cssi/SciSciGPT-SciSciNet huggingface dataset:
Simulation of high speed impact, penetration and fragmentation problems on locally refined Cartesian grids

Techniques are presented to solve problems involving high speed material interactions that can lead to large deformations followed by fragmentation. To simulate such problems in an Eulerian framework on a fixed Cartesian mesh, interfaces (free surfaces as well as interacting material interfaces) are tracked as levelsets; to resolve shocks and interfaces, a quadtree adaptive mesh is employed. This paper addresses issues associated with the treatment of all interfaces as sharp entities by defining ghost fields on each side of the interface. Collisions between embedded objects are resolved using an efficient collision detection algorithm and appropriate interfacial conditions are supplied. Key issues of supplying interfacial conditions at the precise location of the sharp interface and populating the ghost cells with physically consistent values during and beyond fragmentation events are addressed. Numerous examples pertaining to impact, penetration, void collapse and fragmentation phenomena are presented along with careful benchmarking to establish the validity, accuracy and versatility of the approach.
Pulmonary changes following infusion of hepatic lysosomal enzymes in the rat.

Abstract Lysosomal enzymes were prepared from rat liver by differential centrifugation. Injection of the S-2 (nonlysosomal) fraction resulted in a mild depression in mean arterial pressure (MAP) and serum 125 I-fibrinogen with normal lung histology. Injection of the S-3 (lysosomal) fraction produced hypotension, leukopenia, thrombocytopenia, and elevation of 125 I-fibrinogen counts in the lungs. The 125 I-fibrinogen counts in the serum were reduced. Histology showed perivascular hemorrhage and intravascular fibrin verified by immunofluorescent fibrin stains. Reduced platelet counts indicated their role in this process possibly by releasing vasoactive substances and/or mechanically blocking the pulmonary capillaries by aggregation. Animals pretreated with heparin and infused with the S-3 fraction did not become hypotensive. Heparin also blocked the effects of the S-3 fraction in inducing thrombocytopenia and pulmonary parenchymal damage.
Electron irradiation damage in high purity aluminum

An experimental investigation of the defects formed in 99.999% Al following irradiation with 1 MeV electrons up to 10 dpa and at temperatures between 20°C and 200°C has been carried out. The microstructure after irradiation consisted of prismatic and single- and multi-faulted loops, and in excess of 90% of the loops were faulted and interstitial in character. About two-thuds of the prismatic loops were interstitial. In agreement with earlier studies, only an insignificant number of voids were observed, in contrast to nickel and copper which form copious voids when electron irradiated at appropriate temperatures. It is believed that the lack of voids in aluminum is due to a nucleation problem associated with low solubilities in the metal of H2, N2 and O2.
The 4-tert-butylphenyl group as a simple tag for solution phase synthesis

A solution phase synthesis strategy was investigated using 4-tert-butylphenyl group as the tag and a beta-cyclodextrin column as the affinity chromatographic support for the isolation of compounds containing the tag. It was found that compounds containing the tag have significantly longer retention times on the beta-cyclodextrin column than those compounds that do not have such a tag. The tag is chemically inert and can be introduced onto and removed from target compounds readily. This solution phase synthesis method was applied to the synthesis of some simple amino acid derivatives.
Hormone therapy does not modify emotion-induced brain activity in older women

Sex hormones have actions in brain regions important for emotion, including the amygdala and prefrontal cortex. Previous studies have shown that cyclic sex hormones and hormone therapy after menopause modify responses to emotional events. Thus, this study examined whether hormone therapy modified emotion-induced brain activity in older women. Functional magnetic resonance imaging (fMRI), behavioral ratings (valence and arousal), and recognition memory were used to assess responses to emotionally laden scenes in older women currently using hormone therapy (HT) and women not currently using hormone therapy (NONE). We hypothesized that hormones would affect the amount or persistence of emotion-induced brain activity in the amygdala and ventrolateral prefrontal cortex (VLPFC). However, hormone therapy did not affect brain activity with the exception that NONE women showed a modest increase over time in amygdala activity to positive scenes. Hormone therapy did not affect behavioral ratings or memory for emotional scenes. The results were similar when women were regrouped based on whether they had ever used hormone therapy versus had never used hormone therapy. These results suggest that hormone therapy does not modify emotion-induced brain activity, or its persistence, in older women.
In Situ Studies of Chemistry and Structure of Materials in Reactive Environments

Most materials and devices typically operate under specific environmental conditions, many of them highly reactive. Heterogeneous catalysts, for example, work under high pressure of reactants or in acidic solutions. The relationship between surface structure and composition of materials during operation and their chemical properties needs to be established in order to understand the mechanisms at work and to enable the design of new and better materials. Although studies of the structure, composition, chemical state, and phase transformation under working conditions are challenging, progress has been made in recent years in the development of new techniques that operate under a variety of realistic environments. With them, new chemistry and new structures of materials that are only present under reaction conditions have been uncovered.
Comparison of Statistical Methods for Pretest–Posttest Designs in Terms of Type I Error Probability and Statistical Power

The pretest–posttest design is widely used to investigate the effect of an experimental treatment in biomedical research. The treatment effect may be assessed using analysis of variance (ANOVA) or analysis of covariance (ANCOVA). The normality assumption for parametric ANOVA and ANCOVA may be violated due to outliers and skewness of data. Nonparametric methods, robust statistics, and data transformation may be used to address the nonnormality issue. However, there is no simultaneous comparison for the four statistical approaches in terms of empirical type I error probability and statistical power. We studied 13 ANOVA and ANCOVA models based on parametric approach, rank and normal score-based nonparametric approach, Huber M-estimation, and Box–Cox transformation using normal data with and without outliers and lognormal data. We found that ANCOVA models preserve the nominal significance level better and are more powerful than their ANOVA counterparts when the dependent variable and covariate are correlated....
Conventional Force Deterrence in the Presence of Theater Nuclear Weapons

Abandoning nuclear weapons as deterrents to Soviet aggression in Europe requires NATO conventional forces which can stop a blitzkrieg and place the onus of resorting to nuclear war on the Russians....
Reasoning about climate uncertainty

This paper argues that the IPCC has oversimplified the issue of uncertainty in its Assessment Reports, which can lead to misleading overconfidence. A concerted effort by the IPCC is needed to identify better ways of framing the climate change problem, explore and characterize uncertainty, reason about uncertainty in the context of evidence-based logical hierarchies, and eliminate bias from the consensus building process itself.
Inequalities in children’s schooling: AIDS, orphanhood, poverty, and gender

Summary The relationship between orphan status, household economic status, and child school enrollment across low-income countries varies substantially. Orphans sometimes have lower enrollment than non-orphans, but in many countries, the difference is small and not statistically significantly different from zero. The orphan enrollment gap is typically dwarfed by the gap between children from richer and poorer households. Often, even children from richer households have low enrollments—suggesting constraints to enrollment for all children. Girl orphans are typically not disproportionately affected in terms of enrollment. Policies need to assess country-specific situations, focusing on the interaction between orphan status, poverty, and the education system more generally—before considering school-related orphan-specific mitigation measures.
Expression and mapping of protein phosphatase 2Aα in the developing rat heart

Protein phosphatase 2A (PP2A) is a second messenger involved in cell cycle regulation, cell transformation, and cell fate determination. We previously identified a gene encoding the α catalytic subunit of PP2A in the embryonic rat heart, but its role in cardiac morphogenesis was unknown. In this study, we examined the developmental expression of PP2Aα mRNA and protein in the heart using Northern and Western analysis, in situ hybridization, and immumohistochemical staining. We found two major PP2Aα transcripts in the rat heart (1.8 and 2.4 kb), at all stages examined. By Western blotting, PP2Aα protein levels were twice as high in the embryonic rat heart compared with the adult. In situ hybridization on embryonic d 12 showed that PP2Aα mRNA was expressed in the heart, brain, tail, and limb buds. Cardiac PP2Aα expression was regionally restricted to the atrium, ventricle, and truncus arteriosus. PP2Aα expression did not extend into the more distal aortic sac or aortic arches. Cross-sectional hybridization revealed PP2Aα mRNA in the epicardium, pericardium, and endothelium. Later in development, mRNA expression was also detected at high levels in mesenchymal cells populating the endocardial cushions and in myocardium. At term, PP2Aα was highly expressed in endothelial cells, but not in the underlying myocardium. PP2Aα protein had a similar distribution at all embryonic stages examined. These results show that there is transcriptional, translational, and cell-specific regulation of PP2Aα during heart development. We speculate on the role of PP2Aα-mediated dephosphorylation in cardiac morphogenesis and suggest a number of possible molecular targets.
The genus Dendrothele (Agaricales, Basidiomycota) in New Zealand

Abstract Sixteen species of Dendrothele sensu lato are confirmed from New Zealand. Nine new taxa are described: Dendrothele arachispora, D. aucklandica, D. australis, D. cymbiformis, D. leptostachys, D. magnenavicularis, D. navicularis, D. novae-zelandiae and D. subellipsoidea. Ten species were previously reported, but only four are confirmed: D. ampullospora comb. nov., D. biapiculata, D. incrustans and D. pulvinata. Reports of Dendrothele acerina, D. candida, D. commixta and D. nivosa were not confirmed. Furthermore, D. nivosa sensu G. Cunningham and D. corniculata are not true dendrotheles, and D. fasciculata is accepted in Epithele. The new taxa, D. ampullospora, D. biapiculata and D. pulvinata are described and illustrated. A key to Dendrothele s.l. from New Zealand is provided.
The effect of ammonium chloride on metabolism of primary neurons and neuroblastoma cells in vitro

Hyperammonemia is a consistent finding in many metabolic disorders. The excess ammonia (NH4Cl) interferes with brain energy metabolism possibly in part by inhibiting the tricarboxylic acid (TCA) cycle. Inhibition of the TCA cycle may result in depletion of ATP in the brain cells. In this study, the acute and chronic effect of NH4Cl (7.5 mM and 15 mM) on the metabolism of isolated neurons and neuroblastoma cells was examined. These cells were treated with NH4Cl for 15 minutes and 24 hours. Morphologic and metabolic toxicity were greater in neuroblastoma cells than in primary neurons. Following 15 minutes treatment, concentration of lactate increased significantly in neuroblastoma cells but, the concentration of other metabolites did not change significantly in neuroblastoma cells and in primary neurons. Following 24 hours treatment, the glucose utilization increased in both cell types. This high utilization of glucose in neuroblastoma cells was in concert with an increase in lactate and decrease in glutamate and ATP. In primary neurons, following 24 hours treatment, the glucose utilization significantly increased, but the concentration of the other metabolites did not change significantly. Neuroblastoma cells consumed more glucose than primary neurons in absence of NH4Cl, but generated the same amount of lactate as neurons.
Athlete's Heart and Cardiovascular Care of the Athlete Scientific and Clinical Update

“The physiologic capabilities of the heart are enormous, and in judging the effect of any undue exertion on it, we must not regard the murmurs of the irregularity alone, but must also consider carefully, the way in which the heart is doing its work, its strength, as shown by its ability to maintain proper arterial tension, and its recuperative power. As with other muscles, not size but quality tells in the long run.”1 Eugene Darling The heart of the athlete has intrigued clinicians and scientists for more than a century. Early investigations in the late 1800s and early 1900s documented cardiac enlargement and bradyarrhythmias in individuals with above-normal exercise capacity and no attendant signs of cardiovascular disease. Since that time, scientific understanding of the association between sport participation and specific cardiac abnormalities has paralleled advances in cardiovascular diagnostic techniques. It is now well established that repetitive participation in vigorous physical exercise results in significant changes in myocardial structure and function. Recent increases in the popularity of recreational exercise and competitive athletics have led to a growing number of individuals exhibiting this phenomenon. This review provides an up-to-date summary of the science of cardiac remodeling in athletes and an overview of common clinical issues that are encountered in the cardiovascular care of the athlete. Initial reports describing cardiac enlargement in athletes date back to the late 1890s. In Europe, the Swedish clinician Henschen2 used the rudimentary yet elegant physical examination skills of auscultation and percussion to demonstrate increased cardiac dimensions in elite Nordic skiers. Similar observations were made during the same year by Eugene Darling1 of Harvard University in university rowers. In the early 1900s, Paul Dudley White3 studied radial pulse rate and pattern among Boston Marathon competitors, and was the first to report marked resting sinus …
Electrocardiographic findings over time in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Thirty-five patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy underwent serial electrocardiographic (ECG) testing and were evaluated for evidence of ECG progression. Over a median of 43 months, 89% of the patients had evidence of progression, with S-wave prolongation being the most prevalent marker of ECG progression.
Continuous-wave operation of type-I GaSb-based narrow ridge waveguide lasers near 3254nm

Narrow ridge waveguide (5um) laser diodes were fabricated using type-I InGaAsSb/AlInGaAsSb quantum well active regions on GaSb. The devices operate in continuous-wave mode near 3254nm with a total light output of 7.4mW at 20°C (uncoated facets).
SkyView Foods: Eric's Real Dilemma with Channel Partners

As a marketing analyst, Eric is faced with several ethical dilemmas. When asked to engage in unethical and illegal behavior, Eric must decide whether to obey his boss and fudge the numbers (the counts of product purchased in order to get reimbursed more from the manufacturer during special sales) or take the ethical route. The case consists of two parts, with the second part revealing how Eric's dilemma took an unexpected turn for the worst when one manufacturer discovers the discrepancies. The case is based on a real situation in the real world and the teaching note (available online) provides details on what happened in the end.
The case for epigenetic inheritance in evolution

It is commonly thought that genotype is a property assignable exclusively to the nucleic acid genome while phenotype is a property whose assignment must be distributed among entities at many or all levels of biological organization. In evolutionary biology there is a problem of hierarchy in the theory of selection due to this requirement for distributive assignment: to which level(s) is the cause of a particular selective effect to be assigned? There appears to be no comparable perceived problem for theories of inheritance due to the asymmetry of genotype and phenotype. One might argue to the contrary that the genome has an architecture and that linkage, recombination, and gene interaction all point to a hierarchical structure ranging from nucleotides-as-units up to the genome as a whole (Lewontin, 1974). But this hierarchy presents no comparable problem because all of these genomic elements are part of a single inheritance system. The transmission rules used to track nucleotides are the same ones used to track larger genomic elements. In the narrowest sense, then, genotype means DNA (or RNA) sequence. Phenotypes are various, embodying all the morphologies, physiologies, and behaviors of living things. As such, phenotypes are the direct targets or subjects of natural selection and genotypes are the direct subjects of inheritance. However, the evolution of phenotypes depends not only on selection but also on their relation to genotypes that can be transmitted (or reconstituted) in inheritance. Selection without an appropriate genotype-phenotype relation does not result in an evolutionary response. Evolution by natural selection depends on inheritance and selection in equal measures. Belief that the asymmetry of genotype and phenotype is fundamental is reinforced by the fact that the mechanism of nucleic acid-based heredity is so well understood and provides such an exquisite explanation of the genotype-phenotype mapping. Although much is unknown about the details of the ‘‘epi-genetic’’ mapping beyond the primary coding of amino acid sequence, no other known 193
Impaired mobilization of hematopoietic stem/progenitor cells in C5-deficient mice supports the pivotal involvement of innate immunity in this process and reveals novel promobilization effects of granulocytes

We reported that complement cascade (CC) becomes activated in bone marrow (BM) during granulocyte colony-stimulating factor (G-CSF) mobilization of hematopoietic stem/progenitor cells (HSPCs) and showed that, although third CC component (C3)-deficient mice are easy mobilizers, fifth CC component (C5)-deficient mice mobilize very poorly. To explain this, we postulated that activation/cleavage of CC releases C3a and C5a anaphylatoxins that differently regulate mobilization. Accordingly, C3a, by enhancing responsiveness of HSPCs to decreasing concentrations of stromal-derived growth factor-1 (SDF-1) in BM, prevents mobilization and promotes their BM retention. Therefore, in this study, we focused on the mobilization-enhancing role of C5a. We found that C5a receptor (C5aR) is not expressed on the surface of HSPCs, and that C5a-mediated promobilization effects are mediated by stimulation of granulocytes. Overall, our data support the following model. First C5aR(+) granulocytes are chemoattracted by plasma C5 cleavage fragments, being the first wave of cells leaving BM. This facilitates a subsequent egress of HSPCs. In the next step, after leaving BM, granulocytes undergo degranulation in response to plasma C5a and secrete some cationic peptides (cathelicidin, beta-defensin) that, as shown here for the first time, highly enhance the responsiveness of HSPCs to plasma SDF-1 gradient. In conclusion, our data reveal the underappreciated central role of innate immunity in mobilization, in which C5 cleavage fragments through granulocytes orchestrate this process.
Nonlinear dynamic modeling and resonance tuning of Galfenol vibration absorbers

This paper investigates the semi-active control of a magnetically-tunable vibration absorber’s resonance frequency. The vibration absorber that is considered is a metal-matrix composite containing the magnetostrictive material Galfenol (FeGa). A single degree of freedom model for the nonlinear vibration of the absorber is presented. The model is valid under arbitrary stress and magnetic field, and incorporates the variation in Galfenol’s elastic modulus throughout the composite as well as Galfenol’s asymmetric tension–compression behavior. Two boundary conditions—cantilevered and clamped–clamped—are imposed on the composite. The frequency response of the absorber to harmonic base excitation is calculated as a function of the operating conditions to determine the composite’s capacity for resonance tuning. The results show that nearly uniform controllability of the vibration absorber’s resonance frequency is possible below a threshold of the input power amplitude using weak magnetic fields of 0–8 kA m−1. Parametric studies are presented to characterize the effect on resonance tunability of Galfenol volume fraction and Galfenol location within the composite. The applicability of the results to composites of varying geometry and containing different Galfenol materials is discussed.
Practical voltage scaling for mobile multimedia devices

This paper presents the design, implementation, and evaluation of a practical voltage scaling (PDVS) algorithm for mobile devices primarily running multimedia applications. PDVS seeks to minimize the total energy of the whole device while meeting multimedia timing requirements. To do this, PDVS extends traditional real-time scheduling by deciding what execution speed in addition to when to execute what applications. PDVS makes these decisions based on the discrete speed levels of the CPU, the total power of the device at different speeds, and the probability distribution of CPU demand of multimedia applications. We have implemented PDVS in the Linux kernel and evaluated it on an HP laptop. Our experimental results show that PDVS saves energy substantially without affecting multimedia performance. It saves energy by 14.4% to 37.2% compared to scheduling algorithms without voltage scaling and by up to 10.4% compared to previous voltage scaling algorithms that assume an ideal CPU with continuous speeds and cubic power-speed relationship.
Applications of single-grain zircon evaporation analyses to detrital grain studies and age discrimination in igneous suites

Abstract 207 Pb 206 Pb ages determined by evaporation of single zircon grains from rocks of the New England Appalachians in the USA permit an assessment of the applicability of this method to rocks that have been strongly disturbed by orogenesis. Tests conducted on highly metamorphosed and deformed orthogneisses of known protolith age, whose U-Pb upper intercept zircon ages obtained through isotope dilution methods show profound post-crystallization discordance, demonstrate that the evaporation method is successful in recovering protolith ages. Uncertainties are ±10–15 My for rocks of Paleozoic age or older. Preliminary results suggest that the method is particularly useful for provenance studies of sedimentary rocks and in the discrimination among groups of rocks that are known to differ in age but are otherwise difficult to separate on the basis of field or petrographic characteristics. 207 Pb 206 Pb ages of detrital zircon grains from two metasedimentary units from opposite sides of the New England Appalachians reveal the distinct provenances of these rocks. The Missisquoi Formation in southeastern Vermont, USA, is comprised, in part, of detritus derived from the 1.0–1.2 Ga Grenvillian province of Laurentia; whereas this component is conspicuously absent from the Plainfield Formation in easternmost Connecticut. The detrital zircon age data suggest that the Missisquoi Formation accumulated peripheral to the Laurentian craton during the early Paleozoic, whereas the Plainfield Formation detritus was supplied by non-Laurentian, ossibly West African, sources during the Late Proterozoic or early Paleozoic. In southern Vermont, the evaporation method successfully distinguishes between two groups of augen gneisses with ages of ~960 Ma and ~ 1120 Ma, which were first recognized through isotope dilution methods. Collectively, these results indicate that the dating of single zircon grains by the evaporation method can be widely exploited in the study of complexly deformed and strongly metamorphosed rocks.
Strength performance of the pectoralis major muscle after subpectoral breast augmentation surgery.

Abstract Background: Although subpectoral placement of breast implants is a commonly used technique in breast augmentation surgery, the ultimate effects of this procedure on the strength or function of the pectoralis major muscle (PMM) remain undetermined. Objective: In this study, we investigated whether subpectoral placement of mammary implants negatively affects the strength performance (SP) of the PMM. Methods: Twenty women underwent isokinetic testing with the Biodex 3 System (Biodex Medical Systems, Inc, Shirley, NY) before surgery and 2 and 6 weeks after subpectoral placement of breast implants. Nine patients returned for long-term testing. To isolate the PMM, we tested two motions: internal rotation and extension/adduction. The results were evaluated in two ways. We compared postoperative SP to baseline (preoperative) SP using paired Student t tests. P values of less than 0.05 were considered statistically significant. SP was also evaluated with the Biodex 3 System Standards, which consider a postoperative SP of less than 75% of baseline significantly impaired and one more than 75% to be within normal limits. Results: Paired comparisons indicated statistically significant reductions in SP 2 weeks after surgery, followed by increases in SP by 6 weeks. When applying the Biodex 3 System Standards, we found that in both internal rotation and extension/adduction, nearly half of the patients had recovered to 75% of baseline SP 2 weeks after surgery and that more than three- quarters of the patients were fully recovered 6 weeks after surgery. Long-term follow-up in 9 patients revealed retention of SP or further improvement. Conclusions: Subpectoral placement of mammary implants did not produce statistically significant long-term loss of upper-extremity SP. It appears that no permanent loss of strength of the PMM results from subpectoral placement of breast implants. (Aesthetic Surg J 2003;23:92-97.)
A practical alternative to single tree selection

When landowners want to develop and maintain an uneven-aged tree structure in eastern hardwood stands, single-tree selection often is suggested as the only advisable, long-term partial regeneration harvest method. Single-tree selection is preferred because it provides a means for improving quality and controlling stocking of the residual stand necessary for sustained yield of desired products. Although studies have shown that single-tree selection is feasible where desirable shade-tolerant species can be regenerated, it is rarely applied because marking stands for harvest can be dificult and time consuming. Instead, diameter-limit cutting is the most common partial regeneration practice used in eastern hardwoods, primarily because it is much easier to apply. Unfortunately, strict diameter-limit cuts do not provide for control of residual stocking or improve the quality of residual trees. However, based on 20-yr results, most objectives of single-tree selection can be attained with flexible diameter-limit harvest guidelines based on potential value increase of individual trees combined with an improvement cut in small sawtimber trees at each periodic cut.
THE PRODUCTION OF PERSISTENT ALOPECIA IN RABBITS BY X-RAYS OF VARIOUS DEGREES OF HARDNESS

1. The minimum dose of x-ray, of each of three degrees of hardness, required to produce persistent alopecia of the abdominal skin of normal white rabbits has been studied. 40 kilovolt rays filtered by 0.5 mm., 50 kilovolt rays filtered by 1 mm., and 70 kilovolt rays filtered by 1.5 mm. of aluminium were employed. The 70 kilovolt work is unfinished. 2. Under constant conditions of treatment, the animals were found to react with a high degree of consistency. 3. The values of the critical minimum doses expressed in terms of air ionization (pair of ions per gm. of air divided by 1015), for rays produced at 30, 40, 50, and 70 kilovolt peak, are 2.04, 3.7, 4.5, and over 5.1 respectively. The 30 kilovolt value is taken from a previous paper. 4. It is shown that the alopecia reaction does not run parallel to the erythema and pigmentation reactions.
Accelerating Internet streaming media delivery using network-aware partial caching

Internet streaming applications are affected by adverse network conditions such as high packet loss rates and long delays. This paper aims at mitigating such effects by leveraging the availability of client-side caching proxies. We present a novel caching architecture and associated cache management algorithms that turn edge caches into accelerators of streaming media delivery. A salient feature of our caching algorithms is that they allow partial caching of streaming media objects and joint delivery of content from caches and origin servers. The caching algorithms we propose are both network-aware and stream-aware; they take into account the popularity of streaming media objects, their bit-rate requirements, and the available bandwidth between clients and servers. Using realistic models of Internet bandwidth derived from proxy cache logs and measured over real Internet paths, we have conducted simulations to evaluate the performance of various cache management alternatives. Our experiments demonstrate that network-aware caching algorithms can significantly reduce service delay and improve overall stream quality. Our experiments also show that partial caching is particularly effective when bandwidth variability is not very high.
Differentiation of spinous synapses in the mouse organ of corti.

The inner hair cells, the primary auditory receptors, are perceived only as a means for transfer of sound signals via the auditory nerve to the central nervous system. During initial synaptogenesis, they receive relatively few and mainly somatic synapses. However, around the onset of hearing (10-14 postnatal days in the mouse), a complex network of local spinous synapses differentiates, involving inner hair cells, their afferent dendrites, and lateral olivocochlear terminals. Inner hair cell spines participate in triadic synapses between olivocochlear terminals and afferent dendrites. Triadic synapses have not yet been confirmed in the adult. Synaptic spines of afferent dendrites form axodendritic synapses with olivocochlear terminals and somatodendritic synapses with inner hair cells. The latter are of two types: ribbon-dendritic spines and stout dendritic spines surrounded only by a crown of synaptic vesicles. Formation of spinous afferent synapses results from sprouting of dendritic filopodia that intussuscept inner hair cell cytoplasm. This process continues in the adult, indicating ongoing synaptogenesis. Spinous processes of olivocochlear synaptic terminals contact adjacent afferent dendrites, thus integrating their connectivity. They develop about 14 postnatal days, but their presence in the adult has yet to be confirmed. Differentiation of spinous synapses in the organ of Corti results in a total increase of synaptic contacts and in a complexity of synaptic arrangements and connectivity. We propose that spinous synapses provide the morphological substrate for local processing of initial auditory signals within the cochlea.
RESTORATION OF PRESETTLEMENT AGE STRUCTURE OF AN ARIZONA PONDEROSA PINE FOREST

The age structure in 1876, the last year of the natural frequent-fire regime, of an unharvested ponderosa pine forest in northern Arizona was reconstructed from living and dead dendrochronological samples. Approximately 20% of the trees were .200 yr old in 1876 with ages ranging to 540 yr. If dead trees had not been included in the reconstruction, the distribution would have been biased toward younger trees and a 40% shorter age range. The presettlement age distribution was multimodal with broad peaks of establishment, consistent with the model of regeneration in ''safe sites'' where herbaceous competition and fire thinning are reduced. Although fire disturbance regimes and climatic conditions varied over the centuries before 1876, a clear relationship between these variations and tree establishment was not observed. Due to fire exclusion, reduced grass competition, and favorable climatic events, high levels of regeneration in the 20th century raised forest density from 60 trees/ha in 1876 to .3000 trees/ha in 1992. An ecological restoration experiment initiated in 1993 conserved all living presettlement trees and reduced the density of young trees to near-presettlement levels. Two important components for evaluating the restoration treatment effects are monitoring of old-tree persistence and patterns of future regeneration in the context of the presettlement reference age structure.
Effects of cold treatment on synchronous Chinese hamster cells treated in mitosis.

Chinese hamster mitotic cells (95% in mitosis with 85% in metaphase and 10% in anaphase) were shaken loose from monolayer asynchronous cultures and stored at 1°C for up to 28 hours. During this period, the mitotic index did not decrease and the cells remained cytologically normal. However, over a four-hour period, metaphase cells located within 1.8 minutes of anaphase, 10% of the metaphase population, were able to move into anaphase; this point of 1.8 minutes corresponds in time to that reported for the spindle activation marker. When the cells were warmed to 37°C, they were delayed in entering G1 and S (35 and 70 minutes, respectively, after a 4-hour treatment). This delay of 70 minutes was maintained for three cell cycles, during which a high degree of synchrony was maintained. Cold treatment for 12 hours produced delays into G1 and S of 50 and 110 minutes, respectively. A fraction of the metaphase cells (12 or 50% after treatments of 4 or 12 hours, respectively) evidenced chromosomal aggregation, were unable to complete cytokinesis, and appeared in the next division as tetraploid cells. These tetraploid cells were unable to survive and produce macroscopic colonies. It is concluded that this decrease in viability is caused by irreversible effects on the spindle and/or centriolar components in metaphase cells located prior to the spindle activation marker.
The Kinetic Reaction Mechanism of the Vibrio cholerae Sodium-dependent NADH Dehydrogenase.

The sodium-dependent NADH dehydrogenase (Na+-NQR) is the main ion transporter in Vibrio cholerae. Its activity is linked to the operation of the respiratory chain and is essential for the development of the pathogenic phenotype. Previous studies have described different aspects of the enzyme, including the electron transfer pathways, sodium pumping structures, cofactor and subunit composition, among others. However, the mechanism of the enzyme remains to be completely elucidated. In this work, we have studied the kinetic mechanism of Na+-NQR with the use of steady state kinetics and stopped flow analysis. Na+-NQR follows a hexa-uni ping-pong mechanism, in which NADH acts as the first substrate, reacts with the enzyme, and the oxidized NAD leaves the catalytic site. In this conformation, the enzyme is able to capture two sodium ions and transport them to the external side of the membrane. In the last step, ubiquinone is bound and reduced, and ubiquinol is released. Our data also demonstrate that the catalytic cycle involves two redox states, the three- and five-electron reduced forms. A model that gathers all available information is proposed to explain the kinetic mechanism of Na+-NQR. This model provides a background to understand the current structural and functional information.
E-Mail Interviewing in Qualitative Research: A Methodological Discussion

This article summarizes findings from studies that employed electronic mail (e-mail) for conducting indepth interviewing. It discusses the benefits of, and the challenges associated with, using e-mail interviewing in qualitative research. The article concludes that while a mixed mode interviewing strategy should be considered when possible, e-mail interviewing can be in many cases a viable alternative to face-to-face and telephone interviewing. A list of recommendations for carrying out effective e-mail interviews is presented.
Optimal control on Riemannian manifolds with potential fields

This paper is an extension of the work done by I.I. Hussein and A.M. Bloch (2004), where necessary conditions for minimizing the cost function for a trajectory that evolves on a Riemannian manifold and satisfies a second order differential equation together with some interpolation, smoothness and motion constraints were derived. In this paper, we investigate the inclusion of a generalized potential field in the dynamics. This problem is motivated by two-spacecraft interferometric imaging applications, where the formation is evolving in some generalized potential field. The corresponding necessary conditions are derived and connections are made with previous results. The paper is concluded with an example.
Yucatán's Maya Peasantry and the Origins of the Caste War

Acknowledgments Introduction 1. A Rural Society in the New Century 2. The Return to Pagan Antiquity 3. The Other Side of the Golden Age 4. Dilemmas of the Maya Elite 5. The Iman Revolt 6. "The Devil Will Overtake Us" Conclusions Notes Bibliography Index
QUALITATIVE STUDIES OF NEUTRAL 17-KETOSTEROIDS IN NORMAL SUBJECTS*†

TOTAL urinary neutral 17-ketosteroids have been studied extensively as an index of human adrenal cortical activity, although their exact relationship with this activity is not known (1). The urinary 17-ketosteroids may be conversion products of other steroid substances. Administration of any of a wide variety of C19 steroids increases the output of urinary 17-ketosteroids, especially androsterone and etiocholanolone (2, 3). Mason and Kepler (4, 5), and Sayers et al. (6) have suggested that urinary 17-ketosteroids are breakdown products of 21-carbon-atom adrenal cortical steroids. Conn (7) and Polley and Mason (8) reported an increased urinary excretion of 17-ketosteroids following administration of adrenal cortical hormones. Sprague et al. (9) indicate that cortisone may depress urinary 17-ketosteroid excretion due to depression of some of the functions of the cortices, though an increase is reported in patients suffering with Addison's disease. Homburger (10) and Cuyler et al. (11) report no increase in ...
Congress and Defense Policy: 1961 to 1986

Congressional decision making on defense policy has evolved through three distinctive styles since 1961 because of changes in the opportunities, incentives, and freedom for lawmakers to address defense issues. In the 1960s, decision making in Congress was an "inside game": the most senior members of the defense committees-the two Armed Services committees and the two Appropriations Defense subcommittees-dominated the debate. In the 1970s, the congressional reform movement dispersed power in Congress and ushered in a decentralized variant of the inside game. Finally, in the 1980s an "outside game" emerged as congressional activity increasingly has bypassed the traditional channels of power within the defense committees. This new decision-making style has made the defense debate on Capitol Hill more representative of the views of its members and encouraged debate on a broader range of defense issues. Notwithstanding, the outside game also has produced delays in the budgetary process, an erosion of the commi...
Energetic costs of cellular computation

Cells often perform computations in order to respond to environmental cues. A simple example is the classic problem, first considered by Berg and Purcell, of determining the concentration of a chemical ligand in the surrounding media. On general theoretical grounds, it is expected that such computations require cells to consume energy. In particular, Landauer’s principle states that energy must be consumed in order to erase the memory of past observations. Here, we explicitly calculate the energetic cost of steady-state computation of ligand concentration for a simple two-component cellular network that implements a noisy version of the Berg–Purcell strategy. We show that learning about external concentrations necessitates the breaking of detailed balance and consumption of energy, with greater learning requiring more energy. Our calculations suggest that the energetic costs of cellular computation may be an important constraint on networks designed to function in resource poor environments, such as the spore germination networks of bacteria.
Measures of Online Advertising Effectiveness for Market Penetration: The Case of Orange Juice Consumers

Traditionally, research on the impacts of generic advertising on food demand has focused on television advertising and in-store promotions. However, with the an increased use of advertising using social media, such as online banner advertisements, there is a need for investigation to determine whether online advertising has a similar impact as television advertising. We investigate the factors related to both the awareness and impact of online and television advertisements on the frequency of orange juice consumption. A negative time trend is found with regard to awareness of both online and television advertising. The relationship between awareness of orange juice advertisements and frequency of consumption is somewhat surprising. The major surprise is the lack of relationship between online advertising and consumption frequency. Only awareness of online Facebook advertisements is positively related to the number of days per week orange juice is consumed. The lack of relationship with awareness of television advertisements, which at first may be surprising is reflected in a recent decision by the Florida Department of Citrus, which is responsible for the funding and placement of orange juice advertisements, to no longer invest in television advertising. Additional research on whether or not online advertisements are proving ineffective is needed.
Delayed emergence of methamphetamine's enhanced cardiovascular effects in nonhuman primates during protracted methamphetamine abstinence.

Abstract Background Methamphetamine abuse is linked with brain abnormalities, but its peripheral effects constitute an integral aspect of long-term methamphetamine use. Methods Eight male rhesus monkeys with long histories of intravenous methamphetamine self-administration were evaluated 1 day, and 1, 4, 12, 26, and 52 weeks after their last methamphetamine self-administration session. On test days, isoflurane-anesthetized animals received a 0.35 mg/kg IV methamphetamine challenge. A control group consisted of 10 age and gender matched drug naive monkeys. Cardiovascular responses to methamphetamine were followed for 2.5 h. Echocardiograms were acquired at 3 and 12 months of abstinence and in the control animals. Results No pre-methamphetamine baseline differences existed among 7 physiological measures across all conditions and controls. As expected, methamphetamine increased heart rate and blood pressure in controls. However, immediately following the self-administration period, the blood pressure response to methamphetamine challenge was reduced when compared to control monkeys. The peak and 150-min average heart rate increases, as well as peak blood pressure increases following methamphetamine were significantly elevated between weeks 12 to 26 of abstinence. These data indicate the development of tolerance followed by sensitization to methamphetamine cardiovascular effects. Echocardiography demonstrated decreased left ventricular ejection fraction and cardiac output at 3 months of abstinence. Importantly, both cardiovascular sensitization and cardiotoxicity appeared to be reversible as they returned toward control group levels after 1 year of abstinence. Conclusions Enhanced cardiovascular effects may occur after prolonged abstinence in addicts relapsing to methamphetamine and may underlie clinically reported acute cardiotoxic events.
Fundamental differences between glassy dynamics in two and three dimensions

The two-dimensional freezing transition is very different from its three-dimensional counterpart. In contrast, the glass transition is usually assumed to have similar characteristics in two and three dimensions. Using computer simulations, here we show that glassy dynamics in supercooled two- and three-dimensional fluids are fundamentally different. Specifically, transient localization of particles on approaching the glass transition is absent in two dimensions, whereas it is very pronounced in three dimensions. Moreover, the temperature dependence of the relaxation time of orientational correlations is decoupled from that of the translational relaxation time in two dimensions but not in three dimensions. Last, the relationships between the characteristic size of dynamically heterogeneous regions and the relaxation time are very different in two and three dimensions. These results strongly suggest that the glass transition in two dimensions is different than in three dimensions.
How Readable Are Summary Plan Descriptions For Health Care Plans

The summary plan description (SPD) is the primary source of information for workers who participate in an employment-based health care plan. This paper investigates whether private-sector employers' SPDs are written so that an average plan participant can identify and read important information contained in the document, as required by federal law. Summary plan descriptions for 40 health care plans from a diverse national sample were collected and tested and subjected to content and readability analyses. The data from this study provide quantifiable evidence about whether summary plan descriptions cover the necessary topics that participants need to know about their health plans, and the educational level required to read them.
Enhancement of Tensile Ductility in Nanograin Superplastic Ceramics Through Control of Interface Chemistry

The strain rate and tensile ductility of superplastic nanocrystalline ceramics are controlled by the grain boundary cohesive strength and the rate of diffusion along interfaces. In this paper we propose that space charge layers at interfaces can enhance cohesion and ductility. We further propose that non-stoichiometric ceramics are more likely to exhibit such behavior. Data on magnesium aluminate spinels are presented to support this hypothesis. A model for superplastic flow in ceramics with charged layers at interfaces is presented. In addition we present a powder free route for the synthesis of nanocrystalline spinels, where transition metal dopants are employed to produce a uniform and ultrafine grain size.
Dynamic Compaction of Al Alloys

Powders of Al alloy 7091 have been consolidated by means of dynamic compaction. The dependence of density and hardness on projectile velocity has been determined. The resulting as-compacted material has been characterized using analytical transmission electron microscopy and evidence of interparticle melting observed. The microstructural response of the compacted material to heat treatment at 523 and 723°K has been investigated.