cssi/SciSciGPT-SciSciNet huggingface dataset:
New Insight on the Unusually High Ionic Mobility in Chevrel Phases

Chevrel Phases (CPs), MxMo6T8 (M = metal, T = S, Se) are unique materials, which allow for a fast and reversible insertion of various cations at RT. Earlier, CPs were divided into two major types: type I with large immobile cations, which block any ionic transport in the diffusion channels, and type II with small mobile cations. Our analysis of available experimental data shows that the transport behavior in CPs cannot be understood in the framework of the blocking concept; it is much more complex and includes: (i) apparent immobility of the large M cations like Pb2+, Sn2+, Ag+ in the ternary phases, MMo6T8; (ii) coupled M + M′ diffusion in the quaternary phases, MxM′yMo6T8, where both large and small cations can assist; (iii) cation trapping in the Mg−Mo6S8, Cd−Mo6S8, and Na−Mo6T8 systems; (iv) a combination of low and high rate diffusion kinetics at the first and last intercalation stages, respectively, for the Cu−Mo6S8, Mn−Mo6S8, and Cd−Mo6Se8 systems; and (v) a fast ionic transport for small cations l...
First Report of Pythium myriotylum in a Tobacco Seedling Float System in South Carolina

Float bay production of seedlings accounts for approximately 62% of tobacco (Nicotiana tabacum L.) transplant production in South Carolina. Float systems utilize styrofoam trays containing soilless media that float in plastic-lined bays filled with nutrient solution. Oomycete fungi with motile zoospores, such as Pythium spp., can devastate plants grown hydroponically (3). This poses a serious concern for growers because no fungicides are labeled for control of Pythium spp. in nutrient solutions for tobacco greenhouse float systems. In May 1996, Pythium myriotylum Drechs. was recovered from diseased seedlings produced in float bays in Walterboro, SC. The pathogen was isolated on PAR selective medium (2). Koch's postulates were fulfilled by inoculating plants in an experimental float bay and then reisolating the pathogen on PAR from symptomatic plants. Diseased plants appeared chlorotic and stunted, with water-soaked lesions on the stem. Root systems were severely necrotic and infected plants could not be u...
Assessment of potential residues in foods derived from animals exposed to TCDD-contaminated soil

Abstract Animal management systems and food consumption patterns are important factors affecting levels of human exposure to 2,3,7,8-dibenzo- p -dioxin (TCDD) in soil through foods of animal origin. Food residues are maximized when animals have direct access to contaminated soil and human intake is maximized when foods are consumed on farms where they were produced. Projected exposures may vary by several orders of magnitude depending on the values assumed for these factors.
The actors behind the curtain: Representation of women faculty in community college institutional decision making

This chapter presents findings from a study of faculty governance in community colleges, focusing on involvement, perceptions, and experiences of faculty with an emphasis on the differences between men and women faculty.
Compliance as Affected by Task Difficulty and Order of Tasks

Summary The foot-in-the-door (“foot”) and the door-in-the-face (“face”) are two procedures for increasing compliance. In the “foot” procedure, an individual is first asked to comply with a small task and this is followed by a second harder task, the one actually desired. In the “face” procedure, an individual is first asked to comply with an extremely hard task and this is followed by a less difficult task, the one actually desired. The current study examined the effectiveness of these two compliance procedures, varying the order and difficulty level of the tasks. One hundred forty-four persons randomly selected from the telephone directory were called and asked to help a new radio station by carrying out two tasks. The difficulty of each task varied from easy, medium, and hard. All combinations of difficulty levels of the two tasks were employed, and compliance for the second task was measured. The results showed that the “foot” was superior to the “face” for increasing compliance. The most effective pro...
Low crustal velocities and mantle lithospheric variations in southern Tibet from regional Pnl waveforms

We report low average crustal P-wave velocities (5.9–6.1 km/s, Poisson's ratio 0.23-0.27, thickness 68–76 km) in southern Tibet from modelling regional Pnl waveforms recorded by the 1991–1992 Tibetan Plateau Experiment. We also find that the mantle lithosphere beneath the Indus-Tsangpo Suture and the Lhasa Terrane is shield-like (Pn velocity 8.20–8.25 km/s, lid thickness 80–140 km, positive velocity gradient 0.0015–0.0025 s−1). Analysis of relative Pn travel time residuals requires a decrease in the mantle velocities beneath the northern Lhasa Terrane, the Banggong-Nujiang Suture and the southern Qiangtang Terrane. Tectonic and petrologic considerations suggest that low bulk crustal velocities could result from a thick (50–60 km) felsic upper crust with vertically limited and laterally pervasive partial melt. These results are consistent with underthrusting of Indian Shield lithosphere beneath the Tibetan Plateau to at least the central Lhasa Terrane.
Multiwalled carbon nanotube-based aromatic hydrocarbon sensor using electronic dipole spectroscopy

A novel electronic spectroscopy technique based on dipole-dipole interactions for the identification of chemical analytes has been developed. This technique is based on the measurement of the charge transfer of chemical analytes to a multiwalled carbon nanotube mat-based sensing system. This technique was used for the identification of three aromatic hydrocarbons, namely, benzene, toluene, and xylene, at 100 parts-per-billion concentration. This technique was evaluated with multiwalled carbon nanotube mats for rapid, reliable, and robust identification of the three chemicals that belong to the same genre. The technique involves the identification of electronic spectral signatures of these chemicals using frequency domain analysis of the voltage signals generated by the binding of the chemical analytes onto the multiwalled carbon nanotube mat surfaces. This technique has the potential for rapid and accurate identification of multiple chemical analytes in a multiplexed fashion using a single-sensor device. ...
The relationship between serum vascular endothelial growth factor, persistent disease, and survival at second-look laparotomy in ovarian cancer

Abstract Objective . To assess if the angiogenic factors vascular endothelial growth factor (VEGF) and D-dimer are predictive of persistent disease, early relapse, and survival in patients with ovarian cancer who achieve a complete clinical remission after first-line chemotherapy. Methods . Serum levels of VEGF and D-dimer were assessed by ELISA in 62 patients who completed first-line chemotherapy and underwent second-look laparotomy at Duke University Medical Center. Cox Proportional Hazards Modeling was utilized to determine if VEGF and/or D-dimer levels could predict disease-free and overall survival. The Kaplan–Meier method was used to estimate median survival. The Wilcoxon test was used to determine if a significant difference existed in median VEGF and D-dimer levels between patients with positive and negative second-look operations. Results . Forty (65%) of the 62 women who underwent second-look laparotomy had persistent disease. The median VEGF levels were 264 pg/ml (range 109–896 pg/ml) in the group with negative second looks compared to 390 pg/ml (range 99–1011 pg/ml) in those with positive second-looks ( P = 0.1). High levels of VEGF were marginally associated with the presence of persistent ( P = 0.10) and gross ( P = 0.07) disease at the time of second look laparotomy. After adjusting for CA125, women with high VEGF serum levels had a worse overall survival ( P = 0.004). Conclusions . This study suggests that serum VEGF may be a clinically important marker for persistent disease and is predictive of survival in ovarian cancer patients after first-line chemotherapy.
Analysis of low-molecular weight radiolysis products in extracts of gamma-irradiated polymers by gas chromatography and high-performance liquid chromatography

Abstract Estimating exposure to radiolysis products of polymers is an important part of the regulatory evaluation of packaging materials for use in food irradiation. However, as Koni Grob recently put it, the comprehensive analysis of migrants is a challenge. This paper discusses some of the analytical difficulties and presents results obtained with extracts of irradiated polystyrene and polyamide-6. The results indicate that headspace or thermal desorption techniques may, in some instances, lead to an overestimation of radiolysis product concentrations. It is concluded that validated analytical methods and a better understanding of the underlying radiation chemistry would greatly facilitate the safety assessment of irradiated packaging materials.
Field Trial Results of a Drilling Advisory System

Field tests of a real-time Drilling Advisory System (DAS) have demonstrated value in several drill well surveillance applications. This system receives drilling data and transmits recommended operating parameters to the driller using existing rig systems and Wellsite Information Transfer Specification (WITS) data records. Using this industry standard, DAS can be deployed to any suitable data acquisition system on the diverse rig equipment available in the industry. The DAS computer may also be connected to a company network to enable desktop viewing of the drilling recommendations in the office. The method embodied in the software comprises both a learning mode and an application mode. In learning mode, systematic changes in parameters are recommended to explore the operating space, and calculation of an objective function determines results. Complex decisions to change operating parameters such as weight on bit, rotary speed, and flow rate can also be made with the assistance of DAS via early detection of drilling dysfunctions which change with depth and formation. The operator’s ROP (Rate of Penetration) management process is focused on MSE (Mechanical Specific Energy) surveillance, and the DAS process extends this methodology to a real-time operating system. DAS is designed to assist the driller by capturing and organizing real-time data without imposing on their judgment and control. It is intended to be a digital helper that enhances the driller’s ability to interpret current drilling conditions and make effective decisions. Remote access capabilities and customized output to the driller’s display were demonstrated in field trials, and key lessons from field trials have been implemented. The field trials included multiple hole sections in onshore and offshore wells across a wide variety of drilling conditions. In one example provided in this paper, the use of DAS provided 35% higher ROP when DAS was used to avoid drilling dysfunctions.
Renal resistance in essential hypertension; relation to the effect of sympathectomy on blood pressure.

ConclusionA relation of the preoperative renal resistance to the postoperative blood pressure has been demonstrated in patients with hypertension subjected to sympathectomy. A complete test of the reliability of this relation in predicting the result of sympathectomy requires additional data.
Palaeoclimates in central and south America since 18,000 BP based on pollen and lake-level records

Abstract The last 18 ka of palaeoclimates are discussed at 3 ka intervals based on palaeoenvironmental changes shown in pollen and lake level records from Central and South America. A total of 61 pollen records fulfill the requirements of continuity and chronology to be used in this synthesis: 8 records from tropical and subtropical lowlands in Central and South America; 7 records from the Central American Highlands; 26 records from the High Andes, north and south of the equator; 2 records from the southern subtropics; and 18 from the southern Andes and subantarctic islands. Palaeoclimatic interpretation of the pollen records is semiquantitative, based on bioclimatic parameters such as e.g. elevational temperature gradients or latitudinal precipitation gradients that can be related to vegetation zonation. Additional palaeoclimatic information is obtained from lake-level records, derived either from dated shorelines, or from the limnological history of lake sediment sections. Large-scale palaeoclimatic comparison of the proxy data records indicates that full- and late-glacial climates throughout Central and South America were cooler than today, by about 4 to 5°C, but that moisture patterns showed regional differentiation. Thus, in both the southern subtropics and high latitudes in southern Chile, conditions were substantially moister than today during full- and late-glacial times, whereas everywhere else conditions were far drier than today. In terms of palaeocirculation, this scenario can be interpreted as a poleward shift of the subtropical as well as the westerly circulation, a scenario that has been suggested by palaeoclimatic simulations from general circulation models (GCM). Another major palaeoclimatic aspect predicted by the GCM simulations is the suppressed early Holocene summer monsoon in the southern subtropics. Although proxy records are few from this zone, their palaeoenvironmental history during that time shows a period of aridity that would support the model. One of the most controversial aspects of South American palaeoclimates concerns the existence of a Younger Dryas equivalent, a cold period between 11 and 10 ka BP. Based on the existing data from South America, that show a great diversity of palaeoclimatic trends, the concept of an interval that is characterized by the same climatic signal as documented for the North Atlantic seems too simplistic. Moreover, at this point, only very few records have been analysed in sufficient detail to yield unambiguous climatic information for the interval in question. The principal outcome of this palaeoenvironmental and palaeoclimatic synthesis is the better understanding of the type and quality of data available at present, and the realization of regions and periods where much more and concerted effort is needed to address problems of intra- and interhemispheric palaeoclimatic correlations. Only then can questions concerning the mechanism of climatic change be tackled successfully.
Exploring patterns of environmental injustice in the Global South: Maquiladoras in Ciudad Juárez, Mexico

Decades of research in countries of the Global North have revealed distinct environmental injustices whereby industrial hazards tend to be located in poor and minority neighborhoods; few studies have investigated similar relationships between humans and hazards in the Global South. This study uses conventional quantitative environmental justice methodology to investigate spatial relationships between residential socio-demographics and maquiladoras (i.e., final assembly plants) in Ciudad Juarez, Mexico. When predicting maquiladora density using percent children and social class in a spatial error regression model, we find that percent children was a positive and significant predictor, while social class was not significant. Adding formal residential development to the model, social class becomes a negative and significant predictor. Formal residential development and percent children are also positive and significant. As is the case in the Global North, relationships between neighborhood characteristics and transnationally operated maquiladoras along the northern border of Mexico are linked to urban development.
Scouts in hyperspace

Abstract A one-person, checkers-like pegboard game in n -space is described. The goal of the game is to advance a peg as far as possible from an initial configuration of pegs. Using an argument based on the golden mean, we demonstrate bounds for how far a peg can travel as well as how many pegs are needed to achieve a particular goal. Finally, the game is viewed as automata moving about so as to achieve their collective goal.
Measurement of Maternal-Infant Interaction

Evaluating the quality of the maternal-infant relationship is a challenge to researchers and clinicians interested in infant development and quality of early parenting. The purpose of this article is to describe and critique commonly used measures of maternal-infant interaction to assist researchers in making informed decisions about measuring this variable. The measures reviewed are valuable approaches to assessment of parent-child interaction for research; several are adaptable for clinical use as well. In selecting the most appropriate measure for a particular study, investigators are encouraged to consider the conceptual model on which the instrument is based, accessibility of training, extent of previous use, evidence of reliability and validity, and specific requirements for equipment, specialized laboratory setting, administration, and scoring. Using maternal-infant interaction measures that are appropriate for clinical practice could assist psychiatric-mental health nurses and other mental health ...
A morphometric investigation of the duodenal mucosa of normal, vitamin D-deficient, and vitamin D-replete rats

Light and electron microscopy were utilized to determine differences in morphology and size in duodenal villi and microvilli from normal, vitamin D-deficient, and vitamin D-replete rats. An increase in villus diameter and surface area was observed in vitamin D-deficient rats. Administration of vitamin D reversed the increase in diameter but the height of villi increased resulting in longer, thinner villi without a significant change in surface area. A decrease in microvillus surface area seen in vitamin D-deficient animals was reversed by the administration of vitamin D.
Development of first-generation schizonts of Eimeria bovis in cultured bovine cells.

SYNOPSIS. Monolayer primary and secondary cultures of embryonic bovine kidney, spleen, intestinal and testicle cells, and secondary cultures of embryonic bovine thymus, maintained in lactalbumin hydrolysate, Earle's balanced salt solution and ovine serum were observed for a maximum of 21 days after inoculation of E. bovis sporozoites. The sporozoites entered the cells in all of these cultures but underwent development only in primary cultures of kidney and intestinal cells and in secondary cultures of kidney, spleen, thymus, intestinal, and testicle cells. In acellular media, the sporozoites retained motility no longer than 21 hr. In the cell cultures, free motile sporozoites were seen for as long as 18 days after inoculation. Sporozoites entered cells anterior end first; the process of penetration required a few seconds to about a minute. Sporozoites were also observed leaving host cells. Intracellular sporozoites were first seen 3 min after inoculation; they were observed at various intervals up to 18 days after inoculation. In transformation of sporozoites into trophozoites a marked change in size and appearance of the nucleus took place before the change in shape of the body occurred. Trophozoites were first found 7 days after inoculation, multinucleate schizonts after 8 days, and schizonts with merozoites after 14 days. Schizonts containing merozoites were seen only in kidney, spleen, and thymus cells. The mature schizonts were smaller and represented a much lower proportion of the total number than in comparable stages of infections in calves. Schizonts with many nuclei occurred in intestinal cells; the most advanced stage seen in testicle cells was the binucleate schizont. Nuclear and cytoplasmic changes were observed in the infected cells.
High resolution accurate mass measurements of FAB-generated ions by use of peak matching and multichannel analyzer techniques.

Abstract Accurate mass measurement at a resolution of 10,000 has been performed with very small ion currents generated by fast atom bombardment ionization. With the use of a peak matching unit to switch accelerating voltage and a multi-channel analyzer to acquire the data, determination of exact mass can be routinely made with less than 5 ppm error on ion currents of insufficient intensity for accurate peak matching in the conventional mode. Glycerol cluster ions generated during the FAB experiment are suitable mass references. Calibration of the peak matching unit voltage offset allows the use of a single reference mass for exact mass calculation.
Roadblocks to the Implementation of Biotreatment Strategies

The Department of Defense (DoD) has over 21,000 contaminated sites requiring some form of remediation. Contaminants on these sites include explosive compounds (i.e., TNT, RDX, HMX), chlorinated solvents (i.e., PCE, TCE, TCA), polycyclic aromatic hydrocarbons (i.e., benzo-a-pyrene), and polychlorinated biphenyls (i.e., aroclors). Current technology has centered around incineration, air stripping, and the use of activated carbon. Frequently, this technology is not cost effective nor publicly acceptable. Biotreatment offers a possible alternative. Biotreatment can cost effectively eliminate contaminants and avoid the use of harsh chemicals and physical treatments. However, special care must be employed to ensure that the proper remediation system is designed and engineered to optimize clean-up and minimize costs. Unfortunately, not all bioremediation efforts have been successful. In an attempt to develop bioremediation technology from the flask (bench scale) to the field (full-scale design), many scientists and engineers have failed to understand the phenomena that influence bioremediation. Issues such as additional mass transport mechanisms/limitations, the presence of multiple phases, spatial heterogeneities, and unfavorable factors for bacterial growth represent only a few of the phenomena that can limit or complicate biodegradation. Successful bioremediation requires a complete examination of the phenomena that can be observed as the scientist and engineer progress together from the bench to the field. An excellent way to examine these phenomena is by using the conceptual scales of observation: microscale, mesoscale, and macroscale. The microscale represents the level at which chemical/microbial species and reactions can be characterized independently of any transport phenomena. These activities are those occurring at the microbial cell level and generally are the focus of bench level work. The mesoscale is the level at which transport phenomena and system geometry are first apparent, with the exclusion of advective or mixing processes. This scale represents those activities that occur at the pore channel, soil particle or microbial aggregate level. The macroscale is the scale at which you have the ability to discern advective or mixing phenomena. These activities are generally associated on a site level and are the focus of the design engineer. The critical path as bioremediation technology is developed from flask to field is to observe and understand the phenomena that exert influence at each scale of observation so that its effects can be incorporated into the final remediation design.
NPY messenger RNA is increased in medial hypothalamus of anorectic tumor-bearing rats

Previous investigations suggest that neuropeptide Y (NPY) feeding mechanisms and corticotropin releasing factor (CRF) are altered in anorectic tumor-bearing (TB) rats. To better determine the relationship of NPY and CRF synthesis to cancer anorexia we measured mRNA for these peptides in medial and lateral hypothalamus of TB and control rats. NPY and CRF mRNA were reliably detected by Northern blot analysis only in medial hypothalamus, where NPY message was elevated significantly in TB rats. CRF mRNA tended to be reduced in both pair-fed (PF) and TB rats, but did not reach statistical significance. Concentrations of NPY or CRF were not altered significantly in either the lateral or medial hypothalamus of TB or PF rats. These results suggest that the transcription of NPY is elevated in PF rats and is increased further in anorectic TB rats. The lack of significant increases in levels of peptides may be related to dilution, due to measuring a relatively large block of hypothalamic tissue. Alternatively, translation of the signal for NPY production may be inhibited, or degradation of peptide levels may be increased.
Photodissociation dynamics of the isomers phenyl cyanide and phenyl isocyanide

Abstract Phenyl isocyanide has about 1 eV more internal energy than phenyl cyanide (benzonitrile). At 193 nm the isomeric molecules are photodissociated into the same pair of radicals phenyl and cyanogen. The translational and internal state distribution of the CN radicals are very similar so that the bulk of the additional energy of the isocyanide appears in the phenyl ring. The dissociation is shown by several arguments to take place on a localized repulsive triplet surface. The lack of strong rotational excitation of the CN radicals shows that they are ejected more or less along the long axis of the molecule.
POLYMERIC MATERIALS FOR NON-LINEAR OPTICS AND PHOTONICS

Abstract The third-order non-linear optical effect providing mechanisms for light control by light is expected to play a major role in the future technology of photonics. Conjugated polymers have emerged as an important class of third-order non-linear optical materials. This paper reviews basic concepts of non-linear optical effects in polymeric materials. Then results from experimental measurements of third-order non-linear optical processes in some representative polymeric structures are presented. These results have been obtained using the state-of-the-art femtosecond time-resolved degenerate four-wave mixing, optical Kerr gate and transient absorption techniques. Experimental studies of optical non-linearities in polymeric waveguides are also described. The paper concludes with a discussion of relevant issues and opportunities in this field for polymer scientists.
Data Analysis for Unsteady Turbulence Measurements over Airfoils

Studies of unsteady flows about pitching airfoils and flows with unsteady freestream components require a consistent method of nonstationary data analysis for proper characterization of unsteady turbulent behavior. A method has been developed for data analysis of flows composed of high-frequenc y turbulence fluctuations superimposed upon a time-dependent low-frequency component or ensemble-averaged mean velocity with the goal of establishing a consistent method for the presentation of results from varying tests and flow situations. A nonstationary mean was determined by ensemble-aver aging and frequency-domain low-pass filtering. Turbulence intensities were calculated based on a local mean using frequency-domain low-pass filtering methods. A nonstationary power spectral density estimator was developed to estimate the time-varying spectral characteristics of a turbulent boundary layer subjected to an unsteady freestream disturbance. A discussion concerning the choice of cutoff frequencies and digital filters is included.
Sexual dichromatism in the marbled salamander, Ambystoma opacum

Reports of sexual dichromatism in salamanders are rare and have been generally restricted to a few species in the families Hynobiidae and Salamandridae. We used image analysis techniques to examine...
Recent advances in understanding structure-function relationships in the type II topoisomerase mechanism.

DNA topos (topoisomerases) are complex, multisubunit enzymes that remodel DNA topology. Members of the type II topo family function by passing one segment of duplex DNA through a transient break in another, a process that consumes two molecules of ATP and requires the co-ordinated action of multiple domains. Recent structural data on type II topo ATPase regions, which activate and enforce the directionality of DNA strand passage, have highlighted how ATP physically controls the catalytic cycle of the enzyme. Structural and biochemical studies of specialized DNA-binding domains in two paralogous bacterial type IIA topos (DNA gyrase and topo IV) show how these enzymes selectively negatively supercoil or decatenate DNA. Taken together, these findings expand our understanding of how disparate functional elements work together to co-ordinate the type II topo mechanism. Abbreviations: CAP, catabolite gene activator protein; CTD, and NTD, C- and N-terminal domains respectively; G-, and T-segments, gate and transfer segments respectively; topo, topoisomerase
Loss of chromosome 14 increases the radiosensitivity of CGL1 human hybrid cells but lowers their susceptibility to radiation-induced neoplastic transformation

Loss of active tumor suppressor alleles on fibroblast chromosomes 11 and 14 are involved in radiation-induced neoplastic transformation of human hybrid CGL1 cells. Loss of either chromosome 11 or 14 alone is not sufficient for neoplastic transformation. To gain insight into the potential functions of these tumor suppressor loci, we have investigated the effects of chromosome 11 or 14 loss on radiation-induced neoplastic transformation. We recently demonstrated that loss of chromosome 11 increases the susceptibility to X-ray induced cell killing, neoplastic transformation and the expression of delayed death. The data suggested that one possible function of the chromosome 11 tumor suppressor gene may be to help maintain genome stability after radiation damage. We postulated that if the chromosome 14 allele is functioning in a similar manner, then the loss of chromosome 14 may also make the hybrid cells more susceptible to radiation-induced cell killing and neoplastic transformation. A hybrid cell line which has lost one copy of chromosome 14 was isolated and designated CON3(-14). CON3(-14) cells were more sensitive to X-ray-induced cell killing when compared with parental CGL1 cells. However, the susceptibility to radiation-induced neoplastic transformation was significantly reduced (by a factor of two) compared with the parental CGL1 cells. The expression of delayed death in the progeny of the irradiated CON3(-14) cells, growing in transformation flasks, was similar to CGL1 cells during the 21 day assay period. Taken together, the data indicate that loss of chromosome 14 alone increased the X-ray sensitivity of the hybrid cells but reduced their susceptibility to radiation-induced neoplastic transformation. These data suggest that the tumor suppressor alleles on chromosomes 11 and 14 may be functionally distinct in terms of their regulation of genomic instability and neoplastic transformation after radiation exposure.
Functional integration of skeletal traits: An intraskeletal assessment of bone size, mineralization, and volume covariance

article i nfo Understanding the functional integration of skeletal traits and how they naturally vary within and across populations will benefit assessments of functional adaptation directed towards interpreting bone stiffness in contemporary and past humans. Moreover, investigating how these traits intraskeletally vary will guide us closer towards predicting fragility from a single skeletal site. Using an osteological collection of 115 young adult male and female African-Americans, we assessed the functional relationship between bone robustness (i.e. total area/length), cortical tissue mineral density (Ct.TMD), and cortical area (Ct.Ar) for the upper and lower limbs. All long bones demonstrated significant trait covariance (p b 0.005) independent of body size, withslenderbones having25-50% lessCt.Arand5-8%higherCt.TMDcomparedto robustbones.Robustnesssta- tistically explained 10.2-28% of Ct.TMD and 26.6-64.6% of Ct.Ar within male and female skeletal elements. This covariance is systemic throughout the skeleton, with either the slender or robust phenotype consistently repre- sentedwithin all longbonesfor each individual.These findingssuggestthateach person attains a unique traitset by adulthood that is both predictable by robustness and partially independent of environmental influences. The variation in these functionally integrated traits allows for the maximization of tissue stiffness and minimization of mass so that regardless of which phenotype is present, a given bone is reasonably stiff and strong, and suffi- ciently adapted to perform routine, habitual loading activities. Covariation intrinsic to functional adaptation sug- gests that whole bone stiffness depends upon particular sets of traits acquired during growth, presumably through differing levels of cellular activity, resulting in differing tissue morphology and composition. The out- comes of this intraskeletal examination of robustness and its correlates may have significant value in our pro- gression towards improved clinical assessments of bone strength and fragility.
The Multinational Firm

This article documents the recent advances in the international trade literature toward understanding the role of multinational firms in the conduct of international commerce. Over the past 10 years, we have developed a better understanding of the incentives firms face in their choice of production location, and we know more about the incentives that induce firms to vertically integrate. Furthermore, the theory literature has progressed from two-country models that cannot capture the richness of multinational firms’ activities to multicountry models that do. The empirics have advanced as well but at a slower pace. Progress has been slowed by the lack of comprehensive data and the difficulties of distinguishing between the various mechanisms proposed by theory.
Fault modeling using the program dependence graph

We present a fault classification scheme and a fault seeding method that is based on the manifestation of faults in the program dependence graph (PDG). We enhance the domain/computation fault classification scheme to further characterize faults as structural and statement level, depending on the differences between the PDG for the original program and the PDG for the faulty program. Structural faults correspond to differences in the control dependence or data dependence information in the PDGs, whereas statement level faults correspond to differences in the information within PDG nodes. We perform transformations on the PDG to produce the different types of faults described in our PDG-based fault classification scheme. To demonstrate the usefulness of our technique, we implemented a fault seeder to embed faults into C programs. We are using our fault seeder to experiment with the effectiveness of unit testing techniques, and are investigating the application of our fault seeder for formulating a fault based testing method. >
A new approach to real-time checkpointing

The progress towards programming methodologies that simplify the work of the programmer involves automating, whenever possible, activities that are secondary to the main task of designing algorithms and developing applications. Automatic memory management, using garbage collection, and automatic persistence, using checkpointing, are both examples of mechanisms that operate behind the scenes, simplifying the work of the programmer. Implementing such mechanisms in the presence of real-time constraints, however, is particularly difficult.In this paper we review the behavior of traditional copy-on-write implementations of checkpointing in the context of real-time systems, and we show how such implementations may, in pathological cases, seriously impair the ability of the user code to meet its deadlines. We discuss the source of the problem, supply benchmarks, and discuss possible remedies. We subsequently propose a novel approach that does not rely on copy-on-write and that, while more expensive in terms of CPU time overhead, is unaffected by pathological user code. We also describe our implementation of the proposed solution, based on the Ovm RTSJ Java Virtual Machine, and we discuss our experimental results.
Unambiguous description of chain code picture languages

Abstract There exists a regular (context-free) chain code picture language which is not described by any picture-unambiguous regular (context-free) language. Every recursively enumerable chain code picture language is described by a picture-unambiguous context-sensitive language.
Approximations in Renewal Theory

A renewal process [N(t), t ≥ 0] with interarrival times Xi, for i ≥ 1 and renewal function m (t) is considered. Let Gn, λ denote the gamma distribution with parameters n and λ–that is, dGn, λ(x) = λe–λx(λx)n-1/(n – 1)In Section 1 we show how m(t) can be approximated by f m(s) dGn, n/t(s). In addition, we show that these approximations constitute an increasing sequence of lower bounds when the interarrival distribution has the decreasing failure rate property. In Section 2 we show how the integrated renewal function can be approximated in a similar fashion by a decreasing sequence of upper bounds. In Section 3 we consider the problem of approximating the residual life (also called excess life) and the renewal age distribution and their means, and in Section 4 we consider the distribution of N(t). Finally, in Section 5 we remark on the relationship between our approximations and the Feller technique for inverting a Laplace transform.
Inhibition of carcinogenesis by minor anutrient constituents of the diet.

A continuing study of chemopreventive agents has focused on several categories of naturally occurring compounds that inhibit carcinogen activation and are effective in preventing carcinogen-induced neoplasia when administered at short time-intervals before carcinogen challenge. The inhibitory compounds are: aromatic isothiocyanates found in cruciferous vegetables, monoterpenes present in citrus fruits and caraway-seed oil, and organosulphur compounds occurring in Allium species. Preliminary work indicates that glucobrassicin and indoles existing in cruciferous vegetables also have these attributes. Almost all carcinogens that are consumed in food require metabolic activation. Thus, inhibition of carcinogen activation reactions could be effective against this type of exposure. In addition, three naturally occurring compounds, i.e. phenethyl isothiocyanate, D-limonene and dipropyl sulphide inhibit activation of the tobacco-specific carcinogen NNK, and accordingly may have the capacity to diminish carcinogenic response to exposures to tobacco. The property of cruciferous vegetables, orange oil, benzyl isothiocyanate, and D-limonene, to act as both blocking and suppressing agents has been discussed. Two possible mechanisms for this multi-phase activity were presented. The first is that these inhibitory substances activate a complex integrated defence mechanism against toxic compounds which entails both blocking and suppressing components. The blocking component is the initial line of defence, and the suppressing component constitutes a 'fail-safe' backup to assure that if any of the toxic material attacks cellular constituents, its effects will be nullified. The second possible mechanism considered is that the inhibitors, because of high reactivity, have multiple biological effects that are separate and not part of a single, coordinated response. Inhibitors that have both blocking and suppressing effects could be particularly useful as chemopreventive agents. A simple interim classification of foods in terms of their potential impact on the occurrences of cancer has been proposed.
A review of augmentation therapy for alpha-1 antitrypsin deficiency.

Introduction: Alpha-1 antitrypsin deficiency (AATD) is a relatively common, but under-recognized condition which manifests commonly with liver cirrhosis and emphysema. Specific therapy for lung-affected individuals with AATD is augmentation therapy, which consists of intravenous infusion of purified human plasma-derived alpha-1 antitrypsin (AAT). Augmentation therapy was first approved by the United States Food and Drug Administration (FDA) in 1987 for emphysema associated with severe AATD and today, six augmentation therapy preparations, all of which derive from pooled human plasma, have received FDA approval. Areas covered: This paper reviews augmentation therapy for AATD, including the various available commercial preparations, their processing and biochemical differences, evidence regarding biochemical and clinical efficacy, patterns of clinical use, adverse effect profiles, cost-effectiveness and potential uses in conditions other than emphysema associated with AATD. Novel and emerging strategies for...
Is there a direct relationship between serum level of methotrexate and clinical efficacy and tolerability

We have read with interest the article by Schiff et al 1 comparing oral with subcutaneous administration of methotrexate (MTX). The authors, as one would have predicted, have shown that there is higher bioavailability of subcutaneous MTX compared with oral administration.2–4 We are somewhat confused, however, with the interpretation of some of the data. First, Figure 1 in the article clearly shows that there is an increase in area under the curve (AUC) of MTX with an increase in dose of subcutaneous MTX up to 25 mg. The authors state that with an oral dose of MTX, the AUC plateaus at 15 mg. Yet, in figure 1, it appears there is an increase in AUC of oral MTX 15 mg from approximately 1850 ng.h/mL to approximately 2000 ng.h/mL with 20 mg of oral MTX. The recommended dose of MTX is …
Reports of Smoking in a National Survey: Data from Screening and Detailed Interviews, and from Self- and Interviewer-Administered Questions

Abstract PURPOSE: This study compares responses to questions about smoking in a brief screening interview with those from a subsequent, more detailed interview; it also compares responses to self-administered questions and questions administered by interviewers. The data are from the 1994 National Household Survey on Drug Abuse (NHSDA). METHODS: About 22000 respondents completed the main questionnaire of the 1994 NHSDA. Earlier, a member of each sample household had been asked to provide screening information, including smoking status, for each person in the household. Then, one or more persons in the household were interviewed about their own smoking and drug use; for some respondents, the questions about smoking were self-administered and for others they were administered by an interviewer. We examined discrepancies between reports about smoking from the screening data and main interview data; we also compared the results across the two versions of the main interview smoking questions (self and interviewer-administered). RESULTS: The screening data produced lower estimated rates of smoking than did the main interview data, particularly when proxies provided the screening data. In the main interviews, self-administered questions produced higher estimates of the prevalence of smoking than interviewer-administered questions, but only for adolescents. CONCLUSIONS: Proxies can provide some information about smoking, although the data are likely to be biased for younger age groups and for infrequent smokers. For adolescents, self-administration appears to elicit more candid reports about smoking than interviewer administration. In addition, multiple items may help to capture smoking reports by persons who are reluctant to admit they have smoked recently or whose status as smokers is unclear.
Acclimation to Singlet Oxygen Stress in Chlamydomonas reinhardtii

In an aerobic environment, responding to oxidative cues is critical for physiological adaptation (acclimation) to changing environmental conditions. The unicellular alga Chlamydomonas reinhardtii was tested for the ability to acclimate to specific forms of oxidative stress. Acclimation was defined as the ability of a sublethal pretreatment with a reactive oxygen species to activate defense responses that subsequently enhance survival of that stress. C. reinhardtii exhibited a strong acclimation response to rose bengal, a photosensitizing dye that produces singlet oxygen. This acclimation was dependent upon photosensitization and occurred only when pretreatment was administered in the light. Shifting cells from low light to high light also enhanced resistance to singlet oxygen, suggesting an overlap in high-light and singlet oxygen response pathways. Microarray analysis of RNA levels indicated that a relatively small number of genes respond to sublethal levels of singlet oxygen. Constitutive overexpression of either of two such genes, a glutathione peroxidase gene and a glutathione S-transferase gene, was sufficient to enhance singlet oxygen resistance. Escherichia coli and Saccharomyces cerevisiae exhibit well-defined responses to reactive oxygen but did not acclimate to singlet oxygen, possibly reflecting the relative importance of singlet oxygen stress for photosynthetic organisms.
Use of Hypothetical Situations in a Study of Spanish American Illness Referral Systems

This paper has three objectives: ( 1) to describe an application of the hypothetical situation in individual and group interviewing; (2) to modify the concept of "illness referral system" as used by several other investigators; and (3) to contribute to the ethnography of Spanish American culture. The data were gathered from 1959 through 1962 on field trips totaling about seventeen months. The summer of 1959 was spent as a participant observer studying the cultural context of health behavior in Abajo (a fictitious name), a village of approximately 600 persons in northern New Mexico. The summers of 1960 and 1961 were utilized to interview acculturated urban migrants and parteramedicas (midwife-health specialists) in or near two cities of 5,000 and 35,000 population within 100 miles of the village. Finally, seven months of 1962 were spent in Abajo investigating factionalism and social structure. Although all of the material gathered on these occasions contributed to the overall understanding of health action...
Lattice low-density parity check codes and their application in partial response systems

This paper introduces a combinatorial construction of high rate low-density parity check codes based on two-dimensional integer lattices. A class of codes with a wide range of lengths, column weights and minimum distances is obtained. The resulting codes are doubly circulant, i.e. the matrix of parity checks is an array of circulant matrices. The bounds on the minimum distance are established and the performance of these codes in partial response channels is investigated.
Play disabilities: a reason for physical educators to rethink the boundaries of special education.

Disabilities are commonly conceptualized in dualistic ways—specifically as mental or physical in nature and as located in the self rather than in the “other” or “out there.” In this essay I reflect on the consequences of a more holistic understanding of both handicaps and special education. This new approach, I suggest, would reveal something called a play disability. I review the nature of play before discussing the symptoms of this impairment. I discuss play handicaps on the side of human personality and attitude as well as on the side of the world or would be playgrounds. I speculate on what special education pedagogies for the play disabled might look like, cite the life experience of a handicapped pianist in arguing for the importance of play as a central component of good living, and then conclude with reflections on our unique opportunities and obligations in physical education to address any play deficit disorders we find among our students.
Components of Young Children’s Trait Understanding: Behavior-to-Trait Inferences and Trait-to-Behavior Predictions

Trait attribution is central to people's naive theories of people and their actions. Previous developmental research indicates that young children are poor at predicting behaviors from past trait-relevant behaviors. We propose that the cognitive process of behavior-to-behavior predictions consists of two component processes: (1) behavior-to-trait inferences and (2) trait-to-behavior predictions. Experiment 1 demonstrates that 4-, 5-, 7-, and 9-year-olds can infer trait labels from behaviors. Experiment 2 demonstrates that 4-, 5-, and 7-year-olds can predict behaviors from trait labels but not from past behaviors. Experiment 3 demonstrates that 4- and 5-year-olds understand traits as predictive and stable over time. Taken together, these three studies show that young children, in possessing component trait-reasoning processes, have a nascent understanding of traits.