cssi/SciSciGPT-SciSciNet huggingface dataset:
Treatment of Nonsyndromic Anomalies of Tooth Number

Nonsyndromic tooth agenesis represents a common odontogenic condition that should be managed by a multidisciplinary specialty team. The genetic basis for agenesis of teeth reflects the key transcriptional events involved in mesenchymal-epithelial interactions during tooth formation. Mutations of genes including PAX9, MSX1, AXIN2, and EDA are implicated. Clinicians should be aware of familial history of tooth agenesis. Treatment may involve orthodontists and prosthodontists early in the management of these individuals. In all cases, the establishment of oral health, stable occlusion, and establishment of a conceptual framework for treatment resulting in efficient tooth replacement and aesthetic outcomes should be considered in the mixed dentition phase. Definitive tooth replacement using conventional or implant prostheses should be reserved for individuals with complete facial growth and maturation.
The Discovery of New Enzymes in the Human Gut Microbiome

A previously unknown metabolic pathway for the utilization of L-galactose was discovered in a prevalent human gut bacterium, Bacteroides vulgatus. The new p...
Successful Implantation of Cardiac Defibrillators Without Induction of Ventricular Fibrillation Using Upper Limit of Vulnerability Testing

Introduction: Conventionally, the implantable cardioverter-defibrillator (ICD) is tested at implantation by measurement of defibrillation threshold (DFT), which involves repeated induction of ventricular fibrillation (VF). We report our data on successful ICD implantation without VF induction using a modified upper limit of vulnerability (ULV) testing method, compared to standard DFT testing. Methods: Fourteen patients underwent ICD implantation using a modified ULV testing method by delivering a 15 J shock during the vulnerable period on the peak of the T wave, and if VF was not induced 15 J shocks were repeated at −20 and −40 msec before the peak of T wave. Failure to induce VF, indicating a ULV <15 joules (J), suggested a DFT ≤20 J based on previous studies demonstrating a close correlation (±5 J) between ULV and DFT. If VF was induced, a 20 J rescue shock was delivered. ICD therapy was then programmed on the basis of ULV testing. All patients underwent pre-discharge DFT testing to confirm adequate DFT. Results: Using a modified ULV testing method, ICD implantation was completed without induction of VF in 8 patients and only a single episode of VF in 6 patients. The mean number of VF episodes (0.42 ± 0.5) induced with ULV testing was significantly lower (p < .001) than the number induced during DFT testing (3.9 ± 0.8). Pre-discharge DFT testing did not alter ICD programming in any patient. During follow-up of 14.85 ± 12.31 months, three patients had seven episodes of VT/VF, six of whom were converted with the programmed first-shock strength, while one required a second high-energy shock to convert. This patient had a pre-discharge DFT of 10 joules. Conclusions: Successful ICD implantation can be safely performed with no or fewer episodes of VF induction using a modified ULV testing method.
Varying Instructional Methods to Fit Trainee Characteristics.

One problem facing teacher training programs is that of determining the most effective methods for training large numbers of individuals possessing dissimilar patterns of abilities. Both learner and instructional system alike may be expected to benefit greatly when individuals can be identified whose progress can be facilitated through varying instructional goals and objectives. However, while the need has been documented and the ideal has been expressed, little has been done in any formal, systematic way toward the individualization of teacher education. At the present time, it seems possible to develop educational procedures more sensitive to individual differences than our procedures have been in the past. Earlier contributors to the literature (Fuller, 1969; Hereford, 1971; Merrill, 1968) have emphasized the importance of patterns of adaptation to individual differences in which educational objectives, pacing, and sequencing are varied. An alternative approach provides varying instructional methods for different students to reach the same educational goals (Cronbach, 1967). Instructional methods differ. A review of the literature (Cronbach & Snow, 1969) suggests that a person learns more easily from one method than another, that this best method differs from student to student, and that such differences between treatments are related to learner
A New Method for Evaluating Floquet Characteristic Exponents of Periodic Linear Systems

It is well-known that the stability of linear periodic (LP) systems can be assessed using Floquet Characteristic Exponents (FCE). In this paper, a new method is presented for evaluating FCE for nth-order scalar periodic linear systems based on a recently developed unified eigenvalue theory for linear time-varying (LTV) Systems [1]. The new theory allows FCEs to be evaluated from the DC term of the Fourier series of periodic PD-eigen-values of a LP system. Comparing to the well-known Monodromy Matrix (MM) method and Infinite Dimensional Determinant (IDD) method for evaluating FCE 1 the solutions obtained by the new method have rapid local convergence. This new method also allow stability boundaries in the parameter space of a LP system to be evaluated and plotted directly. The new results shed some light OL the general stability assessment problem for vector periodic linear systems and aperiodic LTV systems. Further studies along this direction are also discussed in this paper.
Gene expression of a vacuolar peroxidase with stress-induced pathogenesis in wheat sheaths☆

Abstract Changes in peroxidase composition and gene expression of a vacuolar-localized peroxidase (cDNA, pCD1311), which has previously been reported to be involved in resistant interactions between barley and Erysiphe graminis were examined in two wheat-endophytic fungal pathosystems. These changes were examined in wheat infected with endophytic, Fusarium proliferatum ( F.p. ) that produced symptomatic plants only under conditions of host stress and Fusarium culmorum , a ubiquitous and potent pathogen. Increased apoplastic peroxidase specific activity and the induction of three novel cationic peroxidase isozymes (pI 8.0, 9.0, 10.0) occurred only in sheaths infected with the F.p . Induction of these isozymes was not found in wheat sheaths infected with F. culmorum that exhibited a classical susceptible response or in the non inoculated, control sheaths. A 1.5 kb mRNA transcript accumulated in the F.p. -infected wheat sheaths and not in those infected with F. culmorum or in the non infected controls. Further investigation using in situ hybridization analysis revealed that accumulation of pCD1311-related mRNA transcripts in F.p. -infected sheaths occurred in the epidermal, vascular bundle sheath and xylem cells and coincided to the localized areas of F.p. infection.
Influence of Biota on Erodibility of Sediments

Living sediments contain biota, organic matter, chemical gradients, adhesive substances, bubbles, feces, animal tracks and tubes, all of which can affect sediment erodibility. Cohesive sediments are affected by a variety of factors, many of which are in turn affected by biota. These include pH, organic content, and chemical changes associated with changes in redox potential. The few studies that demonstrate or quantify the influence of entire communities of biota on erodibility are reviewed. Many of these studies, including studies of bioturbation, show an overall stabilizing effect. The ubiquity and rapid growth of microbes capable of secreting mucus, together with natural selection of organisms that secrete binding substances in a potentially unstable sedimentary environment, may account for the apparent overall influence. Additional studies are needed that address the time-averaged, net influence of communities of biota on sediments, especially when both stabilizing and destabilizing influences are possible, as with organisms whose bioturbation stimulates microbial growth as well as stirs the sediment.
Abstract P383: Possible Effect Modification of Beta-Blockers on the Association Between Heart Failure and Fracture Risk: A Cohort Study

Introduction: Heart failure (HF) is a chronic illness that occurs within a context of multiple comorbidities, including osteoporosis and fractures. While the causal pathway leading to elevated fracture risk in HF has yet to be determined, a potential mechanism may be increased sympathetic activation that inhibits bone formation and enhances resorption. By antagonizing sympathetic tone, β-blockers may protect against bone loss and, thereby, fractures. We assessed the association of HF with subsequent osteoporotic fractures by β-blocker use in a community setting. Methods: Olmsted County, Minnesota, residents meeting Framingham criteria for incident HF from 1990-2002 and community controls without HF, who were matched (1:1) to cases on age, sex, and index year, were studied using the resources of the Rochester Epidemiology Project. Major osteoporotic fracture (proximal femur, lumbar/thoracic vertebrae, distal forearm, or proximal humerus) risk in HF was compared directly with that in their matched controls utilizing a stratified Cox model with the case/control pairs forming the strata. Death as a competing risk was accounted for using the Fine & Gray model. Results: Among 1,050 participants (50% women; 525 with HF and 525 controls) 229 developed osteoporotic fractures during a mean follow-up of 6 years. The incidence rates of osteoporotic fracture per 1,000 person-years were 47.5 in HF cases and 30.4 in controls ( P =0.001). After adjustment for prior fracture and Charlson comorbidity score, the hazard ratio (HR) for fracture in HF cases vs. controls was 1.70 (95% CI: 1.17-2.47). β-blockers were prescribed in 45% of HF cases after diagnosis. The association between HF and fractures differed according to β-blocker usage. The HRs were 1.45 (95% CI: 0.86-2.47) and 2.16 (95% CI: 1.23-3.79) in HF cases prescribed and not prescribed β-blockers, respectively, when compared with their matched controls. Accounting for death as a competing risk, the HRs were 1.06 (95% CI: 0.64-1.76) and 1.63 (95% CI: 0.99-2.70) in HF cases on and off β-blockers, respectively. Conclusion: These findings suggest a modifying effect of β-blockers on the association between HF and osteoporotic fractures, which warrants a more thorough evaluation.
Experimental studies of triplet exciton bands of molecular crystals

Methods of studying properties of triplet exciton states of organic crystals are presented with an emphasis on exposing the dimensionality of excitons. Results of isotopic replacement spectra for 1,4-dibromonaphthalene which is a linear chain, and for halogenated benzenes, which are likely to be linear chains, are presented. Luminescence studies of linear chain exciton systems are shown to yield information about the stationary states of small clusters. Finally some preliminary studies of two-photon spectra of naphthalene excitons are described.
Dissolution Chemistry of Gold and Silver in Different Lixiviants

Cyanide has been recognized for a long time as a powerful lixiviant for gold and silver, forming very stable cyano complexes with both metals. While cyanide is very effective in leaching free milli...
Early Paleoindian Mobility and Watercraft: An Assessment from the Mississippi River Valley

Several researchers have suggested use of watercraft during the Early Paleoindian period 11,500 and 10,800 rcybp (13,400–12,700 cal B.P.), but none have brought empirical data to bear on this possibility. This paper addresses the potential for fluted point-making groups to have made and used boats circa 11,000 rcybp (13,000–12,800 cal B.P.). Fluted point data from a large region of the upper and central Mississippi River valley strongly suggest that the Mississippi River was a barrier to movement and that Early Paleoindians in the midcontinent did not routinely use watercraft.
Highly efficient incorporation of functional groups into aromatic main-chain polymer using iridium-catalyzed C-H activation and suzuki-miyaura reaction.

We report a mild, iridium-catalyzed borylation of aromatic polysulfone with bis(pinacolato)diboron [B2(pin)2] to form the corresponding borylated polysulfones up to high concentrations with nearly constant efficiency. The Suzuki−Miyaura cross-coupling reactions of the borylated polysulfones with functionalized aryl bromides allows installation of various functional groups such as ketone, amine, hydroxyl, and aldehyde to the polysulfone main chain in excellent conversion.
Image reconstruction/synthesis from nonuniform data and zero/threshold crossings

We address the problem of reconstructing functions from their nonuniform data and zero/threshold crossings. We introduce a deterministic process via the Gram-Schmidt orthonormalization procedure to reconstruct functions from their nonuniform data and zero/threshold crossings. This is achieved by first introducing the nonorthogonal basis functions in a chosen 2-D domain (e.g., for a band-limited signal, a possible choice is the 2-D Fourier domain of the image) that span the signal subspace of the nonuniform data. We then use the Gram-Schmidt procedure to construct a set of orthogonal basis functions that span the linear signal subspace defined by the nonorthogonal basis functions. Next, we project the N-dimensional measurement vector (N is the number of nonuniform data or threshold crossings) onto the newly constructed orthogonal basis functions. Finally, the function at any point can be reconstructed by projecting the representation with respect to the newly constructed orthonormal basis functions onto the reconstruction basis functions that span the signal subspace of the evenly spaced sampled data. The reconstructed signal gives the minimum mean square error estimate of the original signal. This procedure gives error-free reconstruction provided that the nonorthogonal basis functions that span the signal subspace of the nonuniform data form a complete set in the signal subspace of the original band-limited signal. We apply this algorithm to reconstruct functions from their unevenly spaced sampled data and zero crossings and also apply it to solve the problem of synthesis of a 2-D band-limited function with the prescribed level crossings.
RELATIVE STABILITY OF MULTIPLE STATIONARY STATES RELATED TO FLUCTUATIONS

We apply the eikonal approximation to the stochastic master equation for reaction-diffusion systems. Its stationary solution is expressed as an excess work and is shown to be a Lyapunov function for the deterministic evolution of inhomogeneous systems. From this result we establish a new stochastic criterion of relative stability and equistability of systems with multiple homogeneous stationary states in terms of inhomogeneous fluctuations.
Characteristics of tinnitus in acoustic trauma.

Several parameters of tinnitus were investigated in a group of 102 subjects suffering from acoustic trauma. These parameters were then compared to the results of the hearing tests and subjective complaints. The frequency and intensity of tinnitus were established by the usual matching technique with a clinical audiometer. The most effective masking of the tinnitus due to acoustic trauma was by pure tones. There seems to be a correlation between the tinnitus level and the hearing loss level at the frequency at which the hearing loss was most severe. A significant association was found between the matched tinnitus level and its description by the patient. There is also an association between the severity of the acoustic trauma and the perceived loudness of the tinnitus, as well as other subjective complaints.Nous avons examine un groupe de 102 sujets aˇges de 18 a 3 5 ans, ayant subi un certain nombre de traumatismes sonores et presentant des bourdonnements dont la frequence et l'intensite furent determinee...
Longitudinal Study of Depression and Health Services Use Among Elderly Primary Care Patients

The objective of this study was to describe the prevalence and 9-month incidence of depressive symptoms among a cohort of elderly primary care patients and to determine whether different patterns of depression are associated with different patterns of health services use.
Fire induced flow through an opening

Abstract The buoyantly driven flow of fire gases out through a window or door of a burning room is calculated for a constant density hot gas layer. An experimental model employing kerosene and water is developed to test the validity of the theory. The results indicate that the theory, with flow coefficients determined from the experiment can adequately predict the behavior. While the theory discussed fails to predict the room layer depth at low inflow rates by a large factor, the absolute error of only a few inches is of no practical consequence. Fire safety implications for doorway and window design are noted. Flow formulas useful for practical calculations are presented.
Circuits of the cell

Abstract Networks of gene regulation control many aspects of cellular biology, ranging from development and differentiation to the cell cycle and apoptosis. However, the precise control of genetic regulation is poorly understood for whole cells and large systems. Technical achievements in the genome-wide measurement of DNA, mRNA and proteins – and their assorted interactions – have enabled systematic approaches to regulation in molecular biology, which promise to shed new light on the complex architecture of gene regulatory networks. Detailed knowledge of such systems is crucial for our understanding of molecular phenotypes; similarly, our ability to treat and cure many diseases will depend on our understanding of molecular disease at its regulatory and mechanistic roots.
Imaging through diffusive layers using speckle pattern fractal analysis and application to embedded object detection in tissues

The absorption effect of the back surface boundary of a diffuse layer was studied via laser generated reflection speckle pattern. The spatial speckle intensity provided by a laser beam was measured. The speckle data were analyzed in terms of fractal dimension (computed by NIH ImageJ software via the box counting fractal method) and weak localization theory based on Mie scattering. Bar code imaging was modeled as binary absorption contrast and scanning resolution in millimeter range was achieved for diffusive layers up to thirty transport mean free path thick. Samples included alumina, porous glass and chicken tissue. Computer simulation was used to study the effect of speckle spatial distribution and observed fractal dimension differences were ascribed to variance controlled speckle sizes. Fractal dimension suppressions were observed in samples that had thickness dimensions around ten transport mean free path. Computer simulation suggested a maximum fractal dimension of about 2 and that subtracting information could lower fractal dimension. The fractal dimension was shown to be sensitive to sample thickness up to about fifteen transport mean free paths, and embedded objects which modified 20% or more of the effective thickness was shown to be detectable. The box counting fractal method was supplemented with the Higuchi data series fractal method and application to architectural distortion mammograms was demonstrated. The use of fractals in diffusive analysis would provide a simple language for a dialog between optics experts and mammography radiologists, facilitating the applications of laser diagnostics in tissues.
Race, socioeconomic factors, and area of residence are associated with asthma prevalence.

Asthma prevalence in the United States has been reported to be higher in minority groups such as Blacks and Hispanics. Because a disproportionate number of individuals from such minority groups are of low socioeconomic status (SES), it is unclear how much of the racial/ethnic differences in asthma prevalence is related to low SES. We investigated the effect of SES on the relationship between race/ethnicity and asthma prevalence in a cohort of families with a history of asthma or allergies from the Boston, Massachusetts area. From 499 families, a cohort of 998 parents and 307 children was identified. We used total yearly family income ( or = $50, 000), highest level of education ( or = college), and residence in high-poverty areas vs. low-poverty areas as measures of SES. Yearly family income <$50,000, < or = high school education, and residence in high poverty areas were all associated with increased risks for asthma in both cohorts. In the parental cohort, Blacks and Hispanics (OR = 2.1, 95% CI = 1.5, 2.8; and OR = 2.2, 95% CI = 1.5, 3.2, respectively) were at greater risk for asthma than Whites. In the cohort of children, Black and Hispanic children (OR = 2.9, 95% CI = 1.0, 8.0; and OR = 5.3, 95% CI = 1.6, 17.5, respectively) were also at increased risk for asthma. When the three measures of SES were included in the multivariable models, the risks associated with Blacks and Hispanics decreased in both cohorts: OR = 1.4, 95% CI = 0.9, 2.0; and OR = 1.6, 95% CI = 1.0, 2. 6, respectively, for the parents; and OR = 0.8, 95% CI = 0.2, 3.0; and 2.5, 95% CI = 0.5, 11.7, respectively, for the children. We conclude that a large proportion of the racial/ethnic differences in asthma prevalence in our study is explained by factors related to income, area of residence, and level of education.
Filling the Catalytic Site of Cytochrome c Oxidase with Electrons REDUCED CuB FACILITATES INTERNAL ELECTRON TRANSFER TO HEME a3

Abstract In the reductive phase of its catalytic cycle, cytochrome c oxidase receives electrons from external electron donors. Two electrons have to be transferred into the catalytic center, composed of heme a3 and CuB, before reaction with oxygen takes place. In addition, this phase of catalysis appears to be involved in proton translocation. Here, we report for the first time the kinetics of electron transfer to both heme a3 and CuB during the transition from the oxidized to the fully reduced state. The state of reduction of both heme a3 and CuB was monitored by a combination of EPR spectroscopy, the rapid freeze procedure, and the stoppedflow method. The kinetics of cytochrome c oxidase reduction by hexaamineruthenium under anaerobic conditions revealed that the rate-limiting step is the initial electron transfer to the catalytic site that proceeds with apparently identical rates to both heme a3 and CuB. After CuB is reduced, electron transfer to oxidized heme a3 is enhanced relative to the rate of entry of the first electron.
A biphasic radio-controlled stimulator.

Abstract A stimulator is described which generates biphasic, 100-Hz square wave pulses. The stimulator is small enough to be mounted on the skull of the rat. The stimulator design allows remote control of pulse-train duration and interpulse-train interval; stimulation current is adjusted by a potentiometer on the stimulator. Some of the difficulties associated with the use of monophasic stimulators are discussed, and it is suggested that the use of radio-controlled stimulators may eliminate the problem of crosstalk.
Confidence interval estimating procedures for standardized incidence rates

Performances of some common confidence interval construction procedures for direct standardized incidence or mortality rate were compared. The asymptotic method, the method based on matching moments, the method based on gamma distribution and the method based on beta distribution were investigated through Monte Carlo simulations based on data from an epidemiologic study of cardiovascular disease and randomly generated scenarios. These interval estimation procedures, as well as some mixed procedures developed for the present study, were evaluated in terms of their coverage probability and expected length.
Local adaptation in adult feeding preference and juvenile performance in the generalist herbivore Idotea balthica.

Populations can respond to environmental heterogeneity by genetic adaptation to local conditions. Evidence for local adaptation in herbivores with relatively broad host breadth is scarce, either because generalists rarely locally adapt or because fewer studies have tested for local adaptation. The marine isopod Idotea balthica, a small ( Zostera) and southern adults (Ulva > Fucus > Zostera) closely mirrored ranking of juvenile growth rates, suggesting that preference and performance are strongly correlated across these macrophytes. Several of our assays included isopods that had parents reared under uniform laboratory conditions, indicating that geographic differences are genetically mediated and unlikely to reflect phenotypic plasticity or maternal effects. Local adaptation in host use traits may be common in broadly distributed, generalist herbivores in marine and terrestrial systems, and will manifest itself as local shifts in the preference ranking of hosts.
Parallel computations of turbulent diffusion in convective boundary layers on shared-memory machines

Abstract Currently, time-splitting finite difference or finite element schemes are commonly used in air-pollution modeling. In light of the recent advances in parallel processing, it is crucial to evaluate the performance of these time-splitting schemes on different multiprocessors. In this paper, we use a K-theory diffusion model and a second-order closure model to simulate turbulent diffusion in convective boundary layers. The objective is to assess the “portability” of time-splitting finite element schemes for shared-memory multiprocessors, such as IBM 3090-600J, the Alliant FX/8, the Sequent Symmetry S81 and the Encore Multimax. It was found that significant speed-ups were obtained as a result of parallelization with small programming efforts. Furthermore, our two- and three-dimensional results also suggest that second-order closure models are now computationally affordable and feasible for realistic air pollution modeling.
Dynamic Origins of Interdomain Cooperativity in the Vav1 Proto-Oncoprotein

Multi-domain signaling proteins exhibit complex behaviors due to cooperative interactions between domains. In many such proteins a core regulatory interaction, involving binding of an inhibitory domain to the active site of a catalytic domain, is cooperatively enhanced by additional intramolecular domain-domain contacts. However, the physical basis of this cooperativity, and thus the energetic construction of multi-domain systems, is not well understood. The five-domain N-terminal regulatory element of the Vav1 proto-oncoprotein is representative of this class of signaling molecules. The catalytic activity of the Vav1 Dbl homology (DH) domain is autoinhibited by binding of an adjacent helix into the enzyme active site. This core inhibitory process is cooperatively enhanced through an unknown mechanism by intramolecular contacts of the N-terminal calponin homology (CH) domain of the protein. Here we show by NMR spectroscopy that the isolated helix-DH module exists in equilibrium between a ground state where the active site is blocked by the inhibitory helix, and an excited state where the helix is dissociated. The rate of phosphorylation of the helix, an event that relieves autoinhibition, is linearly related to the population of the excited state. Thus, phosphorylation only occurs efficiently through the excited state, and internal dynamics are required for and control the rate of activation of the helix-DH module. In the full five-domain element this regulatory equilibrium is further biased 10-20-fold toward the closed state, implying that regulatory cooperativity derives from thermodynamic coupling between the helix-DH equilibrium and other interdomain binding equilibria in the protein. This explains the transforming activity of truncated Vav1 proteins lacking the CH domain, and suggests that Vav1 activation in vivo likely involves integration of kinase signals and signals to the CH or other domains of the molecule.
On the existence of heavy fermion ytterbium compounds

Author(s): Fisk, Z; Maple, MB | Abstract: Evidence for heavy fermion behavior in ytterbium compounds is examined. © 1992.
Variability of the productive habitat in the eastern equatorial Pacific

It is shown that satellite ocean color data can be used to define the spatial extent of the region of enhanced biological production (the productive habitat) in the eastern equatorial Pacific. The degree of interannual variability in the areal extent of the productive habitat and in the estimated primary production of the region is determined. Frequency distributions of satellite-derived pigment concentrations are used to determine whether major changes in phytoplankton biomass have taken place from one period to the next.
Insulin stimulates the phosphorylation of the 66- and 52-kilodalton Shc isoforms by distinct pathways.

In contrast to the 52-kDa Shc isoform, insulin stimulation caused a quantitative, time-dependent decrease in the SDS-PAGE mobility of 66-kDa Shc in both Chinese hamster ovary/IR cells and 3T3L1 adipocytes. Alkaline phosphatase treatment and direct phosphoamino acid analysis demonstrated that insulin stimulated an increase in serine phosphorylation of the 66-kDa isoform but not 52-kDa Shc, although the latter displayed a marked increase in tyrosine phosphorylation. To identify the responsible kinase pathway, we compared the effects on 66-kDa Shc serine phosphorylation by insulin, anisomycin, and osmotic shock, agents that specifically activate the ERK, JNK, or both pathways, respectively. Insulin and osmotic shock both stimulated a decrease in 66-kDa Shc mobility, whereas anisomycin had no effect. Furthermore, expression of a dominant-interfering Ras mutant (N17Ras) prevented the insulin-stimulated, but not the osmotic shock-induced serine phosphorylation of 66-kDa Shc. Consistent with a MEK-dependent path...
An electroejaculator for the collection of semen from the domestic cat

An electroejaculator for the collection of cat semen and for the evaluation of electroejaculation protocols is described. The electroejaculator contains an adjustable signal generator and allows for the precise control and monitoring of the electrical stimulus to the animal. The electroejaculator incorporates controls for the selection of the frequency, potential and waveform of the electrical stimulus and controls for either manual or automatic delivery of stimuli of specified characteristics to the rectal probe. In the automatic mode, the operator may also preset the rate and duration of stimulus application and the interval between successive stimuli. The electroejaculator output to the probe is controlled with an on-off foot-switch which allows for the collection of semen from an anesthetized cat by one operator. Diagrams of the functional block, the component circuits of the electroejaculator, and the accessories which facilitate the collection of cat semen are provided.
The Structure of Actin

The protein actin exists as both a monomer (G-actin) and polymer (F-actin). There have been more than 80 different crystal structures of G-actin and related homologs over the years, and at least 4 different structures/models for F-actin have been proposed using a combination of techniques. Comparison of the G-actin crystal structure with the most recent F-actin structures suggests that there are several structural rearrangements, the most significant being a relative rotation of subdomains that results in a propeller-like twist of the protein. To investigate these structures in more detail, we performed multi-microsecond molecular dynamics simulations of the muscle ADP-actin monomer (pdb 1J6Z) and the two most recent ADP F-actin structures (2ZWH and 3MFP). We find that G-actin monomer deviates quite far from its crystal structure over the course of its simulation while the F-actin protomer shows a more modest shift from its starting point. The most interesting result is that the equilibrium structures of the monomer and F-actin protomer are much more similar than previously thought and their conformational spaces show significant overlap. We will present detailed analysis of the conformational dynamics, as well as analysis of the filament conformation, twist, and structures of the barbed and pointed ends.
Oscillatory Behavior of a Striped Bass Population Model Controlled by a Ricker Function

Abstract The oscillatory properties of a striped bass (Morone saxatilis) population model controlled by a Ricker function were examined by plotting the value of the parameter alpha above which the population will oscillate with an amplitude equal to or greater than 1% of the equilibrium stock size. The value of alpha required for persistent oscillation was affected by the age distribution and the reproductive age structure of the model population. The most stable age structure was found to exist at an instantaneous mortality rate of about 1.0. The results support the notion that fluctuations in the abundance of striped bass stock are largely due to density-independent influences on survival.
Lysosome-related organelles in intestinal cells are a zinc storage site in C. elegans.

Zinc is an essential trace element involved in many biological processes and human diseases. Because zinc deficiency and excess are deleterious, animals require homeostatic mechanisms to maintain zinc levels in response to dietary fluctuations. Here, we demonstrate that lysosome-related organelles in intestinal cells of C. elegans, called gut granules, function as the major site of zinc storage. Zinc storage in gut granules promotes detoxification and subsequent mobilization, linking cellular and organismal zinc metabolism. The cation diffusion facilitator protein CDF-2 plays a critical role in this process by transporting zinc into gut granules. In response to high dietary zinc, gut granules displayed structural changes characterized by a bilobed morphology with asymmetric distributions of zinc and molecular markers. We defined a genetic pathway that mediates the formation of bilobed morphology. These findings elucidate mechanisms of zinc storage, detoxification, and mobilization in C. elegans and may be relevant to other animals.
Validity of the Short Form of the Parenting Stress Index for Fathers of Toddlers

We examined the psychometric properties of two scales of the parenting stress index-short form (PSI-SF) in a low-income sample of fathers of toddlers. The factor structure, reliability, and validity of the parental distress and parent–child dysfunctional interaction subscales were assessed for 696 fathers in a multi-site study of Early Head Start. Confirmatory factor analyses (CFA) compared the fit of the developer recommended two-factor scales with five-factor scales theoretically derived and supported with mothers. Our results suggested that two subscales from the PSI-SF were reliable and valid for this sample of racially diverse, low-income fathers of toddlers. However, these subscales capture multiple dimensions of parenting stress and results also supported the use of more narrowly defined aspects of parenting stress that included general distress, distress specifically related to parenting demands, problematic interactions of the father–toddler dyad, perceptions of the child, and parental perceptions of self as a parent. These unidimensional scales may prove useful in research and clinical activities by allowing researchers to elucidate the mechanisms through which stress impacts parenting and permitting clinicians information to develop more targeted interventions for young children and their families.
Games of bounded deviation, additivizations of games and asymptotic martingales

We consider games in coalition function form on a, generally infinite, algebra of coalitions. For finite algebras the additive part mappingv →E(v ¦ ) is the usual. The concern here is the analogue for infinite algebras. The useful construction is the finitely additive stochastic process of additive parts of the game on the filtration f of finite subalgebras of .
Challenges of critical colleagueship: examining and reflecting on mathematics teacher study group interactions

This article examines mathematics teacher collegiality by focusing on both the ways in which teachers interacted as critical colleagues in a long-term professional development project and the evolving role of the teacher–educator–researcher as the facilitator of this project. The professional development collaboration comprised two phases: one focused on reading classroom discourse literature and one focused on supporting each other through cycles of action research related to mathematics classroom discourse. Lord’s (1994) critical colleagueship framework is used to examine how a study group of middle-grades (ages 11–16) mathematics teacher–researchers took (or did not take) a more critical stance toward their own teaching practice and that of their colleagues. We found that challenging interactions were related to instances in which the teachers interacted as critical colleagues and were marked by particular features including the use of particular words and the use of personal experience as a form of evidence. We present the ways in which we came to understand what it might look like to scrutinize one’s practice and findings related to the development of this type of collegiality across the two different phases of this project. We end with a section in which the teacher–educator–researcher who facilitated the professional development project reflects on the ways in which the analysis caused her to reconsider both the nature of argumentation in mathematics study group settings and what implications this has with respect to her own practice as a facilitator.
Global Crop Production Forecasting: A simulation analysis of the data system problems and their solutions

Marshall Space Flight Center has been analyzing the NASA long-term objective of providing by 1985 a bi-weekly Global Crop Production Forecast of major crops having worldwide food and/or economic significance. The goal of this analysis was to determine probable data related issues in achieving this objective and the recommendation of alternatives for their resolution.A quantification of the data volumes and the acquisition expectation for different system configurations are essential to establishing realistic design parameters. The required information must be obtained at precise times during the growing seasons. The opportunities are limited by the orbital mechanics of the satellites by climatological conditions. The use of simulation to combine the dynamics of crop phenology, cloud probabilities, and orbital dynamics to obtain a faithful representation of data acquisition and processing performance is discussed in this paper along with some results.
Body image and quality of life after head and neck cancer surgery.

objectives: The purpose of this paper is to describe the process of body image reintegration as it relates to quality of life in the surgical head and neck cancer patient. materials and methods: To illustrate the course of body image reintegration after head and neck cancer surgery, the results of two major studies are presented. In the first study, a cohort sample of 75 adults about to undergo disfigurative surgery for head and neck cancer was examined to determine levels of anxiety before and after the procedure. The State Trait Anxiety Inventory was administered before and after surgery on postoperative days 4 through 6. In the large study, from which the cohort sample was derived, 117 adults about to undergo disfigurative surgery were investigated to determine the relationship between coping with surgical disfigurement/dysfunction and length of hospital stay. The Ways of Coping Checklist was administered before surgery. Disfigurement/dysfunction, as measured by the Disfigurement/Dysfunction Scale, and postoperative coping behaviors, as measured by the Coping Behaviors Score, were accounted for in both samples. Self-care and resocialization behaviors were observed and measured on postoperative days 4 through 6. results: In the cohort study, anticipation of disfigurative facial surgery was associated with extremely high levels of anxiety. In the large sample, coping effectiveness was diminished. The degree of surgical deficit ranged from mild to severe disfigurement and dysfunction. Preoperative coping effectiveness predicted postoperative coping behavior. It was concluded that body image reintegration was characterized by self-care, resocialization, and reduced anxiety. Further, that these components, when taken together, constitute assimilation of the surgical defect into self. conclusions: Body image reintegration is critical to subsequent quality of life after head and neck cancer surgery. When disfigurement/dysfunction is associated with treatment, quality of life may be profoundly and adversely affected. Findings from the studies presented indicate a significant correlation between postoperative self-care and reduction in level of anxiety. The implications of this finding are important to care during the early period after surgery and to long-term follow-up after hospital discharge.
Bilingual Interns' Barriers to Becoming Teachers: At What Cost Do We Diversify the Teaching Force?.

Abstract In this article I present a critical ethnographic study of three Mexican-American bilingual interns reflecting on the ability of an alternative licensure program to address barriers that have traditionally prevented individuals from underrepresented groups in the United States from entering teaching. Most financial and work schedule barriers are addressed through a federal grant supporting the program and the availability of evening and weekend coursework. However, in this program they face new barriers including reduction in salary during the internship, a stressful workload, passing required teacher exams, inability to use their bilingual education knowledge and skills, and mentors with no experience in bilingual education and/or experience at the interns' grade level. In this article, the author offers a vision for transforming alternative licensure programs aimed at diversifying the teaching force.
THERMOPHYSICAL PROPERTIES OF FRESH AND ROASTED COFFEE POWDERS

The present work deals with experimental determination of bulk specific heat, bulk thermal conductivity, bulk and true density and moisture content of Columbian and Mexican coffee bean powders. Specific heat was determined by DSC, thermal conductivity by modified Fitch apparatus, density by stereopycnometer and moisture contents by standard vacuum oven method. Specific heat values showed marginal rise over the temperature range (45 to 150C) studied. Thermal conductivity values, determined in the temperature range of20-60C were not found to have any definite trend with rise in moisture in the experimental range of 4.8 to 9.8% moisture (dry basis). Bulk density ofpowders varied appreciably (1.298 to 0.882 g.cm -3 ), while the change was negligible for true density (1.361 to 1.092 g.cm -3 ) with the degree of roasting. Statistical analysis of the data shows the reliability of the experimental determinations. Suitable correlations were developed to determine bulk specific heat and bulk density.
Application of liquid chromatography-tandem mass spectrometry (LC–MS/MS) for the analysis of stable isotope enrichments of phenylalanine and tyrosine

Whole-body protein synthesis and breakdown are measured by a combined tracer infusion protocol with the stable isotope amino acids L-[ring-(2)H(5)]-phenylalanine, L-[ring-(2)H(2)]-tyrosine and L-[ring-(2)H(4)]-tyrosine that enable the measurement of the phenylalanine to tyrosine conversion rate. We describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of very low tracer-tracee ratios (TTR) of the amino acids L-phenylalanine and L-tyrosine in human plasma. TTR calibration curves of the tracers L-[ring-(2)H(5)]-phenylalanine, L-[ring-(2)H(2)]-tyrosine and L-[ring-(2)H(4)]-tyrosine were linear (r(2)>0.99) in the range between 0.01% and 5.0% TTR and lowest measurable TTR for the tracers was 0.01% at a physiological concentration of 60 microM. The method was applied successfully to plasma samples from a clinical study reaching a steady state enrichment plateau (mean+/-SD) of 3.33+/-0.19% for L-[ring-(2)H(5)]-phenylalanine, 2.40+/-0.43% for L-[ring-(2)H(2)]-tyrosine and 0.29+/-0.07% for L-[ring-(2)H(4)]-tyrosine, respectively. The LC-MS/MS method can be applied for measurement of very low plasma enrichments of phenylalanine and tyrosine for the determination of whole-body protein synthesis and breakdown rates in humans.
Friction and wear reduction of 440C stainless steel by ion implantation

Friction and wear tests on ion-implanted 440C stainless steel discs have been extended to high Hertzian stresses (less than or equal to 3150 MPa). Implantation of 2 x 10/sup 15/ Ti/mm/sup 2/ (180 to 90 keV) and 2 x 10/sup 15/ C/mm/sup 2/ (30 keV) into 440C reduces friction (approx. 40%) and wear (> 80%) for Hertzian stresses as large as 2900 MPa, stresses which significantly exceed the yield strength of 440C (approx. 1840 MPa). Implantation of 4 x 10/sup 15/ N/mm/sup 2/ (50 keV) into 440C reduces friction slightly (approx. 25%) for Hertzian stresses < 1840 MPa but provides little or no reduction in wear. The amount of Ti remaining in the wear tracks correlates with the reductions in friction and wear. The implantation of Ti and C produces an amorphous surface layer which is believed to reduce friction and wear, whereas N implantation is expected to produce hard nitride particles which probably do not modify the hardness of 440C (KHN = 789) significantly.
A better red: The transition from communism to coca-cola in Romania

The transition from central planning to market-oriented economies in Eastern and Central Europe provides a fascinating laboratory for research in economic theory and business practice. With the collapse of communism, the inefficiencies of centralized planning have been laid bare. The classic debates between Mises and Lange on the viability of planning, although long resolved in the minds of free-market advocates, have been settled. Poznanski (1992), in an aptly titled book, Constructing Capitalism, makes the following observation: “The experience of state socialist economies also validates the hypothesis that efficient production is not only impossible without market competition but also without private property as a principle form of resource ownership and use control.” Austrian economists and others recognize that privatization of state-owned enterprises and the establishment of a system of property rights are the most important issues in the transition process. Svejnar (1991), for example, states that the absence of property rights is “the Achilles heel of the transition.” Although economists such as Jeffrey Sachs and others, who have served as advisors to various governments in the transition, recognize that privatization is important, they, however, also add other issues such as fiscal reform (i.e., taxes), monetary stability, and so on. Rothbard (1992) has provided some insight into an Austrian perspective dealing with these issues. Problems dealing with privatization, monetary reforms, and so forth are macro issues. Our research has focused more on what we call the micro issues; that is, managerial and entrepreneurial problems in the transition. Among the many challenges confronting economies in transition is the promotion of entrepreneurs hip and successful business practices. Entrepreneurship involves the ability to predict how consumer demand will change and to find cost-efficient ways of supplying new products that govern business success. Exercising this ability and developing the talent necessary for successful market ventures was foreign to Romanians under the old regime. Responding to consumer demand was impossible in the planned economies. To some extent, the mind-set that existed during the communist era remained intact after the collapse of the dictatorship and the liberalization of the economy. Arzeni (1996) contends