials using either technique may provide more information about whether HIV infection alone, long-term HAART use, or both may increase the risks of or accelerate coronary disease in HIV-infected patients.
Blood Aldosterone-to-Renin Ratio, Ambulatory Blood Pressure, and Left Ventricular Mass in Children

Objective To assess the blood aldosterone-to-renin ratio (ARR) and its relationship to ambulatory blood pressure (ABP) and left ventricular mass (LVM) in children. Study design A cross-sectional clinical study was conducted in 102 children (71.6% African American; 62.7% male) ranging in age from 7 to 18 years (mean, 13.6 years; median, 14 years). ABP (24-hour monitoring) was expressed as blood pressure index (BPI; mean blood pressure/95th percentile by sex and height). LVM was measured by echocardiography and expressed as an index (LVMI = g/height [m] 2.7 ). Regression analyses were used to estimate associations. Results African-American children had significantly lower serum aldosterone concentration and plasma renin activity compared with European-American children (aldosterone: 5.9 ng/dL vs 11.4 ng/dL, P P = .01). However, ARR was not significantly different by race. ARR was not associated with 24-hour ABP but was significantly associated with LVMI (β = 0.4 g/m 2.7 ; P = .02) after adjustment for the ratio of 24-hour urine Na to creatinine excretion, body mass index z - score, and ABP index. Conclusions The data indicated a significant association between ARR and LVMI, but not ABP, in children, suggesting early cardiac remodeling associated with a high ARR.
Design of a robotic tool for percutaneous instrument distal tip repositioning

Manually performed image-guided percutaneous procedures are limited by targeting errors due to instrument misalignment, deflection and an inability to reposition the distal tip of the instrument after it has been percutaneously inserted. These limitations result in suboptimal instrument positioning that limits diagnosis and treatment for a variety of procedures as well as excessive procedure time and radiation dose (in the case of x-ray based imaging). Hence we are developing a robotic tool capable of repositioning the distal tip of a percutaneous instrument after a single insertion into the body. It is based on the concept of deploying a super-elastic pre-curved stylet from a concentric straight cannula. The proximal end of the cannula is attached to the distal end of a screw-spline that enables it to be translated and rotated with respect to the casing. Translation of the stylet relative to the cannula is achieved with a second threaded screw with a splined groove. The device is made of mostly plastic components and actuation is achieved using micro-stepper motors. Measurements of the maximum axial force for the cannula screw-spline and stylet screw were found to match those from design calculations. Evaluation of the mechanism positioning capability demonstrated sub-millimeter and sub-degree translation and angular accuracy. We foresee this robotic tool having wide application across a range of procedures such as biopsy, thermal ablation and brachytherapy seed placement.
Randomized controlled trial of physical activity, cognition, and walking in multiple sclerosis.

The present study adopted a randomized controlled trial design and examined the effect of a physical activity behavioral intervention on cognitive and walking performance among persons with MS who have mild or moderate disability status. A total of 82 MS patients were randomly allocated into intervention or wait-list control conditions. The intervention condition received a theory-based program for increasing physical activity behavior that was delivered via the Internet, and one-on-one video chat sessions with a behavior-change coach. Participants completed self-report measures of physical activity and disability status, and underwent the oral Symbol Digit Modalities Test (SDMT) and 6-minute walk (6MW) test before and after the 6-month period. Analysis using mixed-model ANOVA indicated a significant time × condition × disability group interaction on SDMT scores (p = 0.02, partial-η 2 = 0.08), such that persons with mild disability in the intervention condition demonstrated a clinically meaningful improvement in SDMT scores (~6 point change). There was a further significant time × condition interaction on 6MW distance (p = 0.02, partial-η 2 = 0.07), such that those in the intervention condition demonstrated an increase in 6MW distance relative to those in the control group. The current study supports physical activity as a promising tool for managing cognitive impairment and impaired walking performance in persons with MS, and suggests that physical activity might have specific effects on cognition and non-specific effects on walking performance in this population.
The decomposition of reinecke's salt, NH4[Cr(NH3)2(NCS)4]

Abstract The decomposition of Reinecke's salt takes place in two steps. In the first step, the observed mass loss corresponds to the loss of one NH3 and two HSCN molecules per molecule of complex. The process obeys the second order Coats and Redfern equation with an activation energy of 121 kJ mole−1. The second step also appears to be second order and leads to a product which has 23.0% of its original mass and corresponds to Cr(NH)(NH2).
Synthetic insulin-like growth factor II.

Summary Human insulin-like growth factor II with 67 amino acid residues and three disulfide bridges has been synthesized by the solid-phase method. Homogeneity of the synthetic product is ascertained by chromatofocusing, high performance liquid chromatography and amino acid analysis. In both radioimmunoassay and radioreceptor assay, the synthetic product is indistinquishable from the natural hormone.
Replication Factor C Disengages from Proliferating Cell Nuclear Antigen (PCNA) upon Sliding Clamp Formation, and PCNA Itself Tethers DNA Polymerase δ to DNA

Abstract Replication factor C (RF-C) and proliferating cell nuclear antigen (PCNA) assemble a complex, called sliding clamp, onto DNA. The clamp in turn loads DNA polymerases (pol) δ and e to form the corresponding holoenzymes, which play an essential role in replication of eukaryotic chromosomal DNA and in several DNA repair pathways. To determine the fate of RF-C after loading of PCNA onto DNA, we tagged the RF-C subunit p37 with a protein kinase A recognition motif, so that the recombinant five-subunit RF-C complex could be32P-labeled and quantitatively detected in femtomolar amounts. Nonspecific binding of RF-C to DNA was minimized by replacing the p140 subunit with an N-terminally truncated p140 subunit lacking the previously identified nonspecific DNA binding domain. Neither of these modifications impaired the clamp loading activity of the recombinant RF-C. Using gel filtration techniques, we demonstrated that RF-C dissociated from the DNA after clamp loading or pol δ holoenzyme assembly, while PCNA or PCNA·pol δ complex remained bound to DNA. PCNA catalytically loaded onto the template-primer was sufficient by itself to tether pol δ and stimulate DNA replication. The readdition of RF-C to the isolated PCNA·DNA complex did not further stimulate pol δ DNA synthesis. We conclude that pol δ holoenzyme consists of PCNA and pol δ core and that RF-C serves only to load PCNA clamp.
Brand-Extension Price Premiums: The Effects of Perceived Fit and Extension Product Category Risk:

One of the assumed benefits of extending a strong brand into a new product category is the ability to capture a price premium relative to comparable products associated with lower equity brands. The authors argue that brand-extension price premiums accrue in part due to the ability of a known brand to reduce the perceived risk customers experience in making purchase decisions. Accordingly, price premiums can be expected to vary depending on the risk associated with a purchase decision. The authors manipulated perceived fit between a brand and extension products and three dimensions of extension product category risk. They found that brand-extension price premiums are positively related to the perceived fit between the brand and the extension category. However, this relationship varies considerably depending on the levels of financial and social risk associated with the extension product category. Implications of these findings for theory, practice, and future research are discussed.
Psychopathology and defensive style of alcoholics as a function of congruence-incongruence between psychological differentiation and locus of control.

Witkin's psychological differentiation construct and Rotter's locus of control construct were studied independently and in interaction to assess their ability to predict psychopathology and defensive style in a sample of 160 adult, male alcoholics. As predicted, locus of control was significantly correlated with both psychopathology and defensive style and field articulation was significantly correlated with defensive style. However, the congruent and incongruent construct was not significantly related to either psychopathology or defensive style.
Inhibitors of Polyamine Biosynthesis Decrease the Expression of the Metalloproteases Meprin α and MMP-7 in Hormone-independent Human Breast Cancer Cells

Inhibition of ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, by the irreversible inhibitor alpha-difluoromethylornithine (DFMO) has been shown to decrease the invasiveness of metastatic human breast cancer cell lines. However, the mechanism by which DFMO acts to reduce invasiveness is unclear. Using the human breast cancer cell line MDA-MB-435, the effect of DFMO on metalloprotease gene expression was investigated. DFMO treatment decreases the expression of the metalloprotease meprin alpha, while concurrent treatment with DFMO and the polyamine putrescine partially restored meprin alpha expression levels. Expression of MMP-7 mRNA was reduced by DFMO, while MMPs-1, -2, -3, -14, and meprin beta were unaffected. Treatment of cells with a second inhibitor of polyamine biosynthesis, the S-adenosylmethionine decarboxylase (SAMDC) inhibitor SAM486A, also resulted in a dosage dependent decrease in meprin alpha and MMP-7 mRNA. In addition, DFMO treatment decreased meprin alpha at the protein level by 2 days of treatment, and MMP-7 protein levels at 4 and 6 days. Previous studies have shown that DFMO treatment increases ERK phosphorylation and signaling through the MAP kinase pathway. The decrease in meprin alpha expression was reversed with the MEK inhibitor PD98059, demonstrating that MAP kinase signaling mediates the effect of DFMO and SAM486A. MDA-MB-435 cells treated with the meprin alpha inhibitor actinonin (5 nM) were less invasive in vitro, indicating that meprin alpha is mechanistically involved in invasion. The decrease in meprin alpha expression in DFMO and SAM486A-treated cells indicates a means by which these compounds can decrease the invasiveness of metastatic breast cancer cells.
Concepts Are Not a Natural Kind

In cognitive psychology, concepts are those bodies of knowledge that are stored in long‐term memory and are used by default in human beings’ higher cognitive processes (categorization, inductive and deductive reasoning, etc.). Most psychologists of concepts assume that these mental representations share many scientifically important properties, and the psychology of concepts is expected to describe those properties. Psychologists assume thereby that concepts constitute a natural kind. I call this assumption the natural kind assumption. This article challenges the natural kind assumption. It is argued that a growing body of evidence suggests that concepts do not constitute a natural kind. Hence, the notion of concept is inappropriate, if one aims at formulating scientifically relevant inductive generalizations about the human mind.
On the sensitivity of radiative forcing from biomass burning aerosols and ozone to emission location

[1] Biomass burning is a major source of air pollutants, some of which are also climate forcing agents. We investigate the sensitivity of direct radiative forcing due to tropospheric ozone and aerosols (carbonaceous and sulfate) to a marginal reduction in their (or their precursor) emissions from major biomass burning regions. We find that the largest negative global forcing is for 10% emission reductions in tropical regions, including Africa (−4.1 mWm−2 from gas and −4.1 mWm−2 from aerosols), and South America (−3.0 mWm−2 from gas and −2.8 mWm−2 from aerosols). We estimate that a unit reduction in the amount of biomass burned in India produces the largest negative ozone and aerosol forcing. Our analysis indicates that reducing biomass burning emissions causes negative global radiative forcing due to ozone and aerosols; however, regional differences need to be considered when evaluating controls on biomass burning to mitigate global climate change.
Upper bounds for the arithmetical degrees

On montre qu'il y a une borne superieure d pour les degres arithmetiques tels que d'≥O(ω) mais d n'est pas le degre d'une borne superieure sous uniforme pour les ensembles arithmetiques. En consequence, ce degre n'est pas le degre d'un modele de Th(N). On compare les bornes superieures pour les degres arithmetiques en dessous de O ( ω) et les degres en dessous de O (2)
Qualitative reasoning in economics

Abstract We present a scheme for qualitative reasoning about economic systems. The fundamental element of our scheme is the market, a homeostatic entity that adjusts to restore equilibrium after perturbation. Complex theories are represented in terms of multiple markets, with their interaction realized by variables of one market being parameters to others. We define a simulation process, making it possible to reason about multiple-market models. Comparing final with initial values of market variables implements comparative statics. We define a process of backward reasoning from changes in variables as desired effects to parameter perturbations as possible causes. Our notions are illustrated by consideration of Keynesian IS-LM and general macroeconomic models.
Surface structures and electron affinities of bare and hydrogenated diamond C(100) surfaces

The structure and electronic properties of bare and H-terminated C(100)-2\ifmmode\times\else\texttimes\fi{}1 surfaces have been studied by ab initio molecular dynamics. Stable 2\ifmmode\times\else\texttimes\fi{}1 structures were found for both clean and monohydride-terminated surfaces. The 1\ifmmode\times\else\texttimes\fi{}1 dihydride phase is energetically unstable relative to ${\mathrm{H}}_{2}$ desorption, although a local minimum, consisting of canted dihydride pairs, was found. The bare diamond (100)-2\ifmmode\times\else\texttimes\fi{}1 surface has a positive electron affinity, while a negative electron affinity is obtained for both the 2\ifmmode\times\else\texttimes\fi{}1:H and 1\ifmmode\times\else\texttimes\fi{}1:2H surfaces. The existence of negative electron affinity for the diamond (100)-2\ifmmode\times\else\texttimes\fi{}1:H surface is in good agreement with recent experimental data.
Variability of coronary flow reserve obtained immediately after coronary angioplasty

Coronary flow reserve (CFR) improves in most patients immediately following coronary angioplasty (PTCA). The degree of improvement, however, may be variable and its predictive value for a favorable long-term angiographic result is unknown. To evaluate these issues, we used digital subtraction angiography to measure CFR in 15 patients before and immediately after PTCA. Minimum coronary diameter improved and percent diameter stenosis was reduced immediately following PTCA (from 0.75 ± 0.35 mm to 2.19 ± 0.56 mm, and from 74 ± 12% to 27 ± 15%, respectively; p<0.001). While CFR improved in patients immediately following PTCA (from 1.49 ± 0.75 to 2.68 ± 1.73; p<0.05), a substantial variability in CFR measurements (range 0.80 to 8.33) was present. At repeat arteriography 2.9 ± 0.6 months later, 4 patients demonstrated restenosis. Compared with the 11 patients without restenosis, those with restenosis had similar coronary dimensions and CFRs immediately following PTCA. We conclude that coronary flow reserve, determined by digital subtraction angiography, improves in most patients immediately after PTCA but the degree of improvement is variable. Its ability to predict long-term angiographic outcome remains uncertain.
Adaptability of the U.S. Industrial Relations System

An industrial relations system describes the basic values, laws, institutions, and organizational practices that govern employment relationships. To be effective, an industrial relations system must be well matched to its economic and social environment and able to meet the strategic needs of employers, the workforce, and the larger society. The current state of American industrial relations is assessed against these criteria. The general proposition advanced is that the U.S. system of industrial relations that grew out of the New Deal labor legislation of the 1930s performed effectively from the 1940s through the 1960s. Pressures for change on the system began to build through the 1970s because of changes in the economic and technological environment and in the strategic behavior and needs of the parties. These pressures erupted in the early 1980s to produce a period of experimentation and fundamental change in union-management relations. The critical question in industrial relations today is whether the process of adaptation will be sustained and expanded to cover a broader range of employment relationships.
Postischemic inhibition of GABA reuptake by tiagabine slows neuronal death in the gerbil hippocampus.

The neuroprotective effects of enhancing neuronal inhibition with a γ-aminobutyric acid (GABA) uptake inhibitor were studied in gerbil hippocampus following transient ischemia. We used in vivo microdialysis to determine a suitable dosing regimen for tiagabine (NNC 328) to elevate extracellular levels of GABA within the hippocampus. In anesthetized (normothermic) gerbils, tiagabine (45 mg/kg, i. p.) selectively elevated extracellular GABA levels 450% in area CA1 of the hippocampus. In gerbils subjected to cerebral ischemia via 5-min bilateral carotid occlusion, extracellular GABA levels increased 13-fold in area CA1, returning to baseline within 30–45 min. When tiagabine was injected 10 min following onset of reperfusion, GABA levels remained elevated (200–470%) for 90 min. In addition, tiagabine significantly reduced the ischemic-induced elevation of glutamate levels in area CA1 during the postischemic period when GABA levels were elevated. There was no effect of postischemic tiagabine on aspartate or six other amino acids. Using the same dosing regimen, we evaluated the degree of neuroprotection in the hippocampus of gerbils 4 and 21 days after ischemia. Tiagabine decreased body temperature a maximum of 2.7°C beginning 30 min into reperfusion and lasting 90 min. In untreated gerbils sacrificed 4 and 21 days after ischemia, there was severe necrosis (99%) of the pyramidal cell layer in area CA1. Whereas tiagabine significantly protected the CA1 pyramidal cell layer in ischemic gerbils at 4 days (overt necrosis confined to about 17% of area CA1), the protection diminished significantly 21 days postischemia. When normothermia was maintained both during and after ischemia in a separate group of tiagabine-treated animals, approximately 77% of the CA1 pyramidal cell layer was necrotic at 4 days. Based on these findings, we suggest that (1) tiagabine slows the development of hippocampal degeneration following ischemia, and (2) that mild, postischemic hypothermia is responsible, in large part, for the neuroprotective actions of this drug. We conclude that the histological outcome after administration of cerebral neuroprotectants should be assessed following long-term survival. © 1995 Wiley-Liss, Inc.
Effect of Vitamin D Supplementation on Wintertime and Overall Bone Loss in Healthy Postmenopausal Women

Abstract ▪Objectives:To determine whether relative vitamin D deficiency during the winter months contributes to age-related bone loss and whether rates of change in hard- and soft-tissue mass vary ...
Constant face pain in typical trigeminal neuralgia and response to γ knife radiosurgery.

Background/Aims: Constant pain, especially if prominent, is sometimes considered incompatible with a diagnosis of typical idiopathic trigeminal neuralgia. This study aims to clarify the frequency of patient-reported constant pain in patients with medically intractable, typical, idiopathic trigeminal neuralgia as diagnosed with standard clinical parameters and confirmed by the response to a modified McGill questionnaire, a ‘hold-still’ test that eliminated triggers and the response to Gamma Knife radiosurgery. Method: Forty consecutive patients with typical trigeminal neuralgia were given questionnaires prior to Gamma Knife radiosurgery. Those with constant pain were further tested by being advised to hold completely still for up to 3 min. Final pain relief was evaluated after Gamma Knife radiosurgery. Results: Twenty of forty patients indicated on a questionnaire that they had constant face pain. Pain decreased on the ‘hold-still’ test on all 12 patients who were tested. Following Gamma Knife radiosurgery, there was no significant difference in pain relief in those without or with constant pain. Conclusion: Patients with typical idiopathic trigeminal neuralgia frequently report that 50% or more of their pain is constant. This constant pain is markedly decreased if the patient holds completely still for a few minutes and does not affect the outcome of Gamma Knife radiosurgery.
Seasonal partitioning and utilization of energy reserves in two age classes of the bay scallop Argopecten irradians irradians (Lamarck)

Abstract Seasonal cycles in body component indices, reproductive condition (determined histologically), and storage and utilization of protein, lipid and carbohydrate reserves in various tissue pools, were investigated in two cohorts of the bay scallop Argopecten irradians irradians (Lamarck). Scallops were held in cages at two contrasting localities in Long Island, New York, U.S.A. Gametogenesis occurred mainly at the expense of adductor muscle protein and lipid reserves. Energy loss in the adductor muscle could potentially account for 63 to 99% of the gonadal buildup in the spring. In contrast to prior studies, digestive gland lipid and muscle carbohydrate made an insignificant contribution to the energy demand during reproduction. In first-year, pre-reproductive scallops, adductor muscle protein also contributed 63–66% of the total energy loss during overwintering stress. Senescence of older scallops was evidenced by a more rapid decline in mantle protein reserves than in young individuals. Twenty percent of the older population showed signs of anomalous, advanced oogenesis in March, coincident with the period of highest natural mortality. Results of this study suggest a possible association between senescence and protein metabolism. Contrary to studies showing glycogen to be the main storage product in bivalves such as oysters and mytilids, this study serves to stress the importance of protein as an energy substrate in pectinids.
Parallel Iterative Methods for the Helmholtz Equation With Exact Nonreflecting Boundaries

Parallel iterative methods for fast solution of large-scale acoustic radiation and scattering problems are developed using exact Dirichlet-to-Neumann (DtN), nonreflecting boundaries. A separable elliptic nonreflecting boundary is used to efficiently model unbounded regions surrounding elongated structures. We exploit the special structure of the non-local DtN map as a low-rank update of the system matrix to efficiently compute the matrix-by-vector products found in Krylov subspace based iterative methods. For the complex non-hermitian matrices resulting from the Helmholtz equation, we use a distributed-memory parallel BICG-STAB iterative method in conjunction with a parallel Jacobi preconditioner. Domain decomposition with interface minimization was performed to ensure optimal interprocessor communication. For the architectures tested, and using the MPICH version of MPI, we show that when implemented as a low-rank update, the non-local character of the DtN map does not signicantly decrease the scale up and parallel eciency versus a purely approximate local boundary condition.© 2002 ASME
Hemispace-VHF compatibility.

Abstract Hemispace refers to the external space to the left or right of body midline. To test for hemispace-VHF compatibility, manual RTs to neutral stimuli in the LVF and RVF were obtained from 24 dextrals across three fixation conditions: midline, right hemispace and left hemispace. A hemispace-VHF compatibility effect was found, suggesting that there is a relationship between each hemisphere and the contralateral hemispace.
Electrostatic disturbance forces on a three-axis drag-free sensor

The electrostatic analysis of a multiple-capacitance 3-axis drag-free sensor is presented in this paper. The instrument consists of a proof-mass (a dense metallic ball) floating freely inside a spherical cavity enclosed by the sensor plates and the shield. Since the ball and the cavity are not necessarily concentric, the problem in three-dimensional potential theory for electrostatics is solved by the method of boundary perturbations and specifically in terms of spherical harmonics. The capacitance outputs of the instrument and the electrostatic forces acting on the system are derived as non-linear functions of the ball position, ball charge and the sensor plate potentials. The instrument sensitivity and cross-coupling effects are discussed. The analysis may also be useful for electrostatic gyros and suspensions.
Square-Root Algorithm for Evaluating Mismodeled Process Noise

As the application of sequential filters has grown, the need has arisen to evaluate the sensitivity of these filters to mismodeling of the random process. A numerically reliable square-root algorithm is developed for calculating the covariances of estimates from a sequential filter which incorrectly models process noise. Mismodeling is restricted to the correlation time and standard deviation of a random process represented as a first-order Gauss-Markov sequence. Using a computer program which employs this algorithm, a sensitivity analysis was performed for several types of earth-based tracking data from an interplanetary spacecraft.
Deep Space Climate Observatory: The DSCOVR mission

In 1998, then-Vice President Al Gore proposed a mission to the Earth-Sun first Lagrange point (L1) to observe the Earth as a planet. This mission was named Triana, after the lookout on Christopher Columbus's fleet who is reputedly the first of the European explorers to see the new world. Triana mission development proceeded for 21 months and cost an estimated $249M (in FY07$) before it was de-manifested from the Space Shuttle. The spacecraft has been in a state of “Stable Suspension” since November 2001. After the mission was placed into suspension, it was renamed the Deep Space Climate Observatory (DSCOVR). This paper will cover an overview of the original mission and highlights of refurbishing this mission to launch 16 years after it started, plus an update on its currently planned mission architecture.
Blood compatibility of methyl, methyl vinyl, methyl phenyl, and trifluoropropylmethylvinyl silicone rubber without silica fillers in the spiral‐coiled membrane lung

Spiral-coiled membrane lungs of 0.6 m2 surface area were fabricated from silicone rubber membranes coated with four types of commercially available pure-gum polysiloxane rubber: 1) polytrifluoropropylmethylvinylsiloxane, 2) polymethylphenylsiloxane, 3) polymethylvinylsiloxane, and 4) polydimethylsiloxane. Membranes lungs were tested in an arteriovenous shunt without added heparin after bypass was begun. All group 4 had major rise in resistance to blood flow or clotting in over 33% of the membrane lungs studied, after 6 hr of bypass. Membrane lungs with polydimethylsiloxane (group 4) had no rise in resistance to blood flow during 24 hr of bypass and had the least amount of changes in blood platelet count.
Detection of cellular microchimerism of male or female origin in systemic sclerosis patients by polymerase chain reaction analysis of HLA-Cw antigens.

Objective Systemic sclerosis (SSc; scleroderma), a disease of unknown origin, displays many similarities to chronic graft-versus-host disease. It occurs most frequently in women after the childbearing years. In recent studies, the presence of Y-chromosome DNA derived from male fetuses was detected, but DNA from female fetuses could not be investigated in those studies. The present study was undertaken to investigate cellular microchimerism of either male or female origin in DNA from patients with SSc. Methods DNA from peripheral blood cells of 63 patients with SSc, 64 healthy individuals, and 24 non-SSc disease controls was examined by polymerase chain reaction analysis of HLA–Cw antigens. Results Cellular microchimerism of either male or female origin was detected in 41 of 63 SSc patients (65%), in contrast to 18 of 64 normal controls (28%) (χ2= 15.98, Pcorr = 0.00006) and 8 of 24 disease controls (33%) (χ2= 5.89, Pcorr = 0.015). Conclusion These findings support the hypothesis that microchimeric cells persisting in the circulation or tissues of SSc patients could be involved in disease pathogenesis by initiating a graft-versus-host–like reaction.
Angiotensin II receptor subtypes play opposite roles in regulating phosphatidylinositol hydrolysis in rat skin slices.

Summary Among the many functions of angiotensin II (Ang II) it now appears that Ang II is a growth factor. The concentration of Ang II in rat skin has been shown to increase during wound healing. To investigate the intracellular effect of Ang II in skin we determined the levels of total cytoplasmic inositol phosphates after incubation of skin slices with different doses of Ang II. 10−6 M of Ang II increased significantly the phosphatidylinositol (PI) hydrolysis, and the effect was dose dependent up to 10−4 M Ang II. The majority of inositol phosphates yielded after 1 hour incubation in the presence of lithium was InsP2 with lesser amount of InsP2. Losartan, the Ang II AT1 antagonist, at a dose of 10−4M blocked the effect of Ang II, while PD123319, the Ang II AT2 antagonist, had no antagonistic action; PD123319 at the higher dose of 10−3 M, however, potentiated the effect of Ang II on PI hydrolysis. The results suggest that PI hydrolysis is a second messenger system for Ang II in rat skin. Also, the two subtypes of Ang II receptors mediate opposite effects on PI hydrolysis: Ang II binding to AT, receptors increases inositol phosphate production, while Ang II binding to AT2 receptors decreases inositol phosphate production.
The vinylketene acetal route to aklavinone and 11-deoxydaunomycinone

Abstract 11-Deoxyanthracyclinone precursors 6a and 6b have been prepared regiospecifically by the reaction of bromojuglone methyl ethers 4a and 4b with vinylketene acetal 5 , prepared from the Hagemann's ester ketal 7a .
Gas-liquid chromatographic method for the assay of aminoglycoside antibiotics in serum.

A gas-liquid chromatographic (GLC) method is presented for the rapid analysis of gentamicin, tobramycin, netilmicin, and amikacin from human serum. This procedure may have application to all aminoglycoside drugs. The three isomers of gentamicin are resolved as two bands, while tobramycin, netilmicin, and amikacin appear in this system as single bands. Normal serum constituents do not interfere with chromatograms. Thus far, no assay interference has been found in cases where other drugs and antibiotics were administered concurrently with aminoglycoside therapy. Dose-response data demonstrating linear recovery are included for all four aminoglycosides as well as a comparison of the GLC method with the microbiological method for the assay of gentamicin and amikacin. Quantitation is based upon the relative response of the antibiotics to a fixed amount of the internal standards, either kanamycin A or paromomycin B. These standards are clearly resolved as symmetrical peaks from the antibiotics of assay interest. Isothermal chromatographic analysis time is less than 8 min, while total assay time per single serum specimen is approximately 50 min. Preparation of serum includes: precipitation, evaporative drying of the supernatant, a two-stage derivatization (N-trimethylsilylimidazole, N-heptafluorobutyrylimidazole), and a single hexane extraction with a water wash. The methodology described may be applied to the analysis of other compounds (e.g., saccharides, amino-saccharides, amino acids, etc.) which do not rapidly partition into an organic phase.
Pericardial tamponade: an unusual complication of lobectomy for lung cancer

A rare case of pericardial tamponade developed in a 69-year-old man after a right upper lobectomy for lung cancer. This unusual complication presented in the early postoperative period and was associated with what we believed to be an aberrant right bronchial artery coming off the intrapericardial portion of the aorta. This vessel retracted into the pericardial sac where it bled causing a pericardial tamponade.
In vitro and in vivo percutaneous absorption of benzo[a]pyrene from petroleum crude-fortified soil in the rat.

Concern regarding dermal exposure to soils contaminated with potentially toxic materials such as dioxins, pesticides, heavy metals, polynuclear aromatics (PNA) and petroleum products containing PNA, has prompted government and private sectors to examine and formulate dermal risk assessment methodologies for contaminated soils. In the absence of experimentally determined percutaneous absorption values, many risk assessment schemes substitute available animal toxicology data on the pure contaminant, estimate dermal penetration of pure contaminant based on physicochemical models or, in the extreme, assume 100% bioavailability of the contaminant from soil. Risk assessment based on these approaches is likely to result in an overestimate of dermal bioavailability of contaminants from soil, particularly for the water insoluble lipophilic compounds found in petroleum products. The authors have performed dermal bioavailability studies on a variety of lipophilic materials and special emphasis has been placed on the development and implementation of a modified in vitro technique for evaluating the percutaneous absorption of PNA and PNA mixtures. In the present paper, they apply the modified in vitro technique to evaluate the percutaneous absorption of ({sup 3}H-labelled) benzo(a)pyrene (BaP) in petroleum crude oil sorbed on soil and compare the results with those for the percutaneous absorption of BaP from crude oilmore » alone. Results of the in vitro experiments are compared with findings from parallel in vivo experiments.« less
Problems and Prospects for Programming in the Visual Arts

The education of the artistically gifted student is in transition, according to this educator, who shares his views of the problems inherent in establishing a solid arts curriculum, and provides some insight into future changes.
Structure and organization for collection development: A centralized model

Abstract After describing how collection development is organized in libraries that are members of the Association of Research Libraries, the author details how the collection development effort is structured at his library and how this differs from the pattern in ARL libraries. A traditional, centralized, model is presented, in which collection development activities are linked to an acquisitions department.
Toward Client-Centered Service: Asking Clients for Their Views of TANF, Food Stamps, Child Care, and Medicaid Services

This article presents the results of a randomized study that asked Division of Family and Children Services' (DFCS) clients throughout the state of Georgia to rate their satisfaction with Temporary Assistance to Needy Families (TANF), food stamps, child care services, and Medicaid services, as well as their perspectives of the customer service they received through their county DFCS offices. Telephone interviews were conducted with 2,408 clients. Overall client satisfaction percentages are: TANF, 80%; food stamps, 88%; child care, 92%; and Medicaid, 94%. Satisfaction indices were also created from the data collected. Client suggestions for improvement are presented as well as practice and educational implications.