cssi/SciSciGPT-SciSciNet huggingface dataset:
AN ANALYTICAL APPROACH TO ECOSYSTEM BIOGEOCHEMISTRY MODELING

Models of terrestrial ecosystem carbon and nutrient biogeochemistry commonly utilize several compartments of organic matter (OM) to simulate the storage and turnover of OM in plant–soil systems. While much work has focused on numerical simulations of ecosystems to understand responses to perturbations, relatively little work explores the analytical properties of the mathematical systems used and their implications for the understanding of terrestrial ecosystems. We explore carbon and nutrient dynamics using a 4 × 4 transfer matrix, which is similar to the mathematical core of commonly used simulation models (e.g., Century). The C and N vectors contain one pool for photosynthesizing biomass and several pools for soil detritis. The model yields steady-state solutions for the C pool size of each compartment dependent solely on the amount of the nutrient (nitrogen) stored within the compartment and the C:nutrient ratio. Furthermore, the C and nutrient storage in the model compartments depends on the inputs and losses of nutrients to and from the system as well as the coefficients for turnover from and transfer between compartments. When examining the transient behavior of the system, the eigenvalues for the system provide a useful tool for predicting and understanding the characteristic time scales with which plant–soil systems respond to perturbations. We use the model eigenvalues to examine ecosystem development from freshly exposed parent material as well as the response to a “catastrophic” disturbance event. Ultimately, the model's analytical tools can be extended to characterize soil organic matter (SOM) responses to several major land-use changes occurring in agroecosystems—including the initiation of tillage, the application of industrial fertilizers, and the introduction of reduced-tillage practices. Analysis of the eigenvalues for these cases suggests that agroecosystems tend to lose SOM more rapidly following the initiation of tillage than they can regain SOM after the initiation of conservation-tillage practices. Additionally, the amount of N export (harvesting or loss) places an important control on the storage and future productivity of agricultural systems. Overall, we suggest that the model—with straightforward and accessible steady-state solutions and eigenvalues—offers a complementary perspective to more complex numerical simulations. Corresponding Editor: D. S. Schimel
Understanding adolescent development: Implications for driving safety

Abstract Problem The implementation of Graduated Driver Licensing (GDL) programs has significantly improved the crash and fatality rates of novice teen drivers, but these rates remain unacceptably high. Method A review of adolescent development research was undertaken to identify potential areas of improvement. Results Research support for GDL was found to be strong, particularly regarding early acquisition of expertise in driving safety (beyond driving skill), and to limitations that reduce opportunities for distraction. GDL regimes are highly variable, and no US jurisdictions have implemented optimal regimes. Summary Expanding and improving GDL to enhance acquisition of expertise and self-regulation are indicated for implementation and for applied research. Driver training that effectively incorporates safety goals along with driving skill is another target. Impact on Industry The insurance industry will benefit from further GDL enhancements. Benefits may accrue to improved driver training, improved simulation devices during training, and automated safety feedback instrumentation.
Blood of calcitoninin mirophthalmic (mi/mi) osteopetrotic mouse cannot account for the resistance of bone to this hormone

Abstract Basal and calcium-stimulated levels of calcitonin were measured in blood from microphthaimic-osteopetrotic and normal mice. The basal levels in the osteopetrotic mice were not different from those in normal mice (119.8 ± 8.1 and 93.8 ± 8.6 pg/ml, mean ± s.e.m., respectively). Similarly, the calcium-stimulated increase in calcitonin following injection of calcium was the same in both groups of mice. Previously it has been demonstrated that calvaria from osteopetrotic mice have a blunted response to the biochemical effects of calcitonin compared to calvaria from normal mice. The present data indicates that this decreased response to calcitonin is not due to excessive blood levels of calcitonin or to altered sensitivity of the thyroid gland to blood calcium concentration.
Neural network predictions of significant coronary artery stenosis in men

Objective:: A neural network system was designed to predict whether coronary arteriography on a given patient would reveal any occurrence of significant coronary stenosis (>50%), a degree of stenosis which often leads to coronary intervention. Methodology:: A dataset of 2004 records from male cardiology patients was derived from a national cardiac catheterization database. The catheterizations selected for analysis from the database were first-time and elective, and they were precipitated by chest pain. Eleven patient variables were used as inputs in an artificial neural network system. The network was trained on the earliest 902 records in the dataset. The next 902 records formed a cross-validation file, which was used to optimize the training. A third file composed of the next 100 records facilitated the choice of a cutoff number between 0 and 1. The cutoff number was applied to the last 100 records, which comprised a test file. Results:: When a cutoff of 0.25 was compared to the network outputs of all 100 records in the test file, 12 of 46 (specificity=26%) patients without significant stenosis had outputs @?0.25, but all patients with significant stenosis had outputs >0.25 (sensitivity=100%). Therefore, the network identified a fraction of the patients in the test file who did not have significant coronary artery stenosis, while at the same time the network identified all of the patients in the test file who had significant stenosis capable of causing chest pain. Conclusion:: Artificial neural networks may be helpful in reducing unnecessary cardiac catheterizations.
Nanocomposite Tribological Coatings for Rolling Element Bearings

The performance of rolling element bearings is enhanced by the application of nanocomposite coatings that are composed of metal carbides incorporated into an amorphous hydrogenated carbon matrix (MC/a-C:H). When applied to the rolling elements in tapered roller bearings, MC/a-C:H coatings were found to help increase fatigue life, rib-roller end scuffing resistance, and false brinelling resistance in poorly lubricated environments. This series of performance tests were conducted with both coated and uncoated rollers. The results are attributed to the minimization of adhesive interactions and desirable counterface micro-polishing due to the presence of the thin hard coatings on rollers in the bearings.
Temporal Characteristics of Potassium‐Stimulated Acetylcholine Release and Inactivation of Calcium Influx in Rat Brain Synaptosomes

: The time course of Ca2+-dependent [3H]acetylcholine ([3H]ACh) release and inactivation of 45Ca2+ entry were examined in rat brain synaptosomes depolarized by 45 mM [K+]o. Under conditions where the intrasynaptosomal stores of releasable [3H]ACh were neither exhausted nor replenished in the course of stimulation, the K+-evoked release consisted of a major (40% of the releasable [3H]ACh pool), rapidly terminating phase (t1/2= 17.8 s), and a subsequent, slow efflux that could be detected only during a prolonged, maintained depolarization. The time course of inactivation of K+-stimulated Ca2+ entry suggests the presence of fast-inactivating, slow-inactivating, and noninactivating, or very slowly inactivating, components. The fast-inactivating component of the K+-stimulated Ca2+ entry into synaptosomes appears to be responsible for the rapidly terminating phase of transmitter release during the first 60 s of K+ stimulus. The noninactivating Ca2+ entry may account for the slow phase of transmitter release. These results indicate that under conditions of maintained depolarization of synaptosomes by high [K+]o the time course and the amount of transmitter released may be a function of the kinetics of inactivation of the voltage-dependent Ca channels.
An infinite-series solution for the creeping motion through an orifice of finite length

This paper presents an infinite-series solution to the creeping viscous motion of a fluid through low- and moderate-aspect-ratio pores. The flow field is divided into two simply bounded regions: a cylindrical volume bounded by the walls of the pore and the entrance and exit planes, and an infinite half-space outside the pore. Analytic solutions are first obtained in each region for unknown functions representing arbitrary axial and radial velocity profiles at the pore entrance (exit). These unknown functions are then determined by matching the normal and tangential stress at the pore opening.The results indicate that the velocity profile approaches to within 1·5 per cent of a Poiseuille profile after a short entrance distance of half the pore radius. In the far field the solution matches exactly the streamline pattern for a flow through an orifice of zero thickness obtained by Sampson (1891). The pressure drop across the pore exhibits linear dependence on the aspect ratio and is closely approximated (less than one per cent error) by a simple algebraic expression.
A STATISTICAL OPTIMIZING NAVIGATION PROCEDURE FOR SPACE FLIGHT

In a typical self-contained space navigation system, celestial observation data are gathered and processed to produce est imated velocity corrections. The results of this paper provide a basis for determining the best celestial measurements and the proper t imes to implement velocity correct ions . Fundamenta l to the navigation system is a procedure for processing celestial measurement data which permits incorporation of each individual measurement as i t is made in order to provide an improved es t imate of posit ion and velocity. In order to "opt imize" the navigation, a statistical evaluation of a number of alternative courses of action is made. The various alternatives, which form the basis of a decision process, concern the following: 1) which star and planet combinat ion provides the "best" available observation; 2) whether the best observation gives a sufficient reduct ion in the predicted target error to warrant making the measurement ; and 3) whether the uncerta inty in the indicated velocity correction is a small enough percentage of the correction itself to justify an engine re-start and propellant expenditure. Numerical results are presented which i l lustrate the effectiveness of this approach to the space navigation problem.
Adaptive but non-optimal visual search behavior with highlighted displays

Previous research [Fisher, D. L., & Tan, K. C. (1989). Visual displays: The highlighting paradox. Human Factors, 31(1), 17-30] suggested that making certain items visually salient, or highlighting, can speed performance in visual search tasks. But interface designers cannot always anticipate users' intended targets, and highlighting non-target items can lead to performance decrements. An experiment presented suggests that people attend to highlighting less than what an algebraic visual search model of highlighted displays [Fisher, D. L., Coury, B. G., Tengs, T. O., & Duffy, S. A. (1989). Minimizing the time to search visual displays: The role of highlighting. Human Factors, 31(2), 167-182] predicts. Users adjust their visual search strategies by probability-matching to their visual environment. An ACT-R [Anderson, J. R., Bothell, D., Byrne, M. D., Douglass, S., Lebiere, C., & Quin, Y. (2004). An integrated theory of the mind. Psychological Review, 111, 1036-1060] model reproduced the major effects of the experiment and suggests that learning in this task occurs at very small cognitive and time scales.
ISOLATION OF THE DITERPENOIDS, ENT-KAURAN-16α-OL AND ENT-ATISAN-16α-OL, FROM SUNFLOWERS, AS OVIPOSITION STIMULANTS FOR THE BANDED SUNFLOWER MOTH, Cochylis hospes

Two diterpenoid alcohols, ent-kauran-16α-ol (1) and ent-atisan-16α-ol (2), were isolated from pre bloom (R3-R4 stage) sunflower heads as oviposition stimulants for the banded sunflower moth, Cochylis hospes. Fractionation of a sunflower head extract, by normal-phase flash column chromatography, resulted in an early eluting fraction exhibiting significant activity in an egg-laying bioassay. Compounds 1 and 2, along with ent-trachyloban- 19-oic acid (3) and ent-kaur-16-en-19-oic acid (4), were isolated as the major components of this fraction and identified by their NMR and mass spectra. The purified compounds were individually tested for ovipositional activity in dose-response bioassays. In these bioassays, compounds 1 and 2 gave linear dose responses, with increasing numbers of eggs laid as the dosage of either increased. Compounds 3 and 4 failed to stimulate significant egg-laying at any of the dosages tested. A factorial design bioassay, using compounds 1 and 2, showed that 1 was relatively more stimulatory than 2, and that there was no synergistic effect on oviposition when the two compounds were combined.
Unmasking the trifascicular left intraventricular conduction system by ablation of the right bundle branch.

Abstract Twenty-five patients underwent transcatheter right bundle ablation either for bundle branch reentrant tachycardias or inadvertent or deliberate right bundle ablation during atrioventricular junctional ablation for rate control. Electrophysiologic data and 12-lead electrocardiograms before and after right bundle ablation were available in all patients. Eleven of the patients had no significant intraventricular conduction abnormalities by surface electrocardiograms (group I), whereas 14 patients had underlying intraventricular conduction delays (group II). All group I patients had typical electrocardiographic changes of right bundle branch block after right bundle ablation, with minimal changes in initial or mean QRS axis. In group II, 5 patients had an initial 40 ms QRS axis shift of >45 °, in 7 patients the mean QRS axis changed significantly (leftward in 4 and rightward in 3), and a qR pattern in V 1 was seen in 12 of 14 patients including 2 with structurally normal hearts. These changes, namely new Q waves, and rightward and left-ward axis shifts are most likely the result of septal fascicular, left posterior fascicular, and left anterior fascicular delay/block, which were exposed by exclusive conduction via a diseased left bundle and its fascicles. The trifascicular nature of left intraventricular conduction is more apparent when diseased and unmasked by concomitant block in the right bundle branch.
The Efficacy of Recently Developed Sulfonamides Against Fowl Typhoid

Abstract THE application of sulfonamide therapy to poultry practice appears to offer a significant advancement in the control of certain poultry diseases. Most of the work with these drugs, as therapeutic agents in connection with poultry diseases have been tested on a small scale and therefore must still be considered in the experimental stages of development. However, the antibacterial action of these drugs against closely related organisms affecting other species indicates that beneficial action may be expected. Fortunately, sulfonamides differ in the rate and amount of absorption from the intestinal tract. Thus high concentrations can be obtained in the gastro-intestinal tract as well as in the blood stream by the use of different sulfa-drugs. The phenomenal success of certain sulfa-drugs in combating systemic and enteric infections among the armed forces is common knowledge. It is not surprising that these sulfa-drugs are also giving encouraging results against poultry diseases whether the habitat . . .
Discrete element modeling of Martian pit crater formation in response to extensional fracturing and dilational normal faulting

[1] Pit craters, circular to elliptical depressions that lack a raised rim or ejecta deposits, are common on the surface of Mars. Similar structures are also found on Earth, Venus, the Moon, and smaller planetary bodies, including some asteroids. While it is generally accepted that these pits form in response to material drainage into a subsurface void space, the primary mechanism(s) responsible for creating the void is a subject of debate. Previously proposed mechanisms include collapse into lave tubes, dike injection, extensional fracturing, and dilational normal faulting. In this study, we employ two-dimensional discrete element models to assess both extensional fracturing and dilational normal faulting as mechanisms for forming pit craters. We also examine the effect of mechanical stratigraphy (alternating strong and weak layers) and variation in regolith thickness on pit morphology. Our simulations indicate that both extensional fracturing and dilational normal faulting are viable mechanisms. Both mechanisms lead to generally convex (steepening downward) slope profiles; extensional fracturing results in generally symmetric pits, whereas dilational normal faulting produces strongly asymmetric geometries. Pit width is established early, whereas pit depth increases later in the deformation history. Inclusion of mechanical stratigraphy results in wider and deeper pits, particularly for the dilational normal faulting, and the presence of strong near-surface layers leads to pits with distinct edges as observed on Mars. The modeling results suggest that a thicker regolith leads to wider but shallower pits that are less distinct and may be more difficult to detect in areas of thick regolith.
Apobec-1 interacts with a 65-kDa complementing protein to edit apolipoprotein-B mRNA in vitro.

Abstract The editing of apolipoprotein-B (apoB) mRNA involves the deamination of cytidine at nucleotide 6666 to uridine. The catalytic subunit of the editing enzyme, apobec-1, is a cytidine deaminase that requires other unidentified proteins to edit apoB mRNA in vitro. We partially purified an activity from baboon kidney that functionally complements apobec-1. The complementing activity was protease-sensitive and micrococcal nuclease-resistant, had a native molecular mass of 65 ± 10 kDa on size exclusion chromatography, and sedimented at 4.5 S in glycerol gradients. Purified recombinant His6-tagged apobec-1 immobilized on beads depleted >90% of the complementing activity from partially purified extracts. These beads edited apoB mRNA in vitro in the absence of exogenous apobec-1 or complementing activity. A functional holoenzyme containing apobec-1 and the complementing activity was eluted from the apobec-1-affinity resin using 0.5 M imidazole, whereas buffer containing 0.4 M KCl eluted only the complementing activity. The carboxyl-terminal 59 amino acids of apobec-1 were not required for interaction with the complementing activity in vitro. Our results demonstrate that the complementing protein interacts directly with apobec-1 in the absence of apoB mRNA.
Effects of Street Forms on Suburban Neighboring Behavior

This study is an investigation of the possible effects of linear, curvilinear, and cul-de-sac street-form configurations on suburban neighboring behavior. Based upon a sample survey of single-family household residents in Tulsa, Oklahoma, the findings showed that street design was not influential in predicting neighboring relations as compared to social variables. Number of children living at home, length of residence, and job status of the woman of the household were found to be significant indicators for familiarity and participation among neighbors. Results suggest the importance of familism in determining suburban neighboring behavior rather than possible spatial manipulations of street forms in site planning.
On the 60 mV/dec @300 K limit for MOSFET subthreshold swing

The 60 mV/dec limit for subthreshold swing at 300 K is generally considered a fundamental limit that cannot be defeated. The physical origin of this limit is revisited in this paper and the fact that this limit is in part determined by the density-of-states (DOS) of the source is highlighted. A scheme of engineering this DOS is proposed as a possible way to achieve subthreshold swing much lower than the 60 mV/dec value.
CELL‐ASSOCIATED PROTEOLYTIC ENZYMES FROM MARINE PHYTOPLANKTON1

Despite their central importance in cell metabolism, little is known about proteases in marine phytoplankton. Caseinolytic and leucine aminopeptidase (LAP) activities was surveyed in log-phase cultures of the chlorophyte Dunaliella tertiolecta Butcher, the diatom Thalassiosira weissflogii Fryxell et Hasle, the chrysophyte Isochrysis galbana Parke, the coccolithophorid Emiliania huxleyi Hay et Mohler, and the cyanobacterium Synechococcus sp. LAP activity was very low at pH 200-and <20-kDa proteases in homogenates of log-phase T. weissflogii; only the smaller protease was found in D. tertiolecta. Antibodies in the ATPase subunit (C) of the conserved, chloroplastic Clp protease from Pisum cross-reacted with proteins in Synechococcus, D. tertiolecta, and I. galbana, but no cross-reactions were found for any species with antibodies against the ClpP subunit from either E. coli or Nicotiana. Our results show that phytoplankton contain a diverse complementmore » of proteases with novel characteristics. 46 refs., 6 figs., 1 tab.« less
Radiolabeled peptides and other ligands for receptors overexpressed in tumor cells for imaging neoplasms

For better detection of neoplasms by scintigraphy, ligands that bind specifically to surface receptors overexpressed in tumor cells are being developed. These ligands must be labeled with the readily available radionuclides of iodine, [111In] or [99mTc], without blocking their interaction with the specific cell membrane receptors. The promising ligands include bioactive endogenous peptides or their analogues, inhibitors of glucose transport proteins, estrogen and sigma receptor ligands, growth factors, and cytokines.
Components in interstellar molecular hydrogen.

Results are reported for precise spectrophotometric measurements of the profiles of selected Lyman absorption lines produced by hydrogen molecules in various rotational levels along the line of sight to 13 stars which have shown some evidence for an increase in line width with increasing rotational quantum number (J). The line profiles were measured by multiple scans with the Copernicus satellite telescope. Based on analysis of the radial velocities, derivations of the column densities, and line-profile fitting, the following conclusions are made: (1) the increase in interstellar H2 line width with increasing J results from the presence of the most shortward component, which is relatively weak at low J but becomes more important at higher J; (2) the relative column densities found for the different J levels in each component may be fitted by a theoretical model in which rotational excitation is due to absorption of UV photons followed by radiative quadrupole spontaneous transitions or collisionally induced downward transitions between different J levels; (3) the atomic hydrogen density is between 300 and 1000 per cu cm in the most shortward component for each of three stars; (4) the approaching gas which produces each shortward component must be in the form of thin sheets; and (5) the sheets are the compressed gas behind a shock front moving through the interstellar medium.
Right ventricular dysfunction and organ failure in left ventricular assist device recipients: a continuing problem.

Abstract Background . Although right ventricular assist device (RVAD) use has declined with the introduction of inhaled nitric oxide and phosphodiesterase inhibitors (type III), right ventricular dysfunction (RVD) is still a serious problem in patients receiving left ventricular assist devices (LVAD). Methods . We retrospectively analyzed Thoratec Vented Electrical LVAD recipients between June 1996 and September 1999. RVD was defined as inotropic requirement 14 days or more or need for RVAD postoperatively, or both. Results . Sixty-nine LVAD recipients were analyzed. Twenty-one patients (30.4%) had RVD, with 1 patient requiring RVAD insertion, and there were 48 non-RVD patients. There were no significant differences between both groups for age, sex, etiology of congestive heart failure, days of support, and preoperative hemodynamics. Preoperative right ventricle stroke work index (mm Hg · m −2 · L −1 ) had a trend toward being lower in the RVD group (4.1 ± 3.2 versus 6.1 ± 3.7, p = 0.06). A higher preoperative total bilirubin (mg/dL) was noticed in the RVD group (4.0 ± 5.2 versus 2.1 ± 1.7). The RVD group had a higher postoperative creatinine (2.2 ± 1.4 mg/dL versus 1.5 ± 0.8 mg/dL), incidence of continuous venovenous hemofiltration dialysis (73% versus 26%), transfusion of packed red blood cells (43.2 ± 28.6 units versus 24.7 ± 18.9 units), platelets (58.6 ± 46.1 units versus 30.2 ± 20.4 units), with longer intensive care unit length of stay (33.6 ± 34.7 days versus 9.1 ± 6.9) and higher mortality (42.8% versus 14.5%). When deaths were excluded, both intensive care unit and postoperative length of stay were significantly longer in the RVD group. Conclusions . RVD in LVAD recipients remains poorly identified and is associated with a high transfusion rate and end organ failure that results in increased intensive care unit and hospital length of stay, and a high mortality rate. Preoperative identification of risk factors for RVD may select patients who would benefit from a biventricular assist device and prevent the subsequent end organ failure.
Coronary embolism: surgical management.

Abstract The successful use of Fogarty catheter embolectomy combined with aortocoronary vein bypass graft in 4 patients with an acute myocardial infarction is presented. Three patients sustained acute occlusion of the coronary artery secondary to an embolus during cardiac catheterization. In the fourth patient, the left anterior descending coronary artery was occluded with a fragment of calcium debris during aortic valve replacement. All patients survived the operation. Acute occlusion of the coronary artery secondary to an embolus is uncommon, but its early recognition and appropriate surgical management may be lifesaving.
Relative Strengths of Predictors of Middle School Girls' Suspendable Offenses

This study determines the relative strength of predictors of school violence among a sample of 229 girls enrolled in a single middle school. The four-part questionnaire, comprising sociodemographic items, a school violence inventory, a self-esteem scale, and an attitudes toward violence scale, measured school violence in terms of suspendable school offenses. Hierarchical multiple regression then identified six predictors of school violence (ranked by strength): observation of school violence, gang membership, attitude toward violence, school suspension, grade level, and drug use. Whereas the two strongest predictors can be explained by social learning theory, it is possible that one aspect of the third, a positive attitude toward violence, may help girls justify violent behaviors.
Commentaries on “Knowledge and Empire: The Social Sciences and United States Imperial Expansion”

If periods of generalized crisis offer opportunities to engineer dramatic social and economic changes, the present moment is one to watch. The global crisis of accumulation and the decline of Unite...
Affective images of the public political mind: Semantic differential reference frames for an experience of the 1988 presidential campaign

Abstract What was the public experience of the 1988 presidential campaign? Those “hot” affective cognitions or “images” of the political ‘ ‘public mind “were assessed using the technique of the semantic differential. Four “reference frames” were identified (Distrust, Boredom, Comedy, and Familiarity) for interpreting one group's experience of the presidential and vice‐presidential candidates, the former President Reagan, the ideological labels of liberal or conservative, and their regard for the media/press. The results are discussed relative to the history of the method and as a retrospective analysis of the election outcome. Empirically based speculation also suggested the potential for alternative outcomes. Future analyses of the political “public mind” through the metaphors of the semantic differential are encouraged.
The Mechanism of 1,25-Dihydroxyvitamin D3Autoregulation in Keratinocytes

The synthesis of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) from its precursor, 25-dihydroxyvitamin D(3) (25(OH)D(3)), is catalyzed by the mitochondrial cytochrome P450 enzyme 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase). It has been generally assumed that 1,25(OH)(2)D(3) inhibits the activity of this enzyme by regulating its expression at the genomic level. We confirmed that 1,25(OH)(2)D(3) reduced the apparent conversion of 25(OH)D(3) to 1,25(OH)(2)D(3) while stimulating the conversion of 1,25(OH)(2)D(3) and 25(OH)D(3) to 1,24,25(OH)(3)D(3) and 24,25(OH)(2)D(3), respectively. However, 1,25(OH)(2)D(3) failed to reduce the abundance of its mRNA or its encoded protein in human keratinocytes. Instead, when catabolism of 1,25(OH)(2)D(3) was blocked with a specific inhibitor of the 25-hydroxyvitamin D(3)-24-hydroxylase (24-hydroxylase) all apparent inhibition of 1alpha-hydroxylase activity by 1,25(OH)(2)D(3) was reversed. Thus, the apparent reduction in 1alpha-hydroxylase activity induced by 1,25(OH)(2)D(3) is due to increased catabolism of both substrate and product by the 24-hydroxylase. We believe this to be a unique mechanism for autoregulation of steroid hormone synthesis.
The determination of tungsten, molybdenum, and phosphorus oxyanions by high performance liquid chromatography inductively coupled plasma mass spectrometery.

Abstract The toxic properties of tungsten compounds have recently been brought to the forefront with clusters of human cancer cases, such as in Fallon, NV. Such instances have made the determination of tungsten in natural water supplies vitally important. Tungsten exists in most environmental matrices as the soluble and mobile tungstate anion, although it can polymerize with itself and other anions, such as molybdate and phosphate. Because the geochemical and toxicological properties of these polymer species will vary from the monomeric tungstate parent, determination of tungstate speciation is as critical as determination of total dissolved tungsten concentration. Use of chromatographic separations, followed by element-specific detection is a proven technology for elemental speciation. In the present work, anion exchange chromatography has been coupled to inductively coupled plasma mass spectrometry to determine tungstate, molybdate, and phosphate species at the sub-μg l −1 and μg l −1 levels. The method provides quantitative determination of these species in about 10 min with the capability to simultaneously determine other oxyanion species. The method has been applied to groundwater and extracts of soils amended with tungsten powder. The water soluble tungsten in 1-h deionized water extracts after six months of soil aging was >15 mg l −1 , however, only ∼50% of the tungsten was present as monomeric tungstate.
Everyday spatial activities test for studying differential spatial experience and vocational behavior

Abstract Described is a four-factor, 20-item Everyday Spatial Activities Test (ESAT) developed for use with college students for studying the contribution of differential spatial experiences to educational and vocational behaviors. Item data are presented based on samples of 158 female and 113 male first-year students. Correlations with objective tests, including a test of space visualization, establishes preliminary validity for the ESAT.
Penaeid Shrimps (Decapoda, Penaeidae) Collected Off East Africa By the Fishing Vessel ''Van Gogh'', 1. Solenocera Ramadani Sp. Nov., and Commercial Species of the Genera Penaeus and Metapenaeus

[Description d'une nouvelle espece: Solenocera ramadani, Metapenaeus conjunctus Racek & Dall, 1965, est pour la premiere fois signalee au large de l'Afrique orientale, ce qui elargit l'aire de distribution de cette espece. Penaeus indicus, P. japonicus, P. monodon, P. latisulcatus presentent une valeur commerciale pour la haute mer de l'Afrique orientale. P. indicus domine dans les peches industrielles. Le plateau continental du Mozambique est une region qui ouvre les perspectives les plus prometteuses pour la peche des crevettes. La prise moyenne du bateau de peche ''Van Gogh'' representait environ 70 kg pour un chalutage de 2 heures., Description d'une nouvelle espece: Solenocera ramadani, Metapenaeus conjunctus Racek & Dall, 1965, est pour la premiere fois signalee au large de l'Afrique orientale, ce qui elargit l'aire de distribution de cette espece. Penaeus indicus, P. japonicus, P. monodon, P. latisulcatus presentent une valeur commerciale pour la haute mer de l'Afrique orientale. P. indicus domine dans les peches industrielles. Le plateau continental du Mozambique est une region qui ouvre les perspectives les plus prometteuses pour la peche des crevettes. La prise moyenne du bateau de peche ''Van Gogh'' representait environ 70 kg pour un chalutage de 2 heures.]
Sparse random networks with LTP learning rules approximate Bayes classifiers via Parzen's method

Abstract Analysis is performed of a neuronal cell layer consisting of sparse random anatomical innervation, incorporating anatomically accurate distribution of excitatory and inhibitory cells, appropriate physiological time courses of excitatory-inhibitory interactions, and synaptic modification via long-term potentiation (LTP). One of two input pathways selects cells that learn and the other uses LTP-based learning rules to modify synapses of selected cells. It is found that the resulting network implements Parzen's method for approximating a Bayes classifier. The simple one-layer network can be generalized to include a class of networks including one that adds an input layer of neurons resulting in changes to the kernel used in the Parzen method. The LTP learning rule is nondecremental and limited to a maximum ceiling, which will result in essential saturation of synaptic weights; nonetheless, calculations using reasonable estimates of network parameters indicate a large network capacity.
How Labor Management Relations and Human Resource Policies Affect the Process of Teacher Assignment in Urban School Districts.

Purpose: This study examined how labor–management relations between school districts and teacher associations seem to affect teacher contract provisions regarding the role of seniority in teacher assignment and how contract provisions and teacher assignment policies seem to affect beginning teachers’ perceptions about their work environments. Research Method/Approach: The study took place in five urban districts in a Midwestern state. In each district, we interviewed the human resource director and teacher association president, surveyed novice teachers in Grades 1 to 8, and examined the district’s collective bargaining agreement (CBA). We used district case reports to identify linkages between labor–management relations and contract provisions regarding teacher assignment. We drew on survey data to examine how these factors affected beginning teachers’ perceptions of their work environments. Findings: In four districts, the CBAs featured flexible language regarding the role of seniority in teacher transf...
Neurophysiological characterization of the anterolateral spinal cord neurons contributing to pain perception in man

These studies have examined threshold, frequency, and refractory period characteristics of a neural population in the anterolateral quandrant (ALQ) of the spinal cord of man, stimulation of which produces pain. Subjects were 18 conscious humans undergoing percutaneous anterolateral cordotomy for relief of intractable pain. Pain could be produced by ALQ stimulation in all subjects. Pain thresholds ranged from 120 to 1000 muA (at 50 pulses/sec; 0.2 msec pulses), but the majority of thresholds were below 300 muA. A linear relationship was found between stimulation frequency and percentage of subjects reporting pain. This relationship ranged from 5 to 25 pulses/sec with 100% reporting pain at 25/sec and 0% at 5/sec. In 2 of 3 subjects, increases in stimulation frequency up to 500/sec did not produce pain when stimulation intensity was below threshold at 50/sec. The neuronal refractory period for pain in these subjects ranged between 1.0 and 2.0 msec, but the majority of relative refractory periods fell between 1.0 and 1.5 msec. The threshold, frequency, and refractory period data obtained in this study are similar to those found for wide dynamic range cells in the ventral half of the dorsal horn in the monkey and suggest that activation of these cells is a sufficient condition to produce pain in man.
Neonatal subgaleal hematoma causing brain compression: report of two cases and review of the literature.

Objective and importance Neonatal subgaleal hematomas (SGHs) are infrequent but underdiagnosed collections of blood beneath the galea, often caused by vacuum delivery. With massive bleeding into the subgaleal space, exsanguination and hypovolemic shock can cause death in 20 to 60% of newborn infants. We report the first two known patients with extracranial cerebral compression caused by SGH. Also, the surgical evacuation of neonatal SGH has not been described previously. Clinical presentation One patient was a full-term boy who was delivered via vacuum extraction after an uncomplicated pregnancy. Within a few hours, he developed an expanding fluid collection of the scalp and disseminated intravascular coagulation and shock requiring intubation, inotropic support, and blood transfusions. His head circumference grew from 33 cm at birth to 42 cm. He became progressively lethargic and developed posturing movements. Computed tomography of the head revealed a massive SGH causing gross overlapping of the cranial sutures and diffuse cerebral edema. The other patient was a full-term boy delivered via cesarean section after an unsuccessful attempt at vacuum extraction and forceps delivery. The initial head circumference was 34 cm. Within a few hours, he developed an expanding fluid collection of the scalp and became progressively lethargic with posturing. Magnetic resonance imaging of the head revealed a massive SGH with cranial compromise and diffuse cerebral edema. Intervention Both children had radiographic features indicative of elevated intracranial pressure as well as neurological decompensation. The first patient was taken to the operating room, and the hematoma was evacuated through a small scalp incision. Initially, approximately 150 ml of blood was removed, and a Jackson-Pratt drain diverted another 200 ml of blood during the next 2 days. The infant made a good recovery. In the second case, the patient remained too unstable for operative intervention and died. Conclusion Extracranial cerebral compression represents another way by which neonatal SGH may jeopardize the infant's life. Management consists of measures to correct hypovolemic shock and disseminated intravascular coagulation, as well as surgical intervention to control elevated intracranial pressure.
Statement 133: Not Perfect, but a Step in the Right Direction

Statement 133 represents progress toward achieving the goals of GAAP. To the extent it requires companies to mark their derivatives to market, balance sheets will give investors a clearer, more complete picture of a company's assets and liabilities. But if the fair value accounting prescribed by Statement 133 has provided clarity for investors about corporate derivatives positions, it has also forced some companies—those unable or unwilling to qualify for hedge accounting—to report more volatile earnings, causing the accounting rule to come under heavy criticism. As the author argues, however, such criticism is based on the misperception that the objective of GAAP income statements is to provide a “normalized” measure of financial performance—a single number that can be discounted or capitalized by analysts to arrive at a company's value. In fact, it is mainly the job of the analysts themselves, not accountants, to determine which elements of a company's income statement are recurring and central to the business. What's more, the author argues that the FASB went too far when it allowed hedge accounting for forecasted transactions. Rather than expanding the use of hedge accounting, the FASB should promulgate a comprehensive fair value standard, one that aims to mark all corporate assets and liabilities to market—which would eliminate the need for hedge accounting or any of its associated complexity, and compensate for 133's dearth of disclosures.
Decreases in mediobasal hypothalamic and preoptic area opioid ([3H]naloxone) binding are associated with the progesterone-induced luteinizing hormone surge.

In view of evidence implicating hypothalamic opioid systems in the control of LH release, we have examined the binding of [3H]naloxone (NAL) to slices of mediobasal hypothalamus (MBH) and preoptic area (POA) during the induction of an afternoon LH surge (1630–1700 h) in estradiol benzoate (EB)-primed ovariectomized (OVX; day 0) rats by treatment with progesterone (P; day 2). Such a surge was invariably accompanied by a decrease from early morning (1000 h) values in the number of NAL-binding sites detectable in the MBH, while the affinity of the binding site was not affected over the course of the day. Time-course studies indicated that P injection at 1000 h on day 2 was followed by a transient midday elevation in the amount of NAL bound to slices of MBH; the binding decreased significantly before the onset of and during the LH surge. A similar diurnal change was not observed in MBH slices of either oil-treated OVX rats (controls) or EBtreated OVX rats, which displayed only a 2-fold increase in LH release ...
A boundary element formulation for sheet metal forming

Abstract A boundary element method (BEM) for the analysis of metal-forming processes is presented. This BEM formulation incorporates both material and geometric nonlinearities and admits general follower force boundary conditions. It is capable of using any of a class of combined creep-plasticity constitutive models with state variables for the description of material behaviour. The specific problems considered are in-plane stretching of an ASTM-E8 tensile specimen and plane strain bulging of sheet metals using the material model originally proposed by Hart. The computer program developed here can also be applied to study other plane strain metal forming processes.
Subtle Disturbances of Vision with Compressive Lesions of the Anterior Visual Pathway Measured by Contrast Sensitivity

Contrast thresholds were determined for patients with compressive lesions of the chiasm or optic nerve but whose visual acuity was 20/20 on the Snellen scale. A generalized loss of contrast sensitivity for spatial frequencies ranging from 0.2 to 6.4 cycles per degree was found even in patients with normal color vision and full visual fields. After surgery was performed, improvements in the fields and color vision were seen in those patients who also showed a significant increase in their postoperative contrast sensitivity scores. Contrast sensitivity is shown to be a useful procedure for evaluating very mild visual complaints as well as for establishing early diagnosis and evaluation of surgical therapy in patients with compressive lesions of the anterior visual pathway.
Suitability of Canopy Temperature Depression, Specific Leaf Area, and SPAD Chlorophyll Reading for Genotypic Comparison of Peanut Grown in a Sub-humid Environment

ABSTRACT Peanut (Arachis hypogaea L.) is mostly grown under rainfed production with water deficit being the major limiting factor. Several physiological characteristics have been proposed as surrogates for yield and genotypic selection under water deficit in arid climates, but their suitability for selection under sub-humid rainfed production where water deficit can also occur is not clear. Canopy temperature depression (CTD), specific leaf area (SLA), and SPAD chlorophyll reading of eight virginia-type peanut genotypes were evaluated at three growth stages in field trials involving rainfed and irrigated plants in sub-humid environments in northeastern Virginia-Carolina (VC) region in 2011 and 2012. Significant (p≤0.05) variation in pod yield and all physiological characteristics was observed in response to water regime in both years. Rainfed plants had warmer (CTD 2.2 vs. 3.1 °C) and greener canopies in 2011 but cooler (CTD 3.9 vs. 2.2 °C) and less green canopies in 2012 than the irrigated plants. Compar...
Predicting Treatment Response for Oppositional Defiant and Conduct Disorder Using Pre-Treatment Adrenal and Gonadal Hormones

Variations in adrenal and gonadal hormone profiles have been linked to increased rates of oppositional defiant disorder (ODD) and conduct disorder (CD). These relationships suggest that certain hormone profiles may be related to how well children respond to psychological treatments for ODD and CD. The current study assessed whether pre-treatment profiles of adrenal and gonadal hormones predicted response to psychological treatment of ODD and CD. One hundred five children, 6–11 years old, participating in a randomized, clinical trial provided samples for cortisol, testosterone, dehydroepiandrosterone, and androstenedione. Diagnostic interviews of ODD and CD were administered up to 3 years post-treatment to track treatment response. Group-based trajectory modeling identified two trajectories of treatment response: (1) a High-response trajectory where children demonstrated lower rates of an ODD or CD diagnosis throughout follow-up, and (2) a Low-response trajectory where children demonstrated higher rates of an ODD or CD diagnosis throughout follow-up. Hierarchical logistic regression predicting treatment response demonstrated that children with higher pre-treatment concentrations of testosterone were four times more likely to be in the Low-response trajectory. No other significant relationship existed between pre-treatment hormone profiles and treatment response. These results suggest that higher concentrations of testosterone are related to how well children diagnosed with ODD or CD respond to psychological treatment over the course of 3 years.
Selling versus producing in market fluctuations

Abstract I consider markets in which sellers must expend resources to sell their good as well as for producing it. My particular concern is how the share of labor allocated to selling behaves in market fluctuations, and what behavior this implies for pricing and productivity. The key assumption is that sellers incur a cost in presenting their price to potential buyers. Consumers, upon receiving one or more price quotes, take the lowest price or else do not purchase. This creates a negative externality between sellers' activities--if other firms send out more salesmen, it reduces the probability that my salesman gains a sale at a given price. The market exhibits interesting responses to disturbances that raise output and sales, such as an increase in consumers' preference for the good or a decrease in the cost of producing the good. By expanding the effective market, these disturbances make it profitable for some salesmen to quote lower prices. Such expansions shrink the fraction of labor allocated to selling. In turn, this results both in lower average market price relative to marginal cost and increased physical output per unit of labor.