cssi/SciSciGPT-SciSciNet huggingface dataset:
Nα-Malto-glucagon and Nα-malto, S-methyl methionine27-glucagon: Preparation and characterization of two partial agonists☆

Abstract N α -Maltoglucagon was prepared by demethylation of N α -malto, S -methyl methionine 27 glucagon, and the two derivatives were purified to > 99% and 99.7%, respectively. S -Methylation of glucagon lowers the reactivity of Lys-12 and provides an alternative strategy to ϵ-amino protection for directing glycosylation of glucagon to the α-amino group. Both derivatives are partial agonists, with their adenylate cyclase activation and binding reduced in parallel. N α -Maltoglucagon produces 70% and N α -malto, S -methyl methionine 27 glucagon 40% of the maximum activity of native hormone. N α -Maltoglucagon binds equivalently to N α -biotinyl, N ϵ -acetimidoglucagon whose maximum activity is near 35%, but a p K shift of the imidazole moiety cannot account for the difference in their abilities to produce transduction. Both glycosylated derivatives bind noncooperatively and both inhibit adenylate cyclase at high concentrations. The presence of a maltose residue on the amino terminal of glucagon may be required but, alone provides insufficient structural complementarity for concanavalin A binding to occur. The glycosylated derivatives are resistant to aminopeptidase degradation, are more soluble, and the maltose residue is unlikely to cause toxicity with in vivo use. Such attributes may be advantageous in the development of other analogs.
Transport Between Twisted Graphene Layers

Commensurate-incommensurate transitions are ubiquitous in physics and are often accompanied by intriguing phenomena. In few-layer graphene (FLG) systems, commensurability between honeycomb lattices on adjacent layers is regulated by their relative orientation angle $\ensuremath{\theta}$, which is in turn dependent on sample preparation procedures. Because incommensurability suppresses interlayer hybridization, it is often claimed that graphene layers can be electrically isolated by a relative twist, even though they are vertically separated by a fraction of a nanometer. We present a theory of interlayer transport in FLG systems which reveals a richer picture in which the specific conductance depends sensitively on $\ensuremath{\theta}$, single-layer Bloch-state lifetime, in-plane magnetic field, and bias voltage. We find that linear and differential conductances are generally large and negative near commensurate values of $\ensuremath{\theta}$, and small and positive otherwise. We show that accounting for interlayer coupling may be essential for describing transport in FLG despite its physically insignificant effect on the band structure of the system.
Existence of finitely optimal solutions for infinite-horizon optimal control problems

In this paper, we investigate the existence of finitely optimal solutions for the Lagrange problem of optimal control defined on [0, ∞) under weaker convexity and seminormality hypotheses than those of previous authors. The notion of finite optimality has been introduced into the literature as the weakest of a hierarchy of types of optimality that have been defined to permit the study of Lagrange problems, arising in mathematical economics, whose cost functions either diverge or are not bounded below. Our method of proof requires us to analyze the continuous dependence of finite-interval Lagrange problems with respect to a prescribed terminal condition. Once this is done, we show that a finitely optimal solution can be obtained as the limit of a sequence of solutions to a sequence of corresponding finite-horizon optimal control problems. Our results utilize the convexity and seminormality hypotheses which are now classical in the existence theory of optimal control.
A study of superimposed tin and silver films

Abstract The effects of film structure on the contact depression of the superconducting transition temperature for superimposed Sn and Ag films has been studied before and after annealing. The films were composed of a layer of 550 ± 50 A Sn and a layer of Ag which varied from 20 to 385 A (±30 A). Experimental evidence has shown that the superimposed Sn and Ag films as deposited result in an inberdispersion of Ag 3 Sn compound and Sn rather than a composite of single Sn and Ag films. The depression of transition temperature for such films is not due to a contact effect between two superimposed films but to a contact effect at the adjacent surface between the dispersed Ag 3 Sn crystallites and the Sn matrix. Upon annealing of the superimposed films, grain growth and preferred orientation of the crystallites of Ag 3 Sn and Sn were observed. The decrease in contact surface, due to the grain growth of Ag 3 Sn, thus increases the transition temperatures of the superimposed films after annealing.
Gene-environment interplay and the importance of self-control in predicting polydrug use and substance-related problems

Using the National Longitudinal Study of Adolescent Health (Add Health), the current study applies a general biosocial theoretical model to polydrug use and associated substance-related problems. Along with measures of molecular genetic polymorphisms, neurocognitive skills, self-control, and environmental pathogens a recursive path modeling strategy was used to empirically examine the relations between these biosocial measures and polydrug use, alcohol, and drug-related problems in a subsample of 1136 adolescent males (Mean age=21.96, SD=1.73). Results supported the main predictions of the biosocial model finding significant path coefficients across key constructs. In particular, the role of poor self-regulation was found to be sturdy across path models.
H + NO2 Channels in the Photodissociation of HONO at 193.3 nm†

The H + NO2 channels in the 193.3-nm photodissociation of jet-cooled HONO have been examined by using high-n Rydberg-atom time-of-flight (HRTOF) technique. Center-of-mass (CM) translational energy ...
Experimental Measurements of the Turbulent Boundary Layer on a Yawed, Spinning Slender Body

Abstract : Experimental measurements of the tripped turbulent boundary layer profile characteristics on a yawed, spinning tangent-ogive-cylinder model are described. The profile measurements were made using a flattened total head probe at 30 deg increments completely about the azimuthal plane for three longitudinal stations at M = 3, alpha = 4 deg omega = 0 and 10,000 RPM. Wall static pressure measurements were obtained in order to compute velocity profiles from the measured total head pressure. The data have been analyzed according to law of the wall/law of the wake concepts using a least squares fitting technique. The effect of azimuthal position is revealed in the growth of the wake parameter by a factor of two from the wind to the lee-side. A small but consistent effect of spin is also apparent.
Ecology models and newton vector fields

Abstract We generate phase plane portraits of autonomous differential equations by constructing integrals of motion—even in nonconservative systems, where no integrals produced by quadrature exist. These phase plane portraits are produced with no propagated error. Phase portraits do not usually display the parametrization along orbits. The use of high resolution color graphics allows us to display this parametrization conveniently. We examine three ecology models—the logistic equation in the complex domain, and the predator-prey and competing species equations in the real domain.
Comparing hierarchical models for spatio-temporally misaligned data using the deviance information criterion.

Bayes and empirical Bayes methods have proven effective in smoothing crude maps of disease risk, eliminating the instability of estimates in low-population areas while maintaining overall geographic trends and patterns. Recent work extends these methods to the analysis of areal data which are spatially misaligned, that is, involving variables (typically counts or rates) which are aggregated over differing sets of regional boundaries. The addition of a temporal aspect complicates matters further, since now the misalignment can arise either within a given time point, or across time points (as when the regional boundaries themselves evolve over time). Hierarchical Bayesian methods (implemented via modern Markov chain Monte Carlo computing methods) enable the fitting of such models, but a formal comparison of their fit is hampered by their large size and often improper prior specifications. In this paper, we accomplish this comparison using the deviance information criterion (DIC), a recently proposed generalization of the Akaike information criterion (AIC) designed for complex hierarchical model settings like ours. We investigate the use of the delta method for obtaining an approximate variance estimate for DIC, in order to attach significance to apparent differences between models. We illustrate our approach using a spatially misaligned data set relating a measure of traffic density to paediatric asthma hospitalizations in San Diego County, California.
Comparison of venodilatory effects of nitroglycerin spray and tablets in healthy volunteers

Abstract Nitroglycerin spray has recently been approved for use in this country. The purported advantages of the spray preparation are that it is more stable and better absorbed than tablets in patients who have xerostomia or are edentulous. 1 Although several studies have compared the effects of the spray preparation to tablets on arterial pressure, heart rate, exercise tolerance and ventricular function, 1–3 there has been no comparison of the venodilatory effects of the 2 preparations. This study compares the effects of nitroglycerin spray and tablets on forearm venous tone as determined by plethysmography.
Interstellar MG II and C IV Absorption toward Markarian 205 by NGC 4319: an ``Optically Thick'' QSO Absorption System

We have used the Goddard High-Resolution Spectrograph aboard HST to detect interstellar Mg II and C IV absorption lines toward Mrk 205, a QSO whose sightline passes within 3/h kpc of the foreground galaxy NGC 4319. Absorption is detected from both local Milky Way gas and from NGC 4319, making this the first observation of an isolated, low-redshift galaxy causing an 'optically thick' QSO absorption system. We also observed for the first time Mg II absorption from two local High Velocity Clouds along this same sightline. The data support the premise that metal absorption lines seen at higher redshift in QSO spectra originate in gas associated with intervening galaxies. However, neither the strong absorption by (half) of our own Galaxy, nor the weak absorption by NGC 4319, may be typical of absorbers in general.
Charting ELSI’s future course: lessons from the recent past

We sought to examine the ethical, legal, and social implications (ELSI) literature research and scholarship types, topics, and contributing community fields of training as a first step to charting the broader ELSI community’s future priorities and goals. We categorized 642 articles and book chapters meeting inclusion criteria for content in both human genetics or genomics and ethics or ELSI during a 5-year period (2003–2008) according to research and scholarship types, topics, and the area of advanced training of the first-listed author. Research and scholarship type categories were developed and characterized through in-depth review of 95 randomly sampled publications from the larger group. There is a single dominant approach to ELSI, which focuses on ethical and other social issues “downstream” of advances in genomics, the contributors to which predominately have advanced training in medicine or science fields other than social science. A comparatively low percentage of publications primarily offer policy recommendations, and these are much more likely to be written by those with advanced training in law than is the case for the literature as a whole. Social science studies predominately employ qualitative methods and vary significantly with respect to the extent and types of recommendations offered. Two further types of ELSI research and scholarship offer alternative models for so-called “normative” work in this field. Considering topics, training, and types of ELSI research and scholarship from the most recent past allows for a baseline perspective that is sorely needed in charting this field’s future course. Genet Med 2012:14(2):259–267
Abstract 4637: Cell penetrating antibodies for intracellular targets: Expanding the antibody-based treatments for cancer

Antibody based therapeutics have gained significant interest in recent years. Herceptin, which targets cell surface protein, have been successful for the treatment of cancer. While antibodies are promising platforms for therapy, antibodies have been limited to targeting cell surface proteins because they cannot penetrate cells. Recently, we have developed cell penetrating antibodies engineered from the conjugation of a cell penetrating peptide (CPP) and an antibody. The CPP-mIgG and CPP-anti-RPA1 IgGs were internalized in cells as observed by fluorescence microscopy. Biological activities of these conjugates were determined and the expected anti-proliferative effects of the CPP-anti-RPA1 were subtly distinguishable from the control CPP-mIgG. While RPA1 is a valid anti-cancer target, its function depends on complicated pathways and cell cycle where dosing may have to be optimized. This demonstrates the difficulties in establishing CPP-IgG as an efficient therapeutic. To demonstrate that CPP-IgG bioconjugates are capable of inducing biological effects, we sought a different intracellular target. Antimitotic drugs are standard cancer chemotherapeutic agents. Recently, other proteins involved in the mitotic machinery have gained much attention. For example, kinesin motor protein Eg5 plays an important role in mitosis and inhibiting Eg5 prevents the formation of bipolar spindles resulting to an unmistakable change of morphology during mitosis_a star-like structure called “monoastral”. Small molecules, such as monastrol and (S)-trityl cysteine (STLC), lead to monastral formation. Thus, we chose Eg5 protein as an intracellular target to demonstrate that CPP-IgG bioconjugates are able to penetrate cells and have neutralizing activity. We expect that CPP-anti-Eg5 conjugates will penetrate cells and produce the canonical inhibition of Eg5 protein by observing for the monoastral morphology during mitosis. We tested whether CPP-anti-Eg5 IgG will present the same biological activity as STLC. We bioconjugated the anti-Eg5 with a CPP. Cell cycle synchronized cells were treated with the positive control STLC and CPP-anti-Eg5 showed an atypical star-like structure similar to monoastral. In whole, these studies show that CPP-IgG against intracellular targets are able to enter the cells and show inhibitory activities. We will describe our progress and discuss approaches to expanding the utility of antibodies as therapeutics for intracellular cancer targets. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4637. doi:1538-7445.AM2012-4637
Misfit dislocation injection, interfacial stability and photonic properties of Si-Ge strained layers

Low temperature epitaxy permits the growth of highly strained Si1−xGex/Si multilayers. These exhibit unique optical and electrical properties characteristic of the alloy composition, the tetragonal distortion of the crystal lattice and the periodicity in the growth direction. The kinetics of strain relaxation; misfit dislocation nucleation and propagation for a range of thermal cycles, typical of Si-based device processing, are defined. The early stages of relaxation are characterized using an empirical kinetic model. The interface perfection, interdiffusion and segregation effects in Si1−xGex/Si multilayers are investigated using X-ray scattering techniques. Photoluminescence properties of Si1−xGex quantum wells and alloys, epitaxially deposited on Si are reviewed. Comparison is made between the sharp, near band edge luminescence typical of narrow Si1−xGex quantum wells and the transition to an intense ~ 80 meV broad PL peak obtained from thicker Si1−xGex epitaxial layers. The impact of interfacial roughening during epitaxy on PL character, and the quenching of luminescence due to misfit dislocation injection, are discussed.
Mindfulness Group Work: Preventing Stress and Increasing Self-Compassion among Helping Professionals in Training.

This study examined the effects a 6-week mindfulness group had on 31 college students who were intending to enter helping professions (e.g., nursing, social work, counseling, psychology, and teaching). Group activities included meditation, yoga, a body scan exercise, and qi gong. The group members completed the Perceived Stress Scale, the Mindfulness Attention Awareness Scale, and the Self-Compassion Scale at pre-pre, pre, post, and follow-up intervals. Perceived stress significantly decreased, and mindfulness and self-compassion significantly increased in response to the group. Group members' comments on their experience are reported. Implications for future research and practice are explored.
Stability of numbers but not size of mouse forebrain cholinergic neurons to 53 months.

Abstract In normal mammalian aging there is a reduction of cholinergic markers in a variety of regions. To determine whether this reduction is related to reduced numbers of basal forebrain cholinergic neurons, we counted the number and measured the sizes of the magnocellular acetylcholinesterase-positive neurons in this region of 7, 15, and 53-month-old C57B1/6NNIA mice. Data were collected from coded slides containing the medial septum, nucleus of the diagonal band, magnocellular preoptic nucleus, and nucleus basalis magnocellularis. There was no decline in numbers of basal forebrain acetylcholinesterasepositive neurons in any of the regions studied. However, cell sizes showed a progressive age-related decline which was greatest in the nucleus basalis magnocellularis.
Lithium and recurrence in a long-term follow-up of bipolar affective disorder.

Background. Though previous studies have clearly shown that lithium affords prophylaxis in bipolar affective disorder, these studies have not demonstrated the persistence of this prophylactic effect beyond the first year of recovery. Methods. One hundred and eighty-one patients with bipolar affective disorder recovered during 5 years of semi-annual follow-up. After 8 weeks of recovery, 139 were taking lithium prophylaxis and 42 were not. Analyses used drug status (lithium v. no-lithium) as a censoring variable to compare these two groups by interval-specific probabilities of recurrence. Results. Recurrence was initially less likely in the lithium group but interval-specific probabilities of recurrence did not consistently favour either group after the first 32 weeks of recovery. Conclusions. Biases in treatment decisions may have both reduced the size and altered the specificity of the lithium effects seen here. Nevertheless, the apparent transience of lithium prophylactic effects is unexplained and may reflect important, physiological differences between relapse and recurrence. This possibility invites a controlled lithium discontinuation study, with gradual taper, of patients who have had at least 8 months of sustained euthymia.
Avoidance of Diagnostic Information in Self-Evaluation of Ability

In this study, conditions that led to self-handicapping strategies (Berglas & Jones,1978) were shown to generate avoidance of diagnostic evaluative information. A total of 60 male subjects received contingent or noncontingent success feedback on a test. Later, subjects selected additional problems to do from four tests that varied in diagnosticity and difficulty. The primary' hypothesis, that contingent subjects would prefer high-diagnostic problems, while noncontingent subjects would prefer low-diagnostic problems, was confirmed. There was no effect of contingency on preference for easy or difficult problems, nor were there effects for instructional set or achievement motivation variables on preferences for diagnostic or difficult problems.
TGF-β concentration specifies differential signaling profiles of growth arrest/differentiation and apoptosis in podocytes

Podocyte depletion occurs in most progressive glomerular diseases and is thought to result from podocyte loss while the remaining podocytes are unable to proliferate. The underlying mechanisms for podocyte growth arrest/differentiation and depletion remain poorly understood but may involve TGF-beta, which is typically upregulated in injured glomeruli. The TGF-beta are multifunctional cytokines that regulate growth, differentiation, and apoptosis in most cells. Determinants of functional specificity of TGF-beta signaling in cell-cycle control and apoptosis remain poorly understood. Using a unique system of conditionally immortalized podocytes, it is demonstrated that autocrine TGF-beta2 induces G0/G1 arrest and differentiation under nonpermissive culture through Smad3-dependent induction of the cyclin-dependent kinase inhibitor p15(Ink4b) (Cdkn2b). When exposed to recombinant TGF-beta1 (or TGF-beta2), nonpermissive culture podocytes switch to G2/M arrest and apoptosis, selectively at advanced TGF-beta concentrations and specifically in association with suppression of Cdkn2b and activation of proapoptotic p38 mitogen-activated protein kinase. Thus, distinct signaling profiles activated in a concentration-dependent manner by TGF-beta were identified. Autocrine TGF-beta2/Smad3/Cdkn2b signaling in podocytes specifies G0/G1 arrest associated with podocyte differentiation, whereas increasing TGF-beta concentrations beyond a critical threshold induces G2/M block and apoptosis associated with selective p38 mitogen-activated protein kinase activation and with suppression of Cdkn2b. In summary, the results suggest a new functional requirement of TGF-beta2 in growth arrest and differentiation of murine podocytes in vitro and demonstrate that a critical TGF-beta concentration threshold may specify a molecular switch to proapoptotic signaling profiles and apoptosis.
New design for a microwave discharge lamp.

A simple discharge lamp with a microwave cavity fitting inside provides an intense source of VUV resonance radiation for photochemical work inside a vacuum chamber. Good coupling and minimum reabsorption result in better efficiency (≳1%) and more intense output power (up to 2.5×1016 quanta s−1) than have been achieved previously.
HNETTER-a heuristically driven neural reasoning system

A description is given of a probabilistic reasoning system that attains understanding of simple 2D shapes and their properties from a small number of possibly incorrect examples. The system represents a fusion of heuristic reasoning and artificial neural nets with the former accomplishing generation and pruning of hypotheses and the latter assimilating the arbitrarily complex combinations of relevant hypotheses. The authors discuss the relative advantages of both approaches and suggest how, based on their experience, a learning task can be successfully split between them. >
A coupled micro-mechanical based model for saturated soils

Abstract It is generally accepted that the apparent behavior of geo-materials is the representation of the average micro-mechanical behavior of its constituents. Constitutive models that do not incorporate these micro-mechanical features in calibrating the material parameters cannot address various material localization features in large strain problems such as shear bands and slope failures, etc. In the absence of such micro-mechanical features the calibration of such models may be incorrect. A rigorous formulation that incorporates these micro-mechanical based mechanisms into the general behavior of the saturated soils is presented here. The plastic rotation of particles, the interaction of particles, the rate dependency, the damage, and the coupling of particles with pore fluid pressure are incorporated through the plastic spin, the gradient theory, the visco-plasticity, the damage theory, and the coupled theory of mixtures, respectively. The link between the micro-mechanical mechanisms and the macro-mechanical behavior is made through the use of RVE (representative volume element). As a result, a full formulation for the micro-mechanics implemented continuum plasticity for saturated soils is presented here.
Comparing intra- and inter-specific effects on litter decomposition in an old-field ecosystem

Abstract Plant species can differ in the quantity and quality of leaf litter they produce, and many studies have examined whether plant species diversity affects leaf-litter decomposition and nutrient release. A growing number of studies have indicated that intra-specific variation within plant species can also affect key ecosystem processes. However, the relative importance of intra- versus inter-specific variation for the functioning of ecosystems remains poorly known. Here, we investigate the effects of intra-specific variation in a dominant old-field plant species, tall goldenrod (Solidago altissima), and inter-specific variation among goldenrod species on litter quality, decomposition, and nitrogen (N) release. We found that the nutrient concentration of leaf litter varied among genotypes, which translated into ∼50% difference in decomposition rates. Variation among other goldenrod species in decomposition rate was more than twice that of genetic variation within S. altissima. Furthermore, by manipulating litterbags to contain 1, 3, 6, or 9 genotypes, we found that S. altissima genotype identity had much stronger effects than did genotypic diversity on leaf-litter quality, decomposition, and N release. Taken together, these results suggest that the order of ecological importance for controlling leaf-litter decomposition and N release dynamics is plant species identity⪢genotype identity>genotypic diversity.
Mild Renal Pelvic Dilation is not Predictive of Vesicoureteral Reflux in Children

Objective. To determine if mild renal pelvic dilatation at renal ultrasound (RUS) is a reliable sign of vesicoureteral reflux (VUR) at voiding cystourethrogram (VCUG) in children. Materials and methods. All patients less than 10 years of age who had RUS and VCUG on the same day during a 2-year period were identified in a computerized database. The appearance of the collecting system of each kidney was classified into two groups: group 0 – no dilatation (≤ 2-mm anteroposterior diameter of the renal pelvis) and group 1 – 3 to 10-mm AP diameter of the renal pelvis without caliectasis. VUR at VCUG was graded using the International Reflux Study Committee system. Results. Four hundred fifty-five patients (76 boys; 379 girls) with 910 kidneys were included. VUR occurred in 268 kidneys in 174 patients. There were 820 group 0 kidneys and 90 group 1 kidneys. Kidneys classified as group 1 (25.0 % had reflux) were no more likely to have reflux than were kidneys with nondistended (group 0) collecting systems (31.2 % had reflux). There was no statistical difference in the rate of reflux in patients with group 1 renal pelvic distention (39.2 % refluxed) and a normal collecting system (33.3 % refluxed) (P = 0.365). Conclusion. The frequency of vesicoureteral reflux in children with mild renal pelvic distention is not significantly different than in children with no distention. Therefore, mild dilatation of the renal pelvis should not be considered an indication for voiding cystourethrography.
On the impact of noise on mobile ad hoc networks

Network simulators such as NS-2, Glomosim, and OPNET are extensively used to validate and evaluate the performance of network protocols for mobile ad hoc networks (MANETs). For accurate simulations, realistic signal propagation and noise models should be used to simulate the radio channels in MANETs. A significant amount of emphasis is put on the correctness of signal propagation, while the ambient noise (due to external sources) is modeled as a constant noise. Based on the noise levels measured in a wireless ad hoc network testbed, we present two analytical models to describe the noise levels in a real network: a generalized extreme value (GEV) random process model and a Markov chain model. We incorporate GEV noise model in the Glomosim network simulator and show that it impacts the network performance significantly.
An application of generalizability theory to evaluate the technical quality of an alternate assessment

Although federal regulations require testing students with severe cognitive disabilities, there is little guidance regarding how technical quality should be established. It is known that challenges exist with documentation of the reliability of scores for alternate assessments. Typical measures of reliability do little in modeling multiple sources of error, which are characteristic of alternate assessments. Instead, Generalizability theory (G-theory) allows researchers to identify sources of error and analyze the relative contribution of each source. This study demonstrates an application of G-theory to examine reliability for an alternate assessment. A G-study with the facets rater type, assessment attempts, and tasks was examined to determine the relative contribution of each to observed score variance. Results were used to determine the reliability of scores. The assessment design was modified to examine how changes might impact reliability. As a final step, designs that were deemed satisfactory were e...
Research Note: Effect of Force-Feeding at an Early Age on Body Growth and Composition of Chicks

Abstract The effect of early force-feeding of chicks allowed free access to feed on total feed intake, body weight, and composition was determined. Intubation of feed two or three times daily from 3 to 7 days of age resulted in supplying 33 and 55%, respectively, of the total feed intake; but the feed intake was not significantly different from that of control birds fed with ad libitum access to feed. Body weight at 7 days of age was depressed below that of the controls in chicks intubated three times daily; but after 2 wk of ad libitum access to feed, no difference was evident. Liver weight and the amount of abdominal and carcass fat at either 7 or 21 days were not significantly different for intubated or nonintubated chicks with ad libitum access to feed.
A robotic system for testing dental implants

Abstract Previous studies have attempted to predict the manner in which potentially harmful levels of force are transmitted to human bone surrounding dental implants and adjacent teeth. However, the analysis models previously used are dependent on unknown biomechanical behaviors. In order to develop in vitro testing to measure the force transmission between dental implants and attached prostheses, an accurate simulation of the chewing motion is crucial for data validation. This paper proposes a new approach involving a robot simulation system. The system has been designed to produce simulated mandibular movements and occlusal contact forces so that various implant designs and procedures can be thoroughly tested and evaluated. This paper describes the various components and operation of the test apparatus, including sample results. The primary components of the system are a robot, a test fixture and a measurement system. The robot is a commercially available robot with four primary degrees of freedom. The current technique used to teach the robot mandibular motion trajectories is based on the use of a dental articulator (Wang et al., in Proceedings of the 4th National Applied Mechanics and Robotics Conference, AMR95-094, 1995) [1] ). The articulator is then replaced by the actual test specimen consisting of a simulated lower jaw mounted to the robot base and a simulated upper jaw mounted to the robot end effector. A set of noncontact displacement probes are used to measure lower jaw–implant deformations during simulated chewing. A multi-axis force–torque sensor is mounted on the end effector for measurement and feedback of overall force levels, and a system of strain gages is used to ascertain force levels transmitted by individual teeth. Multi-tooth dental bridges consisting of combinations of natural teeth and implants are the primary focus of the research. The objective is to determine the manner in which overall force levels are distributed during various chewing cycles. This information will be useful in understanding the manner in which potentially harmful levels of force are transmitted to human bone surrounding dental implants and adjacent teeth by providing more accurate force input data for finite element models which are under development. The use of a robotic system for generating motion and force transmission patterns will facilitate the standardization of procedures in evaluating implant designs.
Globalization, Labor, and Violence in Colombia's Banana Zone

This article examines how globalization and violence have shaped workers' organizations in the Uraba banana zone in northern Colombia from the 1960s to the present. Early unions found allies in leftist political and guerilla organizations. The banana growers relied on the neoliberal state and rightist paramilitaries to unleash an extraordinary wave of violence to crush the leftist unions. They also wooed the right within the unions by pleading a set of common interests in reforming the global banana trade to the benefit of Colombian producers. By the 1990s, a newly right-dominated union in Uraba proved adept at labor-management collaboration in the interest of their joint regional stake in the industry, but it also promoted international labor unity aimed at pressuring banana transnationals to accept minimum labor standards.
Perceived stress and blood pressure in early adolescent children.

The objective of this investigation was to determine the individual contributions of perceived daily, major, and total stressors to blood pressure in early adolescent children. Toward this goal, cardiovascular risk factors were assessed in 74 6thgrade students. Height and body weight, measured in standard fashion, were used to calculate body mass index (BMI). Waist and hip circumferences and triceps and calf skinfolds were take to determine the distribution and percentage of body fat, respectively. Seated resting blood pressure was obtained using a mercury sphygmomanometer. The dietary sodium-to-potassium ratio was calculated from a food intake questionnaire. Family history of hypertension was self-reported by participant’s parents, and physical activity and perceived stress levels were determined by questionnaire. When added to the hierarchical regression models, the perceived stress variables did not significantly predict any additional variance in systolic or diastolic blood pressure in this early adolescent sample. Additionally, bivariate correlations between the stress variables and blood pressure were nonsignificant. The nonpsychological hypertension risk factors accounted for 25%–35% of the total variance in systolic and diastolic blood pressure. Further, regression analyses revealed that with the exception of BMI and the sodium-to-potassium ratio, no other risk factors were independent predictors of systolic or diastolic blood pressure. Further identification and understanding of environmental precursors of childhood hypertension is recommended.
Surveillance for Surgical Site Infections: The Uses of Antibiotic Exposure

Conventional methods of surveillance for surgical site infections are resource intensive, thus creating an incentive to develop simpler alternatives. Antibiotic exposure may serve as a satisfactory marker for a physician's belief that infection is present and, therefore, may be a more efficient, and perhaps more accurate, measure than identification of an explicit diagnosis in the medical record. Surveillance strategies that use antibiotic exposure may provide resourceefficient adjuncts for surveillance of surgical site infections or be used in selected circumstances as substitutes for conventional surveillance methods (Infect Control Hosp
A mixed design reveals that glucose moieties facilitate extinction of a conditioned taste aversion in rats

Separate groups of water-deprived rats had four trials with 15-min access to 0.0073 M saccharin, 0.3 M alanine, 0.3 M glucose, 0.1 M maltose, 0.3 M fructose, 0.06 M sucrose, or 0.03 M Polycose. Trials 1–3 were followed by injections of either 0.15 M LiCl (1.33 ml/100 g b.w., i.p.) or saline; Trial 4 (Test) was CS only. Extinction included either 48-h access to water alone or to the appropriate CS, both followed by a 24-h, two-bottle choice of CS and water. This 3-day cycle was repeated five to six times. All rats acquired comparable conditioned taste aversions (CTAs), but extinction rates varied with the test and the taste CS. No CTA extinguished during the two-bottle choices following 2 water days. During one-bottle CS exposure, all CTAs extinguished, but the aversion continued longer in the probe two-bottle tests. Intake of glucose moieties recovered rapidly, often in two cycles; the other CSs took four to six cycles. Thus, CTA extinction varies with the nature of the taste CS.
Thermodynamic Roles of Solubility in Taste Responses of Amino Acids

Bitter, sour and sweet responses of amino acids were related to their solubilities S w , which are virtually equal to the reciprocals of activity coefficients at infinite dilution in water γ w , and also related to their excess partial molar entropies of transfer TΔS t E .
The Effect of a College Sexual Assault Prevention Program on First-year Students' Victimization Rates

Objective: Although a variety of sexual assault prevention programs are currently available to college health professionals, there is a dearth of information about the effect of these programs on sexual assault victimization rates. Participants: The authors evaluated the efficacy of a sexual assault prevention program for first-year students at a college in the Northeast (N = 1,982). Methods: They used a retrospective cohort design and assessed the prevalence of sexual assault victimization among students exposed to the sexual assault prevention program and students 1 year their senior who were not exposed. Results: Students who had no exposure were more likely to report that they were sexually assaulted during their first year of college (odds ratio = 1.74, 95% confidence interval [1.32-2.29]). Results suggest that the program was effective for males and females, but not for students with a prior history of sexual assault victimization. Gay, lesbian, and bisexual students were at increased risk for victi...
Unsteady flow and heat transfer for cylinder pairs in a channel

Abstract The incompressible, two-dimensional, unsteady flow past a pair of cylinders of square cross-section, placed in tandem normal to the flow in a channel, has been investigated by dye visualization and direct numerical simulation. The objective has been to evaluate the effect of cylinder separation distance, λ, on the flow behavior and heat transfer, for cylinder diameter ratios, D d , of 1 and 2 over a range of Reynolds numbers 200 ⩽ Re ⩽ 1600, based on the larger (downstream) cylinder diameter. A comparison between the experimental and numerical results for cylinders of equal cross-section dimensions shows very good agreement. The results for D d = 1 reveal three distinct flow patterns as a function of λ and Re which, apparently, have not been previously reported: (1) For 0.25 ⩽ λ ⩽ 4 with Re ⩽ 200, the inter-cylinder flow consists of a pair of steady counter-rotating eddies which do not exchange fluid with the surrounding flow and eddy shedding is observed only for the downstream cylinder. (2) For 0.25 ⩽ λ ⩽ 1.0 with 400 ⩽ Re ⩽ 1600, vertical flow oscillations arise in the inter-cylinder space, and the periodic ingestion of backward-jetting fluid from the top and bottom walls of the downstream cylinder into the inter-cylinder space is observed. For fixed λ the unsteadiness increases with Re but only the downstream cylinder sheds large eddies. (3) At a critical inter-cylinder spacing related to Re according to λ c ∼ Re − 2 3 , the shedding of large eddies also occurs at the upstream cylinder and this results in a highly mixed inter-cylinder flow. For a cylinder diameter ratio of D d = 2 , with the smaller cylinder located upstream of the larger heated cylinder, it is shown that for Re fixed an optimal location exists for the upstream cylinder such that the heat transfer from the downstream cylinder is maximized. The optimal location corresponds to a spacing smaller than the critical inter-cylinder spacing.
catena-Poly[[dichloridozinc(II)]-μ-1,4-bis­(3-pyridylmeth­yl)piperazine]

In the title compound, [ZnCl2(C16H20N4)]n, tetra­hedrally coordinated divalent Zn atoms are ligated by two Cl atoms and two N-donor atoms from two 1,4-bis­(3-pyridylmeth­yl)­piperazine (3-bpmp) ligands. The tethering 3-bpmp ligands promote the formation of [ZnCl2(3-bpmp)]n chains situated parallel to (\overline{1}02). These chains aggregate via C—H⋯Cl inter­actions to form supra­molecular layers, which in turn stack to construct the three-dimensional crystal structure.
Minimal scattering events in enhanced backscattering (EBS) of light: Origin of low-coherence EBS in discrete tissue models

We report that low-coherence EBS originates from the time-reversed paths of double scattering events in weakly scattering media, providing a potential method for the analysis of the low-coherence EBS signals from biological tissue.
Songs of comfort and joy

The music industry's story is a vivid reminder that entire industries can fail to see shifts in the market.
Discretely disordered photonic bandgap structures: a more accurate invariant measure calculation

In the one-dimensional optical analog to Anderson localization, a periodically layered medium has one or more parameters randomly disordered. Such a randomized system can be modeled by an infinite product of 2x2 random transfer matrices with the upper Lyapunov exponent of the matrix product identified as the localization factor (inverse localization length) for the model. The theorem of Furstenberg allows us, at least theoretically, to calculate this upper Lyapunov exponent. In Furstenberg's formula we not only integrate with respect to the probability measure of the random matrices, but also with respect to the invariant probability measure of the direction of the vector propagated by the random matrices. This invariant measure is difficult to find analytically, and, as a result, the most successful approach is to determine the invariant measure numerically. A Monte Carlo simulation which uses accumulated bin counts to track the direction of the propagated vector through a long chain of random matrices does a good job of estimating the invariant probability measure, but with a level of uncertainty. A potentially more accurate numerical technique by Froyland and Aihara obtains the invariant measure as a left eigenvector of a large sparse matrix containing probability values determined by the action of the random matrices on input vectors. We first apply these two techniques to a random Fibonacci sequence whose Lyapunov exponent was determined by Viswanath. We then demonstrate these techniques on a quarter-wave stack model with binary discrete disorder in layer thickness, and compare results to the continuously disordered counterpart.
Concentration fluctuations and dilution in two-dimensionally periodic heterogeneous porous media

Dilution of solute in two-dimensionally periodic heterogeneous porous media is assessed by numerically simulating advection-dispersion. The concentration fluctuations, created by advective heterogeneity, are destroyed by local dispersion, over a characteristic variance residence time (VRT). For an impulse introduction of solute, initially, plumes become increasingly irregular with time—the coefficient of variation (CV) of concentration grows with time. A priori, the spatial second moment and mean concentrations are insufficient measures of dilution, because concentration fluctuations can be large. At large times (t > VRT) the relative concentration fluctuations weaken—the concentration CV was observed to slowly decrease with time. At the center of mass the general trend of the decreasing CV follows VRT/t (predicted by Kapoor and Gelhar). The VRT is found to be an increasing function of the log hydraulic conductivity microscale. In employing effective dispersion coefficents to model the mean concentration, it needs to be recognized that excursions of concentrations around the mean are singularly determined by local dispersion.
Diffraction of Transient Elastic Waves by a Spherical Cavity

The diffraction of transient elastic waves by a spherical cavity is treated. Two cases are considered: (a) a suddenly applied normal point load, and (b) the impingement of a plane transient pulse on the cavity. The method used determines the solution only in the shadow zones; that is, those points which cannot be connected to the source of disturbance by straight-line rays. Analytical results are obtained and evaluated for the displacements at the cavity wall. The analysis is based on the Laplace transform (on time) and the Watson transformation. This well-known transformation makes it possible to convert an infinite series involving a discrete real wave number into one involving a generalized wave number. This leads to transient solutions the components of which have a one-to-one correspondence with the modes of the underlying frequency equation. These solutions have a form convenient for numerical analysis and for obtaining approximate solutions. The results given here are for the displacements evaluated at the cavity wall. It is found that the behavior of the diffracted wave fronts is similar to that associated with the simpler equations governing scalar diffraction problems (see Friedlander, "Sound Pulses" , Cambridge, 1958). In both problems the Rayleigh disturbance predominates for long time, being singular at its arrival time in the point load case and non-singular in the plane wave case.
Properties of fibre reinforced concrete using recycled fibres from carpet industrial waste

A study was carried out to evaluate the use of recycled fibres from carpet industrial waste for reinforcement of concrete at 1 and 2 vol% fractions. Compressive, flexural, splitting tensile and shrinkage tests were performed. Significant increases in shatter resistance, energy absorption and ductility were observed. This paper reports on the experimental programme and compares the effectiveness of such recycled fibres with that of virgin polypropylene fibres specially made for fibre reinforced concrete (FRC). The paper also discusses the benefits of using such FRC for construction applications and possible ways to further enhance the performance of such FRC.
788 NONSPECIFIC VAGINITIS (NSV) IS AN IMPORTANT CAUSE OF VAGINITIS IN CHILDREN

In most published studies an etiology has been defined in less than half of cases of vulvovaginitis in prepubertal girls. NSV,a synergistic infection involving Gardnerella vaginalis and anaerobic bacteria, is a common cause of vaginitis in adults, but has not been described in children. We studied 17 girls, age 2-11 yrs. (mean-5-5 yr), who presented because of vulvovaginitis; 5 of these girls were known or suspected of to have been sexually abused. Cultures were examined for bacteria, including Chlamydia trachomatis, viruses, yeasts and Trichompnas vaginalis. In addition, a vaginal wash specimen was also examined. NSV was diagnosed if the wash contained “clue cells” and gave off a fishy odor when 10% KOH was added. We were able to make a microbial diagnosis in 11/17 (65%) pts: 3 of 4 girls with NSV were successfully treated with metronidazole with reversion of the vaginal wash to normal. NSV was the most frequent identifiable cause of vaginitis in these children. The results of this study also illustrated the value of the vaginal wash specimen for the diagnosis of vaginitis in prepubertal girls.