cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanisms for redox-regulation of protein kinase C

Protein kinase C (PKC) is comprised of a family of signal-regulated enzymes that play pleiotropic roles in the control of many physiological and pathological responses. PKC isoforms are traditionally viewed as allosterically activated enzymes that are recruited to membranes by growth factor receptor-generated lipid cofactors. An inherent assumption of this conventional model of PKC isoform activation is that PKCs act exclusively at membrane-delimited substrates and that PKC catalytic activity is an inherent property of each enzyme that is not altered by the activation process. This traditional model of PKC activation does not adequately explain the many well-documented actions of PKC enzymes in mitochondrial, nuclear, and cardiac sarcomeric (non-sarcolemmal) subcellular compartments. Recent studies address this dilemma by identifying stimulus-specific differences in the mechanisms for PKC isoform activation during growth factor activation versus oxidative stress. This review discusses a number of non-canonical redox-triggered mechanisms that can alter the catalytic properties and subcellular compartmentation patterns of PKC enzymes. While some redox-activated mechanisms act at structural determinants that are common to all PKCs, the redox-dependent mechanism for PKCδ activation requires Src-dependent tyrosine phosphorylation of a unique phosphorylation motif on this enzyme and is isoform specific. Since oxidative stress contributes to pathogenesis of a wide range of clinical disorders, these stimulus-specific differences in the controls and consequences of PKC activation have important implications for the design and evaluation of PKC-targeted therapeutics.
Effect of Disorder on the Kondo Behavior of Thin Cu(Mn) Films

The behavior of magnetic impurities in metals, and in particular the Kondo effect [1], has been of interest for several decades [2, 3, 4]. Even so, a number of important issues in this area remain unresolved. Indeed, the many interesting papers in this volume show that the subject continues to be the focus of much effort.
Uterine Adenocarcinoma in Mice Treated Neonatally with Genistein

The developing fetus is uniquely sensitive to perturbation with estrogenic chemicals. The carcinogenic effect of prenatal exposure to diethylstilbestrol (DES) is the classic example. Because phytoestrogen use in nutritional and pharmaceutical applications for infants and children is increasing, we investigated the carcinogenic potential of genistein, a naturally occurring plant estrogen in soy, in an experimental animal model previously reported to result in a high incidence of uterine adenocarcinoma after neonatal DES exposure. Outbred female CD-1 mice were treated on days 1-5 with equivalent estrogenic doses of DES (0.001 mg/kg/day) or genistein (50 mg/kg/day). At 18 months, the incidence of uterine adenocarcinoma was 35% for genistein and 31% for DES. These data suggest that genistein is carcinogenic if exposure occurs during critical periods of differentiation. Thus, the use of soy-based infant formulas in the absence of medical necessity and the marketing of soy products designed to appeal to children should be closely examined.
Who's the Boss? Issues with Co-Domiciliary Parenting in the State of Louisiana

The definitive standard used in determining custody arrangements in the State of Louisiana has been the best interest of the child, since being codified January 1, 1994. Those arrangements, as set forth in the Louisiana Civil Code, have been designated to include sole custody and variations of joint custody. However, some Louisiana courts have turned to another custody arrangement- the co-domiciliary arrangement. Arising out of joint custody, the co-domiciliary arrangement gives both parents an equal, effectual legal say in the rearing and upbringing of the child. Seen as a fair compromise, the co-domiciliary arrangement has become a somewhat popular custody arrangement in Louisiana family court. Nevertheless, the five circuits comprising the Louisiana judicial system have very different views on whether co-domiciliary parents are in the best interest of the child. Molony v. Harris, a recent decision from the Louisiana Fourth Circuit Court of Appeal overturning a co-domiciliary arrangement, is the focal point of this analysis and the center of the issue as to whether co-domiciliary parents are beneficial to the child’s well-being. It is concluded that while this arrangement seems beneficial, it can be a dangerous compromise to the mental health and safety of a child who is more than likely fragile from divorce. This article will also look at opinions of the other Louisiana circuits that have made rulings on co-domiciliary parents, as well as how other states handle the issue of joint custody arrangements. Furthermore, it will attempt to suggest the critical impact of this arrangement, the reasons this arrangement cannot work completely, and less restrictive alternatives for the court to consider in the future.
$B_{s,d} \to \ell^{+}\ell^{-}$ in a Two-Higgs-Doublet Model

Abstract We compute the branching fractions of B s,d →l + l − in the type-II two-Higgs-doublet model with large tan β . We find that the parameters of the neutral Higgs sector of the two-Higgs-doublet model cancel in the result, so that the branching fractions depend only on the charged Higgs mass and tan β . For large values of tan β and a charged Higgs mass above the bound from b→sγ , we find that the branching fractions can be enhanced by up to an order of magnitude or suppressed by up to a factor of two compared to the Standard Model result. We point out that previous calculations in the literature are gauge-dependent due to the omission of an important diagram, which gives the dominant contribution in the 't Hooft–Feynman gauge. We have analyzed in detail the region of the (M H + , tan β) plane to be probed by searches for B s →μ + μ − in Run II of the Tevatron. Since the branching fraction increases like tan 4 β , this decay mode is complementary to b→sγ and efficiently probes the large tan β region. For tan β=60 , an integrated luminosity of 20 fb −1 in an extended Run II will probe charged Higgs masses up to 260 GeV, if the background to B s →μ + μ − is small. For the same value of tan β , the LHC may be able to explore charged Higgs masses up to 1 TeV using this decay.
Slope Aspect Mediates Fine-Scale Tree Establishment Patterns at Upper Treeline during Wet and Dry Periods of the 20th Century

Abstract Previous research collectively demonstrates the importance of taking local moisture availability and biotic threshold responses into account when seeking to reveal the ecological manifestations of climate change within upper treeline ecotones. Yet dendroecological studies that explicitly address the role of slope aspect in this context are non-existent. In this paper, we examine whether slope aspect and related temperature-precipitation interactions mediate abrupt increases in tree establishment and pulses of upper treeline advance (≥10 m) on contrasting north- and south-facing slopes during wet and dry periods of the 20th century. We used regime-shift analysis to quantify episodic changes in the rate of tree regeneration at each site (p < 0.05). We employed a climatic water deficit approach to define fine-scale moisture conditions to compare with dendroecological data from opposite aspects on eleven mountain peaks along a latitudinal gradient in the U.S. Rocky Mountains. Regime-shift analysis me...
Differential Utilization of Enzyme-Substrate Interactions for Acylation but Not Deacylation during the Catalytic Cycle of Kex2 Protease

Kex2 protease from Saccharomyces cerevisiae is the prototype for a family of eukaryotic proprotein processing proteases belonging to the subtilase superfamily of serine proteases. Kex2 can be distinguished from degradative subtilisins on the basis of stringent substrate specificity and distinct pre-steady-state behavior. To better understand these mechanistic differences, we have examined the effects of substrate residues at P(1) and P(4) on individual steps in the Kex2 catalytic cycle with a systematic series of isosteric peptidyl amide and ester substrates. The results demonstrate that substrates based on known, physiological cleavage sites exhibit high acylation rates (> or =550 s(-1)) with Kex2. Substitution of Lys for the physiologically correct Arg at P(1) resulted in a > or =200-fold drop in acylation rate with almost no apparent effect on binding or deacylation. In contrast, substitution of the physiologically incorrect Ala for Nle at P(4) resulted in a much smaller defect in acylation and a modest but significant effect on binding with Lys at P(1). This substitution also had no effect on deacylation. These results demonstrate that Kex2 utilizes enzyme-substrate interactions in different ways at different steps in the catalytic cycle, with the S(1)-P(1) contact providing a key specificity determinant at the acylation step.
Disruption of the Murine α1-Antitrypsin/PI2 Gene

Alpha-1-antitrypsin (α1-AT) is a member of the serine protease inhibitor family regulating numerous proteolytic processes. The genetic disorder, α1-AT deficiency, is well known as a cause of hereditary pulmonary emphysema and liver cirrhosis. To create an animal model of human α1-AT deficiency, we disrupted the major murine isoform PI2, which is similar to human α1-AT and is one of 7 α1-AT isoforms found in the mouse. The ability of the serum to inhibit the activities of human leukocyte elastase (HLE) and human chymotrypsin (CYT) was significantly lower in heterozygous mice (α1-AT/PI2 -/+) than wild-type (α1-AT/PI2 +/+) mice (73.2% vs. 100% for HLE and 67.8% vs.100% for CYT, respectively; P<0.05). The distribution of genotypes among F2 progeny was not in accordance with Mendelian distribution (P<0.01), as the percentages of wild-type, heterozygotes and homozygotes were 47.8%, 37.3% and 14.9%, respectively. Thus, it is likely that impairment of the protease inhibitor had a critical effect on fetus development. The α1-AT/PI2 deficient mouse will be a useful animal model for elucidating the function of α1-AT in fetal development, studying the mechanisms of chronic inflammatory disease and evaluating therapeutic candidates for the treatment of inflammatory disease.
Age, Breed, Trait, and Regional Variation in the Regression of Daughters on Herdmates

Abstract A total of 418,139 mature-equivalent (ME) lactation records representing cows of five dairy breeds calving from October, 1964, to September, 1965, was used to estimate the intrasire regression of daughters on herdmates. Differences in the regressions from breed, lactation number, trait, and region were studied. Regressions for first lactations were generally lower than those for later lactations. Guernseys and Holsteins had the highest regressions for milk and fat yield, followed by Ayrshire, Jerseys, and Brown Swiss. Holsteins and Ayrshires had the highest regressions for fat per cent. Regional differences in the Holstein regressions were substantial. New England, the South, and California had the highest regressions for yield. The South and California had the highest regressions for fat per cent, but the Northeast was intermediate. The accuracy of the adjustment of sire evaluations for performance of herdmates can be improved by considering these differences. Regressions for first-lactation fat per cent were around 0.7, indicating that the deviation of herdmates from breed average should be considered in evaluating sires.
Implications of a fluctuating fish predator guild on behavior, distribution, and abundance of a shared prey species: the grass shrimp Palaemonetes pugio

Abstract In some systems, the identity of a prey species' dominant predator(s) may not be constant over time. In cases in which a prey species exhibits different responses to various predator species, such changes in predator identity may have population-wide consequences. Our goals were to determine (1) whether mortality of and refuge use by the grass shrimp, Palaemonetes pugio , were predator-specific, and (2) how effects of prey size and habitat interacted with predator type. Striped bass ( Morone saxatilis ) exerted twice as much predation pressure as mummichog ( Fundulus heteroclitus ), although not equally as great on large (female) and small (male) shrimp. Mummichog, which fed preferentially on large shrimp, forced a partitioning of habitat between the two shrimp size classes. In contrast, large and small shrimp occupied similar habitats when subjected to striped bass, which fed on both size classes equally. Refuge use of grass shrimp depended on predator type. In the presence of mummichog, which occupied shallower depths in the water column than striped bass, shrimp stayed deep and close to structural habitat. Striped bass, which were deeper, caused shrimp to move high in the water column away from structural habitat. When both predators were present, shrimp distribution was similar to that when only striped bass were present, striped bass predation rate was enhanced, and overall mortality was higher than with either predator alone. Results suggest that at times when mummichogs are the dominant predators, large (female) shrimp experience higher predation than small (male) shrimp and are physically separated from their potential mates. When striped bass are more abundant, male and female shrimp may share a similar, shallow, less structure-oriented distribution and be subjected to higher mortality. When both predators are present, mortality rates may be higher still. This predator-, size-, and habitat-specificity of grass shrimp behavior suggests significant population and distribution consequences of fluctuating predator guilds and fluctuating cover of structural habitats in the field.
Adjustment of maternal serum alpha-fetoprotein levels in women with pregestational diabetes.

Objective Decreased second trimester levels of maternal serum alpha-fetoprotein (MSAFP) have been reported in women with pregestational diabetes leading some laboratories to use a correction factor. The aim of this study is to determine if MSAFP levels in pregnant women with diabetes managed on oral antidiabetic agents is lower than non-diabetic controls and require adjustment similar to those on insulin. Study design We performed a nested case/control study of an existing dataset using women with pregestational diabetes who had routine MSAFP values available. Results Before adjusting the MSAFP value for weight, both the diabetic patients who used insulin (n = 68) and those who used oral antidiabetic agents (n = 37) showed a non-significant trend toward a lower multiples of the median (MoM) as compared with controls (n = 244). After converting the raw MSAFP values to race-adjusted MoM and adjusting for weight, the median MSAFP MoM for women taking insulin (1.01) versus those on oral antidiabetic agents (1.00) were essentially the same. Furthermore, both of the diabetic groups were virtually identical to non-diabetic controls. Conclusions In our study, women with pregestational diabetes managed on either insulin or oral antidiabetic agents had weight-adjusted MSAFP MoM levels equivalent to those in control pregnancies and did not require a correction factor. Copyright © 2011 John Wiley & Sons, Ltd.
Starting with gaps between k-free numbers

We survey various developments in Number Theory that were inspired by classical papers by Roth [On the gaps between squarefree numbers, J. London Math. Soc. 26 (1951) 263–268] and by Halberstam and Roth [On the gaps between consecutive k-free integres, J. London Math. Soc. 26 (1951) 268–273].
LATENCY TO RESPOND AND PERFORMANCE ON VISUAL ASSOCIATION OF THE ILLINOIS TEST OF PSYCHOLINGUISTIC ABILITIES

Summary.-The relationship between latenq to respond and performance on Visual Association, a subtest of the Illinois Test of Psycholinguistic Abilities, was investigated for 50 preschool children. The children were observed as they took the test. Response latencies and correct responses were recorded. Performance on the test was a function of age and latenq to respond. It was concluded that for children who do not have the appropriate search strategy, Visual Association, a subtest of the Illinois Test of Psycholinguistic Abilities, does not give a valid assessment. A child who responds before examining several alternatives of problems with response uncertainty apparently does not have or is unwilling to exercise control over his first response in problem solving. This type of behavior is counterproductive in test situations. Conversely, a child who controls and delays his response to consider plausible alternatives should be at an advantage in test situations. The present study investigated the effects of latency to respond on performance (correct response) on Visual Association, a subtest of the Illinois Test of Psycholinguistic Abilities (Kirk, McCarthy, & Kirk, 1968). The objective of the subtest is to assess the child's ability to relate visually received stimuli in a meaningful way. Performance on the subtest has been shown to be correlated with age (Paraskevopoulos & Kirk, 1969). It was hypothesized that performance was a linear function of age and that the addition of response latency to the prediction equation with age would add significantly to accuracy of prediction. Subjects were 50 children between the ages of 47.77 to 71.37 mo, w~th a mean of 58.24 mo. and a standard deviation of 6.00. The sample contained 32 girls and 18 boys. Items 1 through 10 from Visual Association-Illinois Test of Psycholinguistic Abilities (Kirk, et al., 1968) were used. A handactivated electronic timer was used to measure latency to respond. Mean number of correct responses for the group was 5.34 (a = 2.20). Mean response time was 31.86 (a = 20.79). The correlation between performance and response latency was .43 (p < .001). The correlation between performance and age was .66 (p < ,001). There was no significant relation'Request reprints from H. G. Green, Ph.D., Early Childhood Research Laboratory, Deoartment of Curriculum and Instruction. Northern Illinois Universiw. DeKalb, 1L
Unsupervised Neural Network for Tool Breakage Detection in Turning

An unsupervised neural network is introduced for on-line tool breakage detection in machining using multiple sensors. This neural network performs detection by classifying the measurements either as normal or abnormal. However, it performs classification by relying only on the normal category, so that it does not need to establish the abnormal category requiring samples of measurements taken at tool breakage. This Single Category-Based Classifier (SCEC) also adapts the prototype values on-line so as to continuously update the normal category, and employs the noise suppression techniques: contrast enhancement and ding, in order to cope with different levels of noise in measurements. The performance of the SCBC is evaluated in turning. Extensive tests were performed which produced six tool breakage cases. Four measurements which were clear indicators of tool breakage in these tests were used as inputs to the SCBC and to two other classifiers utilizing Kohonen's Feature Mapping and Adaptive Resonance Theory (ART2). The results indicate that the SCBC was the only classifier that could detect all of the tool breakages.
Reformulated radial basis function neural networks with adjustable weighted norms

This article presents a new family of reformulated radial basis function (RBF) neural networks that employ adjustable weighted norms to measure the distance between the training vectors and the centers of the radial basis functions. The reformulated RBF model introduced in this article incorporates norm weights that can be updated during learning to facilitate the implementation of the desired input-output mapping. Experiments involving classification and function approximation tasks verify that the proposed RBF neural networks outperform conventional RBF neural networks and reformulated RBF neural networks employing fixed Euclidean norms. Reformulated RBF neural networks with adjustable weighted norms are also strong competitors to conventional feedforward neural networks in terms of performance, implementation simplicity, and training speed. © 2003 Wiley Periodicals, Inc.
Laser-induced Fluorometric Determination of Aluminium by the Lumogallion Complex

Laser-induced fluorescence of aluminium-ion lumogallion complex was studied and the limit of detection was determined by the reagent blank. The blank fluorescence was equivalent to 0.7 ± 0.2 μg Al+3/l, At concentrations less than 6 μg Al+3/l, the stoichiometry of the complex changes, yielding higher sensitivities but poorer precision.
Determination of detonation cell size and the role of transverse waves in two-dimensional detonations☆

Abstract Two-dimensional time-dependent numerical simulations have been performed to study the structure and propagation of self-sustained detonations. The simulations are first used to develop a systematic approach for determining the detonation cell size. This approach involves simulating systems with channel widths both larger and smaller than the transverse cell spacing. The cell size estimated using this approach is compared with experimental data. The simulations also provide insight into some aspects of the mechanism by which a two-dimensional, self-sustained detonation propagates. The evolution of the curvature of the transverse wave appears to be a crucial feature. It is shown that depending on the curvature of the transverse wave at the time of its reflection from either a neighboring transverse wave or a wall, flattened cells or pockets of unreacted gas can be formed.
A preliminary evaluation of the effects of primary and secondary radiation forces on acoustic contrast agents

Primary and secondary radiation forces result from pressure gradients in the incident and scattered ultrasonic fields. These forces and their dependence on experimental parameters are described, and the theory for primary radiation force is extended to consider a pulsed traveling wave. Both primary and secondary radiation forces are shown to have a significant effect on the flow of microbubbles through a small vessel during insonation. The primary radiation force produces displacement of microspheres across a 100 micron vessel radius for a small transmitted acoustic pressure. The displacement produced by primary radiation force is shown to display the expected linear dependence on the pulse repetition frequency and a nonlinear dependence on transmitted pressure. The secondary radiation force produces a reversible attraction and aggregation of microspheres with a significant attraction over a distance of approximately 100 microns. The magnitude of the secondary radiation force is proportional to the inverse of the squared separation distance, and thus two aggregates accelerate as they approach one another. We show that this force is sufficient to produce aggregates that remain intact for a physiologically appropriate shear rate. Brief interruption of acoustic transmission allows an immediate disruption of the aggregate.
The status of preimplantation genetic diagnosis in Japan: a criticism

Advances in preimplantation genetic diagnosis (PGD) are occurring worldwide. New clinics specializing in this approach to the control of disease genes or imbalanced chromosome numbers in human preimplantation embryos continue to increase. One exception is Japan, where the Japanese Society of Obstetrics and Gynecology disapproves of this practice because it discriminates against people with genetic abnormalities. Yet, some doctors there wish to introduce this method to help their couples to improved forms of IVF. This paper stresses the rights of patients to have a healthy baby, if necessary by the use of PGD. It argues against prohibition, since it complements the current nature of prenatal diagnosis and avoids the need for abortions in case of afflicted embryos. Consideration is also given to other attempts at restriction that have failed.
Modulation by peripheral serotonin of the threshold for sexual reflexes in female rats.

Using immunohistochemical techniques, a large number of serotonergic paracrine cells were identified in the urethral mucosa of the female rat. The functional significance of these cells was investigated. A model for the study of sexual climax in the anesthetized, acutely spinalized female rat was used. In this model, distension of the urethra with saline elicits a stereotyped coordinated genital response which closely resembles the neuromuscular muscular concomitants of sexual climax. Addition of serotonin to the urethal perfusate (10−4–10−7 M) caused a dosed-dependent decrease in the mechanical threshold necessary to elicit the climax-like response. This effect was blocked by a specific 5-HT3 receptor antagonist. The physiological implications of these findings are discussed.
The Possible Role of Prolactin in the Circadian Rhythm of Leptin Secretion in Male Rats

In humans there is a circadian rhythm of leptin concentrations in plasma with a minimum in the early morning and a maximum in the middle of the night. By taking blood samples from adult male rats every 3 hr for 24 hr, we determined that a circadian rhythm of plasma leptin concentrations also occurs in the rat with a peak at 0130h and a minimum at 0730h. To determine if this rhythm is controlled by nocturnally released hormones, we evaluated the effect of hormones known to be released at night in humans, some of which are also known to be released at night in rats. In humans, prolactin (PRL), growth hormone (GH), and melatonin are known to be released at night, and adrenocorticotropic hormone (ACTH) release is inhibited. In these experiments, conscious rats were injected intravenously with 0.5 ml diluent or the substance to be evaluated just after removal of the first blood sample (0.3 ml), and additional blood samples (0.3 ml) were drawn every 10 min thereafter for 2 hr. The injection of highly purified sheep PRL (500 microg) produced a rapid increase in plasma leptin that persisted for the duration of the experiment. Lower doses were ineffective. To determine the effect of blockade of PRL secretion on leptin secretion, alpha bromoergocryptine (1.5 mg), a dopamine-2-receptor agonist that rapidly inhibits PRL release, was injected. It produced a rapid decline in plasma leptin within 10 min, and the decline persisted for 120 min. The minimal effective dose of GH to lower plasma leptin was 1 mg/rat. Insulin-like growth factor (IGF-1) (10 microg), but not IGF-2 (10 microg), also significantly decreased plasma leptin. Melatonin, known to be nocturnally released in humans and rats, was injected at a dose of 1 mg/rat during daytime (1100h) or nighttime (2300h). It did not alter leptin release significantly. Dexamethasone (DEX), a potent glucocorticoid, was ineffective at a 0. 1-mg dose but produced a delayed, significant increase in leptin, manifest 100-120 min after injection of a 1 mg dose. Since glucocorticoids decrease at night in humans at the time of the maximum plasma concentrations of leptin, we hypothesize that this increase in leptin from a relatively high dose of DEX would mimic the response to the release of corticosterone following stress in the rat and that glucocorticoids are not responsible for the circadian rhythm of leptin concentration. Therefore, we conclude that an increase in PRL secretion during the night may be responsible, at least in part, for the nocturnal elevation of leptin concentrations observed in rats and humans.
A Review of “Sustainable Transportation: Problems and Solutions”

In Sustainable Transportation, William R. Black defines sustainable transportation, examines five problems with our current transport system, and analyzes several possible solutions in twenty-two c...
Insect infestation of stored oats in Florida and field evaluation of a device for counting insects electronically.

Automated methods of monitoring stored grain for insect pests will contribute to early detection and aid in management of pest problems. An insect population infesting stored oats at a seed processing plant in north-central Florida was studied to test a device for counting insects electronically (Electronic Grain Probe Insect Counter, EGPIC), and to characterize the storage environment. The device counts insects as they fall through an infrared beam incorporated into a modified grain probe (pitfall) trap and transmits the counts to a computer for accumulation and storage. Eight traps were inserted into the surface of the grain bulk, and the insects trapped were identified and counted manually at weekly intervals. Grain temperature and moisture content also were recorded for each trap location. Manual and automatic counts were compared to estimate error in the EGPIC system. Both over- and undercounting occurred, and errors ranged from −79.4 to 82.4%. The mean absolute value of error (±SE) was 31.7% (±4.3). At least 31 species, or higher taxa, were detected, but the psocid Liposcelis entomophila (Enderlein) and the foreign grain beetle, Ahasverus advena (Waltl), accounted for 88% of the captured insects. Species diversity, phenology, and spatial distribution are presented, as well as temporal and spatial distribution of grain temperature and moisture content. The data sets generated will find application in population modeling and development of integrated pest management systems for stored grain.
(Salen)CrIIIX Catalysts for the Copolymerization of Carbon Dioxide and Epoxides: Role of the Initiator and Cocatalyst

The copolymerization of CO(2) and cyclohexene or propylene oxide has been examined employing (salen)Cr(III)Nu complexes (Nu = Cl or N(3)) as catalysts. The addition of various cocatalysts, including phosphines and PPN+ or Bu4N+ Cl- salts serves to greatly enhance the rate of copolymer production. In these instances, the mechanism of the initiation step appears to be unimolecular in catalyst concentration, unlike the bimolecular process cocatalyzed by N-methylimidazole. The copolymers were produced with >95% carbonate linkages with TOFs in the range 39-494 mol epoxide consumed/mol Cr.h. In the presence of phosphine cocatalysts, no cyclic carbonate was produced as a byproduct.
Preparative fractionation of lignin by gel-permeation chromatography

The combination of an agarose gel (Bio-Gel A) and a dioxane–water (1:1) solvent system allowed the fractionation, on a preparative scale, of a very polydisperse, non-derivatized lignin preparation (enzymatically liberated lignin prepared from sweetgum sapwood with Lenzites trabea). Three fractions differing markedly in molecular weight were obtained. A gel of crosslinked alkylated dextran (Sephadex LH-20) with the same solvent system allowed division of the lowest molecular weight fraction into two fractions. These materials were characterized by measurements of intrinsic viscosity and number-average molecular weights in dimethylformamide and dioxane–water. It was established that the two highest molecular weight fractions were associated in an average trimeric form in dioxane-water (1:1) as compared to the form (considered to be molecular) that occurred in dimethylformamide. Molecular size distributions and eluant volumes of the fractions were determined with a Sephadex G-100–formamide system, the latter being one of the most powerful nonaqueous solvents for lignin. Adsorption effects were known to be absent in this case, and the lignin molecules were considered to be unassociated in formamide. The four fractions were distinguishable with the formamide–G-100 system, thus indicating that the original fractionation was based on molecular size. The enzymatically liberated lignin contained molecules that comprised a continuum of molecular weights from approximately monomeric to molecules that were at the limit of the solvating power of dioxane–water (1:1) and dimethylformamide. Limited physicochemical data were consistent with a compact, approximately spherically symmetric shape of the lignin in solution.
Position-sensitive low-temperature detectors

Position-sensitive detectors are under development for various applications. These detectors are well suited for applications where the rate of detected photons is low and large area detectors are desired. They also may be used in applications where the required pixel size is smaller than the smallest single- pixel detectors that can be built today. I will review the present status of this technology as well as the trade-offs inherent in their design. Different approaches to position resolution in a detector will be discussed along with future concepts for very large format arrays.
Equilibrium Charge States of Fast Heavy Ions

Measurements of equilibrium charge distributions for a wide variety of ions are being reported frequently in current literature. These measurements have improved the accuracy of various interpolations for velocity or ion species which may be needed in accelerator design or in planning experiments. Certain major effects and several minor ones have been identified and these must be considered in making such estimates. The relative importance of some of the factors affecting equilibrium distributions are discussed.
Cretaceous paleogeography and depositional cycles of western South America

Abstract The western margin of South America was encroached upon by a series of marine advances that increased in extent from the Early Cretaceous to a maximum in the early Late Cretaceous for northern South America (Venezuela to Peru). In southern South America, however, the area covered by the marine advances decreased from a maximum in the Early Cretaceous to a minimum during mid-Cretaceous time, followed by a widespread advance at the end of the period. A series of unconformity-bounded depositional cycles was recognized in these sequences: five cycles in northern South America, and six (but not exactly equivalent) cycles in the Cretaceous back-arc basins of southern South America (Neuquen and Austral, or Magallanes, Basins). Both widespread anoxic facies and maximum flooding of the continent in northern South America coincide in general terms with recognized global trends, but this is not the case in southern South America. Here, anoxic facies are restricted to the Lower Cretaceous and seem to be controlled by local aspects of the basin evolution and configuration. The contrasts observed between northern and southern South America can be explained by differences in tectonic setting and evolution. To the north, sediments were deposited around the tectonically stable Guayana-Brazilian Massifs, and thus registered global “signals” such as anoxic events and major eustatic changes. The southern portion of the continent, on the contrary, developed in an active tectonic setting. Here, the mid-Cretaceous Peruvian Orogeny overprinted, to a large extent, world-wide trends and only the earliest and latest Cretaceous conform to global depositional patterns.
Very low bit rate speech coding in tandem connections

A very low bit rate speech coder, that operates at an average rate of 1.2 kbit/s in tandem connection situations, is described and analysed. LSF quantisation results and subjective listening tests show that, both in one and two tandem connections the 1.2 kbit/s encoding scheme is clearly superior to the 2.4 kbit/s MELP coder.
The effectiveness of mentoring programs in corporate settings: A meta-analytical review of the literature

Abstract Many studies over the last 20–25 years have examined the benefits of mentoring for the protege and the organization. A review of these studies being published revealed that there is not only a lack of studies utilizing or reporting comparison group information but also a general lack of experimental research about mentoring. This quantitative meta-analytic review provides a critical analysis of the effectiveness of mentoring, with an emphasis on research designs that compared career outcomes of mentored individuals to non-mentored individuals. The overall mean effect size of mentoring was significant, indicating that mentoring does improve career outcomes for individuals. Individual career outcomes were analyzed and reported. Informal mentoring produced a larger and more significant effect on career outcomes than formal mentoring. There is a need for more research comparing proteges and non-proteges to determine if it is the receipt of mentoring or individual characteristics that leads to career success.
A technology assessment of alternative communications systems for the space exploration initiative

Telecommunications, Navigation, and Information Management (TNIM) services are vital to accomplish the ambitious goals of the Space Exploration Initiative (SEI). A technology assessment is provided for four alternative lunar and Mars operational TNIM systems based on detailed communications link analyses. The four alternative systems range from a minimum to a fully enhanced capability and use frequencies from S-band, through Ka-band, and up to optical wavelengths. Included are technology development schedules as they relate to present SEI mission architecture time frames.
Semi-automated color segmentation of anatomical tissue

We propose a semi-automated region-based color segmentation algorithm to extract anatomical structures, including soft tissues, in the color anatomy slices of the Visible Human data. Our approach is based on repeatedly dividing an image into regions using Voronoi diagrams and classifying the regions based on experimental classification statistics. The user has the option of reclassifying regions in order to improve the final boundary. Our results indicate that the algorithm can find accurate outlines in a small number of iterations and that manual interaction can markedly improve the outline. This approach can be extended to 3D color segmentation.
The front line battle against P2P

One of the prevalent topics under discussion in educational environments today is the use of P2P (peer-to-peer) software. Aside from being major bandwidth-eaters, the use of such software to distribute and download copyrighted material has significant legal and financial implications for the campus community. Having a clear and concise policy restricting such use is one matter; enforcing said policy has proved to be an entirely different and complex task. Although it is elementary to prevent P2P traffic by blocking well-known ports used by such software, the vast majorities majoritymof P2P software, such as BitTorrent, download and upload pieces of files from different sources on different ports[?]. P2P protocols and client programs are working around 'issues' that prevent them from functioning and are becoming more and more 'intelligent'. The detection of P2P traffic based on well-known ports and 'port guessing' do not match the intelligence in newer generation P2P protocols and software. False positives generated with the use of well-known ports for detection are another serious concern. A good approach would be a solution that detects P2P and other undesirable traffic based on packet payload, as opposed to source and destination ports. Commercial products available to address these issues are expensive and not as flexible as the solution we discuss in this paper. Our proposed model is a combination of several open-source solutions to which changes have been made to suit our environment and requirements. We also discuss other possible model solutions and discuss the pros and cons of such solutions.
39K(d, 3He)38Ar and the s-d shell structure of 38Ar

Abstract The positive-parity level structure of 38 Ar is investigated with the 39 K(d, 3 He) 38 Ar reaction on a KI target at a bombarding energy of 34.5 MeV. Seven residual levels are found to be strongly excited, three with l p = 2 characteristics at 0.00, 2.17 and 7.11 MeV excitation energy and four with predominant l p = 0 characteristics at 3.94, 4.57, 5.15 and 5.55 MeV excitation energy. These experimental results are examined from the viewpoint of several recent shell-model calculations. No extant calculations provide a quantitative interpretation of the occurrence of as many as four strong l = 0 levels. It seems likely that the extra l = 0 levels arise from 2p-4h excitations into the 1f shell and are populated via the large components of the ( s 1 2 −1 − d 3 2 −1 ) configuration mixed into these 2p-4h states. The (d, 3 He) reaction on the 127 I in the target yields evidence that the 5 2 + ground state of this nucleus contains significant 2 d 5 2 admixtures.
Magnetic resonance cholangiopancreatography.

Magnetic resonance cholangiopancreatography (MRCP) uses MR imaging to visualize fluid in the biliary and pancreatic ducts as high signal intensity on T2-weighted sequences; it is the newest modality for biliary and pancreatic duct imaging. MRCP is of proven utility in a variety of biliary and pancreatic diseases, including choledocholithiasis, congenital anatomic variants, chronic pancreatitis, post-cholecystectomy disorders, and neoplastic duct obstruction. MRCP is an evolving technique, but it has reached the stage of development where it is clinically useful and of comparable accuracy to conventional cholangiography. With further progress, it is likely that by the start of the new millennium MRCP will replace diagnostic endoscopic retrograde cholangiopancreatography as the modality of choice for imaging the biliary and pancreatic ducts. J. Magn. Reson. Imaging 1999;9:157–162. © 1999 Wiley-Liss, Inc.
Improving HF Radar Estimates of Surface Currents Using Signal Quality Metrics, with Application to the MVCO High-Resolution Radar System

AbstractEstimates of surface currents over the continental shelf are now regularly made using high-frequency radar (HFR) systems along much of the U.S. coastline. The recently deployed HFR system at the Martha’s Vineyard Coastal Observatory (MVCO) is a unique addition to these systems, focusing on high spatial resolution over a relatively small coastal ocean domain with high accuracy. However, initial results from the system showed sizable errors and biased estimates of M2 tidal currents, prompting an examination of new methods to improve the quality of radar-based velocity data. The analysis described here utilizes the radial metric output of CODAR Ocean Systems’ version 7 release of the SeaSonde Radial Site Software Suite to examine both the characteristics of the received signal and the output of the direction-finding algorithm to provide data quality controls on the estimated radial currents that are independent of the estimated velocity. Additionally, the effect of weighting spatial averages of radia...
Analysis of insertion mutants reveals two new genes in the pNRC100 gas vesicle gene cluster of Halobacterium halobium

Abstract The archaebacterium, Halobacterium halobium, achieves buoyancy through synthesis of intracellular gas-filled vesicles. The plasmid-encoded gene (gvpA) specifying the major structural gas vesicle protein has previously been cloned and sequenced allowing the analysis of high-frequency mutations to the vesicle negative phenotype. Among eighteen gas vesicle mutants analyzed, four were observed to contain insertion elements 0.2 to 2 kb upstream of the structural gene. To explain the phenotype of these mutants, the upstream area was analyzed by DNA sequencing and transcriptional mapping. This analysis showed the presence of two open reading frames, gvpD and gvpE, which are of opposite transcriptional orientation to gvpA (gene order gvpA-D-E). gvpD begins 201 nucleotides from the gvpA structural gene and is 1608 nucleotides long while gvpE begins two nucleotides from the 3'-end of gvpD and is 573 nucleotides long. Primer extension analysis showed the occurrence of divergent promoters in the gvpA-gvpD intergenic region with the transcription start sites separated by 109 nucleotides. The sites of three insertion sequences in gas vesicle mutants mapped within gvpE while the fourth insertion site mapped near the N-terminal coding region of gvpD. Homology between the gvpDE gene region and a chromosomal site in a H. halobium NRC-1 derivative and in several other Halobacterium strains was identified by Southern hybridization.
Inhaled carbon monoxide or nebulized sodium nitrite protect against hemorrhagic shock-induced mitochondrial dysfunction

Shock induces mitochondrial damage, which can lead to tissue injury and inflammation. Resuscitative adjuncts to limit mitochondrial injury may be effective to reduce tissue injury and protect against the sequelae of hemorrhagic shock (HS). Others and we have demonstrated the protective effects of inhaled carbon monoxide (CO) or nebulized sodium nitrite (NaNO2) in models of HS. Our aim was to test the hypothesis that CO and NaNO2 protect against hemorrhagic shock-induced tissue injury/inflammation by limiting mitochondrial damage and preventing bioenergetic failure.
Fermionization of a bosonic gas under highly elongated confinement: A diffusion quantum Monte Carlo study

The diffusion quantum Monte Carlo technique is used to solve the many-body Schr\"odinger equation fully quantum mechanically and nonperturbatively for bosonic atomic gases in cigar-shaped confining potentials. By varying the aspect ratio of the confining potential from 1 (spherical trap) to 10 000 (highly elongated trap), we characterize the transition from the three-dimensional regime to the (quasi-)one-dimensional regime. Our results confirm that the bosonic gas undergoes ``fermionization'' for large aspect ratios. Importantly, many-body correlations are included explicitly in our approach.
Impact of weighted density distribution function features on land mine detection using hand-held units

Landmine detection using metal detector (MD) and ground penetrating radar (GPR) sensors in hand-held units is a difficult problem. Detection difficulties arise due to: 1) the varying composition and type of metal in landmines, 2) the time-varying nature of background and 3) the variation in height and velocity of the hand-held unit in data measurement. In prior research, spatially distributed MD features were explored for differentiating landmine signatures from background and non-landmine objects. These features were computed based on correlating sequences of MD energy values with six weighted density distribution functions. In this research the effectiveness of these features to detect landmines of varying metal composition and type is investigated. Experimental results are presented from statistical analysis for feature assessment. Preliminary experimental results are also presented for evaluating the impact on MD feature calculations from varying height and sweep rate of the hand-held unit for data acquisition.
Design and Demonstration of Hybrid Multilayer Structures: Layer-by-Layer Mixed Covalent and Ionic Interlayer Linking Chemistry

We report on the growth of layered molecular assemblies where the interlayer attachment chemistry is controlled layer-by-layer. We demonstrate the compatibility of chemistry where the layers are connected by ionic coordination chemistry [ROPO32-−Zr4+−-O2CR]+OH- and by the formation of covalent urea moieties. A maleimide−vinyl ether (MVE) copolymer containing pendant benzoic acid and butyl alcohol functionalities is used for ionic layer growth. Coupling of covalently bonded adlayers to the MVE polymer is achieved by the attachment of poly(ethylene imine), PEI, to the MVE surface. Subsequent reaction of the PEI surface with diisocyanates and diamines produces urea-linked covalent multilayers. The covalent multilayers can be converted to ionic growth chemistry by treatment of the aminated terminal surface with POCl3 and water followed by further reaction with MVE polymer and Zr4+ ions. We report the reaction schemes for these hybrid layer structures and the characterization of these novel materials by optica...