cssi/SciSciGPT-SciSciNet huggingface dataset:
Metric variation in Afromeryx and Libycosaurus (Anthracotheriidae: Mammalia) and its utility for biochronology

In mammal groups with few genera at any one time, such as the Neogene anthracotheres of Africa, not only can dental data yield evidence of geological age, but so can postcranial evidence. In the case of Late Neogene suids, which comprised several contemporaneous genera, dental data is useful for biochronology, but only when morphological and metric data are combined. In such groups, postcranial evidence is not as valuable because it is difficult to determine with confidence to which group such bones belong. In Africa, in contrast, anthracotheres had low diversity throughout the Neogene, with usually three or fewer taxa present at most levels older than 17.5 Ma, and only one after ca 16 Ma to the end of the Late Miocene. Evidence shows that this lineage increased in size throughout its existence. The aim of this contribution is to re-examine the question of variability in the Chad sample of Libycosaurus and to compare it to collections from other African localities in order to determine whether the size differences observed are compatible with a single species (Lebatard et al., 2008) or whether they support the presence of two species in the region (Pickford, 2008a, 2008b). If two taxa occur at Toros-Menalla, then this would have implications for the biochronology of the deposits (Pickford, 2008a, 2008b) whereas if only one highly sexually dimorphic species is present, it would have implications for understanding the ecology of these anthracotheres.
The Germinal Cell, Histogenesis, and Lineages of Nerve Cells

From its inception by Wilhelm His in 1887, the conncept of subclasses of germinal cells that are the progenitors of corresponding classes of neurons and glial cells has been opposed by the concept of multipotential progenitors, put forward by Vignal (1888), Schaper (1849a, b), and Koelliker (1897). Both concepts have continued to exert powerful heuristic effects for more than a century.
Myotonic dystrophy types 1 and 2

Myotonic dystrophies (dystrophia myotonica, or DM) are inherited disorders characterized by myotonia and progressive muscle degeneration, which are variably associated with a multisystemic phenotype. To date, two types of myotonic dystrophy, type 1 (DM1) and type 2 (DM2), are known to exist; both are autosomal dominant disorders caused by expansion of an untranslated short tandem repeat DNA sequence (CTG)(n) and (CCTG)(n), respectively. These expanded repeats in DM1 and DM2 show different patterns of repeat-size instability. Phenotypes of DM1 and DM2 are similar but there are some important differences, most conspicuously in the severity of the disease (including the presence or absence of the congenital form), muscles primarily affected (distal versus proximal), involved muscle fiber types (type 1 versus type 2 fibers), and some associated multisystemic phenotypes. The pathogenic mechanism of DM1 and DM2 is thought to be mediated by the mutant RNA transcripts containing expanded CUG and CCUG repeats. Strong evidence supports the hypothesis that sequestration of muscle-blind like (MBNL) proteins by these expanded repeats leads to misregulated splicing of many gene transcripts in corroboration with the raised level of CUG-binding protein 1. However, additional mechanisms, such as changes in the chromatin structure involving CTCN-binding site and gene expression dysregulations, are emerging. Although treatment of DM1 and DM2 is currently limited to supportive therapies, new therapeutic approaches based on pathogenic mechanisms may become feasible in the near future.
Can a detector in live-time mode give a true count rate?

Count rate in the live-time mode of a nuclear detection system should ideally be directly proportional to the disintegration rate of the sample assayed. The authors examine the linearity of the relationship by measuring the deadtimes using two different detection systems. For the sodium iodide (NaI) crystal detector system, iodine-125 ({sup 125}I) was used with the two-source method and the results were confirmed by the decaying-source method in which indium-113m ({sup 113m}In) was employed. For the cadmium telluride (CdTe) semiconductor detector system, the decaying-source method and {sup 113m}In were used. In both systems, they found that nonlinearity at a high count rate could be significant.
Orthopaedic Residency: How to Get Into a Program and Succeed Once You’re There

Laith M. Jazrawi, Craig J. Della Valle, Basil Elbeshbeshy, Kenneth J. Koval, and Joseph D. Zuckerman, editors. New York: NYU—Hospital for Joint Diseases, Department of Orthopaedic Surgery; 2001. 160 pages. $20.00 (This is an in-house publication from NYU—Hospital for Joint Diseases. The information for purchasing the book can be obtained at the following e-mail address: cynthia.bastien@med.nyu.edu.) The beauty of this small book is that it was written primarily by orthopaedic residents for both medical students and residents. Eighteen of the twenty contributors are residents in the Department of Orthopaedic Surgery at New York University—Hospital for Joint Diseases. In addition, …
No species barrier by call in an avian hybrid zone between California and Gambel's quail (Callipepla californica and C. gambelii)

Acoustic signals sometimes act as premating isolating barriers between animal species, but we know little about the circumstances that dictate the presence and strength of these barriers. Among insects, barriers to backcrossing are strengthened by acoustic signals that are under genetic control. Hybrid signals tend to be intermediate to parental signals, and signals are recognized only by like-types, which results in reinforced species boundaries. This is not typically the case in avian taxa. Instead, acoustic signal transmission is controlled by some combination of genes and learning, and perhaps as a consequence of this variation, vocalizations play a diversity of roles in avian hybrid zones. I used California and Gambel's quail (Callipepla californica and C. gambelii), hybridizing birds that do not learn to vocalize, to explore whether genetically determined vocalizations function as a species barrier. Using spectral analysis, I measured temporal features of calls of uniquely colour-banded quail that were recorded across one area of the California and Gambel's quail hybrid zone. Species discrimination is known to occur under captive conditions, though its basis is unexplored. Here I show that differences in the calls of parental species are likely great enough to permit species discrimination. Hybrid call components were intermediate to those of the parental species and covaried with genetic traits, as assessed with seven highly polymorphic microsatellite loci. Contrary to expectation, males as frequently called in response to unlike- as like-type females who had initiated antiphonal calling, which is a courtship call between a female and a male. Furthermore, paired males and females did not share like-type assembly calls, nor was there a correlation between the female's genetic or plumage traits and her mate's advertisement call. Based on these results, I conclude that California and Gambel's quail recognize each other and hybrids as potential mates and backcrossing occurs frequently. Thus, compatible mating signals could contribute to increased mixing of gene pools and slow the rate of speciation. I suggest that selection to respond to wide signal variation within species and imprinting on calls of mixed-species coveys may cause mating signal compatibility between classes within the area of hybridization. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86, 253–264.
In-Home Family Therapy as a Prevention of Foster Care Placement: Clients' Opinions About Therapeutic Services

The purpose of this qualitative study was to explore clients' perceptions of the in-home family therapy services they received. The sample consisted of 20 low-income families who were at risk for having their children placed in foster care, but who had ultimately retained custody of their children. Results indicate that families view in-home family therapy as a useful intervention. They expressed appreciation for the therapists, their availability, and the support offered. Participants also stated that they wished services could have been more frequent and longer-term. Implications for researchers and practitioners are discussed.
Revealing Praxis: A Study of Professional Learning and Development as a Beginning Social Studies Teacher Educator.

This self-study reports on the professional learning and development of a beginning social studies teacher educator via an examination of the evolving relationship between the author's beliefs and practices during his first three years preparing social studies teachers. Throughout this time data were systematically collected in the form of written interpretive accounts of his experiences. An analysis of these accounts reveals how the relationship between his beliefs and practices evolved as he moved from embracing certain default assumptions about education, to rethinking the content of social studies, to recognizing that both what and how he taught as a teacher educator held potential significance in the development of preservice teachers. The implications of these stages of understanding for social studies teacher education learning and development are discussed, and avenues for further research are considered.
Intrinsic and Extrinsic Work Values and Career Maturity of 9th- and 11th-Grade Boys and Girls

Sex differences in work values and career maturity were found to a greater extent than were grade differences among 9th- and 11th-grade students. Implications for counselors are discussed.
Extracellular Matrix‐Degrading Proteinases in the Nervous System

The proteolytic activities of matrix metalloproteinases and plasminogen activators as well as their inhibitors are important in maintaining the integrity of the extracellular matrix (ECM). Cell-ECM interactions influence cell proliferation, differentiation, adhesion and migration. In the nervous system, proteolysis of the ECM is involved in neuronal cell migration in the developing cerebellum and in neurite outgrowth. Likewise, in pathological conditions such as brain tumour growth and invasion, leukocyte infiltration into brain tumours, leukocyte trafficking in the central nervous system in inflammatory diseases such as multiple sclerosis and viral encephalitis, and in nerve demyelination, matrix-degrading proteinases and their inhibitors have been implicated. An understanding of cell-ECM interactions and ECM degradation in diseases of the nervous system would provide new insight for drug design and other forms of therapy.
Absence of difference between 11B nuclear spin relaxation and Li ion conductivity relaxation in (LiCl)0.6-(Li2O)0.7-(B2O3)1.0 superionic glasses

Abstract A pronounced difference between 7 Li nuclear spin relaxation and Li ion conductivity relaxation in a superionic lithium chloroborate glass has been observed and explained theoretically by the coupling model. An extension of the theoretical ideas to spin relaxation of nuclei tied permanently to the glassy matrix indicates that the pronounced difference with conductivity relaxation found for the mobile ion nuclear spin relaxation will no longer exist. 11 B nuclear spin relaxation data in the same lithium chloroborate glass are used to support this prediction.
Multitime response functions and nonlinear spectra for model quantum dissipative systems.

Using iterative evaluation of the real-time path integral expression, we calculate four-time correlation functions for one-dimensional systems coupled to model dissipative environments. We use these correlation functions to calculate response functions relevant to third order infrared or seventh order Raman experiments for harmonic, Morse, and quadratic-quartic potentials interacting with harmonic and two-level-system dissipative baths. Our calculations reveal the role of potential features (anharmonicity and eigenvalue spectrum), both on short and long time scales, on the response function. Further, thermal excitation causes dramatic changes in the appearance of the response function, introducing symmetry with respect to the main diagonal. Finally, coupling to harmonic dissipative baths leads to decay of the response function (primarily along the τ3 direction) and a broadening of the peaks in its Fourier transform. At high temperatures two-level-system baths are less efficient in destroying coherence tha...
Can the storage capacity of memories built from unreliable components be determined

A memory is a device in which information is stored at some time and retrieved at a later time . Let the information be stored in form of bits in registers (memory elements) each of which can store a single bit. The information storage capability of a memory is the number of information bits it stores. Building a memory with information storage capability of k bits with reliable memory elements requires k registers. Such a memory is termed as an irredundant memory. This paper considers the problem of building a memory with memory elements and logic gates which fail according to a known random mechanism. The required minimum redundancy memory in which makes arbitrarily reliable information possible is discussed. For a reliable storage, the information needs to be stored in coded form . To ensure reliability, a correcting circuit is employed which performs error correction and updates the contents of the registers with an estimate of the original codeword.
Hydrogen concentration profiles in quartz determined by a nuclear reaction technique

The nuclear reaction 19F(1H, αγ) 16O has been used to determine the hydrogen concentration in natural and synthetic quartz samples. The depth-profile of the hydrogen concentration in these samples has been determined in detail for the smoky and Xo quartzes. These profiles exhibit a region of high hydrogen concentration in the near surface region (down to a depth of ∼2000A), with a lower concentration in the bulk of the sample. The results provide a plausible explanation for the substantial disagreement between previous hydrogen analysis in these quartzes by other techniques. Evidence for hydrogen mobility in crystalline quartz under ion beam bombardment is presented and discussed.
Extreme Elongation of Vesicles Under DC Electric Fields

Motive. The motivation of the current study is to investigate the response of vesicles to applied electric fields, with potential applications in electroporation-mediated molecular delivery [3]. In this technique, an applied field transiently permeabilizes the cell membrane to gain access to the cytoplasm, and deliver active agents such as genes, RNA, proteins into the cell. Although widely applied in classical and emerging areas such as drug delivery and stem cell research, current electroporation techniques suffer from low efficiency and high cell death [4]. The present work is a step towards understanding the complex fundamental processes involved in electroporation, and possibly improving it via parametric optimization. For this purpose we use vesicular cellular mimics as our model to provide good controllability, and to focus on the dynamics of the lipid membrane. Our preliminary results show extreme elongation of the vesicles under high-strength, short-duration DC pulses. Such deformation may significantly affect electroporation, and hence the efficiency of molecular delivery.Copyright © 2008 by ASME
The role of the social cost of carbon in policy

Estimates of the marginal value of carbon dioxide—the social cost of carbon (SCC)—were recently adopted by both the U.S. and U.K. Governments in order to satisfy requirements to value estimated greenhouse gas (GHG) changes of new federal regulations. However, the development and use of SCC estimates comes with significant challenges and controversial decisions. This paper summarizes the key issues and then derives guidance for developing, selecting, and applying the estimates that follows from the fundamental scientific nature and economic principles associated with GHGs and climate change, as well as an understanding of the state of the art for estimating the SCC. The paper evaluates recent estimates in light of the guidance and finds the estimates inconsistent with the guidance in a number of significant areas. The paper also differentiates SCC policy applications in terms of policies with incremental versus nonincremental implications for global GHGs, and identifies serious issues for application of the SCC in setting and evaluating climate policy targets. WIREs Clim Change 2012, 3:163–195. doi: 10.1002/wcc.163 For further resources related to this article, please visit the WIREs website.
Genetic effects of deoxyribonucleotide pool imbalances

In vivo DNA precursor imbalances can have profound genetic consequences in prokaryotes and eukaryotes. In vitro studies have demonstrated that DNA replication fidelity is dependent on correct balances of deoxyribonucleoside triphosphates during DNA synthesis. These findings suggest that intracellular concentrations of DNA precursors may be regulated in order to minimize the frequency of genetic change. In addition, they indicate the existence of important nonDNA targets for the induction of mutation, recombination, chromosome aberrations, etc. In this article, the genetic effects of deoxyribonueleotide pool imbalances are reviewed.
Interferon inhibits induction of endogenous murine leukemia virus production.

Abstract In 5-iododeoxyuridine (IUDR) induction of murine leukemia virus (MLV) in Balb cells transformed by SV40 (Balb SV40) or AKR cells, interferon inhibited virus production. This could have been due to inhibition of the X- and N-tropic virus induced or to inhibition of subsequent reinfection of the mouse cells by the N tropic virus. Cycloheximide, however, activates KBalb 3T3 cells ( Balb 3T3 cells transformed by Kirsten sarcoma virus) to produce only an X-tropic virus which could not reinfect mouse cells. In this system, interferon treatment also decreases virus yields and, therefore, an event in the virus induction process.
Female fecundity in highland Papua New Guinea

Abstract Demographers often assume that interpopulation variation in birth spacing is attributable primarily to behavioral differences (e.g., in breastfeeding, coital frequency, or contraceptive practice), and that the contribution of physiological factors is negligible. This assumption may be correct, but it should be tested, especially in light of recent evidence that there may be more variation in ovarian function among human populations than was previously believed. In this paper, we apply a stochastic model of the determinants of fecundability (the monthly probability of conception) to endocrinological data collected among the Gainj, a tribal population in highland Papua New Guinea. Based on previous research, the Gainj are known to have age patterns of ovarian function that differ markedly from the Western norms. When account is taken of the late menarche, early menopause, and long ovarian cycles that appear to characterize Gainj women, mean apparent fecundabilty across the female reproductive span ...
THE PURCHASING‐LOGISTICS INTERFACE: A “SCOPE OF RESPONSIBILITY” TAXONOMY

To date, integration research has paid little attention to defining and exploring the interface between purchasing and logistics. This research seeks to catalog the set of joint activities that define this interface, and to analyze the way in which this interface is structured, in terms of how companies assign collective responsibility across the activity set. A cluster analysis of a set of 15 boundary-spanning activities reveals a preliminary taxonomy of three purchasing-logistics interface structures: (a) Purchasing-Dominant; (b) Segregated; and (c) Logistics-Dominant. The analysis also reveals limited evidence that the choice of purchasing-logistic interface structure has an influence on supply base performance. In addition, the choice of purchasing-logistics interface structure appears to be influenced by firm size.
Effects of PCBs sorbed to algal paste and sediments on the stress protein response (HSP70 family) in the eastern oyster, Crassostrea virginica.

This study examined the stress protein response (HSP70 family) of reproductively inactive oysters fed 0.7 g algal paste containing 0, 0.35 and 3.5 μg polychlorinated biphenyls (PCBs) daily. A second set of treatment groups investigated the combined effect of PCBs and sediments (0.3 g sediments daily per oyster) on HSP70 response. After 8 weeks of PCB exposure, oyster tissues (mantle and gill) were sampled and analyzed for HSP70. Preliminary results did not show a significant effect in HSP70 response in oysters fed PCB sorbed to algal paste, albeit PCBs accumulated up to 1342 ng/g dry weight in the mantle, and up to 180 ng/g dry weight in gill tissues. However, the addition of sediments caused a significant increase in HSP70 levels of gills and mantle, although the mantle was less sensitive to the sediments.
Roundoff-induced periodicity and the correlation dimension of chaotic attractors.

Due to roundoff, digital computer simulations of orbits on chaotic attractors will always eventually become periodic. The expected period, probability distribution of periods, and expected number of periodic orbits are investigated for the case of fractal chaotic attractors. The expected period scales with roundoff \ensuremath{\epsilon} as ${\ensuremath{\epsilon}}^{\mathrm{\ensuremath{-}}d/2}$, where d is the correlation dimension of the chaotic attractor.
Analysis of errors in sampled-data feedback systems

The system error in sampled-data feedback systems resulting from the application of a test function is an important design parameter. The ?system error? is defined as the difference between the actual output of the system and the desired output. There are two components which contribute to this error: one, called ?organic error,? is brought about by the system energy storages, and the other, called ?ripple,? is brought about by the sampling process. Formulation of the system error is obtained by the application of the Laplace and z-transformations. Both the system error time function in intersampling times and the rms system error are formulated in terms of the system parameters. Illustrative examples demonstrate the theory.
Episiotomy: can its routine use be defended?

Episiotomy is routinely used before delivery in the United States. The rationale for routine episiotomy is based on two foundation arguments: that episiotomy reduces perineal trauma and that it prevents subsequent pelvic relaxation. A careful review finds little evidence to support these arguments. Episiotomy may predispose the gravid woman to third- and fourth-degree lacerations. Efforts should be directed to determine whether episiotomy is beneficial. (AM J OesTET GYNECOL 1989;160:1027-30.)
Synthesis of dirhodium(II) tetrakis[methyl 1-(3-phenylpropanoyl)-2-oxaimidazolidine-4(S)-carboxylate], Rh2(4S-MPPIM)4

Abstract The large-scale synthesis with greatly improved yields of methyl 1-(3-phenylpropanoyl)-2-oxaimidazolidine-4(S)-carboxylate and the chiral dirhodium(II) carboxamidate derived from it, Rh2(4S-MPPIM)4, is described. The key step in the overall synthesis is the Hofmann rearrangement of Boc-protected l -asparagine, the procedure for which has been modified to achieve near quantitative yield.
Rethinking political structures: from ‘ordering principles’ to ‘vertical differentiation’ – and beyond

‘Structure’ in the discipline of International Relations, for all the criticism of Kenneth Waltz’ work, still typically means the Waltzian triad of ordering principles, functional differentiation, and distribution of capabilities. I argue, however, that this triad not only does not in Waltz’ particular presentation but cannot provide an adequate account of political structures. In its place I sketch a five-part framework of the elements of political structures. Three types of structural differentiation are identified: vertical differentiation, which establishes hierarchical ranking; horizontal differentiation, which establishes non-hierarchical segmentation; and unit differentiation, which assigns certain types of actors a privileged status. Two dimensions of structural elaboration are also identified: norms and institutions and technology and geography. This framework highlights the central place of ranking in international political structures, developing a tripartite account of ‘ordering principles’ that identifies autarchic, single-hierarchic, and heterarchic systems. It also draws attention to the diversity of international orders and opens structural analysis to the concerns and contributions of constructivism.
Chronic intracortical microelectrode arrays induce non-uniform, depth-related tissue responses

Objective. Brain-implanted microelectrode arrays show promise as future clinical devices. However, biological responses to various designs, compositions and locations of these implants have not been fully characterized, and may impact the long-term functionality of these devices. In order to improve our understanding of the tissue conditions at the interface of chronic brain-implanted microdevices, we proposed utilizing advanced histology and microscopy techniques to image implanted devices and surrounding tissue intact within brain slices. We then proposed utilizing these methods to examine whether depth within the cerebral cortex affected tissue conditions around implants. Approach. Histological data was collected from rodent brain slices containing intact, intracortical microdevices four weeks after implantation surgery. Thick tissue sections containing the chronic implants were processed with fluorescent antibody labels, and imaged in an optical clearing solution using laser confocal microscopy. Main Results. Tissue surrounding microdevices exhibited two major depth-related phenomena: a non-uniform microglial coating along the device length and a dense mass of cells surrounding the implant in cerebral cortical layers I and II. Detailed views of the monocyte-derived immune cells improve our understanding of the close and complex association that immune cells have with chronic brain implants, and illuminated a possible relationship between cortical depth and the intensity of a chronic monocyte response around penetrating microdevices. The dense mass of cells contained vimentin, a protein not typically expressed highly in CNS cells, evidence that non-CNS cells likely descended down the face of the penetrating devices from the pial surface. Significance. Image data of highly non-uniform and depth-dependent biological responses along a device provides novel insight into the complexity of the tissue response to penetrating brain-implanted microdevices. The presented work also demonstrates the value of in situ histological collection of brain implants for studying the complex tissue changes that occur, and the utility of pairing thick-tissue histology with appropriate optical clearing solutions.
Regulation of citrate metabolism by cell pH in potassium-depleted rat diaphragm

Regulation of citrate metabolism by cell pH in potassium-depleted rat diaphragm. It is unknown whether metabolic changes occurring in potassium deficiency are due to altered cell pH or to decreased tissue potassium. To study this problem intact rat diaphragms were acutely potassium-depleted in vitro , cell pH was calculated using DMO distribution and the cell pH and citrate metabolism of these tissues was compared to the same measurements made in diaphragms not potassium-depleted. Potassium depletion had no significant effect on either cell pH or citrate decarboxylation when extracellular pH was 7.40. By contrast, in extracellular metabolic acidosis (pH, 6.90), cell pH was lower in potassium-depleted diaphragms, citrate decarboxylation was higher and muscle citrate concentration was reduced. However, in metabolic acidosis, when extracellular pH in diaphragms not potassium-depleted was made lower than in potassium-depleted tissue, cell pH became identical in the two groups and the differences in citrate decarboxylation and citrate concentration disappeared. Thus, at the same cell pH, citrate metabolism in muscle was identical despite marked differences in tissue potassium. These experiments indicate that the changes in muscle citrate metabolism found in potassium depletion are due to potassium-induced changes in cell pH and are not due to the lower tissue potassium concentration itself.
Brachytherapy for the interventional cardiologist and vascular surgeon.

Abstract Purpose. There has been recent interest in the use of brachytherapy for the possible prevention of restenosis after angioplasty. However, this field is unfamiliar to most interventional cardiologists. This article is meant to serve as an introduction to the principles of brachytherapy especially as it applies to intravascular brachytherapy. Because the intended audience is the interventional cardiologist, the details of physics, radiobiology, and radiation jargon has been kept at a minimum. Methods. The main advantages of brachytherapy are that it can irradiate small volumes and conform to the target volume while sparing the surrounding normal tissues from the deleterious effects of irradiation. Various gamma- or beta-emitting radioisotopes can deliver the brachytherapy dose. In general, the beta emitters have fewer radiation exposure hazards, but the limited penetration of beta emitters can be a problem if deeper tissues need to be irradiated. Gamma sources can irradiate deeper but suffer from greater radiation exposure hazards. It should be remembered that the biological effects of radiation depend on a number of parameters, including the radiation modality, dose, dose rate, fractionation, treatment duration, dose prescription point, and the volume irradiated. The use of low energy isotopes, beta emitters, and remote-controlled afterloading has reduced the radiation exposure to the medical caregivers. Conclusion. Intravascular brachytherapy is currently considered to be experimental. Those wishing to start a new intravascular brachytherapy program should comply with the required federal and state regulatory guidelines issued by the Nuclear Regulatory Commission, Food and Drug Administration, and their individual Institutional Review Board.
An analysis of scanning postures among grocery cashiers and its relationship to checkstand design

Mounting evidence suggests that musculoskeletal disorders are prevalent among US retail food workers. Cashiers who use electronic scanners appear to be at especially high risk for upper extremity musculoskeletal disorders. Checkstand design has been implicated as a contributor to musculoskeletal injury among cashiers because workstation design can significantly impact working posture. The present study examines working posture among two groups of cashiers to determine if checkstand design is associated with substantial differences in posture and movement during scanning. The work activities of twenty grocery cashiers using one of two checkstand designs (front-facing and right-hand takeaway) were examined. Videotapes of cashiers performing scanning tasks were observed and associated postures and movements were visually coded. The right-hand takeaway design was associated with a significantly higher percentage of non-neutral trunk postures than the front-facing design. However, there were no significant differences in shoulder posture, grasp, or scanning motion associated with checkstand/scanner design. Factors that appeared to affect cashier work posture during scanning included stature, order size, and product type. Although improving the checkstand design may reduce the occurrence of certain awkward postures and static muscle loading conditions among cashiers, the success of these interventions is likely to be limited unless follow-up programmes are instituted to ensure that cashiers are able to use these designs effectively. Furthermore, fundamental changes in cashier work may be required to fully eliminate hazards for musculoskeletal disorders from this job.
Physician support for covering the uninsured: is the cup half empty or half full?

In this issue, Ackermann and Carroll report that a plurality of a nationwide sample of physicians supports national health insurance in one form or another. Whether this support is sufficient to mo...
Dialogic Process and Psychological Assessment: A Case Study.

Abstract The recenl movement locating community mental health services within urban schools signals an enhanced role for school professionals in caring for youth, and presents opportunities for furthering the connections between children, schools and communities. When psychological services are located in schools, opportunities to challenge the borders which traditionally exist between education and psychology are created. Location, however, does not guarantee that these connections will be made, or that the divide between education and psychology, bridged. Psychological assessment especially, which continues to be the primary function of psychologists in urban schools, has traditionally taken place outside of the contexts in which children live. It has historically been viewed as a shorthand for learning about people, offering a quicker and more efficient methodology than in-depth interviewing. As education increasingly turns towards reconceptual-izing learning and school practices as meaning making acti...
High-Temperature-Aging-Induced Encapsulation of Metal Particles by Support Materials: Comparative Results for Pt, Pd, and Rh on Cerium–Zirconium Mixed Oxides

Abstract High-temperature-aging-induced deep encapsulation of metal particles by the support material in supported-metal catalysts, recently observed in ceria–zirconia-supported Pd catalysts, is also found in comparable Rh catalysts but not Pt catalysts. Aging temperature and Pd loading thresholds to encapsulation are compared for supported Pd catalysts made from ceria–zirconia of varying surface area stability and composition.
Multi-turn, tension-stiffening catheter navigation system

In poorly constrained extra-vascular environments such as hollow viscera, current catheter navigation techniques are restricted to simple paths and therefore limit a doctor's ability to position the catheter. This paper presents a new catheter positioning system that enables faster and more accurate catheter placement, with fewer scans. The proposed robotic catheter navigation system can execute curved paths and maintain any number of three-dimensional turns using tension stiffening guide-wires composed of a set of disposable friction-locking beads. An external, reusable control system is used to automate the movement of the catheter. This control system uses a custom-designed graphical kinematic analysis program that predicts contact forces, changes in conformation due to external forces, tip deflection and failure modes of the catheter as it advances.
13C-Isotopic Enrichment of Glutathione in Cell Extracts Determined by Nuclear Magnetic Resonance Spectroscopy

An NMR method was developed for measuring the isotopic enrichment of glutathione in extracts of cells fed a medium containing [3, 3'-13C2]cystine. Two sublines of human mammary adenocarcinoma MCF-7 cells were exposed to growth medium containing the labeled cystine for varying periods, treated with monobromobimane, harvested, and extracted with perchloric acid. The glutathione-bimane adduct was partially purified by solid-phase extraction before analysis by 1H NMR spectroscopy. The isotopic enrichment of the beta-carbon of the cysteinyl residue of glutathione was determined directly in the cell extracts without further purification. These isotopic enrichment data can be used to determine the rate of synthesis of glutathione in cell and tissue extracts.
Constructing Battlefield Understanding: A Comparison of Experienced and Novice Decision Makers in Different Contexts:

Understanding the evolving, complex events on a battlefield requires a decision maker to gather and integrate data from disparate sources. The work described herein is the final in a series of studies that investigates the decision making processes employed by military decision makers. Twenty-one Army officers participated in a simulation of an offensive military operation. The results of this study are compared to the results of three previous studies involving participants with differing levels of expertise (experienced versus novice) and using different types of scenarios (defense versus offense). Results strongly suggest that performance of military decision makers varies based on levels of experience and the data they gather vary according to context. Implications for design of decision support systems are also discussed.
The prevention of cataract caused by oxidative stress in cultured rat lenses. II. Early effects of photochemical stress and recovery.

Previous work has demonstrated that photochemically induced oxidative stress generated with 4 μM riboflavin in a 4% oxygen atmosphere utilizing daylight type radiation is capable of causing cataract in cultured rat lenses. Such cataract is prevented by the GSH peroxidase type mimic, AL-3823A. Examination of the early stages of cataract formation produced by short-term oxidative stress and recovery is now reported. A 24-hr oxidative stress, under the above conditions, causes loss of transparency, particularly in the equatorial region, increased hydration, loss of glyceraldehyde-3-PO4 dehydrogenase activity, oxidation of non-protein thiol and a decrease in 86 Rb and [14C]choline uptake and ATP levels. Examination of recovery of these parameters during a 72-hr period indicates, in most cases, little or no reversal of oxidative damage. Hydration and loss of non-protein thiol continued during the recovery period. The presence of AL-3823A during the stress period prevented change in all parameters. Transport systems appear to be particularly vulnerable to this type of oxidative stress losing 50% or more activity within 4 hr. Even after a 2-hr stress, choline transport did not recover even though, under these conditions, ATP levels had only decreased slightly. Cytosolic components such as non-protein thiol and glyceraldehyde-3-PO4 dehydrogenase also showed little change after a 4-hr insult. 86Rb efflux experiments indicated no change in permeability during a 24-hr stress period. The overall conclusion from these studies is that a 24-hr oxidative stress which appears to reflect physiological conditions existing during cataract development, causes extensive, irreversible damage. In some cases, the extent of the damage is not apparent until some time later. Repair is minimal during a 3-day post-insult period.
The New Electromechanics Laboratory at Stanford

This paper describes the new electromechanics laboratory facilities at Stanford and the philosophy governing the teaching approach to the laboratory course. A typical experiment is described to illustrate how a relatively simple electromechanical device can be used to maximize student learning in the laboratory.
Long-term relative stability of thermistors

Abstract The relative stability of four glass-bead thermistors has been analyzed for 44 months to determine if thermistors have sufficient relative stability to be used as feedback sensors for milliKelvin levels of temperature control. The thermistors were measured at 20 ± 0.1 °C using commercial two-wire instrumentation. The thermistors have a nominal resistance of 12.5 kΩ and sensitivity of −4.5%/°C at 20°C. They are nested together inside several layers of thermal resistance and capacitance, which are held at nominal 20°C with a temperature-controlled, recirculating air chamber. After correction for instrumentation drift with two high-stability reference resistors, the average relative rms drift of the thermistors is 50 ± 15 μK, with an rms fitted drift rate of 0.26 ± 0.16 μK/week.
Nonoperative Management of Scleroderma of the Hand With Tadalafil and Subatmospheric Pressure Wound Therapy: Case Report

Scleroderma, or systemic sclerosis (SS), is an autoimmune disease leading to ischemic fibrosis and widespread collagen deposition, invariably affecting the hands. Optimized medical management remains the mainstay of therapy for SS. Surgery can be considered in refractory or severely disabling cases. However, microvascular insufficiency and fibrosis can lead to wound complications and, ultimately, amputation. We present the case of a 61-year-old man with a known history of scleroderma who presented with pain, chronic infection, and ulcerations in the left hand. Initially, amputation seemed a reasonable intervention. After medical optimization with tadalafil, his ulcerations persisted. Instead of amputation, we applied a subatmospheric pressure wound therapy device to his hand. In 4 months, his wounds had healed, there was no evidence of infection, and no digits were amputated.
Stimulation of RNA synthesis in developing frog embryos by microinjection of ribosomes

Oocyte ribosomes stimulate H3–5–uridine incorporation into RNA when microinjected into the vegetal cells of early cleavage embryos. Preparations with a low percentage of monosomes, such as those of swimming larvae and adult frog liver, give little stimulation. E. coli ribosomes fail to affect RNA synthesis. Short term labeling experiments at the gastrula stage in which only nuclear RNA was labeled suggest that added ribosomes may increase nuclear transcription and not cytoplasmic conservation of D-RNA in polysomes.
A Computational Study of Charge Delocalization and Ring Fluoro Substituent Effects in 4-Fluoromethylphenoxides

The degree of charge delocalization in 4-fluoromethylphenoxide anions has been investigated with ab initio molecular orbital calculations at the Hartree-Fock and MP2 levels and with the B3LYP density functional using the 6-31+G(d) and 6-311+G(2d,p) basis sets. The effect of aqueous solvation on the rotational profiles has been investigated using the AM1-SM2 solvation model. These anions serve as model systems for fluorinated tyrosine derivatives, which have been used as substrates for the enzyme tyrosine phenol-lyase. The importance of the double-bond/no-bond resonance structure has been assessed through an analysis of conformational profiles, geometries and charge distribution. The effect of ring fluorination on the degree of charge delocalization was investigated to aid in the interpretation of previous experimental mechanistic studies of the tyrosine phenol-lyase enzyme. Calculations were also carried out on benzyl fluoride, and the inclusion of diffuse functions was found to result in the perpendicular conformation as the predicted lowest-energy conformation by a small margin. Previous studies with smaller basis sets found the planar structure to be the lowest-energy conformation. The results indicate that the placement of an electron-donating group (O(-)) in the para ring position acts to increase the fluoride character of the fluoromethyl group and that this effect is not substantially modulated by the placement of fluorines on the ring.
Effect of setting conditions on mineral trioxide aggregate flexural strength.

This study evaluated the effect of setting conditions (time and hydration) on mineral trioxide aggregate (MTA) flexural strength. MTA beam specimens were allowed to set for either 24 or 72 hours with specimens exposed to moisture on either one or two specimen surfaces. These moisture conditions were used to simulate MTA setting with only external tissue moisture (one-sided moisture) versus tissue moisture in combination with a moistened intracanal cotton pellet (two-sided moisture). Ten specimens were stored at 37 degrees C under each of the four experimental setting conditions (1) 24-hour/moist/2-sided; (2) 24-hour/moist/1-sided; (3) 72-hour/moist/2-sided; (4) 72-hour/moist/1-sided. After storage at respective setting conditions, MTA specimens were tested to failure with three-point bend test to measure flexural strength. Flexural strength of the 24h/moist/2-sided specimens, 14.27 +/- 1.96 MPa, was significantly higher (p 0.05). Clinically, these results suggest that a moistened cotton pellet should be placed on the intracanal MTA surface under a temporary restoration; and if possible, to optimize flexural strength, the moistened pellet should only remain in place for 24 hours.
Regulation of the cerebral circulation by cytochrome P450 epoxygenase activity

Abstract Cytochrome P450 epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which can dilate cerebral vessels. In glial cell cultures, glutamate stimulates the release of EETs. Thus, an astrocyte-based epoxygenase pathway could form a link in the coupling of blood flow to neuronal activity. To test this hypothesis, neuronal activation was produced by mechanical displacement of the whiskers of anesthetized rats while monitoring red cell flux by laser-Doppler flowmetry over whisker barrel sensory cortex. N-methylsulfonyl-6-(2-propargyloxyphenol) hexanamide (MS-PPOH) or miconazole, two different types of P450 epoxygenase inhibitors, were superfused over the cortical surface in different groups of rats. Both inhibitors markedly reduced the increase in cortical perfusion during whisker stimulation. To test the effect of these inhibitors on the increase in blood flow evoked by N-methyl- d -aspartate (NMDA), drugs were delivered via microdialysis probes in the striatum, while local blood flow was measured by the hydrogen clearance technique. Both MS-PPOH and miconazole blocked the increase in striatal blood flow during microdialysis perfusion of NMDA. These results support a role for P450 epoxygenase activity in the coupling of cortical blood flow to whisker stimulation and to pharmacological activation of NMDA receptors in striatum.
Driving on Mars with RSVP

The rover sequencing and visualization program (RSVP) suite of tools has been a critical factor in the success of the Mars exploration rover (MER) missions. It would be impossible to prepare the large command loads each sol without the capabilities that it possesses. It has proven to be robust and easy to use and capable of answering key questions about sequence validity and constraints. Certainly, training is required to use RSVP, but this is primarily in the general area of command sequencing and rover operations. Once these concepts are understood, RSVP feels natural for building sequences. RSVP has met its prime requirements of supporting rapid assimilation and understanding of the terrain and operational constraints, rapid sequence generation and validation, and production of documentation and archival products. This can be seen in the very limited number of sols lost due to errors in the command sequences. The success of the MER mission and the tremendous amount of science data collected attest to the capability of RSVP