cssi/SciSciGPT-SciSciNet huggingface dataset:
Electron beam dose calculations.

Electron beam dose distributions in the presence of inhomogeneous tissue are calculated by an algorithm that sums the dose distribution of individual pencil beams. The off-axis dependence of the pencil beam dose distribution is described by the Fermi-Eyges theory of thick-target multiple Coulomb scattering. Measured square-field depth-dose data serve as input for the calculations. Air gap corrections are incorporated and use data from 'in-air' measurements in the penumbra of the beam. The effective depth, used to evaluate depth-dose, and the sigma of the off-axis Gaussian spread against depth are calculated by recursion relations from a CT data matrix for the material underlying individual pencil beams. The correlation of CT number with relative linear stopping power and relative linear scattering power for various tissues is shown. The results of calculations are verified by comparison with measurements in a 17 MeV electron beam from the Therac 20 linear accelerator. Calculated isodose lines agree nominally to within 2 mm of measurements in a water phantom. Similar agreement is observed in cork slabs simulating lung. Calculations beneath a bone substitute illustrate a weakness in the calculation. Finally a case of carcinoma in the maxillary antrum is studied. The theory suggests an alternative method for the calculation of depth-dose of rectangular fields.
Pathogen associated molecular pattern-induced TNF, IL-1β, IL-6 and CXCL-8 production from feline whole blood culture

Abstract Whole blood culture ( C wb ) is a method to evaluate leukocyte response to stimuli. We used C wb to evaluate the inflammatory response to pathogen associated molecular patterns (PAMPs) in cats. Blood was collected from diluted with RPMI and stimulated with various concentrations of lipopolysaccharide (LPS), lipoteichoic acid (LTA), peptidoglycan (PG) or control (PBS). Multiple concentrations of LPS, LTA and PG significantly stimulated tumor necrosis factor (TNF), interleukin (IL)-1β and CXC chemokine ligand (CXCL)-8 in feline C wb . All PAMPs failed to stimulate IL-6 production and PG failed to stimulate CXCL-8 production. Lipopolysaccharide was a more potent inducer of IL-1β and CXCL-8 than LTA or PG and LTA is a more potent inducer of CXCL-8 than PG. Based on these data, PAMPs from gram positive and negative bacteria induce TNF, IL-1β and CXCL-8 production in feline whole blood. Cats appear to be relatively more sensitive to gram negative compared to gram positive bacteria.
Regulation of Fibroblast Motility by the Protein Tyrosine Phosphatase PTP-PEST

The protein tyrosine phosphatase PTP-PEST is a cytosolic enzyme that displays a remarkable degree of selectivity for tyrosine-phosphorylated p130Cas as a substrate, bothin vitro and in intact cells. We have investigated the physiological role of PTP-PEST using Rat1 fibroblast-derived stable cell lines that we have engineered to overexpress PTP-PEST. These cell lines exhibit normal levels of tyrosine phosphorylation of the majority of proteins but have significantly lower levels of tyrosine phosphorylation of p130Cas than control cells. Initial cellular events occurring following integrin-mediated attachment to fibronectin (cell attachment and spreading) are essentially unchanged in cells overexpressing PTP-PEST; similarly, the extent and time course of mitogen-activated protein kinase activation in response to integrin engagement is unchanged. In contrast, the reduced phosphorylation state of p130Cas is associated with a considerably reduced rate of cell migration and a failure of cells overexpressing PTP-PEST to accomplish the normally observed redistribution of p130Casto the leading edge of migrating cells. Furthermore, cells overexpressing PTP-PEST demonstrate significantly reduced levels of association of p130Cas with the Crk adaptor protein. Our results suggest that one physiological role of PTP-PEST is to dephosphorylate p130Cas, thereby controlling tyrosine phosphorylation-dependent signaling events downstream of p130Cas and regulating cell migration.
Opposing effects of androgen ablation on immune function in prostate cancer

Although it is recognized that immune function is modulated by androgen ablation therapy for prostate cancer, the long-term consequences are not completely understood. We recently showed that both effector and inhibitory immune mechanisms are amplified by androgen ablation, providing one explanation for only transient increases in immune function after castration.
Quantitative models in crime control

In this study we propose several mathematical models for describing the behavior of crime-related systems. In the first part is presented a simple model for describing and measuring crime systems with recidivism. This model may be used in estimating the quantitative effects of alternative policies on crime rates. An important factor not recognized by the model is deterrence. One derivative of the mathematical analyses is a proposed method for measuring the relative severity of sentencing in a given system. The second part of the paper deals with the criminal population as a whole, trying to bring into account the non-stationary behavior of the system. This study should be regarded as a preliminary attempt to develop elementary mathematical models fitting crime systems. Some of the assumptions do not have substantial direct support by data.
Physical mechanism for gating and mechanosensitivity of the human TRAAK K + channel

Activation of mechanosensitive ion channels by physical force underlies many physiological processes including the sensation of touch, hearing and pain. TRAAK (also known as KCNK4) ion channels are neuronally expressed members of the two-pore domain K(+) (K2P) channel family and are mechanosensitive. They are involved in controlling mechanical and temperature nociception in mice. Mechanosensitivity of TRAAK is mediated directly through the lipid bilayer--it is a membrane-tension-gated channel. However, the molecular mechanism of TRAAK channel gating and mechanosensitivity is unknown. Here we present crystal structures of TRAAK in conductive and non-conductive conformations defined by the presence of permeant ions along the conduction pathway. In the non-conductive state, a lipid acyl chain accesses the channel cavity through a 5 A-wide lateral opening in the membrane inner leaflet and physically blocks ion passage. In the conductive state, rotation of a transmembrane helix (TM4) about a central hinge seals the intramembrane opening, preventing lipid block of the cavity and permitting ion entry. Additional rotation of a membrane interacting TM2-TM3 segment, unique to mechanosensitive K2Ps, against TM4 may further stabilize the conductive conformation. Comparison of the structures reveals a biophysical explanation for TRAAK mechanosensitivity--an expansion in cross-sectional area up to 2.7 nm(2) in the conductive state is expected to create a membrane-tension-dependent energy difference between conformations that promotes force activation. Our results show how tension of the lipid bilayer can be harnessed to control gating and mechanosensitivity of a eukaryotic ion channel.
Application of high-performance liquid chromatography and thermospray high-performance liquid chromatography-mass spectrometry to the analysis and identification of 2',3'-dideoxyadenosine and its metabolite in biological media

Abstract Reversed-phase high-performance liquid chromatographic (HPLC) procedures are described for determining the stability of 2′,3′-dideoxyadenosine (DDA) in biological fluids at therapeutic dosages. The validated methodology uses both direct injection and solid-phase extraction techniques. Deamination of DDA to 2′,3′-dideoxyinosine (DDI) in plasma by adenosine deaminase was monitored by HPLC, and the identification of DDI verified by thermospray HPLC-mass spectrometry. This methodology should prove useful in future studies concerning the stability and metabolism of dideoxynucleosides.
Comparison of a single-view and a double-view aerosol optical depth retrieval algorithm

We compare the results of a single-view and a double-view aerosol optical depth (AOD) retrieval algorithm applied to image pairs acquired over NASA Stennis Space Center, Mississippi. The image data were acquired by the Department of Energy's (DOE) Multispectral Thermal Imager (MTI), a pushbroom satellite imager with 15 bands from the visible to the thermal infrared. MTI has the ability to acquire imagery in pairs in which the first image is a near-nadir view and the second image is off-nadir with a zenith angle of approximately 60°. A total of 15 image pairs were used in the analysis. For a given image pair, AOD retrieval is performed twice---once using a single-view algorithm applied to the near-nadir image, then again using a double-view algorithm. Errors for both retrievals are computed by comparing the results to AERONET AOD measurements obtained at the same time and place. The single-view algorithm showed an RMS error about the mean of 0.076 in AOD units, whereas the double-view algorithm showed a modest improvement with an RMS error of 0.06. The single-view errors show a positive bias which is presumed to be a result of the empirical relationship used to determine ground reflectance in the visible. A plot of AOD error of the double-view algorithm versus time shows a noticeable trend which is interpreted to be a calibration drift. When this trend is removed, the RMS error of the double-view algorithm drops to 0.030. The single-view algorithm qualitatively appears to perform better during the spring and summer whereas the double-view algorithm seems to be less sensitive to season.
Finite-rank perturbations of the Dirac operator

Abstract In this paper we determine those relativistic point interactions for which renormalization of the coupling constant occurs when the corresponding potentials are approximated by local, short-range perturbations of the free Dirac operator in one dimension. We also find a general formula for the renormalization constant for the entire four-parameter family of relativistic point interactions. Our results, which unify and extend earlier work on relativistic point interactions, include perturbations of the Dirac operator by finitely many δ or δ′ potentials, as well as relativistic scalar and magnetic point interactions. In addition, we show that similar methods may be used to define more general perturbations of the Dirac operator, including time-dependent ones. These operators are shown to depend continuously on the perturbation in the sense of strong resolvent convergence.
Metabolic rate and thyroxine monodeiodinase activity in iron-deficient female Sprague-Dawley rats: Effects of the ovarian steroids☆

Abstract Iron deficiency results in altered thyroid hormone metabolism throughout the estrous cycle. To assess the interactions of the ovarian steroids, thyroid hormones, and iron deficiency, we examined indices of thyroid function in ovariectomized iron-deficient animals and control animals treated with estradiol (mean plasma concentration, 260 pmol/L), progesterone (mean plasma concentration, 45 nmol/L), estradiol and progesterone, or no steroid (sham-treated). Neither steroid affected plasma triiodothyronine (T 3 ) concentrations relative to sham-treated animals, but estradiol treatment (either alone or with progesterone) elevated plasma thyroxine (T 4 ) concentrations ( P ⩽ 0.001). Plasma T 3 and T 4 concentrations were lower in iron-deficient ovariectomized rats ( T 3 = 0.38 ± 0.08 nmol/L; T 4 = 22.0 ± 9.7 nmol/L) relative to ovariectomized controls ( T 3 = 0.44 ± 0.11 nmol/L; T 4 = 27.4 ± 8.4 nmol/L; P ⩽ 0.05 and 0.01, respectively. Hepatic thyroxine monodeiodinase activity was lower in iron-deficient rats (422 ± 241 versus 565 ± 251 pmoles I · mg protein −1 · 20 minutes −1 ; P ⩽ 0.03). Brown adipose tissue deiodinase activity decreased in estradiol-treated groups relative to sham-treated animals ( P ⩽ 0.03); however, the brown adipose tissue thyroxine monodeiodinase was unaffected by iron deficiency. Metabolic rates were elevated in iron-deficient rats ( P ⩽ 0.003) and were lower in estradiol-treated rats. Iron-deficient rats exhibit an altered thyroid response to exogenous ovarian steroids. In conclusion, plasma parameters of thyroid function are altered in iron-deficient rats, and these appear to be affected by the ovarian steroids. Tissue deiodinase activities are lower and metabolic rates are higher in iron-deficient rats.
LASTING BIOLOGICAL EFFECTS OF EARLY ENVIRONMENTAL INFLUENCES VI. EFFECTS OF EARLY ENVIRONMENTAL STRESSES ON METABOLIC ACTIVITY AND ORGAN WEIGHTS

Specific pathogen-free mice were exposed to three different kinds of environmental stress during early life: (a) by infecting them with a mouse enterovirus on the second day after birth; (b) by placing the mother during pregnancy and lactation on a mildly deficient diet containing wheat gluten supplemented with See PDF for Structure small amounts of lysine and threonine; (c) by combining a (neonatal infection) and b (early malnutrition). All animals survived the three types of stresses, but all exhibited marked depressions of metabolic activity, and of body weights and organ weights. These depressions lasted throughout the experimental period even though all animals were placed under optimum conditions of nutrition and husbandry after weaning, and maintained under these same conditions thereafter. Metabolic activity was determined by measuring the turnover of 14C-acetate and 14C-glucose in respiratory CO2, and their incorporation in total lipids of liver and brain. The utilization of 14C-acetate was profoundly depressed in all experimental groups with regard to both elimination in respiratory CO2 and their incorporation in total lipids of liver and brain. In contrast, the utilization of 14C-glucose was much less affected; its incorporation into lipids was not decreased and its elimination in respiratory CO2 was depressed only in animals having experienced both neonatal infection and early malnutrition. The extent of weight depression per 100 g of body weight differed according to the organ and the type of stress. Irrespective of the organ, however, depression of weight was largest in animals having experienced both neonatal infection and early malnutrition. And irrespective of the type of stress, the brain exhibited the smallest depression of weight relative to total body weight.
The characterization of thermally-produced metastable excited-state atomic species using resonance ionization mass spectrometry

Abstract Resonance ionization mass spectrometry (RIMS) has been used to study atom plumes produced by thermal vaporization. Experimental results are presented for the elements Fe, Ni, Mo and Re. Ion intensity vs. laser wavelength spectra consistently demonstrate that low-level energy states are significantly populated in the interaction volume of the mass spectrometer. The experimental results are explained by assuming a Boltzmann distribution of states for atoms leaving the heated surface. Since collisional relaxation does not occur in the high-vacuum thermal atom source and the transitions from the excited state to ground state are not radiatively allowed, the Boltzmann distribution of states is maintained in the atom plume. Since many elements possess low-level energy states, both spectroscopic sensitivity and selectivity will be reduced. However, the greater number of intense lines per element allows an increased range of elements to be studied by RIMS in a given wavelength region and opens the possibility of multielement capabilities. The implications for more energetic atomization techniques such as ion sputtering or laser ablation are discussed.
A New Pathway for Salvaging the Coenzyme B12 Precursor Cobinamide in Archaea Requires Cobinamide-Phosphate Synthase (CbiB) Enzyme Activity

The ability of archaea to salvage cobinamide has been under question because archaeal genomes lack orthologs to the bacterial nucleoside triphosphate:5′-deoxycobinamide kinase enzyme (cobU in Salmonella enterica). The latter activity is required for cobinamide salvaging in bacteria. This paper reports evidence that archaea salvage cobinamide from the environment by using a pathway different from the one used by bacteria. These studies demanded the functional characterization of two genes whose putative function had been annotated based solely on their homology to the bacterial genes encoding adenosylcobyric acid and adenosylcobinamide-phosphate synthases (cbiP and cbiB, respectively) of S. enterica. A cbiP mutant strain of the archaeon Halobacterium sp. strain NRC-1 was auxotrophic for adenosylcobyric acid, a known intermediate of the de novo cobamide biosynthesis pathway, but efficiently salvaged cobinamide from the environment, suggesting the existence of a salvaging pathway in this archaeon. A cbiB mutant strain of Halobacterium was auxotrophic for adenosylcobinamide-GDP, a known de novo intermediate, and did not salvage cobinamide. The results of the nutritional analyses of the cbiP and cbiB mutants suggested that the entry point for cobinamide salvaging is adenosylcobyric acid. The data are consistent with a salvaging pathway for cobinamide in which an amidohydrolase enzyme cleaves off the aminopropanol moiety of adenosylcobinamide to yield adenosylcobyric acid, which is converted by the adenosylcobinamide-phosphate synthase enzyme to adenosylcobinamide-phosphate, a known intermediate of the de novo biosynthetic pathway. The existence of an adenosylcobinamide amidohydrolase enzyme would explain the lack of an adenosylcobinamide kinase in archaea.
Dense material associated with apparent presynaptic elements in cell cultures of the CNS

In cell cultures of the rat cerebellum, electron-dense material has been found occasionally between adjacent cells. More often than not, presynaptic elements on one side of the dense material faced either neuronal or nonneuronal cells on the other side. The 20 nm thick material was stained either with the osmium-uranyl-lead (OsUL) procedure or with the ethanolic phosphotungstic acid (E-PTA) procedure. To determine the source of the dense material, various compounds were added to cultures at 7 days in vitro. Only a crude nuclear fraction was able to duplicate the appearance of the dense material associated with the apparent presynaptic elements. It was concluded that apparent presynaptic elements were associated with the polybasic dense material and that this type of association may duplicate an interaction in the normal development of synaptic contacts.
Approximate multipartite version of the Hajnal-Szemerédi theorem

Let q be a positive integer, and G be a q-partite simple graph on qn vertices, with n vertices in each vertex class. Let @d=kk+1, where k=q+O(logq). If each vertex of G is adjacent to at least @dn vertices in each of the other vertex classes, q is bounded and n is large enough, then G has a K"q-factor.
Halftone image quality analysis based on a human vision model

The perceived quality of a printed image depends on the halftone algorithm and the printing process. This paper proposes a new method of analyzing halftone image quality in the frequency domain based on a human vision model. First, the Fourier transform characteristics of a dithered image are reviewed. Several commonly used dither algorithms, including clustered-dot dither and dispersed-dot dither, are evaluated based on their Fourier transform characteristics. Next, images halftoned with the dither algorithms and the Floyd-Steinberg error diffusion algorithm are compared in the frequency domain. Factors affecting printed image quality in a printing process are also discussed. Finally, a perception-based halftone image distortion measure is proposed. This measure reflects the quality of a halftone image printed on an ideal bi-level device and viewed at a particular distance. The halftone algorithms are ranked according to the proposed distortion measure. The effects of using human visual models with different peak sensitivity frequencies are examined.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The pathogenesis of infantile malignant osteopetrosis: Bone mineral metabolism and complications in five infants

Abstract Bone mineral metabolism was studied in five infants aged 8 to 22 months with severe osteopetrosis. There were findings consistent with biochemical osteomalacia. These included hypocalcemia, hypophosphatemia, high serum acid phosphatase and alkaline phosphatase activity, high levels of serum parathyroid hormone, and high urinary cyclic AMP. Serum 1,25(OH) 2 vitamin D 3 level was high in the one patient tested. Radiographs in all infants revealed rachitic changes in the metaphyses. However, dense bones on radiographs, calcium balance studies, and radiocalcium absorption studies demonstrated markedly positive calcium balance. Iliac crest bone biopsies showed increased quantity of woven bone with abundant numbers of osteoclasts, excessive amounts of osteoid, myelofibrosis, and a decreased number of Howship's lacunae. The wide bands of unmineralized osteoid did not take up tetracycline. In vitro bone resorbing activity due to osteoclast activating factor from cultured stimulated leukocytes was normal. Bone turnover however, was low as evidenced by low urinary hydroxyproline levels. We interpret these findings as indicating there is decreased bone remodeling and resorption in spite of increased humoral stimuli and osteoclasts. Since calcitonin levels were normal for age, the most likely cause of the impaired bone remodeling sequence was defective osteoclast function. We postulate that there may be a common genetic defect in phagocyte cells, including monocytes, neutrophils, and osteoclasts, which accounts for the abnormalities of mineral metabolism and previously reported hematologic, neurologic, and infectious complications.
Detection and characterization of infectious Hepatitis E virus from commercial pig livers sold in local grocery stores in the USA

Hepatitis E virus (HEV) is a zoonotic pathogen of which pigs are reservoirs. To determine the presence of HEV RNA in commercial pig livers sold in local grocery stores in the USA, 127 packages of commercial pig liver were purchased and tested by a universal RT-PCR assay capable of detecting all four known HEV genotypes. Among the 127 livers tested, 14 were positive for HEV RNA. Sequence and phylogenetic analyses revealed that the 14 isolates all belonged to genotype 3. An animal study was subsequently conducted in pigs to determine whether the PCR-positive pig livers still contained infectious virus. The results showed that pigs inoculated with two of the three PCR-positive pig-liver homogenates became infected, as evidenced by the detection of faecal virus shedding, viraemia and seroconversion. The data demonstrated that commercial pig livers sold in grocery stores are contaminated by HEV and that the contaminating virus remains infectious, thus raising a public-health concern for food-borne HEV infection.
Hepatic toxicity of Vitamin A and synthetic retinoids

Vitamin A and synthetic retinoids have recently been used increasingly in a variety of health related concerns. Hepatic toxicity is an uncommon but serious side-effect of several Vitamin A derivatives which may lead to cirrhosis. This review will focus on the clinical and pathologic findings of hepatic involvement in chronic hypervitaminosis A and on the evidence concerning the potential hepatotoxicity of currently available synthetic retinoids.
Ready, Set, Slow: How Aspiration-Relative Product Quality Impacts the Rate of New Product Introduction

Performance feedback research addresses how firms respond to performance that diverges from their aspirations. Whereas the majority of research in this vein involves financial performance, we apply this framework to product quality performance, arguing that when performance diverges either below or above aspirations, firms will pursue a slower subsequent product introduction rate, either to identify the cause of the underperformance or to incorporate the successful product characteristics in the case of overperformance. We also investigate whether our predictions hold when two boundary conditions are applied. Since product quality aspirations are derived from the “reputations for quality” of the firm and its peers, we argue that the stability of these reputations will amplify the delaying effects of below- and above-aspiration performance. Consistent with research on firm responses to financial performance, we also predict that greater sales revenues relative to sales aspirations will attenuate the delayi...
Conservation of rare plant habitat: Insights from the recent history of vegetation and fire at crystal fen, Northern Maine, USA

Abstract Crystal Fen in north-central Maine has become well-known as a locality with numerous rare plants. Recent observations of apparent drying and an increase in abundance of woody vegetation in the fen have led to concerns that an adjacent railroad bed and drainage ditch may be causing changes that threaten the habitat of several rare and interesting plant taxa. A description of these changes comes from analysis of (1) aerial photographs dating from 1938 to the present; (2) characteristics of the present vegetation, including the age of living woody plants; (3) evidence of fire on the fen; and (4) the fossil-pollen and charcoal stratigraphy for the past 200 years from an area of the fen that is becoming increasingly wooded. Results indicate that during much of its history the fen may have been at least partially wooded, except in the area that is wettest and most open today. Construction of the railbed in 1893, and the passing of cinder-producing steam locomotives along the tracks thereafter, apparently promoted expansion of fen vegetation by impeding drainage and by igniting occasional fires that reduced the abundance of woody stems. Thus, the extensive open habitat where populations of some rare plants occur is, in fact, an artificial result of human activities. Recent drier conditions post-date the construction of a drainage ditch in 1937 and the introduction of diesel-powered locomotives around 1950, which largely eliminated the ignition of fires and allowed the re-expansion of woody taxa over most of the fen. This trend represents a partial retreat to natural conditions. The study demonstrates that (1) rare plants occur in a variety of habitats (open, lightly forested, and heavily forested) at Crystal Fen, suggesting that these populations would be best served by maintaining such habitat diversity; and (2) past human disturbance led to expansion of open areas, which is the habitat most suitable for some of the rare taxa. In the future, both open fen areas and overall habitat diversity could be artificially enhanced using a variety of management practices including cutting, prescribed burning, and manipulating drainage to maintain a mixture of vegetation types.
Maximum likelihood estimation in generalized linear models with multiple covariates subject to detection limits

The analysis of data subject to detection limits is becoming increasingly necessary in many environmental and laboratory studies. Covariates subject to detection limits are often left censored because of a measurement device having a minimal lower limit of detection. In this paper, we propose a Monte Carlo version of the expectation-maximization algorithm to handle large number of covariates subject to detection limits in generalized linear models. We model the covariate distribution via a sequence of one-dimensional conditional distributions, and sample the covariate values using an adaptive rejection metropolis algorithm. Parameter estimation is obtained by maximization via the Monte Carlo M-step. This procedure is applied to a real dataset from the National Health and Nutrition Examination Survey, in which values of urinary heavy metals are subject to a limit of detection. Through simulation studies, we show that the proposed approach can lead to a significant reduction in variance for parameter estimates in these models, improving the power of such studies.
Reaction time slowing in adults with HIV: results of a meta-analysis using brinley plots.

Abstract A meta-analysis in the form of Brinley plots was conducted on the mean reaction times of HIV+ and HIV− groups. HIV+ reaction times were regressed on HIV− reaction times across 122 task conditions from 29 studies, producing a highly linear function (r2=.94), with a slope b=1.039, which was not significantly different than b=1.00. Asymptomatic and symptomatic HIV+ reaction times were also separately regressed on HIV− reaction times across 67 task conditions from 13 studies. Both functions were highly linear (r2=.97 and .90 respectively), with slopes of 1.034 and 1.117 respectively. Only the slope for symptomatic HIV+ groups was significantly larger than b=1.00, suggesting a modest generalized slowing of cognition in these adults.
Morphological development of the Florida Escarpment: observations on the generation of time transgressive unconformities in carbonate terrains

Abstract An unconformity of 100 m.yr magnitude continues to form on the western edge of the Florida-Bahama Platform, near 26°N, where distal Mississippi Fan sediments are progressively burying the Florida Escarpment. Multiple perspectives of the developing unconformity's morphology are revealed using available technologies including GLORIA images of the entire platform's edge, Seabeam bathymetric contours, and Deep-Tow's high resolution side-scan data calibrated with bottom photographs. The structure and stratigraphy of the buried escarpment and the associated unconformity are resolved by airgun, sparker, and Deep-Tow's 4 kHz seismic reflection data; we summarize the morphological data on the exposed part of the unconformity and the sedimentary deposits accumulating in the basin above the unconformity. The exposed cliff face is composed of a staircase of bedding-plane terraces which are developed along joint planes. The terraces extend 100–1000 m along the escarpment's face, and the intervening vertical walls are up to 100 m high. The jointed morphology of this Mesozoic limestone cliff apparently reflects erosional exposure of its interior anatomy rather than its accretionary shape. The change in slope between the platform face and the abyssal plain is very abrupt. In places along the contact between the escarpment and fan sediments, reduced chemical-charged brine seeps occur, which locally cause carbonate dissolution and precipitation, sulfide mineralization, and the deposition of a fossiliferous and organic carbon-rich lens associated with chemosynthetic communities. These seep deposits and escarpment-derived megabreccias intercalate with basinal sediments that overlie the unconformity. Because surface seismic reflection data do not produce images of the escarpment's face that closely reflect the exposed escarpment's morphology, they must also be of limited value in characterizing the surface of similar steeply dipping buried escarpments. Thus, the downslope extent of the heavily eroded platform edge is unclear.
The distribution of sulfur dioxide and other infrared absorbers on the surface of Io

The Galileo Near Infrared Mapping Spectrometer was used to investigate the distribution and properties of sulfur dioxide over the surface of Io, and qualitative results for the anti-Jove hemisphere are presented here. SO2, existing as a frost, is found almost everywhere, but with spatially variable concentration. The exceptions are volcanic hot spots, where high surface temperatures promote rapid vaporization and can produce SO2-free areas. The pervasive frost, if fully covering the cold surface, has characteristic grain sizes of 30 to 100 µm, or greater. Regions of greater sulfur dioxide concentrations are found. The equatorial Colchis Regio area exhibits extensive snowfields with large particles (250 to 500 µm diameter, or greater) beneath smaller particles. A weak feature at 3.15 µm is observed and is perhaps due to hydroxides, hydrates, or water. A broad absorption in the 1 µm region, which could be caused by iron-containing minerals, shows a concentration in Io's southern polar region, with an absence in the Pele plume deposition ring.
The Graphical Asymmetric Traveling Salesman Polyhedron: SymmetricInequalities

A present trend in the study of the symmetric traveling salesman polytope is to use, as a relaxation of the polytope, the graphical traveling salesman polyhedron ($\g$). Following a parallel approach for the asymmetric traveling salesman polytope, we define the graphical asymmetric traveling salesman problem on a general digraph $D$ and its associated polyhedron $\ga(D)$. We give basic polyhedral results and lifting theorems for $\ga(D)$ and we give a general condition for a facet-defining inequality for \g\ to yield a symmetric facet-defining inequality for \ga. Using this approach we show that all known major families of facet-defining inequalities of \g\ define facets of \ga. Finally, we discuss possible extension of these results to the asymmetric traveling salesman polytope.
Zinc supplementation does not attenuate alcohol-induced cerebellar Purkinje cell loss during the brain growth spurt period.

Background: Alcohol-induced zinc deficiency is one of the mechanisms proposed as a cause of developmental brain damage associated with fetal alcohol syndrome. It is known that alcohol exposure during the brain growth spurt period leads to cerebellar Purkinje cell loss. Therefore, this study examined whether zinc supplementation was capable of preventing alcohol-induced Purkinje cell loss in the cerebellar vermis in a neonatal rat model system. Methods: Sprague-Dawley rat pups were given alcohol (EtOH; 4.5 g/kg/day), zinc (Zn; 0.54 mg/ml diet; [10 times the regular diet Zn concentration]), or both from postnatal days (PD) 4 through 9 using the artificial-rearing paradigm. A gastrostomy control (GC) and a suckle control group (SC) also were included. All pups were killed on PD 10. Following perfusion, the cerebellar vermis was dissected and processed for stereological cell counting. The total number of Purkinje cells and the volume of the cerebellar vermis were determined. Results: Alcohol produced a significant loss of Purkinje cells compared with that in the GC group (no EtOH and no Zn supplement). The zinc supplementation had no effect in attenuating alcohol-induced Purkinje cell loss in the cerebellar vermis. In fact, the serum zinc concentration data indicated higher zinc concentrations following either EtOH or Zn treatment. Interestingly, the GC group showed a significantly lower zinc concentration compared with the SC group, even though no significant difference in Purkinje cell numbers was observed between these two control groups. Conclusion: These findings indicate that alcohol exposure during the third trimester equivalent did not result in zinc deficiency in this neonatal rat model system, nor did zinc supplementation rescue the alcohol-induced Purkinje cell loss in the cerebellar vermis. These findings showed clearly that the serum zinc concentration was not correlated with Purkinje cell loss, suggesting that alcohol-induced loss of cerebellar Purkinje cells in this neonatal rat model system is independent of the availability of serum zinc.
Magnetic analysis of the radiation components of a 10 MV photon beam.

For megavoltage x-ray beams, the percent depth dose increases considerably with field size in the buildup region, with a concomitant shift in the position of the maximum dose (d/sub max/) to a shallower depth. Various authors disagree as to the cause of this effect. The radiation components contributing to absorbed dose in the buildup region of 10-MV photon field were analyzed as a function of field size by placing an electromagnet next to the Clinac 18 treatment head. The percent depth dose curves in the buildup region, obtained with a parallel plate chamber downstream from the magnetic field at 85 cm SSD, exhibited no d/sub max/ shift and a much reduced dependence on field size, in clear distinction with similar data taken with zero magnetic field. Confirmatory data were obtained at 100 and 120 cm SSD. These results clearly show that scattered electrons are the primary cause for the d/sub max/ shift and the dose increase in the buildup region with increasing field size.
CAN TOTAL QUALITY MANAGEMENT SUCCEED AT YOUR COLLEGE—NOW? (DOES YOUR COLLEGE MEET THE ESSENTIAL PREREQUISITES AND UNDERLYING ASSUMPTIONS OF TQM?)

The focus of this article is on providing answers to the following questions: What is TQM? What are the prerequisites for its success? What are the underlying assumptions on which it is based? What are the cultural barriers in colleges that hinder its implementation? What are the odds of successfully implementing TQM at your college?
Critical slowing down in the X-Y model: Comparing chaotic molecular dynamics and hybrid Monte Carlo

Abstract We discuss the chaotic molecular dynamics algorithm, a generalization of molecular dynamics with ergodic equations of motion. We compare simulations of the 2D XY model using this algorithm to simulations using hybrid Monte Carlo with varying trajectory lengths. We find small systematic errors, and statistical errors which are better than the hybrid Monte Carlo. We also find that error bars on certain observables increased with trajectory length in the hybrid Monte Carlo simulations.
Case report 583

Un cas d'elastofibrome dorsal, tumeur benigne des tissus mous, chez un homme de 56 ans. Description des signes tomodensitometriques de cette lesion et revue de la litterature. Discussion des signes histopathologiques. Role de l'hyperplasie reactionnelle des fibres elastiques dans la genese de cette lesion
Space charge limited ac conduction with non-blocking electrodes

Abstract A model calculation has been performed for space charge limited ac transport at a reversible interface. The continuity equation for current carriers is solved by a numerical method. The calculated frequency dependence of the conductance and the capacitance agrees with the experimental results on solution-silver chloride-solution couples.
Childhood Domestic Violence, Alcoholic Parents, and Adult Psychological Features

Purpose: In this study relationships of different types of domestic violence experiences and parental alcoholism in childhood with adult mental and family health were explored. Adult mental health outcomes included resilience, sense of belonging, life satisfaction, and depression. Methods: Data for this secondary analysis were from a cross-sectional study employing a web-based survey of 206 Koreans, including 30 adult children of alcoholics (ACOAs). A two-step cluster analysis was performed with seven domestic violence experience items as determinants of cluster membership. Results: In the ACOA cohort, four clusters were identified by childhood domestic violence experience—Low Violence, Witness, Emotional Violence, and Multiple Violence. Only two clusters were found among non-ACOAs—None versus Multiple Violence. All adult mental health and family health characteristics were significantly different between these six empirically-derived clusters. The ACOAs in the Emotional Violence group showed the lowest resilience and sense of belonging, and highest depression scores, which were significantly different from each corresponding score of the ACOAs in the Witness group. ACOAs who experienced multiple violence showed lowest level of family health among the six clusters. Conclusion: The findings indicate that ACOAs and non-ACOAs may have very different patterns of childhood domestic violence, which are associated with distinct psychological entities in adulthood.
What level of dialtone penetration constitutes ‘universal service’?☆

Abstract This paper focuses on estimating whether a natural level of non-penetration exists, and if so, what the maximum attainable penetration rate is. Universal service penetration levels have steadily increased over the last decade. This paper hypothesizes that penetration levels will level off over time at some point below 100%. Econometric models have been created to estimate penetration rates as a function of several explanatory variables, including per capita personal income, price changes for residential local service, price changes for toll services, and the existence of lifeline programs. The modeling results also provide information on cross-elasticities between toll and local service and the effects of the FCC's subscriber line charges and lifeline programs on the universal service policy goal. In summary, this research provides new information on the topic of what constitutes universal service and provides considerable data regarding own-price and cross-price elasticities associated with residential local service.
Marker-Assisted Selection for Resistance to Black Shank Disease in Tobacco.

ABSTRACT Bulked segregant (BSA) and random amplified polymorphic DNA (RAPD) analyses were used to identify markers linked to the dominant black shank resistance gene, Ph, from flue-cured tobacco (Nicotiana tabacum) cv. Coker 371-Gold. Sixty RAPD markers, 54 in coupling and 6 in repulsion phase linkage to Ph, were identified in a K 326-derived BC1F1 (K 326-BC1F1) doubled haploid (DH) population. Thirty RAPD markers, 26 in coupling and 4 in repulsion phase linkage to Ph, were used to screen 149 K 326-BC2F1 haploid plants. Complete linkage between the 26 coupling phase markers and Ph was confirmed by screening 149 K 326-BC2F1 DH lines produced from the haploid plants in black shank nurseries. RAPD markers OPZ-5770 in coupling and OPZ-7370 in repulsion phase linkage were used to select plants homozygous for the Ph gene for further backcrossing to the widely grown flue-cured cultivar K 326. Black shank disease nursery evaluation of 11 K 326-BC4S1 lines and their testcross hybrids to a susceptible tester confir...
Digitopolis meets encalming technology

Digitopolis (the city-like ecosystem of the computer industry) has to keep expanding its installed base or it will go into a major depression. To stay vibrant, Digitopolis requires a rapidly expanding market for computerized gadgets. Given the ever-shorter life cycles for hi-tech products, this is becoming increasingly difficult-unless the units shipped or profit margins go up dramatically. The answer: build network appliances, automobiles, telephones, games, and wallet computers as fast as consumers will adopt them. Thus, the next big thing will be gadgets. The author looks at two scenarios of what might happen in the industry's network appliance segment. In the first scenario, the network appliance is all user interface. In the second, the network appliance is invisible; it disappears.
Sinus histiocytosis in non-diagnostic scalene lymph node biopsies

In view of the reported low incidence of sinus histiocytosis (SH) in benign diseases, an attempt was made to document whether the presence of SH in scalene lymph node biopsies was a reliable indicator of underlying cancer. Of 141 consecutive scalene node biopsies, 38 (27%) were diagnostic for various diseases and 3 were inadequate. The remaining 100 cases were analyzed for presence or absence of SH, and these findings were correlated with the presence or absence of clinically and pathologically documented cancer. SH was found not to be useful as an indicator of the presence of cancer, since only 26 of 41 SH-positive cases were proven to have cancer. In lung cancer patients, the presence or absence of SH in scalene nodes did not provide useful prognostic information, since the rates of operability and of 1-year survival were similar among SH-positive and SH-negative cases.
Effect of Interfacial Reaction on the Thermal Conductivity of Al–SiC Composites with SiC Dispersions

The effect of interfacial reactions between Al and SiC on the thermal conductivity of SiC-particle-dispersed Al-matrix composites was investigated by X-ray diffraction and transmission electron microscopy (TEM), and the thermal barrier conductance (h c ) of the interface in the Al-SiC composites was quantified using a rule of mixture regarding thermal conductivity. Al-SiC composites with a composition of Al (pure Al or Al-11 vol% Si alloy)-66.3 vol% SiC and a variety of SiC particle sizes were used as specimens. The addition of Si to an Al matrix increased the thermal barrier conductance although it decreased overall thermal conductivity. X-ray diffraction showed the formation of Al 4 C 3 and Si as byproducts in addition to Al and SiC in some specimens. TEM observation indicated that whiskerlike products, possibly Al 4 C 3 , were formed at the interface between the SiC particles and the Al matrix. The thermal barrier conductance and the thermal conductivity of the Al-SiC composites decreased with increasing Al 4 C 3 content. The role of Si addition to an Al matrix was concluded to be restraining an excessive progress of the interfacial reaction between Al and SiC.
Maintaining phase of the tri-phasic crab pyloric rhythm

Synaptic depression is a type of short-term plasticity that is observed in many rhythmically active networks [1]. We examine the role that synaptic depression plays in determining the phase of a group of neurons of the crab stomatogastric nervous system. We mathematically construct and analyze a model network consisting of an oscillator neuron that inhibits two follower neurons. We show that constant phase maintenance can be achieved solely through the interplay of the two follower neurons due to the depressive nature of their synaptic connectivity.
Cell cycle G2/M arrest through an S phase-dependent mechanism by HIV-1 viral protein R

Cell cycle G2 arrest induced by HIV-1 Vpr is thought to benefit viral proliferation by providing an optimized cellular environment for viral replication and by skipping host immune responses. Even though Vpr-induced G2 arrest has been studied extensively, how Vpr triggers G2 arrest remains elusive. To examine this initiation event, we measured the Vpr effect over a single cell cycle. We found that even though Vpr stops the cell cycle at the G2/M phase, but the initiation event actually occurs in the S phase of the cell cycle. Specifically, Vpr triggers activation of Chk1 through Ser345 phosphorylation in an S phase-dependent manner. The S phase-dependent requirement of Chk1-Ser345 phosphorylation by Vpr was confirmed by siRNA gene silencing and site-directed mutagenesis. Moreover, downregulation of DNA replication licensing factors Cdt1 by siRNA significantly reduced Vpr-induced Chk1-Ser345 phosphorylation and G2 arrest. Even though hydroxyurea (HU) and ultraviolet light (UV) also induce Chk1-Ser345 phosphorylation in S phase under the same conditions, neither HU nor UV-treated cells were able to pass through S phase, whereas vpr-expressing cells completed S phase and stopped at the G2/M boundary. Furthermore, unlike HU/UV, Vpr promotes Chk1- and proteasome-mediated protein degradations of Cdc25B/C for G2 induction; in contrast, Vpr had little or no effect on Cdc25A protein degradation normally mediated by HU/UV. These data suggest that Vpr induces cell cycle G2 arrest through a unique molecular mechanism that regulates host cell cycle regulation in an S-phase dependent fashion.
Boolean comparison of hardware and flowcharts

Boolean comparison is a design verification technique in which two logic networks are compared for functional equivalence using analysis rather than simulation. Boolean comparison was used on the IBM 3081 project to establish that hardware flowcharts and the detailed hardware logic design were functionally equivalent. Hardware flowcharts are a graphic form of a hardware description language which describes the logical behavior of the machine in terms of the inputs, outputs, and latches. The logical correctness of the hardware flowcharts was previously established via cycle simulation. The concepts and techniques of Boolean comparison as used on the IBM 3081 project are described.