cssi/SciSciGPT-SciSciNet huggingface dataset:
Zona pellucida protein binding ability of porcine sperm during epididymal maturation and the acrosome reaction.

In many mammals, the first interaction between gametes during fertilization occurs when sperm contact the zona pellucida surrounding the egg. Although porcine sperm first contact the zona pellucida via their plasma membrane, the regions of the sperm surface that display zona receptors have not been determined. We have used the Alexa 488 fluorophore conjugated to solubilized porcine zona pellucida proteins to observe zona receptors on live boar sperm. Zona proteins bound live, acrosome-intact sperm on the anterior portion of the sperm head, concentrated in a thin band over the acrosomal ridge. When sperm membranes were permeabilized by fixation or acrosome reactions induced by the ionophore A23187, zona binding was extended to a broad area covering the entire acrosomal region. Zona binding proteins were present in the acrosomes of sperm from all regions of the epididymis. In contrast, zona binding sites were found on the plasma membrane of most sperm from the corpus and cauda epididymis, but on only 6% of caput epididymil sperm. In conclusion, acrosome-intact boar sperm exhibit concentrated zona protein binding over the acrosomal ridge and acquire this binding in the corpus region of the epididymis, correlating with the developmental stage at which sperm gain the ability to fertilize oocytes.
Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the canine heart

Single-beat imaging of myocardial activation promises to aid in both cardiovascular research and clinical medicine. In the present study we validate a three-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of simultaneous 3D intracardiac mapping to assess its capability to localize endocardial and epicardial initiation sites and image global activation sequences during pacing and ventricular tachycardia (VT) in the canine heart. Body surface potentials were measured simultaneously with bipolar electrical recordings in a closed-chest condition in healthy canines. Computed tomography images were obtained after the mapping study to construct realistic geometry models. Data analysis was performed on paced rhythms and VTs induced by norepinephrine (NE). The noninvasively reconstructed activation sequence was in good agreement with the simultaneous measurements from 3D cardiac mapping with a correlation coefficient of 0.74 ± 0.06, a relative error of 0.29 ± 0.05, and a root mean square error of 9 ± 3 ms averaged over 460 paced beats and 96 ectopic beats including premature ventricular complexes, couplets, and nonsustained monomorphic VTs and polymorphic VTs. Endocardial and epicardial origins of paced beats were successfully predicted in 72% and 86% of cases, respectively, during left ventricular pacing. The NE-induced ectopic beats initiated in the subendocardium by a focal mechanism. Sites of initial activation were estimated to be ∼7 mm from the measured initiation sites for both the paced beats and ectopic beats. For the polymorphic VTs, beat-to-beat dynamic shifts of initiation site and activation pattern were characterized by the reconstruction. The present results suggest that 3DCEI can noninvasively image the 3D activation sequence and localize the origin of activation of paced beats and NE-induced VTs in the canine heart with good accuracy. This 3DCEI technique offers the potential to aid interventional therapeutic procedures for treating ventricular arrhythmias arising from epicardial or endocardial sites and to noninvasively assess the mechanisms of these arrhythmias.
Dermatoglyphic variation in Europe

We describe the geographic variation patterns of 236 dermatoglyphic variables (118 for each sex) for 74 samples in Europe. Using principal components analysis and rotating to simple structure, we simplified these patterns to the first 20 axes, representing 74.2% of covariation. We then used heterogeneity tests, interpolated surfaces, one-dimensional and directional correlograms, and distances between correlograms to analyze the factor scores of these 20 axes. We also ordinated the 74 localities. The data are remarkable for showing little spatial autocorrelation, despite significant heterogeneity among localities. Only three factor axes exhibit consistently significant correlograms, indicating that there are few spatial patterns in the original variables in Europe. Almost all correlations between pairs of variables occur within serially homologous character sets and are thus developmentally determined. There is some support for demic diffusion from the southeast in finger patterns and ridge counts. We compare these results to those of previous studies and note that Lapps and Icelanders are outliers with respect to both genetics and finger tip variables, whereas Tatars are outliers with respect to craniometrics and dermatoglyphics.
Empowerment interventions for older adults.

There has been much discussion regarding the need to empower older adults to make informed health decisions and to test interventions targeting empowerment to promote health among older adults. It has been suggested that an empowerment approach may nurture an older adult’s participation in health care decisions and promote positive health outcomes. The purpose of this article is to report the findings of a critical review of published empowerment intervention studies with community-dwelling older adults. A descriptive literature review was conducted to examine how empowerment is conceptualized across interventions, the guiding theoretical frameworks, the outcomes measured, as well as the health outcomes of these interventions. Based on the findings from this review, recommendations for future empowerment intervention research with older adults as well as implications for practice are proposed.
Classical atomistic simulations of surfaces and heterogeneous interfaces with the charge-optimized many body (COMB) potentials

Interest in atomic scale computational simulations of multi-phase systems has grown as our ability to simulate nanometer-sized systems has become commonplace. The recently developed charge optimized many body potential (COMB) potentials have significantly enhanced the atomic-scale simulation of heterogeneous material systems, including chemical reactions at surfaces and the physical properties of interfaces. The COMB formalism, which merges variable charge electrostatic interactions with a classical analytical potential, has the capacity to adaptively model metallic, covalent, ionic and van der Waals bonding in the same simulation cell and dynamically determine the charges according to the local environment. Presented here is the theoretical background and evolution of the COMB potential family. The parameterization of the potential is described for several metals, ceramics, a semiconductor, and hydrocarbons, with the intent that the final parameter sets are consistent among materials. The utility of this approach is illustrated with several examples that explore the structure, stability, and mechanical and thermal properties of metallic systems and metal-ceramic and semi-conductor oxide interfaces, including surfaces and/or interfaces of copper and cuprite, copper and silica, silicon and silica, silicon and hafnia, and copper and zinc oxide. The potential is also applied to the simulation of atomic scale processes such as early stage oxidation of copper surfaces, tensile test of polycrystalline zirconium, and hyper-thermal deposition of ethyl radicals on selected copper surfaces.
Effect of heating on dissociation of water vapor in high-frequency plasmas and formation of hydrogen peroxide in a cold trap downstream of the plasma

At low flow rates (0.7–2.8 mmol hr−1) and long residence times (2.3–8.5 s) nearly 60% of the input water vapor was decomposed by a 13.56-MHz rf discharge. Downstream of the discharge a trap cooled by liquid nitrogen collected nearly constant yields of H2O2. The decomposition is representable by the equation 2H2O=H2O2+H2. The overall rate of decomposition was found to depend on the absorbed power density. Heating the rf plasma and its spatial afterglow from 25 to 600°C did not significantly change the percent decomposition of H2O and the formation of H2O2. Above 600°C, however, a continuous decrease in H2O2 yield was observed with increasing temperature, and this was associated with the increasing formation of H2O from the dissociated products such as highly excited OH radicals which otherwise produce the precursors of H2O2. The same heating effects were observed in the case of the spatial afterglow of a 2.45-GHz microwave cavity discharge in water vapor under essentially similar conditions. It appears that at the high temperatures the reaction OH+OH→H2O+O is favored over the reaction O+OH→O2+H. This limits the formation of O2 and consequently decreases the H2O2 yield.
Molecular Gas in the NGC 6334 Star Formation Region

We present millimeter- and centimeter-wave spectroscopic observations of the southern massive star formation region NGC 6334. The cloud has been mapped in several transitions of CO,13CO, CS, and NH3. The molecular gas shows a complex structure of filaments, in which the massive star formation occurs, and bubbles, some of which contain photodissociated gas. There is an anticorrelation between the presence of dense gas and the 6 cm radio flux: the hottest stars, with the hardest FUV radiation, have dispersed the dense gas from which they formed, whereas the cooler stars have not yet been able to do so. There is a velocity gradient along the star-forming ridge such that the radial velocity peaks in the center of the ridge. Several blueshifted emission features were discovered, one of which was identified with the 3-kpc arm of the Galaxy. Excitation model calculations were used to determine the physical conditions of the molecular gas in NGC 6334. The average kinetic temperature, hydrogen volume, and column densities at the continuum sources are as follows: -->img1.gif = 56 ± 11 K, log -->img2.gif -->img3.gif (cm-3) = 3.5 ± 0.3, and -->img4.gif -->img3.gif (1022 cm-2) = 7 ± 4, respectively. The properties of the molecular gas are compared to those in other massive star-forming clouds to determine that NGC 6334 is representative of massive star-forming regions in the Galaxy and can therefore be used to test the predictions of the theoretical models of photodissociation regions. The properties of the individual sites of star formation in the cloud are also discussed.
The maintenance and disambiguation of object representations depend upon feature contrast within and between objects.

The brain processes many aspects of the visual world separately and in parallel, yet we perceive a uniﬁed world populatedby objects. In order to create such a “bound” percept, the visual system must construct object-centered representations outof separate features and then maintain the representations across changes in space and time. Here, we examine the role offeatures themselves in maintaining and disambiguating the representations of the objects to which they belong. In threeexperiments, we measure how the perceived motion of two objects traversing ambiguous trajectories is affected by thecontrast between the features and surrounding ﬁelds, by the contrast between features, and by changes to orientation oftexture within objects. We report that the maintenance and disambiguation of object representations depend on the contrastof the features relative to their surrounds and on the extent of feature differences between the two objects. These featuredependencies indicate that object representation relies on relative response to many stimulus dimensions.Keywords: feature correspondence, object representation, object ﬁle, stream bounceCitation: Caplovitz, G. P., Shapiro, A. G., & Stroud, S. (2011). The maintenance and disambiguation of objectrepresentations depend upon feature contrast within and between objects. Journal of Vision, 11(14):1, 1–14,http://www.journalofvision.org/content/11/14/1, doi:10.1167/11.14.1.
The reactivity of red blood cell membrane glycophorin with "cold-reacting" antibodies.

Abstract The major human erythrocyte membrane glycoprotein, glycophorin, was isolated by the method of Marchesi, using LIS (lithium 3,5-diiodosalicylate). The antigens reacting with the “cold-reacting” antibodies, anti-I, anti-i, and anti-P (Donath-Landsteiner antibody), were demonstrated to be present on the glycophorin molecule by inhibition of antibody-induced lysis or of antibody adsorption, using radiolabeled, purified antibodies. Although these antibodies do not react with red cells at 37°C, they react with isolated glycophorin at this temperature.
Value of the cerebrospinal fluid as an indicator of cerebral metabolic changes.

Abstract Ventilation with a gas mixture containing 8% O2 produces cerebral hypoxia in the dog and a shift to anaerobic metabolism and increases the release of lactate by the brain, which is evident immediately in the CSF. These changes were detected within 10 minutes and would indicate that the CSF is an adequate and sensitive indicator of cerebral metabolism. The CSF parameters, therefore, seem to be a true reflection of cerebral metabolic status and confirm the reliability of the use of CSF to study alterations in brain metabolism.
Myocyte Enhancer Factor 2 Mediates Calcium-dependent Transcription of the Interleukin-2 Gene in T Lymphocytes A CALCIUM SIGNALING MODULE THAT IS DISTINCT FROM BUT COLLABORATES WITH THE NUCLEAR FACTOR OF ACTIVATED T CELLS (NFAT)

The second messenger calcium plays an essential role in the T cell receptor-mediated signal transduction pathways leading to transcription of the interleukin-2 gene. A key mechanism of calcium signaling has been shown to be mediated by calcineurin and NFAT. We report herein that the transcription factor myocyte enhancer factor (MEF)-2 is another calcium signal transducer involved in the regulation of the interleukin (IL)-2 promoter. A MEF2-binding site was identified in proximity to the TATA box of the IL-2 promoter. This site was shown to be bound by MEF2 in both resting and activated T cells. Overexpression of MEF2 enhanced, while overexpression of a dominant negative form of MEF2 or the MEF2-specific transcriptional corepressors Cabin1 and histone deacetylase 4 inhibited, the T cell receptor-dependent activation of an IL-2 reporter gene. Down-regulation of MEF2 by RNA interference in primary human T cells led to the inhibition of endogenous IL-2 transcription. These results suggest that MEF2 is required for the transcriptional activation of IL-2 and likely other cytokine genes in response to calcium signaling and may serve as a novel target for development of immunosuppressants.
Suspended sediment and thermal stratification in Santa Barbara Channel, California

Abstract Utilizing suspended detritus as a natural tracer, a continuously-recording beam transmissometer and combined temperature probe aided in determining the geometry of a two-current surface water circulation pattern with numerous large and small eddies in Santa Barbara Channel. In addition, this instrument has revealed a close association between turbid layers and vertical thermal gradients off southern California. Thermoclines with only a 0·1°C change are commonly the locus of major concentrations of suspended matter. The influence of temperature-induced density gradients in surficial waters over the continental shelf constitutes an important obstacle to suggested processes of fine-grained particle transport involving low-density downslope flow. Transmissometer observations in Santa Barbara Channel show near-bottom turbid layers becoming detached from the bottom at the shelf-break.
EFFECT OF PH, SULFATE AND SODIUM ON THE EDTA TITRATION OF CALCIUM

Abstract The ethylenediaminetetraacetic acid (EDTA) titration method limits the measurement of calcium concentration to 50 mg/l in water. However, various acids and salt solutions are used in the investigation of the durability of concrete, and the adaptability of the EDTA titration method to determine the calcium in these solutions must be investigated. Hence, the purpose of this study was to investigate the interfering effects of hydrochloric acid, sulfuric acid, sodium chloride and sodium sulfate on measuring the calcium in the aqueous leaching solutions using the EDTA titration method. The calcium standard solutions were prepared using CaCl2 with initial pH from −0.8 to 7 and calcium concentration up to 160 mg/l. Sulfuric acid and hydrochloric acid were used to prepare calcium solutions with lower pH. Salt solutions with 3% NaCl and 3% Na2SO4 were used to evaluate the interfering effects of salt elements such as sulfate and sodium on the EDTA titration. Results indicated that the EDTA titration method was reliable in measuring the calcium up to 160 mg/l, the maximum concentration investigated in this study, in hydrochloric acid with pH higher than zero and 3% sodium chloride solution. Sulfuric acid with pH higher than zero and 3% sodium sulfate solutions showed 3% to 4% less calcium in the solutions. Acid solutions with pH less than zero showed interference with calcium measurement.
The linear cutting stapler may reduce surgical time and blood loss with muscle transection: a pilot study.

Because of skeletal muscle’s density and vascularity, its transection with standard electrocautery can be tedious. In a pilot study we asked whether a linear cutting stapling device decreased surgical time, blood loss, transfusion rates, and complications in patients undergoing above-knee amputation when compared to traditional electrocautery. We retrospectively reviewed 11 patients with above-knee amputation cases using a linear cutting stapling device over a 10-year period and compared those to 13 patients in whom we used electrocautery. The patients treated with the linear cutting stapling device had an average of 97 minutes of surgical time, 302 cc blood loss, and 1.55 units transfusion, compared to an average 119 minutes, 510 cc, and 2.15 units, respectively, with the electrocautery cases. Despite the trends, these parameters, as well as major complications, were similar in these two small groups. In skeletal muscle transection, we believe the linear cutting stapler is a reasonable and potentially cost-effective technical alternative to electrocautery, possibly resulting in less blood loss and shorter surgical time with similar rates of complications. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Alterations in postnatal intestinal function during chronic hypoxemia.

ABSTRACT: Growth failure is a major complication of chronic hypoxemia, as seen in infants and children with cyanotic congenital heart disease. To determine whether chronic hypoxemia during infancy affects the gastrointestinal tract, we examined small intestinal growth and digestive enzyme activities in chronically hypoxemic newborn lambs and in age-matched controls. Chronic hypoxemia was produced by placing an inflatable occluder around the main pulmonary artery and performing a balloon atrial septostomy. Aortic oxygen saturation was reduced to 60− 74% for 2 wk, after which the small intestine was removed for analysis. During chronic hypoxemia, somatic growth rate was decreased to 60% of control (hypoxemic, 135 $$ 20 versus control, 216 $$ 26 g/d5Jp < 0.02). No differences in caloric intake were found (hypoxemic, 129 $$ 4 versus control, 128 $$ 4 kcal/kg/d). Chronic hypoxemia did not alter small intestinal growth, as measured by jejuno-ileal weight, jejuno-ileal length, mucosal weight, or mucosal protein or DNA contents. However, sp act of lactase, the principal disaccharidase of the infant lamb intestine, were significantly decreased (hypoxemic, 0.08 ± 0.01 versus control, 0.146 ± 0.03 units of enzyme activity/mg DNA, p < 0.05), as were the total small intestinal contents of lactase (hypoxemic, 61.7 ± 7.0 versus control, 120.6 ± 21.7 units of enzyme activity, p < 0.01). There also were decreases in specific and total activities of other digestive enzymes such as maltase, amino-oligopeptidase, and alkaline phosphatase in hypoxemic intestine that did not achieve statistical significance. In conclusion, chronic hypoxemia in infancy is associated with decreases in activities of intestinal lactase, which may result in diminished capacity for absorption of dietary carbohydrate. Alterations in intestinal function may contribute to growth failure associated with chronic hypoxemia.
The Behavioral Economics of Driving After Drinking Among College Drinkers

BACKGROUND: Driving after drinking (DAD) among college students is a significant public health concern, yet little is known about specific theoretical risk factors for DAD, beyond drinking level, among college student drinkers. This study had the following aims: (i) to examine the associations between elevated alcohol demand and DAD, (ii) to determine whether demand decreases in response to a hypothetical driving scenario, (iii) to determine whether drivers who report DAD in the past 3 months would show less of a reduction in demand in response to the hypothetical driving scenario, and (iv) to determine whether delayed reward discounting (DRD) is associated with DAD. METHOD: Participants were 419 college students who reported at least 1 day of past-month alcohol use. Participants completed 2 alcohol purchase tasks (APTs) that assessed hypothetical alcohol consumption across 17 drink prices with and without a driving scenario, a delay-discounting task, and a series of questions regarding DAD. RESULTS: In logistic regression models that controlled for drinking level, demographics, and sensation seeking, participants reporting higher demand intensity (95% confidence interval [95% CI] [1.04, 2.34]), breakpoint (95% CI [1.23, 2.28]), Omax (95% CI [1.03, 1.53]), and lower elasticity (95% CI [0.15, 1.02]) were more likely to report DAD. Additionally, in analyses of covariance, DAD(+) participants exhibited significantly less of a reduction in demand between the standard and the driving APT (intensity, p CONCLUSIONS: DAD is associated with elevated/inelastic demand and less sensitivity to a hypothetical driving scenario. Drinkers with elevated demand should be prioritized for DAD intervention efforts. Language: en
The Epitaxial Growth of Copper on the (111) Surface of Silicon

The progression of the epitaxy of Cu(111) on Si(111) has been studied using surface sensitive techniques and the as-grown film studied using high resolution transmission electron microscopy (HRTEM). A molecular beam epitaxy (MBE) system has been used to deposit films on 3-inch-diameter silicon substrates. Across this large area a graded thickness of 0 to 10 nm of copper was deposited and scanned using Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). For films grown at 373 K, silicon alloys with the copper up to a thickness of 5.0 nm. LEED indicates an ordered $$\sqrt{3}\times\sqrt{3}$$ Cu(11) surface which results from the alloying of copper and silicon. HRTEM images from the interface region show the alloy to be 2.3 nm thick, crystalline, and epitaxial to the Si(111) surface. There are indications that the interface alloy may be a metastable copper silicide. This alloy is important in the mechanism for the growth of Cu(111) on Si(111).
Decrement of visual and haptic müller-lyer illusion on repeated trials: A study of crossmodal transfer

Abstract Twenty adults, 10 male and 10 female, ranging in age from 22 to 54 years, were asked to set the centre arrowhead of a Muller-Lyer pattern for 80 consecutive trials. Ten of the subjects did so visually, while 10 blindfolded subjects made the settings haptically, i.e. by active palpation. Following the 80th trial, those subjects who had been making settings visually were blindfolded and were asked to make six haptic settings. Conversely, those who had made 80 haptic settings proceeded to make six settings visually. The initial size of the illusion was essentially identical for the visual and haptic groups. Both groups showed significant decrement, since 19 of the 20 subjects had a smaller illusion on trials 71–80 than on trials 1–10. There was significant transfer of the decrement to the six settings made in the other modality. However, transfer effects were greater for the subjects who went from touch to vision than for those who went from vision to touch. Verbalization did not appear to be the ve...
Psychological Distress among the Community Elderly: Prevalence, Characteristics and Implications for Service

This paper reports the results of a survey of elderly persons living in a predominantly blue collar, New England town. Data about psychological distress and its relationship to demographic and social interaction characteristics are explored. Vulnerability to the stresses of aging increases where there is a habitual pattern of dependency, poor interpersonal skills and lack of social initiatives. Mental health services were not reaching the elderly in need and there was minimal utilization of other helping services. Some possible preventive interventions are discussed.
The Evolving Role of E-Books at The University of Alabama Libraries

During the fall of 2008, the librarians at Rodgers Library and the Associate Dean for Collections examined circulation statistics for print materials published in the past five years. At the same time, they were examining use of electronic resources in science and engineering. The difference in use was staggering. While the use of electronic resources continues to rise, the circulation of print materials falls. Statistics showed that only one third of the print materials ordered over the past five years have circulated, many only one time. Based on this information, the authors began discussing alternatives. While e-books will constitute a possible substitute for print books, they know that the two formats are complementary and will continue to maintain a balance in their collection. E-book acquisitions continue to evolve as new options become available.
HPMA Copolymer-Aminohexylgeldanamycin Conjugates Targeting Cell Surface Expressed GRP78 in Prostate Cancer

Purpose This study focused on the synthesis and in vitro characterization of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates for the delivery of geldanamycin to prostate cancer tumors. Conjugates were modified to incorporate WIFPWIQL peptide, which binds to cell-surface-expressed Glucose-regulated protein 78.
Effects of dexamethasone and indomethacin on elastase, α1-proteinase inhibitor, and fibronectin in bronchoalveolar lavage fluid from neonates

Elastase activity and concentrations of α 1 -proteinase inhibitor, albumin, and fibronectin were measured in bronchoaleolar lavage (BAL) fluid from ventilated lungs in preterm neonates with lung disease before and after treatment with dexamethasone or indomethacin. Treatment with dexamethasone was associated with a significant decrease in BAL elastase activity but no change in fibronectin, albumin, or α 1 -proteinase inhibitor concentrations. In contrast, treatment with indomethacin was associated with an increase in BAL elastase activity and fibronectin concentration, with no change in albumin or α 1 -proteinase inhibitor concentrations. Control groups showed no changes in these BAL fluid biochemical markers during a similar time period. These data indicate that treatment with corticosteroids decreases lung inflammation as measured by BAL elastase activity. Corticosteroid treatment may not inhibit the development of pulmonary fibrosis, because fibronectin concentrations in BAL fluid were unaffected. Indomethacin treatment may augment lung inflammation and fibrosis by increasing BAL elastase activity and fibronectin concentration.
A description of the Lorenz attractor at high prandtl number

Abstract We use the ideas of matched asymptotic expansions to construct a ‘solution’ of the Lorenz equations in the limit r≈σ→∞. Unlike the case r→∞, σ≈1 which exhibits limit cycle behaviour, the solutions in the present case can be ‘chaotic’; nevertheless, their structure can be analysed. Our aim is to obtain an analytic approximation of the ‘Lorenz map’ which plots successive maxima of the variable Z. Particularly, we are able to explain the peculiar cusp of this map. and indeed to predict the existence of many such cusps. It is our hope that the methods and ideas presented here may be of use in elucidating the nature of other systems which exhibit chaotic behaviour.
Family support and African American delinquency

Researchers have long noted the importance of family support in the prevention of delinquency. The presence of supportive family relationships is posited to decrease the probability of deviant attitudes and behaviors and to enhance a youth's competence, coping and self‐control skills (Wills et al., 1996). Although these assumptions have been empirically documented, research examining the nexus between family support and delinquency (and other mental and behavioral outcomes) has rarely analyzed how the variable impacts the lives of majority youths (Dilworth‐Anderson and Marshall, 1996) or its influence across different criteria. In this article, the role of family support in the delinquency of African American youths is examined. The study attempts to identify what factors influence perceptions of family support and examines the protective effects of family support on the prevalence of serious, moderate, and minor delinquency. The article begins with an overview of social support theory and how it differs ...
The role of methylation in the intrinsic dynamics of B- and Z-DNA.

Methylation of cytosine at the 5-carbon position (5mC) is observed in both prokaryotes and eukaryotes. In humans, DNA methylation at CpG sites plays an important role in gene regulation and has been implicated in development, gene silencing, and cancer. In addition, the CpG dinucleotide is a known hot spot for pathologic mutations genome-wide. CpG tracts may adopt left-handed Z-DNA conformations, which have also been implicated in gene regulation and genomic instability. Methylation facilitates this B-Z transition but the underlying mechanism remains unclear. Herein, four structural models of the dinucleotide d(GC)5 repeat sequence in B-, methylated B-, Z-, and methylated Z-DNA forms were constructed and an aggregate 100 nanoseconds of molecular dynamics simulations in explicit solvent under physiological conditions was performed for each model. Both unmethylated and methylated B-DNA were found to be more flexible than Z-DNA. However, methylation significantly destabilized the BII, relative to the BI, state through the Gp5mC steps. In addition, methylation decreased the free energy difference between B- and Z-DNA. Comparisons of α/γ backbone torsional angles showed that torsional states changed marginally upon methylation for B-DNA, and Z-DNA. Methylation-induced conformational changes and lower energy differences may contribute to the transition to Z-DNA by methylated, over unmethylated, B-DNA and may be a contributing factor to biological function.
Classification of medically important viruses II: RNA viruses

The early attempts to classify viruses were based on diseases they caused or on the site of their recovery. They were grouped according to the assumed trophism or affinity for different systems or organs of the body. Thus, human viruses were classified as neurotropic--i.e., those affecting the nervous system (poliomyelitis, rabies), pneumotropicm i.e., those affecting the respiratory system (influenza, common cold), dermotropic i.e., those producing the skin lesions (smallpox, chickenpox, measles), and viscerotropic---i.e., those affecting the visceral organs (yellow fever, hepatitis). This system did not gain acceptance because different viruses could cause similar symptoms. In 1941, Bawden suggested that the viral nomenclature and classification should be based on the properties of the viruses and not upon the host responses. From early 1950s, viruses began to be classified into groups on the basis of their physicochemical and structural features. Currently, viruses are classified into two major groups on the basis of the type of nucleic acid they possess: the riboviruses (RNA-containing) and deoxyriboviruses (DNA-containing). Further classification is based on the other properties of the viruses such as the strandedness of nucleic acid (single or double), polarity of nucleic acid (positive or negative), capsid symmetry (icosahedral, helical, or complex), site of capsid assembly (nucleus or cytoplasm), envelope (presence or absence), site of envelopment (surface membrane, nuclear membrane, or intracytoplasmic membrane), virion and capsid diameter, number of capsomeres, and molecular weight of nucleic acid in the virion. Another striking feature of the present classificatiou is that the virus family names end in "...viridae," subfamily names end in "...virinae," and genus names end in "...virus." So far, twenty-one families of animal viruses have been described. As the knowledge increases, periodic revisions among different groups are made by an international nomenclature committee. The committee, originally established in 1966 as the International Committee on Nomenclature of Viruses (ICNV), was changed in 1974 to International Committee on Taxonomy of Viruses 0CTV). Information on classification of animal viruses will appear in two successive articles in this newsletter, starting in this issue with Part I, the DNA viruses. The chemical and mo~phologic properties of DNA-containing animal virus families are shown in Table 1.
The incidence of cystic fibrosis

We develop a statistical model for estimating cystic fibrosis (CF) incidence among infants born in the U.S.A. that accounts for under-diagnosis due to death prior to diagnosis and we apply it to the Cystic Fibrosis Foundation Patient Registry data for the years 1989 to 1991. The resulting estimate of incidence relative to live births among whites is 1:3419 while that among non-whites is 1:12,163. As a by-product of the modelling approach, estimates of the underlying average diagnosis age given survival to diagnosis are 4.09 years for whites and 4.55 years for non-whites, but this difference was not statistically significant and appears to demonstrate that diagnosis efforts may be approximately the same for whites and non-whites. Also, as another by-product of the modelling approach, CF mortality was estimated as more severe for females than males and marginally more severe for non-whites than whites. A variety of statistical methods underlie achievement of these results, including semi-parametric maximum likelihood, survival analysis, multiple imputation and bootstrap techniques.
High-pressure liquid chromatographic analysis of hemolymph plasma catecholamines in immune-reactive Aedes aegypti

Tyrosine and catecholamines have been implicated as substrates for the encapsulation reactions involved in the immune response of mosquitoes to microfilariae (mff). Identification and quantitation of tyrosine and catecholamines present in Aedes aegypti hemolymph plasma were accomplished by ion-pair high-pressure liquid chromatography with electrochemical detection at either +650 or +850 mV vs Ag/AgCl. Tyrosine, dopamine, and N-beta-alanyldopamine were detected in the hemolymph plasma of naive A. aegypti. Although no differences in these compounds were observed in hemolymph plasma from A. aegypti inoculated with Dirofilaria immitis mff, the chromatogram showed a single major peak (PI) (65 microM, expressed as dopamine equivalents) that was not present in naive hemolymph plasma. Saline-inoculated controls contained only 5% of the PI in immune reactive hemolymph plasma. A high concentration of PI (127 +/- 39 microM) was also detected after treatment of hemolymph plasma with mild alkaline conditions (pH 9.0), indicating that it is normally present as an electrochemically inert form in naive mosquitoes. High concentrations of PI were also detected in the naive hemolymph plasma from three other mosquito species, but no PI was found in A. trivittatus under any conditions. PI did not cochromatograph with any of the catecholamines commonly thought to be involved in immune responses of dipterans against metazoan parasites, suggesting that it may be a unique substrate for these reactions. The biological relevance of PI was evidenced by its appearance in the hemolymph plasma of two strains of D. immitis-inoculated A. aegypti.
Kinetic compartmental analysis of carnitine metabolism in the dog

This study was undertaken to quantitate the dynamic parameters of carnitine metabolism in the dog. Six mongrel dogs were given intravenous injections of L-[methyl-3H]carnitine and the specific radioactivity of carnitine was followed in plasma and urine for 19-28 days. The data were analyzed by kinetic compartmental analysis. A three-compartment, open-system model [(a) extracellular fluid, (b) cardiac and skeletal muscle, (c) other tissues, particularly liver and kidney] was adopted and kinetic parameters (carnitine flux, pool sizes, kinetic constants) were derived. In four of six dogs the size of the muscle carnitine pool obtained by kinetic compartmental analysis agreed (+/- 5%) with estimates based on measurement of carnitine concentrations in different muscles. In three of six dogs carnitine excretion rates derived from kinetic compartmental analysis agreed (+/- 9%) with experimentally measured values, but in three dogs the rates by kinetic compartmental analysis were significantly higher than the corresponding rates measured directly. Appropriate chromatographic analyses revealed no radioactive metabolites in muscle or urine of any of the dogs. Turnover times for carnitine were (mean +/- SEM): 0.44 +/- 0.05 h for extracellular fluid, 232 +/- 22 h for muscle, and 7.9 +/- 1.1 h for other tissues. The estimated flux of carnitine in muscle was 210 pmol/min/g of tissue. Whole-body turnover time for carnitine was 62.9 +/- 5.6 days (mean +/- SEM). Estimated carnitine biosynthesis ranged from 2.9 to 28 mumol/kg body wt/day. Results of this study indicate that kinetic compartmental analysis may be applicable to study of human carnitine metabolism.
Markers to Evaluate the Quality and Self-Renewing Potential of Engineered Human Skin Substitutes In Vitro and after Transplantation

We screened a series of antibodies for their exclusive binding to the human hair follicle bulge. In a second step these antibodies were to be used to identify basal keratinocytes and potential epithelial stem cells in the human epidermis and in engineered skin substitutes. Of all the antibodies screened, we identified only one, designated C8/144B, that exclusively recognized the hair follicle bulge. However, C8/144B-binding cells were never detected in the human epidermal stratum basale. In the bulge C8/144B-binding cells gave rise to cytokeratin 19-positive cells, which were also tracked in the outer root sheath between bulge and the hair follicle matrix. Remarkably, cytokeratin 19-expressing cells were never detected in the hair follicle infundibulum. Yet, cytokeratin 19-expressing keratinocytes were found in the epidermal stratum basale of normal skin as a subpopulation of cytokeratin 15-positive (not C8/144B-positive) basal keratinocytes. Cytokeratin 19/cytokeratin 15-positive keratinocytes decreased significantly with age. We suggest that cytokeratin 19-expressing cells represent a subpopulation of basal keratinocytes in neonates and young children (up to 1.5 years) that is particularly adapted to the lateral expansion of growing skin. Our data show that cytokeratin 19 in combination with cytokeratin 15 is an important marker to routinely monitor epidermal homeostasis and (at least indirectly) the self-renewing potential of engineered skin.
Effects of Low Levels of Salinity on Production Characteristics of Fingerling Channel Catfish Reared from Fry

Abstract Two production trials were conducted to determine the effects of low levels of salinity on production characteristics of fingerling channel catfish Ictalurus punctatus reared from fry under simulated nursery pond conditions. In each trial, fry were stocked into 10,000-L earthen-bottom pools at salinities of 0, 1, 2, or 4 g NaCl/L and reared for 170-d to produce fingerling catfish. At termination, selected production characteristics (weight, length, total yield, percent survival, feed conversion ratio, and feed consumption) were determined. In both trials, final weight and length of fish was greatest at a salinity of 1 g/L. Total yields of fish reared at salinities of 0, 1, or 2 g/L were not significantly different; however, yield was reduced at a salinity of 4 g/L. Survival and feed conversion ratio were not significantly affected by salinity levels tested. The total amount of feed fed to fish reared at a salinity of 4 g/L was significantly less than that fed to fish reared at salinities of 0 and...
Initial epistemological beliefs transformation in one teacher education classroom: Case study of four preservice teachers

Abstract Education literature suggests that preservice teachers hold similar initial beliefs, viewing the teacher as the authority figure passing knowledge to the students. In consistency with constructivist practice, these beliefs should be challenged to enable the preservice teachers to develop alternative ideas, seeing the students capable of constructing knowledge with the help of the teacher. These beliefs are found difficult to change in the course environment. Drawing on surveys and teaching observations from four preservice teachers in an introduction methods course, the study showed that the four participants had different epistemological beliefs, some beliefs being more resistant to change than others.
Interfacial tensions of binary and ternary two‐phase liquid systems

A theory is developed to enable prediction of interfacial tension in unsymmetrical, regular, binary liquid systems from solubility data. This is also shown to be applicable to nonregular aqueous binary systems by using solubility parameters and molar volumes calculated from mutual solubilities as substitutes for true molar volumes and the solubility parameters obtained from energies of vaporization. The theory is extended to include unsymmetrical, regular, ternary liquid systems, and is shown to be applicable to systems consisting of perfluoro-n-hexane and other nonpolar organic liquids. The theory is not adequate for aqueous ternary systems.
A concept learning network based on correlation and backpropagation

A new concept learning neural network is presented. This network builds correlation learning into a rule learning neural network where the certainty factor model of traditional expert systems is taken as the network activation function. The main argument for this approach is that correlation learning can help when the neural network fails to converge to the target concept due to insufficient or noisy training data. Both theoretical analysis and empirical evaluation are provided to validate the system.
Demazure Crystals and Extended Young Diagrams

For a suitable sequence of Weyl group elements {w(l)}l≥0 we give explicit combinatorial descriptions of the crystals Bw(l)(kΛ0) for the Demazure modules Vw(l)(kΛ0) of the quantum affine Lie algebra in terms of extended Young diagrams.
Surprising consequences of ion conservation in electro-osmosis over a surface charge discontinuity

A variety of microfluidic technologies utilise electrokinetic transport over rigid surfaces possessing rapid variations in charge. Here, as a paradigmatic model system for such situations, we consider electro-osmosis past a flat plate possessing a discontinuous jump in surface charge. Although the problem is relatively simple to pose, our analysis highlights a number of interesting and somewhat surprising features. Notably, the standard assumption that the electric field outside the diffuse screening layer is equal to the uniform applied field leads to a violation of ion conservation, since the applied field drives an ionic surface current along the diffuse layer downstream of the jump, whereas there is zero surface current upstream. Instead, at the surface charge discontinuity, field lines are drawn into the diffuse layer to supply ions from the bulk electrolyte, thereby ensuring ion conservation. A simple charge conservation argument reveals that the length-scale over which this process occurs is of the order of the ratio of surface-to-bulk electrolyte conductivities, LH=σs/σb. For a highly charged surface, LH can be several orders of magnitude greater than the Debye screening length λD, which is typically nanometres in size. Remarkably, therefore, nano-scale surface conduction may cause micrometre-scale gradients in the bulk electric field. After a distance O(LH) downstream, the bulk field ‘heals’ and is once again equal to the applied field. Scaling all distances with the ‘healing length’ LH yields a universal set of equations for the bulk field and fluid flow, which are solved numerically. Finally, we discuss the role of surface conduction in driving a non-uniform ion distribution, or concentration polarization, in the bulk electrolyte.
Hydroxyurea and Etoposide: In Vitro Synergy and Phase I Clinical Trial

L1210 murine leukemia cells were treated with hydroxyurea (10-200 microM) for 24 hours and/or etoposide (0.17-3.4 microM) for 2 hours. Combination treatments used a fixed molar hydroxyurea:etoposide ratio of 58.9:1, and drug-drug interactions were quantitated according to the median effect principle. Hydroxyurea and etoposide were antagonistic at low doses at which the survival fraction was greater than 0.5 and synergistic at higher doses at which the survival fraction was less than 0.25. In a phase I clinical trial, 19 patients were treated with the two drugs at one of three dose levels. The dose-limiting toxic effect was myelosuppression. Doses of 100 mg of etoposide/m2 per day by continuous infusion and 500 mg of hydroxyurea orally every 4 hours, both for 3 days, are recommended for phase II trials.
Prepregnancy body mass index in a first uncomplicated pregnancy and outcomes of a second pregnancy.

Objective This study examined the effect of body mass index (BMI) before a first uncomplicated pregnancy on maternal and fetal outcomes in a subsequent pregnancy, including preterm births, preeclampsia, cesarean delivery, small for gestational age, large for gestational age, and neonatal deaths. Study Design We conducted a population-based cohort study (n = 121,092) using the Missouri maternally linked birth registry (1989 through 2005). Multivariable binary logistic regression models were fit to estimate odds ratios and 95% confidence intervals for the parameters of interest after controlling for sociodemographic and pregnancy-related confounders in the second pregnancy. Results Compared to women with a normal BMI in their first pregnancy, those who were underweight prepregnancy had increased odds for preterm birth by 20% and small for gestational age by 40% in their second pregnancy, while those with prepregnancy obesity had increased odds for large for gestational age, preeclampsia, cesarean delivery, and neonatal deaths in their second pregnancy by 54%, 156%, 85%, and 37%, respectively. Conclusion Women starting a first pregnancy with suboptimal BMI may be at risk of adverse maternal and fetal outcomes in a subsequent pregnancy, even if their first pregnancy was uncomplicated or if they reached a normal weight by their second pregnancy. The long-term consequences of suboptimal BMI carry considerable public health implications.