cssi/SciSciGPT-SciSciNet huggingface dataset:
Changes in smoking status among substance abusers: baseline characteristics and abstinence from alcohol and drugs at 12-month follow-up

The impact of change in smoking status on 12-month substance abuse (SA) treatment outcomes was examined among an HMO population seeking SA treatment. Of the 749 participants who entered the study at baseline, 649 (86.9%) were retained at the 12-month follow-up. At treatment entry, 395 participants were smokers and 254 were nonsmokers. At 12-month follow-up, 13% of the 395 baseline smokers reported quitting smoking and 12% of the 254 baseline nonsmokers reported starting/relapsing to smoking. Those who quit smoking were less likely to be diagnosed as alcohol dependent compared to those that remained smokers. Those who started/resumed smoking were more likely to be diagnosed as both alcohol and drug dependent at treatment entry compared to all other groups. Total days abstinent from alcohol and illicit drugs was greatest for individuals who quit smoking (adjusted M=310.6) or who were nonsmokers (adjusted M=294.7) and lowest for those who started/resumed smoking (adjusted M=246.6) or remained smokers (adjusted M=258.2), even after controlling for demographic (i.e. age, income), psychosocial (ASI psychiatric severity), and other treatment characteristics (length of treatment stay, prescribed bupropion) that were associated with days abstinent at 12 months. Self-initiated smoking cessation does not appear to be detrimental to SA treatment outcomes, and may be beneficial. Starting/resuming smoking after entering SA treatment may be a clinical marker for individuals at greater risk of relapse. Future studies may want to measure the smoking status of all participants at all time points in order to include this higher-risk group of substance using smokers.
An Empirical Dosimetry Model of Aerodynamic Particle Deposition in the Rat Respiratory Tract

AbstractModels of airborne particle behavior in both the rodent and the human lung are needed to evaluate health effects following inhalation exposures for human health risk assessment as well as for therapeutic applications. We describe an empirical dosimetry model that can be used to predict fractional deposition of particles in the aerodynamic size range (i.e., diameter >0.5 μm) in the extrathoracic (ET), tracheobronchial (TB), and alveolar (A) regions of the rat lung. Independent equations for deposition efficiency of monodisperse particles in each of the three regions were selected after evaluating three unique functions as well as different parameterizations of independent variables consistent with the mechanisms of particle deposition in each region. For all of the functions fit to the deposition efficiency data, the asymptotic R2 exceeded 0.95. Based on comparisons of the root mean square error (MSE) from the different deposition efficiency equations, as well as of other statistical tests, the log...
Retrograde but not anterograde bead movement in intact axons requires dynein

Dynein and kinesin have been implicated as the molecular motors that are responsible for the fast transport of axonal membranous organelles and vesicles. Experiments performed in vitro with partially reconstituted preparations have led to the hypothesis that kinesin moves organelles in the anterograde direction and dynein moves them in the retrograde direction. However, the molecular basis of transport directionality remains unclear. In the experiments described here, carboxylated fluorescent beads were injected into living Mauthner axons of lamprey and the beads were observed to move in both the anterograde and retrograde directions. The bead movement in both directions required intact microtubules, occurred at velocities approaching organelle fast transport in vivo, and was inhibited by vanadate at concentrations that inhibit organelle fast transport. When living axons were injected with micromolar concentrations of vanadate and irradiated at 365 nm prior to bead injections, a treatment that results in the V1 photolysis of dynein, the retrograde movement of the beads was specifically abolished. Neither the ultraviolet irradiation alone nor the vanadate alone produced the retrograde-specific inhibition. These results support the hypothesis that dynein is required for retrograde, but not anterograde, transport in vivo. © 1995 John Wiley & Sons, Inc.
Circadian Clock-Regulated Phosphate Transporter PHT4;1 Plays an Important Role in Arabidopsis Defense

The Arabidopsis accelerated cell death 6-1 (acd6-1) mutant shows constitutive defense, cell death, and extreme dwarf phenotypes. In a screen for acd6-1 suppressors, we identified a mutant that was disrupted by a T-DNA in the PHOSPHATE TRANSPORTER 4;1 (PHT4;1) gene. The suppressor mutant pht4;1-1 is dominant, expresses truncated PHT4;1 transcripts, and is more susceptible to virulent Pseudomonas syringae strains but not to several avirulent strains. Treatment with a salicylic acid (SA) agonist induced a similar level of resistance in Col-0 and pht4;1-1, suggesting that PHT4;1 acts upstream of the SA pathway. Genetic analysis further indicates that PHT4;1 contributes to SID2-dependent and -independent pathways. Transgenic expression of the DNA fragment containing the PHT4;1-1 region or the full-length PHT4;1 gene in wild-type conferred enhanced susceptibility to Pseudomonas infection. Interestingly, expression of PHT4;1 is regulated by the circadian clock. Together, these data suggest that the phosphate transporter PHT4;1 is critical for basal defense and also implicate a potential role of the circadian clock in regulating innate immunity of Arabidopsis.
Intensity dependence and white-light gating of two-color photorefractive gratings in LiNbO(3).

Photorefractive gratings have been written in Pr:LiNbO3 by use of a diode laser for writing and of filtered white light (390–520 nm) as a gating source. The gating light increases the writing efficiency by more than 3 orders of magnitude, and the two-step writing process provides nondestructive readout. The material sensitivity for two-color writing rises strongly for gating wavelengths near the bandgap and approaches that of Fe-doped lithium niobate at power densities of a few watts per square centimeter. In addition, we show that the dynamic range of the recording process is strongly dependent on the writing intensity.
Influences on biomedicine in rural Dominican Republic: an analysis of process.

This paper, based on fieldwork among agrarian reform beneficiaries in the Dominican Republic, examines the utilization of health care. Specific attention is given to the consumption of private medical care and its relationship to changes in the system of land tenure, policy in the agrarian reform, and the roles of physicians. A principal concern of the paper is the examination of the adaptive strategies of beneficiaries of the reform in light of political and economic influences. A second concern is the consideration of the integration of critical medical anthropology's perspectives on the political economy with a perspective on decision‐making and adaptive strategies.
Botanical composition of tropical grass-legume pastures estimated with near-infrared reflectance spectroscopy

Quantifying pasture composition requires either laborious or subjective approaches. Evaluations of near-infrared reflectance spectroscopy (NIRS) to determine botanical composition of mixed pasture swards have shown potential. In this study, characterization of botanical composition of pastures comprised primarily of bahiagrass (Paspalum notatum Flugge), aeschynomene (Aeschynomene americana L.) and phasey bean [Macroptilium lathyriodes (L.) Urb.] by NIRS was evaluated. Three approaches (hand-composited samples, single-component samples, and actual pasture samples) were compared for equation development. Theoretical potential of NIRS is illustrated by high coefficients of determination (0.98–0.99) and low standard errors (1.4–2.9%) of equations for the above species from hand-composited samples. Equations developed from the three approaches were evaluated for estimation of the botanical composition of a separate group of pasture samples. Equations developed from hand-composited samples from a single source of each component were not acceptable for estimating composition of pasture samples despite the excellent calibration statistics. Single-component samples approached adequate results only for composite total grass and total legume groups, even though the pasture sample composition appeared to be well represented in the calibration sample set. Equations from pasture samples provided useful estimates of sample means, although some individual samples were poorly estimated. Thus, botanical composition of these pastures may be estimated using equations from actual pasture samples, and estimates of total grass and total legume may be obtained from use of single-component samples, which provides further labor reductions. A comparison of original software and updated software packages CAL, BEST, REG70, and partial least squares principal component regression showed none to be consistently superior. Florida Agric. Exp. Stn. Journal Series no. 8829.
Performance analysis of routing protocols in Zigbee non-beacon enabled WSNs

In recent years, much attention has been given to wireless sensor networks (WSNs) research, due to the growth in Micro-Electro-Mechanical Systems technology. IEEE 802.15.4 is starting to emerge as the next generation wireless standard for low-rate wireless personal area networks. Zigbee is a standard that builds upon IEEE 802.15.4 and offers low power, low data rate, and short range networking for wireless battery powered devices. The Ad hoc On-demand Distance Vector (AODV) routing protocol enables the routing of data between a source and destination in mesh networks. The Dynamic MANET On-demand routing protocol (DYMO) is a successor to AODV that was designed for wireless ad-hoc networks. In this paper, we present a performance comparison of AODV and DYMO based on the Zigbee standard. The performance comparison is based on the following metrics: packet delivery ratio, end-to-end delay, and energy consumption. Our work was implemented for realistic node densities and simulation times in non-beacon enabled Zigbee networks. Our simulations show that the performance of the protocols depend on the network topology. The results obtained indicate that DYMO outperforms AODV with respect to packet delivery ratio (PDR) and energy consumption.
Studies of an in vitro binding reaction between thyroid microsomes and long acting thyroid stimulator globulin (LATS). I. Development of solid-state competitive binding radioassay methods for measurement of antimicrosomal and antithyroglobuin antibodies.

ABSTRACT Using plastic tubes or plastic cups coated with a diluted homogenate of human thyroid microsomes and incubating with radioiodinated long acting thyroid stimulator globulin (LATS-IgG) of very high biologic potency for several hours in the presence of dog serum, we have demonstrated fixation of about 1 % of the label to the tube surface. Addition to the incubate of either the unlabeled LATS-IgG, the original LATS serum, or serum from a patient with Hashimoto's thyroiditis (containing antithyroglobulin and antimicrosomal antibodies) resulted in a dose-dependent inhibition of the binding reaction. Normal human serum, normal human IgG globulin or human TSH neither inhibits the binding reaction nor binds to thyroid microsomes. Evidence is presented which indicates that the binding reaction observed is due to the presence of relatively large amounts of antimicrosomal antibody. The method described permits a quantitative estimation of this antibody with a sensitivity about 10 times that of the immunofluo...
Global anomalies on orbifolds

We consider global anomalies for heterotic string theory formulated on orbifolds. The vanishing of certain characteristic classes in group cohomology provides sufficient conditions for the absence of global anomalies. For abelian orbifolds level matching implies these cohomology conditions, so suffices for the absence of anomalies. For nonabelian orbifolds level matching does not suffice, and there are additional constraints. We give some examples to illustrate these new constraints.
The carotid body in the motorneuron response to protriptyline

Protriptyline (PRT) has been shown to preferentially stimulate upper airway inspiratory motorneurons relative to phrenic activity in hyperoxic hypercapnia in the decerebrate cat via a carotid body-independent mechanism. Since previous studies indicated that carotid body stimulation results in preferential activation of upper airway respiratory muscles during both hypercapnia and hypoxemia, we hypothesized that if PRT preferentially stimulated upper airway motorneurons, the mechanism of action might involve the carotid body. We investigated the effect of PRT on carotid body function by comparing the electrical activity of the hypoglossal (HYP) with that of the phrenic (PHR) nerve in carotid sinus nerve intact (CSNI) and CSN-sectioned (CSNX) anesthetized rats, before and after PRT (0.5 mg/kg i.v.), during 100% O2, 15% O2 (N2 balance), and 4% CO2 (O2 balance) administration. The moving time average (MTA) peak inspiratory electroneurogram activities of both the HYP and PHR nerves increased an equivalent amount after PRT injection during hyperoxia, in both CSNI and CSNX rats. During hypoxia, the HYP activity increased significantly more than the PHR activity only in CSNI rats after PRT injection. During hyperoxic hypercapnia, HYP MTAs increased a similar amount in the CSNI and CSNX rats. We conclude that the HYP and PHR respiratory motorneuron pool responses to PRT depend on the blood gas status at the time of drug administration.
Defining critical landscapes on Mexican ejidos

Abstract Jameson, G.W., 1984. Defining critical landscapes on Mexican ejidos. Landscape Plann., 11: 109–123. The term “critical landscapes” commonly refers to those areas of land that enhance the quality of life which is enjoyed in a given environment. This concept is usually taken to mean that such landscapes are unique for aesthetic or recreational reasons, and values are often associated with them. In areas of the world where severe poverty and subsistence living is the norm, defining “critical” landscape resources for these reasons is meaningless. A case example involving an ejido (communal farm) of northern Mexico is described. Peasant farmers (and perhaps others) are concerned primarily with the productivity of the land, and the profit which can be realized from it. Thus, “critical landscapes” in this case refers to economic characteristics of the landscape. The value of the critical resources is to be measured in terms of costs and benefits associated with how the landscape is managed. These economic characteristics can be identified and subsequently mapped using a combination of current land planning techniques. Linear programming, a widely used approach for determining optimum solutions within a given set of constraints, was used to select preferred management activities. Economically critical landscapes were determined by comparing the contribution margins for each response unit in the study area. This information was then mapped using familiar computer overlay procedures. The idea of assigning values to landscapes is not new. Measuring variables which can be analyzed and employed with map overlays to determine economic relationships, however, can produce better quantified decisions than traditional ranking procedures alone. Management of critical resources can then be based on a better indication of the real values of the landscape.
Soft errors in commercial integrated circuits

The once-ephemeral soft error has recently caused considerable concern for manufacturers of advanced silicon technology as this phenomenon now has the potential for inducing the highest failure rate of all other reliability mechanisms combined. We briefly review the three radiation mechanisms responsible for causing soft errors in commercial electronics and the basic physical mechanism by which ionizing radiation can produce a soft error. We then focus on the soft error sensitivity trends in commercial DRAM, SRAM, and peripheral logic devices as a function of technology scaling and discuss some of the solutions used for mitigating the impact of soft errors in high reliability systems.
Modifiable characteristics of a healthy lifestyle and chronic health conditions in older adults with or without serious psychological distress, 2007 Behavioral Risk Factor Surveillance System.

Objective: The associations between serious psychological distress (SPD), chronic health conditions, healthy behaviors, healthy weight, and use of preventive services were examined among adults 65 years old and older using the 2007 Behavioral Risk Factor Surveillance System (BRFSS).
Sex Endocrines in Development and Prepuberal Life1

AMONG THE large number of contributions to endocrinology during the past twenty years a respectable portion have dealt with internal secretions of the sex glands and internal secretions in relation to sex problems. Considered from the point of view of a complete life history, or ontogeny, involving fertilization, development, juvenile life, puberty, reproduction and senility, the major portion of attention has been given to problems: a) around the puberal age; b) during the age of active reproduction; and c) to some extent to the period of declining activities, suggested by some to be the age of senility. It is somewhat striking that one of the most influential contributions in stimulating interest in general sex problems, and especially in the relation of sex hormones to these problems, published more than a quarter-century ago, dealt entirely with the effects of sex hormones during embryonic life; yet since that publication investigations dealing with the question of sex hormones during embryonic develo...
Mining Interesting Meta-Paths from Complex Heterogeneous Information Networks

Meta-paths in heterogeneous information networks are almost always hand created and have, so far, only been attempted on data sets with very small type systems like DBLP, IMDB, etc. Most real-world heterogeneous information networks have large and complex type systems. As the size and complexity of the type-system grows it becomes more and more difficult for humans to form reasonable meta-path queries. This work introduces a new technique to discover a new market for data called interesting meta-paths from complex heterogeneous information networks. Our interestingness measure is based on classical knowledge discovery principles, but have been applied in such a way that only interesting meta-paths are mined from the hundreds-of-thousands of possible choices. As in classical pattern mining literature, precision and recall statistics are difficult to obtain, instead we evaluate the effectiveness of our results using a quantitative node-similarity analysis as well as a large user study. Finally, we apply the newly discovered interesting meta-paths to find similar nodes on the Wikipedia heterogeneous information networks.
Population structure of the colonial hydroid Hydractinia sp. nov. C in the Gulf of Maine

Abstract The spatial and temporal variation of population parameters were investigated in eight populations of the colonial hydroid Hydractinia sp. nov. C in the Gulf of Maine. Reproduction, juvenile recruitment, and intraspecific competition varied seasonally and the recruitment positions of juvenile colonies, size frequency distribution of colonies, and sex ratio of adults exhibited little interpopulation variation. One gastropod shell species, Littorina littorea (L.), and one host crab species, Pagurus acadianus (Benedict), predominated in all populations. Hydroid colonies were more abundant on shells inhabited by P. acadianus than on those occupied by P. arcuatus (Squires) and laboratory experiments demonstrated that larvae are more likely to settle on shells inhabited by P. acadianus . Hydroid densities and the frequency of intraspecific competition varied widely among populations, but exhibited little variation from year to year within populations. Hydractinia colonies are known to exhibit genetically based variation in colony morphology and morphology has been shown to determine intraspecific competitive ability. Consequently, the frequency of competition in a population should correspond to the intensity of natural selection on morphological variation and interpopulation variation in this parameter may result in variation in the relative abundance of different colony morphologies among populations. kw]Hermit crab; Histocompatibility; Hydractinia ; Intraspecific competition; Morphology; Recruitment
Age-Related Changes in Glycine Receptor Subunit Composition and Binding in Dorsal Cochlear Nucleus

Age-related hearing loss, presbycusis, can be thought of, in part, as a slow progressive peripheral deafferentation. Previous studies suggest that certain deficits seen in presbycusis may partially result from functional loss of the inhibitory neurotransmitter glycine in dorsal cochlear nucleus (DCN). The present study assessed age-related behavioral gap detection changes and neurochemical changes of postsynaptic glycine receptor (GlyRs) subunits and their anchoring protein gephyrin in fusiform cells of young (7-11 months) and aged (28-33 months) Fischer brown Norway (FBN) rats. Aged rats showed significantly (20-30 dB) elevated auditory brainstem-evoked response thresholds across all tested frequencies and worse gap detection ability compared to young FBN rats. In situ hybridization and quantitative immunocytochemistry were used to measure GlyR subunit message and protein levels. There were significant age-related increases in the alpha(1) subunit message with significant age-related decreases in alpha(1) subunit protein. Gephyrin message and protein showed significant increases in aged DCN fusiform cells. The pharmacologic consequences of these age-related subunit changes were assessed using [3H] strychnine binding. In support of the age-related decrease of alpha(1) subunit protein levels in DCN, there was a significant age-related decrease in the total number of GlyR binding sites with no significant change in affinity. These age-related changes may reflect an effort to reestablish a homeostatic balance between excitation and inhibition impacting on DCN fusiform cells by downregulation of inhibitory function in the face of an age-related loss of peripheral input. Age-related decrease in presynaptic glycine release results in altered subunit composition and this may correlate with loss of temporal coding of the aged fusiform cell in DCN. The previously reported role for gephyrin in retrograde intracellular receptor subunit trafficking could contribute to the alpha(1) decrease in the face of increased message.
Phonotaxis in flying crickets: Neural correlates

Abstract Tethered, flying crickets perform stereotyped steering movements when stimulated with sound. Electrophysiological recordings show that identifiable motoneurones respond to acoustic stimulation in a manner which reflects the phonotactic behaviour of the intact cricket. Both steering behaviour and its neural correlates reflect the fine temporal structure of the acoustic stimulus. Decapitation of the cricket eliminates steering movements in response to sound.
Antireductionism and Molecular Biology Though the antireductionist thesis is unwarranted, research in classical biology may well be of value

My general conclusion, then, is that, given the current state of biological science, there may be good heuristic reasons for not attempting in all possible areas to develop physicochemical explanations of biological phenomena, and good reasons for attempting to formulate specifically biological theories. This, however, is an argument which supports an irreducibility thesis for methodological reasons. Any attempt to twist this into a claim of real irreducibility for all time is, in the light of recent work in molecular biology, logically untenable, empirically unwarranted, and heuristically useless.
Investigating sensitivity of phylogenetic community structure metrics using North American desert bats

A relatively recent approach to characterizing structure of natural communities is to use phylogenies of species pools to compare patterns of relatedness between real and simulated communities. Such an approach can provide mechanistic insights into structure. Despite popularity of phylogenetic approaches, we do not yet fully understand how phylogenetic community structure (PCS) metrics might be impacted by changes to the phylogeny or community membership data from which they are calculated. We investigate metric sensitivity and examine PCS of bats from the 4 great desert regions of North America. We inferred a phylogeny of the regional species pool to calculate PCS metrics using community membership data delimited using 3 different methods. We also randomized our phylogeny to determine how reasonable changes to the tree affect PCS metrics. Overall, PCS metrics are quite robust to moderate changes in the phylogeny from which they are calculated. These metrics also are fairly insensitive to our 3 methods of delimiting communities. Additionally, we found that in general, communities are significantly phylogenetically clustered, suggesting habitat filtering has been important in community assembly.
Ductal lavage, nipple aspiration, and ductoscopy for breast cancer diagnosis

The intraductal approach to breast cancer has been invigorated this year by a series of papers exploring ductalbased screening through nipple aspiration and lavage and ductal exploration through endoscopy. The merging of these efforts to define the earliest biologic changes in the progression toward breast cancer is opening new fields for both bench-translational and clinical research. These techniques have already begun to show value in defining the presence and extent of proliferative disease in high-risk patients, allowing for more informed therapeutic decision making.
Cell lysisa using surface acoustic wave devices for sensor applications

This paper reports on the use of surface acoustic wave (SAW) devices for lysis of the Gram-positive bacterium Geobacillus thermoglucosidasius. Vegetative cells were exposed to surface acoustic wave energy for up to 8 min at 5° to 55°C. DNA concentration was quantified by fluorescence, and quantitative PCR was performed to confirm molecular recognition of specific DNA sequences. The successful use of SAW devices for lysis of bacterial cells is reported for the first time in this work, opening the possibility of using SAW as a lysing mechanism in portable DNA detection devices.
Overcurrent Protection on Voltage-Source-Converter-Based Multiterminal DC Distribution Systems

This paper proposes a protection scheme which utilizes modern voltage-source converters as fast-acting current-limiting circuit breakers. This paper investigates the main challenges of detecting and localizing a fault, and interrupting it as quickly as possible in a multiterminal dc system. A system protection scheme consisting of smart relays associated with converters has been developed. The protection relays monitor local quantities to detect and isolate disturbances/faults. It is shown that overcurrent-based schemes can be adopted for these relays to meet the fast response requirements. The effectiveness of the proposed protection scheme is illustrated through simulations
The effects of weather and air pollution on cardiovascular and respiratory mortality in Santiago, Chile, during the winters of 1988 1996

This study quantifies the effects of stressful weather and elevated air pollution levels on cause-specific mortality in Santiago, Chile, during the austral winters from 1988 to 1996. A temporal synoptic index (TSI) is used to form weather classes and air pollution classes. Prior applications of the TSI have formed classes solely on the basis of weather and may have systematically underestimated the impact of air pollution levels on daily mortality. In Santiago, the attribution of increased mortality risk was found to be largely dependent on the type of class formed (weather or pollution). High-mortality weather classes were associated with cold, dry and high-pressure conditions, while high-mortality pollution classes were associated with elevated NO2 and PM10–2.5 concentrations. Cardiovascular disease mortality was more sensitive to weather conditions, and respiratory mortality was more sensitive to pollution levels. Respiratory mortality was most sensitive to stressful conditions at longer lag times (3–6 days), while cardiovascular mortality was most sensitive at shorter lag times (0–2 days). By understanding the relative magnitudes of health risks associated with stressful weather and air pollution conditions we can improve existing air pollution/weather watch systems and better anticipate future risks associated with global climate change. Copyright © 2007 Royal Meteorological Society
Mechanisms of Adenosine-Mediated Actions on Cellular and Clinical Cardiac Electrophysiology

Objective To provide insights into the molecular mechanisms of adenosine-mediated cardiac cellular electrophysiology and how information about these mechanisms can be used to facilitate diagnostic and therapeutic approaches to various clinical arrhythmias. Design A review of (1) adenosine metabolism and receptors in the cardiac system, (2) adenosine-mediated signal transduction pathways in the regulation of cellular electrophysiology in various cardiac cell types, and (3) the clinical usefulness of adenosine in cardiac electrophysiology is presented. Results The effects of adenosine on cardiac electrophysiologic properties are consequences of complex interactions among the specific cardiac target structures, the density and type of adenosine receptors, and the effector systems. The easy application of adenosine and its short half-life, favorable sideeffects profile, and electrophysiologic properties make it an excellent diagnostic and therapeutic tool for the initial assessment of various tachyarrhythmias. Conclusion The direct adenosine-activated K ACh (potassium acetylcholine) channel signal transduction system explains the effects of adenosine on the sinus node, atrioventricular node, and atrial myocardium. The indirect adenosine-inhibited adenylate cyclase system accounts for its negative inotropic effects on the catecholamine-entrained contractility in atrial and ventricular myocardium. Because of the recent purification and cloning of adenosine receptors and subunits of G proteins, additional adenosine-mediated electrophysiologic mechanisms can be explored.
Surgical Management of Proximal Splint Bone Fractures in the Horse

Fractures of Metacarpal and Metatarsal II and IV (the splint bones) were treated in 283 horses over an 11 year period. In 21 cases the proximal portion of the fractured bone was stabilized with metallic implants. One or more cortical bone screws were used in 11 horses, and bone plates were applied in 11 horses. One horse received both treatments. Complications of screw fixation included bone failure, implant failure, radiographic lucency around the screws, and proliferative new bone at the ostectomy site. Only two of the horses treated with screw fixation returned to their intended use. Complications of plate fixation included partial fixation failure (backing out of screws), wound drainage, and proliferative bony response around the plate. Six of the 11 horses treated by plate fixation returned to their intended use. The authors recommend consideration of plate fixation techniques for repair of fractures in the proximal third of the splint bone.
Effect of Ni on vacancy concentrations and hardness in FeAl alloys

The effects of nickel additions to iron aluminides are investigated with respect to vacancy concentrations and solid-solution hardening. Lattice parameters, densities, vacancy concentrations, and hardnesses were measured for FeAl alloys (40, 45, 48, 50, and 51 at. pct Al) with up to 12 at. pct Ni additions, as quenched at both 700 °C and 1000 °C. It is found that Ni does not prevent the elimination of thermal vacancies, as has been suggested in previous studies. However, the equilibrium vacancy concentrations are affected by the Ni additions. No clear evidence of solid-solution hardening by the Ni additions themselves was found. Instead, it appears that the role of Ni in hardening FeAl is through the effect the Ni has on the vacancy concentration. It was found that the hardness of most of the Ni-containing FeAl alloys could be directly correlated to the square root of the vacancy concentration.
The dynamics of an open, isothermal homogeneous, single enzyme, two substrate system

Abstract The dynamics of an isothermal, open, well mixed reaction system, wherein an enzyme reacts with either of two substrates but not both simultaneously, in a Michaelis-Menten fashion, are investigated. An open well mixed environment has been previously postulated as being a useful model for the living cell. The existence of multiple steady operating conditions, and limit cycles are shown to be impossible. Phase plane plots depicting the system's transient approach to the steady state are presented, and the effect of system parameters on the shape of the integral curves are discussed.
Sensitivity of Mesoscale Surface Dynamics to Surface Soil and Vegetation Contrasts over the Carolina Sandhills

A region of contrasting soils exists over the Carolinas region of the southeastern United States. Previous research has shown an increase in mesoscale summertime precipitation over this region. Numerical simulations are analyzed to investigate the relationships between mesoscale surface dynamics and the transition from clay to sandy soils over this region. Numerical modeling experiments using four different soil and vegetation patterns suggest that the presence of the clay-to-sand transition zone produces a surface heat flux gradient and enhanced convergence. The soil contrasts appear to dominate over vegetation contrasts in affecting local surface heating and convergence in the model atmosphere.
Simplifications in the synthesis of short oligonucleotide blocks

Abstract A rapid and convenient procedure has been developed for the synthesis of fully protected mono, di and trideoxyribonucleotides utilizing an aryl phosphoroditriazolide. It affords advantages over coupling strategies employing condensing reagents, such as 2,4,6-triisopropylbenzenesulfonyl tetrazolide in preparing small oligonucleotides and is relatively free of the drawbacks inherent in other approaches using bifunctional phosphorylating reagents. In particular, the synthesis of trinucleotide blocks without purification at the dimer stage is described.
Northern pocket gophers (Thomomys talpoides) as biomonitors of environmental metal contamination.

We live-trapped 40 northern pocket gophers across two years from the Anaconda Smelter Superfund Site, Anaconda, Montana, USA, to determine their exposure to five metal contaminants and effects of exposure on selected measurements. Soil, gopher blood, liver, kidney, and carcass samples were analyzed for arsenic, cadmium, lead, copper, and zinc. Hematological parameters, kidney and liver porphyrins, and red blood cell d-aminolevulinic acid dehydratase (ALAD) activity were also measured. Micronutrients Cu and Zn were detected in all tissues analyzed, and Cd, Pb, and As were detected less frequently. We report differences in metal distribution among different tissues and differences in bioaccumulation for different metals within the same tissue. No significant differences were observed in concentrations of Zn or Cu in any tissue across the study site, but relationships between lead in soil and lead in carcass proved especially strong (r 2 5 0.80; p , 0.001; n 5 18). Among biomarker data, we observed a negative relationship between concentration of lead in the soil and ALAD activity in gophers with detectable concen- trations of lead in their blood (r 2 5 0.45; p 5 0.006; n 5 15). Results of this study suggest that northern pocket gophers are useful biomonitors of environmental Pb, Cd, and As contamination, and their broad geographic range across North America could allow them to be an important component of site-specific metals assessments.
Retention of Conformational Entropy upon Calmodulin Binding to Target Peptides is Driven by Transient Salt Bridges

Calmodulin (CaM) is a highly flexible calcium-binding protein that mediates signal transduction through an ability to differentially bind to highly variable binding sequences in target proteins. To identify how binding affects CaM motions, and its relationship to conformational entropy and target peptide sequence, we have employed fully atomistic, explicit solvent molecular dynamics simulations of unbound CaM and CaM bound to five different target peptides. The calculated CaM conformational binding entropies correlate with experimentally derived conformational entropies with a correlation coefficient R2 of 0.95. Selected side-chain interactions with target peptides restrain interhelical loop motions, acting to tune the conformational entropy of the bound complex via widely distributed CaM motions. In the complex with the most conformational entropy retention (CaM in complex with the neuronal nitric oxide synthase binding sequence), Lys-148 at the C-terminus of CaM forms transient salt bridges alternating between Glu side chains in the N-domain, the central linker, and the binding target. Additional analyses of CaM structures, fluctuations, and CaM-target interactions illuminate the interplay between electrostatic, side chain, and backbone properties in the ability of CaM to recognize and discriminate against targets by tuning its conformational entropy, and suggest a need to consider conformational dynamics in optimizing binding affinities.
Parameter estimation using balanced synchronization

Abstract Synchronization between experimental observations and a dynamical model with undetermined parameters can assist in completing the specification of the model parameters. The quality of the synchronization, a cost function to be minimized, typically depends on the difference between the data time series and the model time series. If the coupling between the data and the model is too strong, this cost function is small for any data and any model, and the variation of the cost function with respect to the parameters of interest is too small to permit selection of a value of the parameters. If the coupling is too small, synchronization is lost. We introduce two methods for balancing the competing desires of a small cost function and the numerical ability to determine parameters accurately. One method of ‘balanced’ synchronization adds a requirement that the conditional Lyapunov exponent of the model system, conditioned on being driven by the data, remain negative but small. The other method allows the coupling to vary in time according to the error in synchronization. This second method succeeds because the data and the model exhibit generalized synchronization in the region where the parameters of the model are well determined.
Instruction selection, resource allocation, and scheduling in the AVIV retargetable code generator

The AVIV retargetable code generator produces optimized machine code for target processors with different instruction set architectures. AVIV optimizes for minimum code size. Retargetable code generation requires the development of heuristic algorithms for instruction selection, resource allocation, and scheduling. AVIV addresses these code generation subproblems concurrently, whereas most current code generation systems address them sequentially. It accomplishes this by converting the input application to a graphical (Split-Node DAG) representation that specifies all possible ways of implementing the application on the target processor. The information embedded in this representation is then used to set up a heuristic branch-and-bound step that performs functional unit assignment, operation grouping, register bank allocation, and scheduling concurrently. While detailed register allocation is carried out as a second step, estimates of register requirements are generated during the first step to ensure high quality of the final assembly code. We show that near-optimal code can be generated for basic blocks for different architectures within reasonable amounts of CPU time. Our framework thus allows us to accurately evaluate the performance of different architectures on application code.
The change in growth mechanism of scales due to reactive elements

An analysis of the effect of reactive elements, or their oxides, upon high temperature-oxidation behavior of chromia-forming alloys is presented in this note. The change in mechanism for the growth of “pure” chromia, cation motion in the scale, to that formed on alloys containing the reactive elements, anion motion in the scale, is attributed to the fact that almost all reactiveelement oxides are, on the basis of ion motion, anionic conductors. Thus, the reactive-element oxide present as an adsorbed layer at the chromia grain interfaces as well as fine particles residing at these interfaces restricts cation motion and imposes anion diffusion along these primary paths of scale growth. The effect of scale adherence is not addressed.
Real‐time X‐ray scattering study of thermal expansion of poly(butylene terephthalate)

Changes in the six lattice parameters of the α-form of poly(butylene terephtalate) (PBT) were obtained from wide-angle x-ray scattering over the temperature range from 35 to 215°C. The linear thermal expansion coefficients relating the unit cell parameters at temperature T to their values at 0°C are found to be a= 4.80(1+2.03x10 -4 T) α= 100.26(1+3.96x10 -5 T); b= 5.98(1+1.22x10 -4 T) β= 114.82(1+8.13x10 -5 T); c= 11.55(1+2.13x10 -4 T) γ= 111.43(1-3.92x10 -5 T). The temperature dependence of the long period, of the lamellar thickness and of the crystallinity of semicrystalline PBT were found to increase with increasing temperature
Cigarette smoking associated with attention deficit hyperactivity disorder.

Objective To evaluate the association between attention deficit hyperactivity disorder (ADHD) and severity of physical dependence on nicotine in a controlled study of adolescents and young adults with ADHD. Study design In controlled longitudinal family studies of ADHD, we examined self-reports on the modified Fagerstrom Tolerance Questionnaire (mFTQ) for degrees of physical dependence on nicotine. Results We obtained mFTQ data from 80 ADHD probands and 86 control probands (mean age, 19.2 years). The smokers with ADHD had significantly higher scores on the mFTQ, indicative of more severe physical dependence on nicotine. Similarly, in current smokers, a positive linear relationship was found between mFTQ score and both inattentive and hyperactive ADHD symptoms. Environmental factors, such as current parental smoking, peer smoking, and living with a smoker, all increased the risk for smoking in those with ADHD compared with controls. Conclusion Male and female smokers with ADHD manifest more severe physical dependence on smoking compared with controls. Important environmental factors appear to add to the risk of smoking associated with ADHD.
Moving toward a unified effort to understand the nature and causes of language disorders

The nature and causes of language disorders are research topics familiar to the readership of Applied Psycholinguistics. Current inquiries place these topics in a dynamic and sprawling multidisciplinary context manifested through investigations of linguistic acquisition, cognitive development, genetics, neurocortical processes, cognitive neurolinguistics, behavioral phenotypes, and language intervention. This list is not complete by any means, but it does suggest the wide front of the current search for better knowledge about what causes language disorders and the dimensions of language acquisition that are affected. Although there is considerable momentum underway in current inquiries, the full potential for scientific advancement is hampered by fragmentation in the field, in part attributable to partitioning by diagnostic categories of affectedness. Investigators (and their funding sources) often focus on a particular clinical group, such as specific language impairment (SLI), autism/autism spectrum disorders (ASD), Williams syndrome (WS), Down syndrome (DS), or fragile X syndrome (FXS). Although this is not exclusively the case, it is relatively difficult to carry out comparative studies across the multiple clinical conditions in which language disorders appear and to monitor developments across such a wide front of investigation. The consequence is that findings are distributed across different publication outlets and different groups of scholars, a situation that can limit our appreciation of the ways in which language disorders are manifest, and the identification of common etiological factors.
Dynamic motions of free and bound Ø29 scaffolding protein identified by hydrogen deuterium exchange mass spectrometry

In the double-stranded DNA containing bacteriophages, hundreds of copies of capsid protein subunits polymerize to form icosahedral shells, called procapsids, into which the viral genome is subsequently packaged to form infectious virions. High assembly fidelity requires the assistance of scaffolding protein molecules, which interact with the capsid proteins to insure proper geometrical incorporation of subunits into the growing icosahedral lattices. The interactions between the scaffolding and capsid proteins are transient and are subsequently disrupted during DNA packaging. Removal of scaffolding protein is achieved either by proteolysis or alternatively by some form of conformational switch that allows it to dissociate from the capsid. To identify the switch controlling scaffolding protein association and release, hydrogen deuterium exchange was applied to Bacillus subtilis phage O29 scaffolding protein gp7 in both free and procapsid-bound forms. The H/D exchange experiments revealed highly dynamic and cooperative opening motions of scaffolding molecules in the N-terminal helix-loop-helix (H-L-H) region. The motions can be promoted by destabilizing the hydrophobic contact between two helices. At low temperature where high energy motions were damped, or in a mutant in which the helices were tethered through the introduction of a disulfide bond, this region displayed restricted cooperative opening motions as demonstrated by a switch in the exchange kinetics from correlated EX1 exchange to uncorrelated EX2 exchange. The cooperative opening rate was increased in the procapsid-bound form, suggesting this region might interact with the capsid protein. Its dynamic nature might play a role in the assembly and release mechanism.
An Investigation of a Kelvin-Helmholtz Billow Cloud

An unusual Kelvin-Helmholtz billow cloud was observed and photographed over New Jersey. A thorough investigation of the cloud's meteorological environment was made. The cloud was found to be associated with the northern boundary of an area of jet stream cirrus, was embedded in a region of considerable wind shear, and was accompanied by a dry neutral lapse rate capped by an inversion.