cssi/SciSciGPT-SciSciNet huggingface dataset:
Inheritance of ventilatory behavior in rodent models

Studies in mice and rats support the hypothesis that ventilation and its components (frequency and tidal volume) are determined to a significant extent by genetic mechanisms. The question can no longer be 'is there a genetic effect?' but rather 'how strong is the genetic component?' and 'what genes are involved?' The computational analyses of selectively bred animals now offer powerful tools to begin to dissect the genetic factors that track with ventilatory traits. Control of the conditions in the colony and in the laboratory are keys to reducing the environmental 'noise' and increasing the likelihood of detecting gene loci that correlate quantitatively with phenotype values before and during the response to chemosensory challenges. Knowing the chromosomal location of genes for ventilation will then permit the identification of proteins systems responsible for the structural and functional components for respiration.
The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors

A major concern in the design of thick-liquid protected inertial fusion reactors of all types is the dynamic response of the shielding liquid to the pulsed explosions. Induced liquid motion can stress and damage solid chamber structures such as the first-wall. In a Z-pinch based inertial fusion (Z-IFE) reactor this issue becomes particularly critical due to the relatively large proposed target yields of several GJ. In this paper we summarize an analysis of the liquid response taking into account ablation of target facing surfaces, pocket venting, and neutron isochoric heating. The impact of varying several reactor parameters is also discussed
Structural control of magnetic anisotropy in a strain-driven multiferroic EuTiO3 thin film

Octahedral distortion plays a key role in engineering the physical properties of heterostructures composed of perovskite oxides. We observe a strong in-plane uniaxial magnetic anisotropy in a strain-enabled multiferroic EuTiO3 thin film epitaxially grown on a (110)o DyScO3 substrate. First-principles calculations show that the magneticanisotropyiscloselycorrelatedwiththeuniaxialTiO6 octahedraltiltingandtheferroelectricpolarization of the film, indicating potential strong magnetoelectric coupling in the strain-engineered multiferroic system.
Cross-sectional investigation of adolescent perceptions of gender roles.

Data from a sample of youngsters, 12 through 18 years old, are analysed to examine the difference in gender role perceptions across age groups. A series of multivariate correlational analyses are employed to examine the relationship between respondent gender, age and self-reported perceptions of gender identity. The results of the study indicate indirect support for Erikson's speculations about resolution of Identity “Crisis”. The youngest respondents showed the greatest disparity between male and female role perceptions. The older subjects, those in adolescence, displayed greater ambiguity toward gender roles. Finally, the oldest respondents, approaching adulthood, indicated a stronger perceived gender identity.
The importance of terminology in teaching K-12 science

Several recent reports concerning the status of science education in K-12 classrooms have emphasized the centrality of textbooks to instruction. Some initial investigations of the nature of textbooks have suggested that typically more new words and terms are introduced than one would expect to find in a similar time frame as foreign languages are studied. This is a review of these initial studies, a review of the studies of mastery of vocabulary in foreign languages, and a review of general research concerning the vocabulary development, especially as it pertains to reading. Twenty-five of the most commonly used textbooks in K-12 science classrooms are analyzed in terms of the occurrence of special/technical words. The number of words introduced at every level is considerable-often more than would be required if a new language were being introduced. In addition, the number of new words in science often approaches the total number that could be expected in terms of total vocabulary increase at a given grade level for a given student. There is strong evidence that one major fact of the current crisis in science education is the considerable emphasis upon words/terms/definitions as the primary ingredient of science-at least the science that a typical student encounters and that he/she is expected to master.
Synthesis, characterization, and electronic properties of a thermally-labile isoindigo

Abstract Addition of tert-butoxycarbonyl (Boc) groups to 6,6′-dibromoisoindigo (3a) provides a highly soluble material that displays π-stacking in the solid state as evidenced by a single crystal X-ray study. This Boc-substituted molecule (3b) was compared to an alkyl-substituted isoindigo using techniques such as TGA, UV–Vis and cyclic voltammetry. TGA analysis reveals the thermolabile Boc groups of 3b can be removed at elevated temperatures to afford the parent isoindigo. Electrochemical analyses, in conjunction with density functional theory (DFT) calculations, reveals enhanced electron affinities of 3b relative to alkyl-substituted isoindigos.
N-ethylmaleimide irreversibly inhibits the binding of [3H]threo-(±)-methylphenidate to the stimulant recognition site

Abstract N-Ethylmaleimide, a nonspecific protein modifier which reacts selectively with the sulfhydryl group of cysteinyl residues under controlled conditions, irreversibly inhibited the binding of [ 3 H ] threo -(±)- methylphenidate to a subset of stimulant binding sites in striatal tissue membranes from the rat in vitro. The inhibition was marked by a decrease in the Bmax of binding of the radiolabelled stimulant drug, while the KD remained unchanged. Pretreatment with excess unlabelled methylphenidate afforded complete protection from inactivation of the binding site by N-ethylmaleimide. Uptake of [3H]dopamine into striatal synaptosomes was likewise reduced after treatment with N-ethylmaleimide; pretreatment with large concentrations of methylphenidate provided partial protection from inactivation of transport. These findings suggest that the stimulant recognition site on the dopamine transport complex contains one or more cysteinyl residues.
Expectation-maximization restoration of band-limited, truncated point-process intensities with application in microscopy

The problem posed in this paper is that of restoring a Poisson-point-process intensity that has been degraded by a band-limiting filter followed by a truncation of the signal. The approach is to derive a maximum-likelihood estimate from the count data of the degraded point process. The expectation-maximization algorithm is used to realize this estimate, while the derivation of this algorithm is an extension to previous developments by Shepp and Vardi [ IEEE Trans. Med. ImagingMI-2, 113 ( 1982)], Snyder et al. [ IEEE Trans. Nucl. Sci.NS-28, 3575 ( 1981)], and others used for positron-emission tomography. We also extend our own work reported earlier by considering the truncated signal, which is analogous to practical situations in both two- and three-dimensional microscopy in which the image of the specimen has been truncated. Computer simulations with one-dimensional and two-dimensional signals demonstrate such a reconstruction with reasonable success. The plausibility of doing such a reconstruction is explained in that for the noiseless case the transformation characterizing the degradation is invertible.
Trusting in others’ biases: Fostering guarded trust in collaborative filtering and recommender systems

Collaborative filtering is being used within organizations and in community contexts for knowledge management and decision support as well as the facilitation of interactions among individuals. This article analyzes rhetorical and technical efforts to establish trust in the constructions of individual opinions, reputations, and tastes provided by these systems. These initiatives have some important parallels with early efforts to support quantitative opinion polling and construct the notion of “public opinion.” The article explores specific ways to increase trust in these systems, albeit a “guarded trust” in which individuals actively seek information about system foibles and analyze the reputations of participants.
Kinetic Results Implicating a Polar Radical Reaction Pathway in the Rearrangement Catalyzed by α-Methyleneglutarate Mutase

α-Methyleneglutarate mutase (MGM) catalyzes the rearrangement of 2-methyleneglutarate to 3-methylitaconate (2-methylene-3-methylsuccinate). A putative mechanism for the MGM-catalyzed reaction involves 3-exo cyclization of the 2-methyleneglutaric acid-4-yl radical to a cyclopropylcarbinyl radical intermediate that ring opens to the 3-hydroxycarbonyl-2-methylenebutanoic acid-4-yl radical (3-methylitaconic acid radical). Model reactions for this mechanism were studied by laser flash photolysis kinetic methods. α-Ester radicals were produced by 266 nm photolysis of α-phenylselenyl ester derivatives. Rate constants for cyclizations of the (Z)-1-ethoxycarbonyl-4-(2,2-diphenylcyclopropyl)-3-buten-1-yl radical ((Z)-8a) and (E)- and (Z)-1,3-di(ethoxycarbonyl)-4-(2,2-diphenylcyclopropyl)-3-buten-1-yl radicals ((E)- and (Z)-8b) were determined. The ester group in (Z)-8a accelerates the 3-exo cyclization in comparison to the parent radical lacking an ester group by a factor of 3, an effect ascribed to a polarized tra...
Phenylethanolamine N-methyltransferase (PNMT) gene and early-onset Alzheimer disease.

The activity of human phenylethanolamine N-methyltransferase (PNMT) is reduced in the neurons of those cells in many subcortical areas of the brain that are known to undergo neurodegeneration in Alzheimer disease (AD). Others have reported that PNMT is decreased in brains of persons with AD and that the decrease in enzymatic activity is due to a reduced amount of the enzyme protein. We have previously described two polymorphisms, G-353A and G-148A, in the promoter region of the gene coding for PNMT. These markers were tested for their association with the occurrence of sporadic AD. Genotyping of 131 necropsy confirmed AD cases, and 947 adult nondemented controls were completed. We observed a significant association between both of the PNMT gene polymorphisms and early-onset AD (EOAD) (P ≤ 0.007), but not in late-onset AD (LOAD). These data suggest that genetic variation in the promoter of the PNMT gene is associated with increased susceptibility to the sporadic form of EOAD. © 2001 Wiley-Liss, Inc.
Feedback-driven self-assembly of symmetry-breaking optical metamaterials in solution

Thermodynamically driven self-assembly offers a direct route to organize individual nanoscopic components into threedimensional structures over a large scale 1–3 . The most thermodynamically favourable configurations, however, may not be ideal for some applications. In plasmonics, for instance, nanophotonic constructs with non-trivial broken symmetries can display optical properties of interest, such as Fano resonance, but are usually not thermodynamically favoured 4 . Here, we present a self-assembly route with a feedback mechanism for the bottom-up synthesis of a new class of symmetry-breaking optical metamaterials. We self-assemble plasmonic nanorod dimers with a longitudinal offset that determines the degree of symmetry breaking and its electromagnetic response. The clear difference in plasmonic resonance profiles of nanorod dimers in different configurations enables high spectra selectivity. On the basis of this plasmonic signature, our self-assembly route with feedback mechanism promotes the assembly of desired metamaterial structures through selective excitation and photothermal disassembly of unwanted assemblies in solution. In this fashion, our method can selectively reconfigure and homogenize the properties of the dimer, leading to highly monodispersed aqueous metamaterials with tailored symmetries and electromagnetic responses. In the last decade, control over structural symmetries has led to novel materials properties and the prediction of potentially exciting applications. Optical metamaterials 5 , unlike conventional materials, can be designed to have negative refraction, rainbow trapping and nonlinear metal optics. However, particularly rich and exciting physics comes into play when symmetry-breaking mechanisms are introduced that have the potential to enable strong anisotropic plasmon hybridization 6 , leading to unusual phenomena including plasmon-induced transparency 7 , anti-Hermitian plasmonic antennas 8 and optical magnetism, and consequently negative-index metamaterials 9 . These intriguing properties can be used in a number of
Bringing cartoons to life.

To understand cells as dynamic systems, mathematical tools are needed to fill the gap between molecular interactions and physiological consequences.
Uric acid concentrations are associated with insulin resistance and birthweight in normotensive pregnant women.

Objective We sought to investigate whether uric acid concentrations are increased in pregnant women with insulin resistance and to correlate both with fetal growth. Study Design Uric acid, glucose, and insulin were measured in plasma at 20.4 (±2.0) weeks' gestation in 263 women. The association between uric acid and insulin resistance, as estimated using the homeostasis model assessment (HOMA), was analyzed and related to birthweights. Results In 212 (80.6%) women who remained normotensive throughout pregnancy, HOMA increased 1.23 U per 1-mg/dL increase in uric acid (95% confidence interval, 1.07–1.42; P = .003). Infants born to normotensive women in the upper quartile of uric acid and lowest HOMA quartile weighed 435.6 g less than infants of women with highest uric acid and HOMA quartiles ( P Conclusion Increasing uric acid concentrations were associated with insulin resistance in midpregnancy. Hyperuricemia was associated with lower birthweight in normotensive women, and this effect was attenuated by insulin resistance.
Performance enhancement at low temperatures and in situ X-ray analyses of discharge reaction of Li/(CFx)n cells

Abstract In the Sandia National Laboratories internally funded Laboratory Directed Research and Development (LDRD) project we are studying the fundamental limitation(s) of the discharge reaction that reduces the operating voltage of the Li/(CF x ) n cells at moderate discharge rates. As a subset of this effort, we are evaluating the electrochemical properties of (CF x ) n electrodes prepared with materials from different vendors at different temperatures and in two different electrolytes in order to provide an optimized system to the above study. The temperatures studied span the range −51 to 72 °C. The electrolytes consist of EC:EMC (3:7 wt.%)–1.2 M LiPF 6 denoted as HCE (Highly Conductive Electrolyte) and EC:PC:EMC (1:1:3 wt.%)–1 M LiBF 4 denoted as SNL-E (Sandia National Laboratories Electrolyte). The four different (CF x ) n materials studied showed comparable capacity at 0 °C and above in the two electrolytes. However, at sub-ambient temperatures the SNL-E performed better than the HCE. The performance improvement with SNL-E comes mainly from a lower interfacial resistance compared to HCE. The different (CF x ) n materials performed differently in the SNL-E especially at sub-zero temperatures. For example, at sub-zero temperatures the delivered capacity varied between 6% and >60% of the room temperature capacity. In order to rationalize this observation, SEM photographs of the powder particles were taken that showed that the particle size of the best performer(s) is smaller than that of the others. Finally, these data seem to indicate that optimization of the properties of the electrolyte as well as the electrode is critical to maximizing delivered capacity especially at sub-ambient temperatures. Our X-ray results shall be presented in more detail in an upcoming manuscript. We have elected to present a brief discussion of these results in this present paper as the findings lend support to the formation of intermediate species in the discharge reaction of Li/(CF x ) n cell.
Power Quality Studies in the Presence of DG

Utility restructuring, technology evolution, and an expanding electricity market are providing the impetus for distributed generation to become an important energy option in the new millennium. Islanding occurs when a portion of the utility system that contains both load and distributed resources remains energized while isolated from the remainder of the utility system. Based on the operating conditions and several other criteria, islanding can cause both positive and negative impacts. Islanding increases the likelihood that DG sources may be allowed to subject the island to out of range voltage and frequency conditions during its existence. So, it is necessary to effectively study the islanding operation in view of various aspects. Hence, this paper is concerned with power quality issues such as harmonic analysis and voltage sags for the operation of distributed generation systems (DGs) in the stand-alone mode of operation. Simulations have been carried on the IEEE 13-bus system using the PSCAD/EMTDC software in time domain using two different types of DGs in both the grid-connected and the stand-alone modes.
Conformation-specific Binding of α-Synuclein to Novel Protein Partners Detected by Phage Display and NMR Spectroscopy

Alpha-synuclein (AS) is an intrinsically unstructured protein in aqueous solution but is capable of forming beta-sheet-rich fibrils that accumulate as intracytoplasmic inclusions in Parkinson disease and certain other neurological disorders. However, AS binding to phospholipid membranes leads to a distinct change in protein conformation, stabilizing an extended amphipathic alpha-helical domain reminiscent of the exchangeable apolipoproteins. To better understand the significance of this conformational change, we devised a novel bacteriophage display screen to identify protein binding partners of helical AS and have identified 20 proteins with roles in diverse cellular processes related to membrane trafficking, ion channel modulation, redox metabolism, and gene regulation. To verify that the screen identifies proteins with specificity for helical AS, we further characterized one of these candidates, endosulfine alpha (ENSA), a small cAMP-regulated phosphoprotein implicated in the regulation of insulin secretion but also expressed abundantly in the brain. We used solution NMR to probe the interaction between ENSA and AS on the surface of SDS micelles. Chemical shift perturbation mapping experiments indicate that ENSA interacts specifically with residues in the N-terminal helical domain of AS in the presence of SDS but not in aqueous buffer lacking SDS. The ENSA-related protein ARPP-19 (cAMP-regulated phosphoprotein 19) also displays specific interactions with helical AS. These results confirm that the helical N terminus of AS can mediate specific interactions with other proteins and suggest that membrane binding may regulate the physiological activity of AS in vivo.
Carbonization Rate of Soot Precursor Particles

Abstract The presence of soot precursor particles in hydrocarbon diffusion flames is made clearly evident by means of contemporary sampling techniques in combination with transmission electron microscopy (TEM). These particles are the immediate predecessors of mature, partially dehydrogenated carbonaceous soot aggregates, and recent analytical tests indicate they contain a mixture of polycyclic aromatic hydrocarbons. In this work, the conversion rate of precursor panicles to carbonaceous soot aggregates is investigated. In one method the time interval for the morphological conversion of precursor particles to aggregates is observed in diluted diffusion flames. Temperature profiles are measured by rapid insertion thermocouple thermometry. This information is supplemented by the observation of the sudden decrease of the hydrogen mole fraction of soot precursor particles as measured by laser microprobe mass spectrometry. The Arrhenius rate constants for the carbonization of precursor particles are derived fr...
Oxidative coupling of mithramycin and hydroquinone catalyzed by copper oxidases and benzoquinone. Implications for the mechanism of action of aureolic acid antibiotics

Abstract The copper oxidases human ceruloplasmin and Polyporous anceps laccase catalyze the oxidative coupling of mithramycin ( 1 ) and its aglycone chromomycinone ( 2 ) with p -hydroquinone to form new mithramycin-hydroquinone ( 3 ) and chromomycinone-hydroquinone adducts ( 4 ), respectively. Similar adducts could be formed by the nonenzymatic mimic of this reaction using benzoquinone and these aureolic acids in buffer solutions. FABMS of 3 indicated that the hydroquinone moiety was attached to the aureolic acid aglycone. Acid hydrolysis of 3 yielded a compound with the same chromatographic and spectroscopic characteristics as 4 . Structure elucidation of 4 by NMR and MS revealed that the hydroquinone was attached to the C-5 position of the aglycone. NMR evidence indicated that 4 consisted of a mixture of ortho -substituted biphenyl rotamers. The mechanism of the copper oxidase catalyzed adduct formation reaction is presumed to involve radical formation through hydrogen removal at the 8-phenolic position, radical isomerization, and coupling with semiquinone radical also formed during enzymatic and nonenzymatic incubations. Identification of the covalent-hydroquinone adduct provides evidence that aureolic acid antibiotics can be metabolically converted to reactive radical intermediates, and it establishes the C-5 position of aureolic acid as an enzymatically reactive site. Unlike mithramycin, the mithramycin-hydroquinone adduct was inactive in the in vivo P388 leukemic antitumor test system.
Use of Life-Sustaining Care for the Elderly

Advanced age has been proposed as one criterion for limiting the use of life-sustaining medical treatment, but very little is known about current practices. We retrospectively studied utilization rates of intensive care (IC) and cardiopulmonary resuscitation (CPR) in admissions to a university hospital over 1 year (n = 9,998), to test whether these treatments are used more selectively for elderly patients. Overall utilization rates did not vary by age. However, among 524 terminal admissions, IC was used for 63% of patients age 35-74 but for only 50% of patients 75 and older (P less than 0.01). Among elderly patients, nursing home residence, diagnosis of advanced malignancy, severe chronic illness, and older age were independent predictors of withholding IC prior to death. Despite more selective use, survival rates were lower for elderly than for younger patients receiving IC (88% vs 78%, P less than 0.001). CPR showed similar but non-significant trends. Intensive care is being used less frequently prior to death for elderly patients, based on diagnosis and functional status as well as chronologic age.
Applications of fourier transform infrared spectroscopy in surface and interface studies

Donnees de base et principes de spectroscopie IR a transformee de Fourier. Applications aux etudes de surface: surfaces de polymeres, degradation en surface, caracterisation de la surface, transformations chimiques a la surface, adsorption des gaz. Applications aux interfaces: revetements organiques sur les substrats, interfaces electrochimiques, adsorption des proteines sur des surfaces solides. References
Ceramic SFF by direct and indirect stereolithography

Direct ceramic stereolithography (SLA) is done using UV-curable suspensions of powders in acrylates in a conventional SLA machine. Hydroxyapatite prototypes for bone tissue scaffolds are built from Image-Based Design files, featuring an interior architecture of void passages. Complex alumina objects are built as digital sculptures. Piezoelectric ceramic actuators from PZT, which are difficult to photocure, are built using indirect stereolithography, where SLAbuilt epoxy molds are used to form a thermal-cured suspension of PZT powders. We report on the thermal-curing behavior of the suspensions, and the fundamentals of part building.
Hepatic enhancement and metastatic lesion conspicuity on CT scans: influence of intravenous glucagon and oral CT contrast material.

PURPOSE: To determine the effect of glucagon and orally administered contrast material on hepatic enhancement and metastatic lesion conspicuity on computed tomographic (CT) scans. MATERIALS AND METHODS: Nine patients with a history of hepatic metastasis underwent two CT examinations with intravenously administered contrast material. Each patient was given orally administered CT contrast material for the first examination. No oral contrast material was given in the second examination. Five patients underwent the initial CT with intravenous administration of 1 mg of glucagon; the second examination was performed without glucagon. Four patients were administered glucagon before the second examination, but no glucagon was administered before the first. Attenuation in the liver, portal vein, and aorta was measured by observers blinded to whether the patient had been given glucagon. Lesion conspicuity was rated on a continuous scale. RESULTS: Greater mean hepatic enhancement was noted on scans of patients in wh...
A Riddle Wrapped in a Mystery Inside an Enigma

For the most part, the basic pathophysiological mechanisms involved in the perpetuation and exacerbation of congestive heart failure, as Churchill’s quote aptly suggests, remain unknown. Why certain groups of patients do “relatively” well and others progress quickly is only beginning to be understood. The article by Parker et al1 in this issue of Circulation brings to the fore an important component of the autonomic nervous system, the presynaptic nerve terminal, which may well impact on the function of the heart in patients with congestive heart failure and thereby influence morbidity and mortality. The intriguing finding is that nonselective blockade of α-adrenergic receptors (ARs) in the heart (selective injection of phentolamine into the left main coronary artery) leads to an increased level of norepinephrine (NE) in the coronary sinus associated with an increase in left ventricular contractility. These changes occur only in patients with congestive heart failure, not in patients with normal left ventricular function. The proposed mechanism for this is that presynaptic α2-ARs are being blocked, leading to enhanced NE release, and that “basal” release of NE is abnormally high in patients with congestive heart failure. The role of ARs in modulating cardiac function has long been recognized. Classically, β-ARs have been documented to increase contractility, heart rate, electrical conduction, and cardiac relaxation.2 These effects come about directly as a result of catecholamines acting on the β-ARs, which reside …
Cytogenetic testing of anembryonic pregnancies compared to embryonic missed abortions.

The objective of this study is to determine the rate of abnormalities detected by cytogenetic testing of first trimester miscarriages, in patients with and without an embryonic pole seen on ultrasound. A retrospective study of 272 D&Cs for missed abortions in an academic infertility practice from 1999 to 2006. Karyotype results were compared with transvaginal ultrasound findings. Chi-squared analysis was used with a P 0.05). The high rate of abnormalities detected in both groups suggests that useful results can be obtained from chromosomal testing of the POC regardless of ultrasound findings. Further studies on the prognostic value and cost effectiveness of chromosomal testing are needed.
Distributed representation in the song system of oscines: Evolutionary implications and functional consequences

This paper reviews the organizational principles and implications that have emerged from the analysis of HVc, a forebrain nucleus that is a major site of sensory, motor, and sensorimotor integration in the song control system of oscine passerine birds (songbirds). Anatomical, physiological, and behavioral data support the conclusion that HVc exists within a hierarchically organized system with parallel pathways that converge onto HVc. The organization of HVc is distributed and redundant, and its outputs exhibit broad divergence. A similar pattern of connectivity exists for neostriatum adjacent to HVc. This and other data support the hypothesis that the song system arose from an elaboration or duplication of pathways generally present in all birds. Spontaneous and auditory response activity is strongly correlated throughout HVc, with auditory responses exhibiting strong temporal modulation in a synchronized fashion throughout the nucleus. This suggests that the auditory representation of song is encoded in the synchronized temporal patterns of activation, and that the predominant selectivity for the individual's own song that is observed for HVc neurons results from interactions of auditory input with central pattern generators for song. Most, or all HVc neurons are recruited during singing. The auditory response and motor recruitment properties of individual HVc neurons have no simple relationship, and the spontaneous activity in HVc may build up in the seconds preceding a song. To the extent HVc participates in perceptual phenomena associated with song, production and perception are not tightly linked in adults but may be linked by shared developmental processes during periods of sensorimotor learning.
Hindered cyclopentadienyl rotation in hexakis(trimethylsilyl)metallocene dichlorides of zirconium and hafnium. Evidence for complete rotation of the tris(trimethylsilyl)cyclopentadienyl ligands

Abstract Reaction of tris(trimethylsilyl)cyclopentadienyllithium with zirconium and hafnium tetrachloride affords 1,1′,2,2′,4,4′-hexakis(trimethylsilyl)zirconocene dichloride and 1,1′,2,2′,4,4′-hexakis(trimethyl-silyl)hafnocene dichloride. These complexes show hindered rotation of the cyclopentadienyl ligands, with barriers to rotation of 11.0±0.02 kcal/mol and 11.3±0.2 kcal/mol being found for the zirconium and hafnium complex, respectively. These values are compared with those of the corresponding 1,1′,3,3′-tetrakis(trimethylsiyl)metallocene dichlorides and a model is proposed to account for the large differences in rotational barriers.
Combinatorial design of semiconductor chemistry for bandgap engineering: “virtual” combinatorial experimentation

Abstract The objective of this paper is to show how one may design combinatorial libraries a priori by integrating data mining techniques with physically robust multivariate data. It is shown that large datasets can be developed from relatively small amounts of experimental and theoretically based information. This involves a process of strategically selecting appropriate physical based parameters that can be analyzed in a multivariate manner. In this paper we identify for the first time the bandgap and lattice parameters of nearly 200 stoichiometries of new and yet to be synthesized compound chalcopyrite semiconductors. The robustness of this “virtual” combinatorial experimentation approach is demonstrated by comparison to band gap predictions from theoretical studies on a range of compositions for a selected quaternary compound semiconductor.
Catalase activity in electrically stimulated muscle

10 min of electrical stimulation resulted in a significant rise in gastrocnemius catalase activity.
Ahemeral lighting of turkey breeder hens. 3. Temporary application and early age at lighting.

Abstract Ahemeral (non-24 h) light-dark cycles are known to increase egg size but when applied continuously have adverse effects on egg production. The purpose of this experiment was to determine whether temporary application of ahemeral light-dark cycles (AH) can overcome the adverse effects of continuous AH and provide improved reproductive performance of turkey hens photostimulated at an early age. Of particular interest was the effect of temporary AH on increasing egg weight at the start of lay because decreased egg weight is a major problem associated with early lighting of turkey hens. The AH treatments started at 26 wk of age and were given for 2 wk, 5 wk, or continuously. Each consisted of 15 h of light per cycle with a cycle length of 28 h duration, that is, 15 h light (L):13 h dark (D). The experiment was started in the winter season and continued for 28 wk. The following variables were measured: BW, feed intake, onset and rate of lay, fertility, hatchability, incidence of floor eggs, egg weight, poult production, and poult weight. It was clear that 5 wk or more of AH followed by standard lighting (15L:9D) increased initial egg weights from those of 26-wk controls and were similar to those of 30-wk controls. This effect was temporary, as it was absent by 8 wk of photostimulation. Also, cumulative eggs per hen to 54 wk of age were increased by 5 wk of AH treatment as compared to those of controls photo-stimulated at 30 wk of age. These eggs had normal fertility, hatchability, and poults per hen in two evaluation periods. A high incidence of AH floor eggs was reduced to that of the controls following a shift to standard light-dark cycles. We concluded that temporary use of AH at the start of photostimulation is better than continuous use of AH throughout lay and resulted in improved reproductive performance of hens photostimulated at an early age.
The structure and dipole moment of globular proteins in solution and crystalline states: use of NMR and X-ray databases for the numerical calculation of dipole moment.

The large dipole moment of globular proteins has been well known because of the detailed studies using dielectric relaxation and electro-optical methods. The search for the origin of these dipolemoments, however, must be based on the detailed knowledge on protein structure with atomic resolutions. At present, we have two sources of information on the structure of protein molecules: (1) x-ray databases obtained in crystalline state; (2) NMR databases obtained in solution state. While x-ray databases consist of only one model, NMR databases, because of the fluctuation of the protein folding in solution, consist of a number of models, thus enabling the computation of dipole moment repeated for all these models. The aim of this work, using these databases, is the detailed investigation on the interdependence between the structure and dipole moment of protein molecules. The dipole moment of protein molecules has roughly two components: one dipole moment is due to surface charges and the other, core dipole moment, is due to polar groups such as NH and CO bonds. The computation of surface charge dipole moment consists of two steps: (A) calculation of the pK shifts of charged groups for electrostatic interactions and (B) calculation of the dipole moment using the pK corrected for electrostatic shifts. The dipole moments of several proteins were computed using both NMR and x-ray databases. The dipole moments of these two sets of calculations are, with a few exceptions, in good agreement with one another and also with measured dipole moments. © 2001 John Wiley & Sons, Inc. Biopolymers 58: 398–409, 2001
Extended x-ray-absorption fine-structure and x-ray-absorption near-edge-structure studies of glassy Ni 66 B 33 : A multishell modeling of the Ni-Ni distribution

Amorphous ${\mathrm{Ni}}_{66}$${\mathrm{B}}_{33}$ is a novel metallic glass in that the metalloid content is much higher than those of conventional transition-metal\char22{}metalloid systems. More interestingly, this amorphous material crystallizes homogeneously into a single ${\mathrm{Ni}}_{2}$B phase of known crystal structure (that of ${\mathrm{Al}}_{2}$Cu) in which there is only one nonequivalent Ni site. The existence of the ${\mathrm{Ni}}_{66}$${\mathrm{B}}_{33}$ composition as a single phase in both the crystalline and glassy states makes it a useful model system for quantitative extended x-ray-absorption fine-structure (EXAFS) investigation of the local atomic environment in metal-metalloid glasses. The local structure of a Ni atom in crystalline ${\mathrm{Ni}}_{2}$B consists of four boron atoms at a distance of 2.14 \AA{}, one Ni atom at 2.37 \AA{}, two Ni atoms at 2.42 \AA{}, and two sets of four Ni atoms at 2.63 and 2.70 \AA{}. The ${\mathrm{Ni}}_{2}$B crystal was used to model the local structure of Ni in the metallic glass as follows: Crystallographic data (coordination numbers and bond distances) were used as fixed inputs to the Fourier-filtered EXAFS of the crystal to generate an envelope function for B and a set of self-consistent phase shifts for the Ni-B and Ni-Ni pairs. These scattering parameters were then transferred as fixed inputs to the Fourier-filtered EXAFS of the glass phase to extract structural parameters. The fitting of the glass EXAFS was performed systematically using sequentially 1 B + 1 Ni shells, 1 B + 2 Ni shells, 2 B + 1 Ni shells, 1 B + 3 Ni shells, 2 B + 2 Ni shells, and 1 B + 4 Ni shells. It was found that the 1 B + 3 Ni shell combination yields the best fit and physically most meaningful results for the glass. It was also found that the nearest boron shell about a Ni atom in the glass remains very similar to that of the crystal, but there is considerable rearrangement of the outer Ni shells. In the glass, the eleven Ni atoms are now distributed into three subshells with the shortest Ni-Ni distance measurably closer to the central Ni atom. This local rearrangement and closer packing of the Ni shells were reflected in the local electronic structure of the glassy phase and manifested in changes of the x-ray-absorption near-edge structure spectrum in going from the crystal to the glassy phase. Ge substitution was made to probe the metalloid environment in glassy ${\mathrm{Ni}}_{66}$${\mathrm{B}}_{15}$${\mathrm{Ge}}_{18}$. The present EXAFS findings are discussed in light of some recent diffraction and NMR results in Ni-B glasses.
The challenge of preparing ethically responsible managers: Closing the rhetoric-reality gap

This article begins by questioning the commitment of business, government, and education leaders to the goal of ensuring that our public and private sector organizations are directed by ethically responsible individuals. Noting that while there appears to be genuine concern with the most recent outbreak of ethical failings as well as widespread support for the concept of morally and ethically educated current and future managers, there is less agreement on the most efficient and effective means of realizing this goal. For perspective purposes, recent research findings and opinions of leaders in higher education and business on the issue of ethics and the curriculum are highlighted.
The First Chiral Organometallic Triangle for Asymmetric Catalysis

A family of chiral organometallic triangles based on cis-Pt(PEt3)2 metallocorners and enantiopure atropisomeric bis(alkynyl) bridging ligands (L1-4) has been synthesized and characterized by 1H, 13C{1H}, and 31P{1H} NMR, UV−vis, and circular dichroism (CD) spectroscopies, FAB and MALDI-TOF mass spectrometry, and microanalysis. Metallocycle 4 which contains three 1,1‘-bi-2-naphthol functionalities in combination with Ti(iOPr)4 has been shown to be an excellent catalyst for highly enantioselective additions of diethylzinc to aromatic aldehydes to afford chiral secondary alcohols. This research illustrates the potential of generating novel functional materials on the basis of supramolecular chemistry.
Mercuric compounds inhibit human monocyte function by inducing apoptosis: evidence for formation of reactive oxygen species, development of mitochondrial membrane permeability transition and loss of reductive reserve

The focus of this investigation was to examine the effects of low concentrations of organic mercuric compounds on human monocyte function and to relate these effects to apoptosis. Following exposure of monocytes to 0-5 microM MeHgCl, phagocytic function and capacity to generate a respiratory burst, following PMA activation, were determined. We found that the mercury-treated cells exhibited reduced phagocytic activity. Exposure to the same mercury concentration range, also caused a marked increase in cell death. To ascertain if monocyte death was due to apoptosis, a number of flow cytometric studies were performed. Mercury-treated cells exhibited increased Hoechst 33258 fluorescence, while maintaining their ability to exclude the vital dye 7-aminoactinomycin D. Furthermore, monocytes exhibited changes in light scatter patterns that were consistent with apoptosis; these included decreased forward light scatter and increased side scatter. The percentage of cells undergoing apoptosis was dependent upon the mercury content of the medium, regardless of whether the metal was present as methyl, ethyl or phenyl mercury. Mercury-treated cells also exhibited changes in lipid organization within the plasma membrane as evidenced by increased uptake of the fluorescent probe, merocyanine 540, and by elevated annexin V binding to phosphatidylserine. Using the fluorescent probes DiOC6(3) and rhodamine 123 we noted that within 1 h of exposure to mercury, monocytes exhibited a decrease in mitochondrial transmembrane potential (psi m). Since a decreased psi m is associated with altered mitochondrial function, the hypothesis that mercury potentiated reactive oxygen species (ROS) generation and that these species promoted apoptosis was tested. We noted that treated cells generated ROS, as evidenced by oxidation of hydroethidine and the generation of the fluorescent product, ethidium. Finally, since ROS would also lower monocyte reductive reserve, we also measured GSH levels in mercury-treated cells. Chemical measurement of GSH indicated that there was thiol depletion. We suggest that the low thiol reserve predisposes cells to ROS damage and at the same time activates death-signaling pathways.
CAD — a user's perspective

Abstract CAD is used extensively in plant design today, affecting design, analysis and production of drawings, specifications, and reports. Each application has been developed independently based on self-justification. We are now on the brink of integrating these standalone applications with the promise of influencing intertask and interdiscipline communications. Although the new venture is formidable, the CAD community is gathering momentum.
Interspecies radioimmunoassay for the major internal protein of mammary tumor viruses.

Abstract An interspecies radioimmunoassay has been developed which detects antigenic determinants shared by type-B mammary tumor viruses (MTVs). This interspecies assay is specific for antigenic sites which the 28,000-dalton major internal protein of MMTVs of laboratory mice (Mus musculus) has in common with polypeptides of MC-MTV. MC-MTV is a new type-B retrovirus isolated from the Asian rodent, Mus cervicolor ( J. Schlom, P. H. Hand, Y. A. Teramoto, R. Callahan, G. Todaro, and G. Schidlovsky, 1978 , J. Nat. Cancer Inst. 61, 1509–1519). Other retrovirus isolates of Mus cervicolor, i.e., M432, CERV-CI, and CERV-CII, as well as other type-C and type-D retroviruses, do not compete in the interspecies assay. The interspecies assay detected MTV cross-reactive antigenic determinants with equal efficiency in milks, lactating mammary glands, and in spontaneous mammary tumors of three distinct species. Particles morphologically indistinguishable from MMTV and MC-MTV have also been detected in Mus cookii mammary tumor cells. The interspecies MTV p28 radioimmunoassay thus provides a potentially useful tool for the detection of etiologically related viruses or viral translational products in species other than the laboratory mouse.
Epidemiology of male and female reproductive disorders and impact on fertility regulation and population growth.

The National Institute of Child Health and Human Development has conducted a series of vision workshops to set an ambitious but tenable broad agenda, transcending traditional organizational and disciplinary boundaries. This presentation sets forth a vision regarding how the aspects of a woman's reproductive lifespan are interrelated, likely starting from childhood all the way to the later reproductive years. As a woman propagates, this circular interaction is then transmitted to the next generation. We need an understanding of the clinical processes, the time course, the natural history, and disruptors of these processes. With that understanding, we can then bring tools to bear to assess these issues, whether these tools are epidemiology, demography, social science, molecular biology, proteomics, genomics, or epigenomics. Our future research agenda should investigate how reproduction affects health and how health affects reproduction.
A qualitative study of immigration policy and practice dilemmas for social work students

Social policy shapes the infrastructure wherein social work is practiced. However, what happens when a particular social policy is seemingly incongruent with the social work code of ethics? How do social work students conceive and resolve potential practice dilemmas that may arise as a consequence? In this study, the authors explored potential practice dilemmas as a result of Proposition 200, an Arizona immigration law that would require social workers employed in the public sector to deny services to undocumented clients. The 6-step analysis found that students recognized various practice dilemmas that the policy would present and conflicts between the policy and social work ethics. Students also identified numerous strategies for resolving the above-mentioned dilemmas.
Claudication intermittente du pied au cours de la dorsiflexion active: le cas instructif de l’artère pédieuse dorsale piégée

Objectif La claudication atypique est un probleme relativement rare dans la population generale. Cependant, l’index de suspicion augmente lorsque des patients jeunes et athletiques presentent des symptomes de claudication au cours de l’effort. Les causes les plus frequentes de claudication atypique sont representees par les variations anatomiques, incluant le syndrome de l’artere poplitee piegee et le syndrome du tunnel tarsien. Ces variations provoquent respectivement une degradation du flux arteriel et une compression nerveuse. Dans cet article, nous rapportons un cas instructif de piege de l’artere pedieuse dorsale par le tendon du court extenseur de l’hallux au cours de la dorsiflexion active du pied. Methodes Le patient etait un homme de 42 ans, sans antecedent medical, qui presentait une claudication bilaterale des pieds au cours de la dorsiflexion active. Des examens Doppler arteriels dynamiques revelaient un flux normal en position neutre et une interruption complete du flux en modes echographique et Doppler au cours de la dorsiflexion du pied. Une angiographie par resonance magnetique dynamique des membres inferieurs montrait une arche pedieuse incomplete avec une terminaison precoce de l’artere tibiale posterieure sur les images statiques et une interruption de l’artere pedieuse en conflit avec le dos du pied durant la dorsiflexion. Le patient fut conduit au bloc operatoire pour une exploration bilaterale des arteres pedieuses. Au cours de l’exploration, un piege de l’artere pedieuse dorsale par le tendon du court extenseur de l’hallux (CEH) fut mis en evidence. Il etait documente par visualisation directe et par l’interruption du signal Doppler per operatoire en dorsiflexion. Le tendon du CEH fournissant uniquement une fonction accessoire au tendon du long extenseur de l’hallux (LEH), le CEH fut sectionne a proximite de son insertion et transpose directement sur le tendon du LEH. Ceci a permis d’obtenir une fonction d’extension normale du gros orteil et de restaurer un signal Doppler triphasique au cours de la dorsiflexion. Conclusion Le piege de l’artere pedieuse dorsale est une nouvelle cause de claudication atypique. Elle est extremement rare puisque les patients doivent presenter a la fois une anatomie anormale et une arche plantaire incomplete pour en ressentir les symptomes. De la meme facon que pour les autres syndromes canalaires, en cas de detection precoce avant la survenue de lesions arterielles, le traitement ne necessite pas de procedure de revascularisation. La resection du tendon associee a sa transposition permet de traiter les symptomes sans alterer la dorsiflexion du gros orteil.