cssi/SciSciGPT-SciSciNet huggingface dataset:
Inaccuracy of perceived competence ratings is associated with problem behaviors in 5-year-old children.

ABSTRACTThe authors examined problem behaviors in preschool children as a function of perceived competence. Prior research has demonstrated a link between inaccuracy of self-perceptions and teacher-reported externalizing behaviors in preschool aged boys. This study extended past research by adding data collected from observed behaviors in a laboratory setting, as well as parent reports of internalizing and externalizing behaviors. Five-year-old children completed the Pictorial Scale of Perceived Competence and Social Acceptance for Young Children (PSPCSA) in the lab, participated in a 10-min puzzle interaction task with their cotwin and mother, and completed a short task assessing cognitive abilities. Children were grouped into 3 self-esteem categories (unrealistically low, realistic, and unrealistically high) based on comparisons of self-reported (PSPCSA) versus actual competencies for maternal acceptance, peer acceptance, and cognitive competence. Results showed that children who overreported their mate...
Further Characterization of In Vitro Conditions Appropriate for GABA Determination in Human CSF: Impact of Acid Deproteinization and Freeze/Thaw

Recently established standardized protocols for collection, handling, and storage of CSF for measurement of gamma-aminobutyric acid (GABA) have proven valuable in the characterization of various CNS disorders. In response to two recent reports which may have an impact on certain widely used protocols, we have, using the confirmed ion-exchange/fluorometric procedure, systematically evaluated the effects of deproteinization with various concentrations of sulfosalicylic acid (SSA) ranging from 0 to 10% (100 mg/ml), as well as the effects of freeze/thaw (F/T) on CSF GABA levels. Results of F/T studies documented that levels are stable to freezing and thawing. Acid deproteinization studies revealed the presence of an equilibrium between strictly free GABA, demonstrable only in acid-free CSF, and a very loosely bound form of GABA, fully demonstrable only in CSF deproteinized with concentrations of SSA above 1% (10 mg/ml). The relationship between GABA concentrations in undeproteinized and acid-deproteinized CSF revealed a highly significant (p less than .001) correlation, suggesting that alterations of central GABAergic activity would be reflected by either the level of strictly free GABA or free plus loosely bound GABA. This hypothesis was upheld in studies of patients with Parkinson's disease (PD) and Huntington's disease (HD), two neurologic disorders in which dysfunctions of the GABA system have been implicated. Results indicated that CSF GABA levels are significantly reduced in both PD and HD patients compared with neurologically normal controls, whether the measurement is of free GABA or free plus loosely bound GABA. Thus, we conclude that the level of strictly free GABA is stable to freezing and thawing and can only be accurately determined in nonacidified CSF; however, existing protocols employing deproteinization in 5% SSA yield data that provide an equally good reflection of central GABAergic transmission.
Structural Basis For The Coupling Between Activation And Inactivation Gating In Potassium Channels

We have known the structure for the closed-state of a potassium channel pore domain (PD) for more than a decade. However, major progress in understanding the molecular basis for activation and inactivation gating in K-channels had to wait until high-resolution structural information of the channel in the open state became available. Recently, we solved the structure KcsA in it fully open conformation, as well four others partial openings, which richly illustrated the channel activation-inactivation pathway. Analysis of these open structures suggested that residue F103 in TM2 interacts with the c-terminal end of the pore helix, compressing the pitch of its first helical turn. As a consequence, the distance between E71-D80 side chains is shortened, strengthening the carboxyl-carboxylate interaction that leads to a non-conductive conformation of the selectivity filter. Perturbation mutagenesis at position 103, affected gating kinetics as predicted from our structural analysis: small side chain substitutions F103A and F103C severely impaired inactivation kinetics, suggesting an allosteric coupling between the inner helical bundle and the selectivity filter. Free energy calculations show strong open state interaction-energies between F103 and surrounding residues. Similar interactions were probed in the Shaker K-channel by mutating highly conserved I470, equivalent to F103, to a smaller side chain. In the mutant I470A, inactivation was abrogated, suggesting that a similar mechanism underlies inactivation coupling in eukaryotic potassium channels. A crystallography study of these mutants in the open KcsA will be reported.
Fetal alcohol syndrome in the United States corrections system

Prenatal alcohol exposure can result in fetal alcohol syndrome (FAS), which may increase the risk of confinement in the corrections system. In the United States each state and four major cities' corrections systems were asked to complete a questionnaire on the prevalence of FAS and alcohol-related neurodevelopmental disorder (ARND) in the offender population, the availability of screening and diagnostic services to identify offenders with FAS and staff training needs related to FAS. The total population in the 54 entities was 3,080,904 inmates. Completed questionnaires were obtained from 42 entities (78%). The mean rate of reported substance abuse in offenders was 60.1%. Specialized programs for persons with mental retardation were reported for 44.4% of corrections facilities and 25.9% of community corrections facilities. Programs for pregnant women were reported for 46.3% of corrections facilities and 29.6% of community facilities. One program (1.9%) reported having a screening program for FAS in the corrections system. Only four programs (7.4%) reported having access to diagnostic services for FAS in the corrections facilities. Of the 3,080,904 offenders, only one offender was reported to have a diagnosis of FAS. Reported staff training needs were very large. In conclusion, corrections systems have high unmet needs to screen, identify, and treat offenders with FAS and ARND. Staff training needs are substantial.
Long-range communication of species identity by song in the Red-winged Blackbird

Adaptations of Red-winged Blackbird (Agelaius phoeniceus) song for communication of species identity over long distances were studied in an upland pasture in Ithaca, New York. This song consists of a series of brief introductory notes followed by a longer concluding trill. The trill contains energy from 2–6 kHz. Sound transmission properties and ambient noise characteristics of the habitat, changes in song composition with propagation, and the behavioral relevance of observed changes in song structure were analyzed. 1. At a height of 1.5 m above the ground in the habitat studied, sound transmission is greates below about 4.5 kHz. Attenuation of sound energy increases monotonically above this frequency (Fig. 3). Peak redwing song energy occurs from about 2.5–4.0 kHz (Fig. 1). 2. With increasing distance from a speaker most or all of the spectral structure in the introductory song components, as well as higher frequencies in the concluding trill, is severely attenuated. Songs of different males converge with distance upon a narrow frequency band (2.5–4.0 kHz) contained within the trill (Fig. 4). 3. This frequency band coincides with a relatively quiet region of the acoustic environment, bordered on the low frequency side by wind disturbance and, in the later part of the breeding season, on the higher frequency end by calls of various orthopteran species (Fig. 6). There may be, then, a ‘noise window’ for optimal long-distance song transmission in this spectral region. 4. The 2.5–4.0 kHz section of the trill is both necessary and sufficient to evoke a strong species-specific behavioral response, and contains sufficient information to do so even after transmission over a distance of at least 100 m. Neither the introductory components by themselves nor the high frequency part of the trill (4–6 kHz) are effective in producing such a response.
A virtual frame system for stereotactic radiosurgery planning.

Purpose We describe a computerized (or virtual) model of a stereotactic head frame to enable planning prior to the day of radiosurgery. The location of the virtual frame acts as a guide to frame placement on the day of the procedure. Methods and Materials The software consists of a triangular mesh representation of the essential frame hardware that can be overlaid with any MR scan of the patient and manipulated in three dimensions. The software calculates regions of the head that will actually be accessible for treatment, subject to the geometric constraints of the Leksell Gamma Knife hardware. DICOM-compliant MR images with virtual fiducial markers overlaid onto the image can then be generated for recognition by the treatment planning system. Results Retrospective evaluation of the software on 24 previously treated patients shows a mean deviation of the position of the virtual frame from the actual frame position of 1.6 ± 1.3 mm. Initial clinical use on five patients indicates an average discrepancy of the virtual frame location and the actual frame location of Conclusions The virtual frame provides a tool for prospective determination of lesion accessibility, optimization of the frame placement, and treatment planning before the day of the procedure. This promises to shorten overall treatment times, improve patient comfort, and reduce the need for repeat treatments due to suboptimally placed frames.
Crowding and the polymerization of sickle hemoglobin

Under physiological conditions, sickle hemoglobin, a natural mutant of human hemoglobin A with a surface hydrophobic valine in place of a negatively charged glutamic acid, polymerizes at high volume occupancy. Equilibrium solubility of sickle hemoglobin entails activity coefficients that can approach 103 at high concentrations. Polymerization occurs by homogeneous and heterogeneous nucleation mechanisms, which are both profoundly sensitive to crowding; homogeneous nucleation rates for example are enhanced by 1010 when the initial concentration is augmented by 50% non-polymerizing hemoglobin. A molecular description of the reaction therefore entails substantial corrections for molecular crowding which are all very accurately described by excluded volume corrections, treating hemoglobin as a hard sphere with volume consistent with the molecular structure of the molecule, and involving no further adjustable parameters. These effects and the descriptions that rationalize this behavior are described. Copyright © 2004 John Wiley & Sons, Ltd.
A vaccinia virus double recombinant expressing the F and H genes of rinderpest virus protects cattle against rinderpest and causes no pock lesions.

Abstract Rinderpest is a highly contagious viral disease of ruminants with greater than 95% morbidity and mortality. We have constructed an infectious vaccinia virus recombinant that expresses both the fusion (F) gene and the hemagglutinin (H) gene of rinderpest virus. The Wyeth strain of vaccinia virus was used for the construction of the recombinant. Cattle vaccinated with the recombinant virus were 100% protected from challenge inoculation with greater than 1000 times the lethal dose of rinderpest virus. No transmission of recombinant vaccinia virus from vaccinated animals to contact animals was observed. The lyophilized form of vaccinia virus is thermostable and allows circumvention of the logistical problems associated with the distribution and administration of vaccines in the arid and hot regions of Asia and Africa. The insertional inactivation of both the thymidine kinase and the hemagglutinin genes of vaccinia virus led to increased attenuation of the virus; this was manifested by the lack of detectable pock lesions in vaccinated animals. This approach may have wide application in the development of safe and efficacious recombinant vaccines for humans and animals. This becomes quite relevant with the concern of the use of vaccinia virus in a population with high incidence of the human immunodeficiency virus.
Fertilizer Consumption and Energy Input for 16 Crops in the United States

Fertilizer use by U.S. agriculture has increased over the past few decades. The production and transportation of fertilizers (nitrogen, N; phosphorus, P; potassium, K) are energy intensive. In general, about a third of the total energy input to crop production goes to the production of fertilizers, one-third to mechanization, and one-third to other inputs including labor, transportation, pesticides, and electricity. For some crops, fertilizer is the largest proportion of total energy inputs. Energy required for the production and transportation of fertilizers, as a percentage of total energy input, was determined for 16 crops in the U.S. to be: 19–60% for seven grains, 10–41% for two oilseeds, 25% for potatoes, 12–30% for three vegetables, 2–23% for two fruits, and 3% for dry beans. The harvested-area weighted-average of the fraction of crop fertilizer energy to the total input energy was 28%. The current sources of fertilizers for U.S. agriculture are dependent on imports, availability of natural gas, or limited mineral resources. Given these dependencies plus the high energy costs for fertilizers, an integrated approach for their efficient and sustainable use is needed that will simultaneously maintain or increase crop yields and food quality while decreasing adverse impacts on the environment.
Sound propagation between two adjacent rectangular workstations in an open-plan office—part II: effects of office variables

Abstract In part I of this paper a general model was developed of sound propagation between adjacent rectangular workstations in a conventional open-plan office. In this paper, the new model is used to investigate the importance of various office design parameters on calculated speech privacy. The additional effects of the side and back panels of complete workstations are examined in detail. Calculations for systematic variations of the principal design parameters show that the separating screen height and the ceiling absorption have the largest effects on expected speech privacy. High speech privacy can only be achieved with the combination of high screens, high ceiling absorption, and high panel absorption. Empirical corrections are developed to estimate how the presence of ceiling lights reduces the effective ceiling absorption. The complete model is shown to accurately predict speech privacy for a range of office design configurations with an RMS error in predicted SII values 0.02.
Efficient Synthesis of an η2-Pyridine Complex and a Preliminary Investigation of the Bound Heterocycle’s Reactivity

Pyridine borane is combined with TpW(NO)(PMe3)(η2-benzene) to form a complex of the heterocycle, which upon treatment with acetone and acid yields the pyridinium complex [TpW(NO)(PMe3)(η2-pyH+)]OTf. Deprotonation in the presence of acetic anhydride delivers the N-acetylpyridinium complex as a 10:1 mixture of coordination diastereomers. This acylpyridinium resists reaction with water or oxygen but readily reacts with acetone, pyrrole, indole, or acrolein and a weak base to stereoselectively form 1,2-dihydropyridine complexes. Treatment of the indole-derived analogue with CuBr2 results in liberation of 3-(pyridin-2-yl)-1H-indole.
Fate of malathion and O,O,S-trimethyl phosphorothioate by-product in Hawaiian soil and water

The fate of malathion (I) and a formulation byproduct,O,O,S-trimethyl phosphorothioate (II), were determined in soil and water from an agricultural area on Kauai, Hawaii. Rapid degradation of I was observed in laboratory soil microcosms (t1/2 = 8.2 h) and in the field (t1/2 = 2 h) and dimethyl phosphorodithioic acid and diethyl fumarate were identified as degradation products. Degradation of II was relatively slow in laboratory soil microcosms (t1/2 = 6.4 d) and the degradation rate of both I and II decreased significantly after γ irradiation. Degradation of I in river, ground and seawater (avg. t1/2 = 4.7 d) was controlled by an elimination reaction; photolysis and biodegradation played minor roles. Dissipation of II in river water was primarily by biodegradation. Strong sorption of I to Lihue silty clay soil (Koc = 405) was determined while II was weakly bound (Koc = 9.8). Rapid degradation and strong sorption of I suggest a low potential for groundwater contamination. Although II degrades slowly and is weakly bound to Lihue soil, the extremely low concentrations found in the dilute formulations applied in fruit-fly control should not present a groundwater problem.
Effects of probe length, probe geometry, and redox-tag placement on the performance of the electrochemical E-DNA sensor.

Previous work has described several reagentless, electrochemical DNA (E-DNA) sensing architectures comprised of an electrode-immobilized, redox-tagged probe oligonucleotide. Recent studies suggest that E-DNA signaling is predicated on hybridization-linked changes in probe flexibility, which will alter the efficiency with which the terminal redox tag strikes the electrode. This, in turn, suggests that probe length, probe geometry, and redox-tag placement will affect E-DNA signaling. To test this we have characterized E-DNA sensors comprised of linear or stem-loop probes of various lengths and with redox tags placed either distal to the electrode or internally within the probe sequence (proximal). We find that linear probes produce larger signal changes upon target binding than equivalent stem-loop probes. Likewise, long probes exhibit greater signal changes than short probes provided that the redox tag is placed proximal to the electrode surface. In contrast to their improved signaling, the specificity of ...
An automated two-view method for determining strain distributions on deformed surfaces

A new approach to surface strain measurement is described in which two complete views of an object are digitized in two dimensions using either a photographic or an automated vision system, corresponding points are identified, and the three-dimensional coordinates are determined from the relationship between the views. Strains are computed in each triangular region into which the surface is divided based on the assumption of pure homogeneous deformation in each triangle, and the strain contours are displayed graphically on the deformed geometry. Results are presented and discussed in terms of known sources of error.
Numerical simulations of fast crack growth in brittle solids

Dynamic crack growth is analysed numerically for a plane strain block with an initial central crack subject to tensile loading. The continuum is characterized by a material constitutive law that relates stress and strain, and by a relation between the tractions and displacement jumps across a specified set of cohesive surfaces. The material constitutive relation is that of an isotropic hyperelastic solid. The cohesive surface constitutive relation allows for the creation of new free surface and dimensional considerations introduce a characteristic length into the formulation. Full transient analyses are carried out. Crack branching emerges as a natural outcome of the initial-boundary value problem solution, without any ad hoc assumption regarding branching criteria. Coarse mesh calculations are used to explore various qualitative features such as the effect of impact velocity on crack branching, and the effect of an inhomogeneity in strength, as in crack growth along or up to an interface. The effect of cohesive surface orientation on crack path is also explored, and for a range of orientations zigzag crack growth precedes crack branching. Finer mesh calculations are carried out where crack growth is confined to the initial crack plane. The crack accelerates and then grows at a constant speed that, for high impact velocities, can exceed the Rayleigh wave speed. This is due to the finite strength of the cohesive surfaces. A fine mesh calculation is also carried out where the path of crack growth is not constrained. The crack speed reaches about 45% of the Rayleigh wave speed, then the crack speed begins to oscillate and crack branching at an angle of about 29° from the initial crack plane occurs. The numerical results are at least qualitatively in accord with a wide variety of experimental observations on fast crack growth in brittle solids.
MODELING OF CONCRETE SLABS UNDER FIRE

The ability to assess the integrity of concrete structures after a severe thermal shock is extremely important not only for fire safety but also for the economy. A mathematical model, capable of rationally determining of fire response and correctly simulating the heat and mass transfer in concrete structures has been developed. Based on the concept of continuum mechanics, the conservation of mass, momenta, and energy equations have been used to yield a set of three coupled nonlinear partial differential equations with time dependent nonlinear mixed boundary conditions. Approximately a finite difference model has been developed for simulating the concrete structure under fire. The discrete set of implicit finite difference equations, after being quasi-linearized, is used and solved by a computer. Efficiently controlling time-step, the running computing time is minimized without detrimental effects on accuracy. The numerical results predict the phenomenon of “moisture clog” and show that: the permeability o...
Traffic video compression system using wavelet analysis

Transmission and storage of traffic video are important to traffic video, algorithms that will take advantage of these properties to ease the video compression should be explored. In this paper, we propose a video compression algorithm that takes advantage of still background of traffic video. By applying the wavelet transform to the compression algorithm, the reconstructed video shows no blocking artifacts as in the discrete cosine transform based approach. A wavelet- based de-blurring preprocessing can also be merged into the video compression algorithm for better reconstructed results if the original video was blurred or foggy.
Accelerated autoxidation and heme loss due to instability of sickle hemoglobin.

Abstract The pleiotropic effect of the sickle gene suggests that factors in addition to polymerization of the mutant gene product might be involved in sickle disease pathobiology. We have examined rates of heme transfer to hemopexin from hemoglobin in dilute aqueous solution (0.5 mg of Hb per ml) at 37 degrees C. HbO2 S loses heme 1.7 times faster than HbO2 A, with apparent rate constants of 0.024 hr-1 and 0.014 hr-1, respectively. In contrast, Hb A and Hb S behave identically in their MetHb forms (very rapid heme loss) and their HbCO forms (zero heme loss). This indicates that the faster heme loss from HbO2 S is due to accelerated autoxidation (HbO2----MetHb) rather than to some other type of instability inherent in the relationship of sickle heme to its pocket in globin. This interpretation is supported by spectrophotometric measurement of initial rates of MetHb formation during incubation at 37 degrees C. This directly shows 1.7 times faster autoxidation, with apparent rate constants of 0.050 hr-1 for HbO2 S and 0.029 hr-1 for HbO2 A. While the participation of this process in the cellular pathobiology of sickle erythrocytes remains unproven, the present data are consistent with, and perhaps help explain, two prior observations: the excessive spontaneous generation of superoxide by sickle erythrocytes; and the abnormal deposition of heme and heme proteins on membranes of sickle erythrocytes.
Insulin-like growth factor-binding protein 2 secreted by a tumorigenic cell line supports ex vivo expansion of mouse hematopoietic stem cells.

Successful hematopoietic stem cell (HSC) transplantation is often limited by the numbers of HSCs, and robust methods to expand HSCs ex vivo are needed. We previously showed that angiopoietin-like proteins (Angptls), a group of growth factors isolated from a fetal liver HSC-supportive cell population, improved ex vivo expansion of HSCs. Here, we demonstrate that insulin-like growth factor-binding protein 2 (IGFBP2), secreted by a tumorigenic cell line, also enhanced ex vivo expansion of mouse HSCs. On the basis of these findings, we established a completely defined, serum-free culture system for mouse HSCs, containing SCF, thrombopoietin, fibroblast growth factor 1, Angptl3, and IGFBP2. As measured by competitive repopulation analyses, there was a 48-fold increase in numbers of long-term repopulating mouse HSCs after 21 days of culture. This is the first demonstration that IGFBP2 stimulates expansion or proliferation of murine stem cells. Our finding also suggests that certain cancer cells synthesize proteins that can stimulate HSC expansion.
A Simultaneous Lay-Up and in situ Cure Process for Thick Composites:

A progressive lay-up and in situ cure process is presented for manufactur ing thick polymeric composite structures. Manufacturing cycle times can be reduced sig nificantly, since this process combines the lay-up and curing. Also, the material degrada tion due to thermal spiking which is generally very large in thick-section composites can be avoided, depending on the judicious selection of process variables such as cure temper ature, ambient temperatures, and material supply rate. A one-dimensional combined thermo-chemical heat transfer model was developed and solved numerically in order to monitor the cure, temperature distributions, and thermal spiking through the thickness. In order to validate the analysis, 12 mm thick graphite/epoxy (AS4/3501-6) plates were manu factured by the current process and were scanned by DSC (differential scanning calorim eter). The predicted temperature and degree of cure profiles are compared with experi ments. Both results are in good agreement which confirms the accuracy...
Global warming. The good, the bad, the ugly and the efficient.

Global climate change has been portrayed largely as an unmitigated catastrophe for humans and the environment but, in reality, the topic is more nuanced. Although scientists agree that the climate is changing and many accept that anthropogenic increases in CO2 are to blame, there is actually both good and bad news about global warming—and some ugly news about abatement strategies. The media and the scientific literature pay little attention to the possible benefits for some parts of the world of a warming climate; bad news always attracts more attention. So let us consider these benefits, as well as the costs, before discussing the current strategies that are being used to alleviate global climate change. > …there is actually both good and bad news about global warming—and some ugly news about abatement strategies Certainly, the global climate will get warmer, but this, in itself, is not intrinsically bad; we do not necessarily live in the ‘best of all possible climates’. The Intergovernmental Panel on Climate Change (IPCC; Geneva, Switzerland) has based its estimates of how much the climate will change on the assumption that economic growth is fuelled by increased energy use, which, in turn, increases the production of greenhouse gases. Accordingly, the models that predict the greatest change in climate are driven by forecasts of rapid worldwide economic growth predominantly fuelled by fossil fuels. Yet some IPCC models, which use more realistic growth rates, predict average temperature increases by the end of this century of 2–3 oC. However, virtually all models predict that the coldest parts of the world—near the polar ice caps—will warm the most, with temperatures likely to increase most during the night and the winter (Gates et al , 1992; Houghton et al , 1992). A 2–3 oC increase is, in fact, a rather moderate climate change; …
Tuning wave dispersion in resonant networks

Resonant guided wave networks is a photonic class with power-splitting elements arranged at waveguides network nodes, which enables the design of enhanced Q-factor resonators, artificial material designed dispersion, and optical devices with programmed functions.
Parenting Stress as a Mediator of the Relation Between Parenting Support and Optimal Parenting

Objective. This study assessed the direct and indirect relations between 2 types of social support - parenting support and general social support - and optimal parenting. Design. Self-report data were gathered from 165 married mothers of firstborn 4th-graders between the ages of 9 and 11 years. Widely accepted measures of warmth, monitoring, general psychological distress, parenting stress, and general social support were used. A measure of parenting support from family and friends was developed for this study. Results. Path analysis indicated that the relation between specific parenting support and optimal parenting was completely mediated by parenting stress and not by general psychological distress. The relation between general social support and optimal parenting was not completely mediated by either parenting stress or general psychological distress. Conclusions. This study integrated essential components from the social support, stress and coping, and parenting research. The authors identify parenti...
Kinesin motors as molecular machines.

Molecular motor proteins, fueled by energy from ATP hydrolysis, move along actin filaments or microtubules, performing work in the cell. The kinesin microtubule motors transport vesicles or organelles, assemble bipolar spindles or depolymerize microtubules, functioning in basic cellular processes. The mechanism by which motor proteins convert energy from ATP hydrolysis into work is likely to differ in basic ways from man-made machines. Several mechanical elements of the kinesin motors have now been tentatively identified, permitting researchers to begin to decipher the mechanism of motor function. The force-producing conformational changes of the motor and the means by which they are amplified are probably different for the plus- and minus-end kinesin motors.
OFF-state degradation and correlated gate dielectric breakdown in high voltage drain extended transistors: A review

Abstract High voltage transistors exhibit unique degradation modes that cannot always be explained based on classical degradation mechanisms. In this paper, we use the specific example of OFF-state degradation in high voltage drain extended transistors to develop a generalized degradation model that can be extended to a wide range of device geometries (DeMOS, LDMOS, CMOS) and bias conditions (OFF-state, sub-threshold, ON-state). We show that hot carriers generated from impact ionization of leakage current components are responsible for OFF-state degradation by breaking interfacial and bulk Si O bonds. The resultant degradation is shown to be universal and the kinetics of Si O bond breaking is explained based on a bond-dispersion model. The generalized “bottom-up” model also explains the correlated gate dielectric breakdown and higher Weibull slopes at OFF-state conditions which are not anticipated based on classical hot carrier models. Our approach unifies hot carrier degradation results from various laboratories across the world within a common conceptual framework.
Instruction combining for coalescing memory accesses using global code motion

Instruction combining is an optimization to replace a sequence of instructions with a more efficient instruction yielding the same result in a fewer machine cycles. When we use it for coalescing memory accesses, we can reduce the memory traffic by combining narrow memory references with contiguous addresses into a wider reference for taking advantage of a wide-bus architecture. Coalescing memory accesses can improve performance for two reasons: one by reducing the additional cycles required for moving data from caches to registers and the other by reducing the stall cycles caused by multiple outstanding memory access requests. Previous approaches for memory access coalescing focus only on array access instructions related to loop induction variables, and thus they miss many other opportunities. In this paper, we propose a new algorithm for instruction combining by applying global code motion to wider regions of the given program in search of more potential candidates. We implemented two optimizations for coalescing memory accesses, one combining two 32-bit integer loads and the other combining two single-precision floating-point loads, using our algorithm in the IBM Java™ JIT compiler for IA-64, and evaluated them by measuring the SPECjvm98 benchmark suite. In our experiment, we can improve the maximum performance by 5.5% with little additional compilation time overhead. Moreover, when we replace every declaration of double for an instance variable with float, we can improve the performance by 7.3% for the MolDyn benchmark in the JavaGrande benchmark suite. Our approach can be applied to a variety of architectures and to programming languages besides Java.
Competition between two submersed aquatic macrophytes, Potamogeton pectinatus and Potamogeton gramineus, across a light gradient

Abstract Competitive abilities of Potamogeton pectinatus L. and Potamogeton gramineus L. were estimated using additive series experiments at across a gradient of total daily irradiance ranging from 1.2 to 9.7 mol m−2 day−1. Results for P. gramineus showed that its mean weight per plant was reduced more by the presence of other P. gramineus plants than by changes in the density of P. pectinatus. However, the difference was statistically significant only at the higher light levels examined. In the case of P. pectinatus, P. gramineus exerted a stronger impact on P. pectinatus plants than did other P. pectinatus plants. Coefficients representing interspecific competition were significantly greater than those representing intraspecific competition at higher light levels. These results indicate that P. gramineus was a stronger competitor when light levels were high. They further indicate that at low light levels, there was little evidence that competition was a strong force in determining either species performance. These results support a theory offered by Grime. However, it was possible to predict that P. gramineus would be a stronger competitor based on its light compensation point which was lower than the one for P. pectinatus. This demonstrates the utility of the R* approach proposed by Tilman. Aspects of both approaches may aid ecologists in understanding community structure.
Dynamic Effects within a Regional System: An Empirical Approach

In this paper we focus on the dynamic effects under which the regional economic growth processes are accomplished, breaking them down into two broad types: neighborhood and economy-wide effects. By means of a proposed dynamic space–time empirical model, the competition structure within a multiregional economic system is developed. Cointegration and error-correction modeling techniques are used to support the existence of this competition structure over both the short and long term. As an application, we show the dynamic effects on the evolution of the regional performance of Spanish regions over the period 1972–2000. Our results indicate that some macroeconomic forces are operating through time on this Spanish system because positive and negative effects are detected both at economy-wide and at neighborhood levels. Further, the findings show that a new taxonomy of the Spanish regions could provide some guidance for the development of appropriate measures for regional economic policy.
Dichotomy and conjugate gradients in the stiff initial value problem

Abstract We propose, analyze, and experiment with solution techniques which employ the conjugate gradient algorithm coupled with prediction steps for solving the algebraic equations arising at each mesh point in the numerical development of solutions of the model stiff system x  = Ax . A stability and error analysis based on a dichotomization of the solutions of the system into rapidly and slowly decaying modes is made, to demonstrate the numerical stability of these methods. Stiff problems are characterized by this dichotomy, and we note that the conjugate gradient algorithm improves in effectiveness with the exaggeration of this characterization.
Cystamine increases l‐cysteine levels in Huntington's disease transgenic mouse brain and in a PC12 model of polyglutamine aggregation

Cystamine, a small disulfide-containing chemical, is neuroprotective in a transgenic mouse and a Drosophila model of Huntington's disease (HD) and decreases huntingtin aggregates in an in vitro model of HD. The mechanism of action of cystamine in these models is widely thought to involve inhibition of transglutaminase mediated cross-linking of mutant huntingtin in the process of aggregate formation/stabilization. In this study we show that cystamine, both in vitro and in a transgenic mouse model of HD (R6/2), increases levels of the cellular antioxidant L-cysteine. Several oxidative stress markers increase in HD brain. We provide further evidence of oxidative stress in mouse HD by demonstrating compensatory responses in R6/2 HD brains. We found age-dependent increases in forebrain glutathione (GSH), and increased levels of transcripts coding for proteins involved in GSH synthesis and detoxification pathways, as revealed by quantitative PCR analysis. Given the general importance of oxidative stress as a mediator of neurodegeneration we propose that an increase in brain L-cysteine levels could be protective in HD. Furthermore, cystamine was dramatically protective against 3-nitropropionic acid-induced striatal injury in mice. We suggest that cystamine's neuroprotective effect in HD transgenic mice results from pleiotropic effects that include transglutaminase inhibition and antioxidant activity.
Detection of Membrane Protein Two-Dimensional Crystals in Living Cells

It is notoriously difficult to grow membrane protein crystals and solve membrane protein structures. Improved detection and screening of membrane protein crystals are needed. We have shown here that second-order nonlinear optical imaging of chiral crystals based on second harmonic generation can provide sensitive and selective detection of two-dimensional protein crystalline arrays with sufficiently low background to enable crystal detection within the membranes of live cells. The method was validated using bacteriorhodopsin crystals generated in live Halobacterium halobium bacteria and confirmed by electron microscopy from the isolated crystals. Additional studies of alphavirus glycoproteins indicated the presence of localized crystalline domains associated with virus budding from mammalian cells. These results suggest that in vivo crystallization may provide a means for expediting membrane protein structure determination for proteins exhibiting propensities for two-dimensional crystal formation.
Ecology of the Black Forest of Colorado

The Black Forest of Colorado is an eastward extension over the plains and tablelands of the foothill forest of ponderosa pine [Pinus ponderosa scopiloru ni (Engelm.) Lemmon]. It covers an area approximately fifty miles long and twentyfive miles wide. The present studies were made near the northern edge of the Black Forest where zonation of pines, scrub oaks, and grasses is especially well marked. The altitude at this point is approximately 6400 feet, and the approximate location is at the intersection of meridian 1040 41' and parallel 390 20'. This region is chiefly underlain by stratified sandstone, and areas of subaqueous deposits are shown on United States Geological Survey maps. The vegetation varies with the topography. Ponderosa pine dominates the hilltops, scrub oak [Qitercus ganb efliii Nutt. and Q. gunnisonii (Torr.) Rydb.] the upper slopes, and the lower hillsides are occupied by both tall and short grasses, together with an abundance of yucca, cacti, various mustards, etc. Apparently the present communities are well stabilized in their respective locations. The zonation in the Black Forest is similar to that of a large area in southeastern Colorado and northern New Mexico and Arizona. Through much of the latter region the hilltops are occupied by trees of western red cedar (Juniperus scopulorumi Sarg.), ponderosa pine, or pinyon pine (Pinus edulis Engelm.). Farther down the hillsides the trees are smaller in size and at the bottom they constitute only a shrubby growth or are lacking entirely. Ramaley ('31), in a study of the chaparral-covered foothills southwest of Denver, Colorado, found heavy growths of scrub oak in the vicinity of the mouth of the Platte Canyon, but as he proceeded higher up the canyon, the oak growth became sparse and the number of pines greater. Weaver and Clements ('38) state: "On the western borders along the front range of the Rockies, postclimax savannah of pines extends outward along streams, escarpments, or plateaus with higher rainfall, far into the mixed prairie." Our problem is, then, todiscover (1) the reason for the extension of the ponderosa pine forest out over the plains, and (2) the causes of the prevailing zonation, especially the peculiar location of the Pines at the tops of the ridges.
The effects of false physiological feedback on tumescence and cognitive domains in sexually functional and dysfunctional men.

A false feedback paradigm was used to produce a discrepancy between expected and “actual” tumescence among 57 sexually dysfunctional and 58 sexually functional men randomly assigned to one of four false tumescence feedback conditions: negative (NEG), neutral (NEU), positive (POS), or no (NO) feedback. Participants predicted an erection score before viewing an erotic film and then received false tumescence feedback based on this score. Tumescence and cognitive ratings were obtained before and after the feedback. It was predicted that discrepancies would differ between dysfunctional and functional participants such that functional participants would have the ability to overcome discrepancies, whereas dysfunctional participants would not. As expected, POS decreased tumescence for dysfunctional participants and NO did not influence tumescence for either group. Unexpectedly, NEU decreased tumescence for dysfunctional participants and NEG decreased tumescence for functional participants. Despite tumescence changes, cognitive ratings generally followed the feedback that was given. These results only partially support current models of sexual dysfunction and behavioral regulation. Anxiety, self-focused attention, cognitive interference, and unexpectedness of the feedback could not account for the partial support. However, most feedback that was outside of the realm of the status quo for both functional and dysfunctional participants did decrease tumescence, despite outcome expectancies. These results suggest that both functional and dysfunctional men may be at risk for erectile failure should feedback about their performance be discrepant from what they expect. Prevention and treatment should focus on preparing men for occasional erectile failure and on helping them overcome discrepant feedback.
Polymerization of lactide by monomeric Sn(II) alkoxide complexes

Monomeric Sn(II) alkoxide complexes of bulky amidinate ligands N,N‘-bis(trimethylsilyl)benzamidinate, [LSiMe3]-, and N,N‘-bis(dimethylphenylsilyl)benzamidinate, [LSiMe2Ph]-, and the corresponding bis(amidinate) compounds were synthesized and structurally characterized by single-crystal X-ray diffraction. The monomeric nature of these complexes in the solid state was retained in solution as evinced by NMR spectroscopy. Both alkoxide complexes were active for dl-lactide (LA) polymerization in toluene solution at 80 °C. The controlled polymerization of LA by LSiMe2PhSn(OCPh3) was observed in the presence of 1.0 equiv of an exogenous alcohol. Under these conditions, the polymerization reaction was found to be first order in [LA] and about one-third order in [LSiMe2PhSn(OCPh3)]0. The polymerization kinetics were further analyzed by applying a model that invokes aggregation of the active species, with one inactive, aggregated form and one active, unaggregated form. The importance of aggregation in understanding...
Fragmentary blackouts: their etiology and effect on alcohol expectancies.

Background: Fragmentary blackouts, or memory loss for intoxicated events that may be later recalled with the provision of cues, are common sequelae of heavy drinking, yet understanding of their characteristics, correlates, and consequences is limited. Consequently, this alcohol-administration study addressed questions regarding the etiology of fragmentary blackouts and their effect on alcohol outcome expectancies. Methods: A placebo-controlled design addressed the etiology of fragmentary blackouts through assessment of memory formation before and after alcohol consumption. The effect of fragmentary blackouts on prospective beliefs about alcohol was assessed by way of a self-report outcome expectancy questionnaire and a measure of response latency for alcohol concepts presented after beverage consumption. Results: Although participants performed similarly on memory indices before consuming beverages, those who reported past fragmentary blackouts and consumed alcohol displayed marked difficulty with recall of a narrative when this was attempted both during intoxication and after detoxification, as well as with a source memory task presented during intoxication. Those reporting fragmentary blackouts also endorsed stronger outcome expectancies for a range of alcohol effects and exhibited greater accessibility for positive alcohol concepts presented after beverage administration. Further, source recall contributed significantly to the episodic recall both during intoxication and after detoxification, as well as to positive outcome expectancies of those receiving alcohol. Conclusions: Findings suggest that fragmentary blackouts result from poor retrieval and that individual differences in retrieval emerge after alcohol is consumed. Further, one's recall of source aspects of material—its time and social context—is an important determinant of recall of stimuli and events encountered during intoxication, as well as of prospective expectations for positive alcohol effects. The collective findings expand our understanding of this complex yet common neuropsychological consequence of heavy drinking.
An ultrastructural study of the retina in the Jansky-Bielschowsky type of neuronal ceroid-lipofuscinosis.

A 7 1/2-year-old boy died of the Jansky-Bielschowsky type of neuronal ceroidlipofuscinosis. Although an electroretinogram showed reduced activity, pigmentary retinal atrophy was not demonstrable by ophthalmoscopy two years before death. At autopsy, the retina had severe loss of photoreceptor cells, pigment displacement, gliosis, and uniformly structured lipopigment bodies with an internal structure of curvilinear profiles in ganglionic and Muller cells, in pigment epithelia, in the remaining photoreceptors, and in the elements of the inner nuclear layer. These findings conformed to those in the juvenile type of neuronal ceroid-lipofuscinosis, differing only as to the severity.