cssi/SciSciGPT-SciSciNet huggingface dataset:
Psychosocial processes underlying the maintenance and persistence of depression: implications for understanding chronic depression.

Abstract The three major theoretical perspectives on the maintenance and persistence of depression in the psychological literature are reviewed. Cognitive theorists, such as Teasdale and Nolen-Hoeksema, focus on how a reciprocal relationship between depressed mood and the individual’s processing of, and response to, their symptoms maintains and prolongs the duration of depressive episodes. Interpersonal theorists, such as Lewinsohn and Coyne, hypothesize that the depressed person’s interpersonal behavior elicits negative reactions from the social environment, leading to a downward spiral of persistent depression. Finally, recent studies have indicated that individuals who experienced childhood adversity are more susceptible to a chronic course of depression. Although these three perspectives vary somewhat in the degree of support they have accumulated, each exhibits some promise for helping to elucidate the maintenance and persistence of depression. However, much of the available empirical literature suffers from a number of critical limitations, including the lack of clinical samples, longitudinal studies, and adequate attention to confounding variables, such as the severity and duration of depression at baseline and comorbid psychopathology. We conclude by suggesting a number of ways in which cognitive and interpersonal factors and early adversity may interact to maintain and prolong depressive episodes.
Skill premia in Mexico: demand and supply factors

Skill premia trends for the Mexican urban labour market are analysed, decomposing into demand and supply factors. Moreover, among the former both between and within effects are studied, in line with the Katz and Murphy decomposition. It is shown that demand factors are more important for explaining the initial increment in skill premia, but supply factors are responsible for driving them down. It is concluded that the North American Trade Agreement (NAFTA) favours unskilled labour.
Effects of Cell Density and Low K on Action Potentials of Cultured Chick Heart Cells

Hearts from 7-day-old chick embryos were separated by 0.05% trypsin and subsequently cultured in a medium containing low (1.4 mM) and normal (4.4 to 5.6 mM) potassium (K) concentration. A method was developed for controlling environmental conditions (pH, temperature, osmolarity) of 1- to 3-day. old cultured heart cells during intracellular recording with microelectrodes. No apparent differences were noted in the measurement of the several components of the action potential as a function of incubation time. Action potential configurations recorded from cells in dense areas of a culture were noticeably different from those potentials obtained in sparse areas of the same culture; the latter were similar to those of the slowly conducting cardiac junctional tissues. This difference was observed both in the presence of normal and low K. The transmembrane potential recorded from cells in densely populated areas in the normal K medium was characterized by large amplitude and steady, high resting potential whereas that recorded from cells in similar areas in the low K medium had a small amplitude, low resting potential and prominent diastolic depolarization. The tissue cultured in low K also showed a tendency to fibrillate and spontaneously defibrillate.
A systematic review of the femoral origin and tibial insertion morphology of the ACL

Transtibial single bundle anterior cruciate ligament (ACL) reconstruction has been the gold standard for several years. This technique often fails to restore native ACL femoral origin and tibial insertion anatomy of the ACL. Recently, there is a strong trend towards a more anatomical approach in single and double bundle ACL reconstruction. Using the anatomic double bundle structure of the ACL as a principle, the entirety of both tibial insertion and femoral origin of both bundles, the posterolateral and anteromedial, may be restored. Reflected by recent publications over the past two years, there is an increasing interest in the anatomy of the ACL. In the current study, a PubMed literature search was performed looking for measurements of the ACL femoral origin and tibial insertion. These studies show a large variability in the size and the anatomy of the femoral origin and tibial ACL insertion using different methods and specimens. The diversity of reported measurements makes clinical application of these data difficult at best. Thus, it is of paramount importance to understand the individual variations in size and shape of the ACL femoral origin and tibial ACL insertion. This study is a systematic review of the morphology of the ACL femoral origin and tibial insertion as reported in the literature.
Intersubband plasmons in semiconductor quantum wires.

Intersubband plasmons in semiconductor quantum wires are studied in the harmonic-confinement-potential model and in the random-phase approximation. For a system with M population subbands, we find there exist M different modes of the intersubband plasmon, each of which represents an electronic collective transition from one subband to its adjacent subband. When the coupling between the modes is neglected, an analytic expression for the frequencies of these M modes is derived. Also, we have included the couplings in a numerical calculation. Our calculation shows that, when one increases the magnitude of the gate voltage [such as in the experiments of Hansen et al., Phys. Rev. Lett. 58, 2586 (1987) and Brinkop et al., Phys. Rev. B 37, 6547 (1988)], which would effectively increase the subband separation and decrease the Fermi energy, the largest frequency of these multiple intersubband plasmon modes displays a quantum-oscillation behavior but with an overall increasing trend. In addition, the average value over the associated oscillation period for this mode falls in a range that is in good agreement with the experimental observations. Finally, the damping of the intersubband plasmon is analyzed.
The preterm labor index and fetal fibronectin for prediction of preterm delivery with intact membranes

Abstract Objective To compare the preterm labor index with the biochemical marker fetal fibronectin in predicting preterm delivery. Methods In 185 women with preterm labor and intact membranes, the preterm labor index was determined based on clinical findings of uterine contractions, bleeding, and cervical dilatation. An immunosorbent assay was used to measure oncofetal fibronectin. Results A significant negative correlation was noted between the preterm labor index and the interval from hospitalization to delivery. Based on a receiver operating characteristic curve, a preterm labor index 4 or higher was defined as positive. Rates of preterm delivery overall and of delivery within 1 week in the preterm labor index–negative group were 55.2% and 13.8%, respectively. Those in the preterm labor index–positive group were significantly higher (88.4% and 56.5%). With respect to predicting when a delivery would occur during the first week of hospitalization, the preterm labor index and fetal fibronectin did not differ in sensitivity (77.7% and 73.8%, respectively), specificity (79.5% and 74.2%), positive predictive value (66.7% and 60.8%), or negative predictive value (84.5% and 83.9%). However, within the preterm labor index-negative group, the rates of preterm delivery (68.4%), delivery within 1 week (28.9%), and neonatal treatment in an intensive care unit (36.8%) were significantly higher in fetal fibronectin-positive than in fibronectin-negative cases (46.2%, 9.0%, and 10.3%, respectively). Conclusion The preterm labor index was similar to the fetal fibronectin assay in its ability to predict preterm delivery.
Survey of tissue diagnostic services in United States dental schools, 1953-1975.

Tissue-diagnostic services in United States dental schools were surveyed to determine activities during 1985. Results were compared with those of similar surveys conducted in 1953, 1958, 1969, 1975, and 1980. A continuing increase in the number of specimens processed has occurred, and there has been a parallel increase in the number of malignant specimens noted. The percentage of malignant specimens in relation to total specimens processed has not changed significantly.
Strategic sourcing and wage bargaining

Abstract We examine how multinational firms strategically source production to mitigate the consequences of wage bargaining with workers. When wage bargaining pressure differs across countries, firms allocate production of goods with high markups toward countries with relatively competitive labor markets, limiting the rents available to workers with strong bargaining power. We use product-level data from the universe of automotive production facilities in North America at a monthly frequency between 1988 and 2009 to structurally estimate variable price elasticities of demand for different vehicles. From the theory we derive an empirical strategy that allows us to distinguish the impact of wage bargaining pressure from other sourcing motives. We find robust evidence that multinational firms strategically source their products across countries in response to differences in wage bargaining pressure.
Glucocorticoid tight binding in rat liver and thymus particles.

Abstract Glucocorticoid binding to certain cell particles of rat liver and thymus following treatments in vivo and in vitro consists in part of a very “tight binding” that resists hot and cold perchloric acid extractions. This binding is found in thymus nuclei and in liver cytoplasmic particles, but not in liver nuclei nor in thymus mitochondria or microsomes. The existence of “tight binding” coincides with the ability of the same particles to bind free corticoid directly in incubations in vitro . The difference in the cellular location of this binding suggests that different methods of glucocorticoid activation exist in the anabolic target tissue, liver, and the catabolic target tissue, rat thymus.
High Degree of Heterogeneity in Alzheimer's Disease Progression Patterns

There have been several reports on the varying rates of progression among Alzheimer's Disease (AD) patients; however, there has been no quantitative study of the amount of heterogeneity in AD. Obtaining a reliable quantitative measure of AD progression rates and their variances among the patients for each stage of AD is essential for evaluating results of any clinical study. The Global Deterioration Scale (GDS) and Functional Assessment Staging procedure (FAST) characterize seven stages in the course of AD from normal aging to severe dementia. Each GDS/FAST stage has a published mean duration, but the variance is unknown. We use statistical analysis to reconstruct GDS/FAST stage durations in a cohort of 648 AD patients with an average follow-up time of 4.78 years. Calculations for GDS/FAST stages 4–6 reveal that the standard deviations for stage durations are comparable with their mean values, indicating the presence of large variations in the AD progression among patients. Such amount of heterogeneity in the course of progression of AD is consistent with the existence of several sub-groups of AD patients, which differ by their patterns of decline.
Effects of uridine in models of epileptogenesis and seizures

Due to the limited efficacy and side effects of current antiepileptic drugs (AEDs), the search for new therapeutic agents is critical. Uridine, a possible endogenous antiepileptic modulator, has been demonstrated to have anticonvulsant effects in some models of epilepsy, but not others. In this study, we examined possible neuroprotective effects of uridine by administering the agent following lithium-pilocarpine induced status epilepticus. The effects of uridine were assessed on EEG patterns, visual-spatial memory in the water maze and histopathology. There was a trend for reduced EEG spike frequency, improved visual spatial memory and better histology score in rats receiving uridine. The antiepileptogenic and anticonvulsant effects of uridine were studied by administering uridine to rats undergoing rapid kindling or following full kindling. In the rapid kindling models, uridine had a moderate antiepileptogenic and anticonvulsant effect. These results suggest uridine may have potential to aid in the prevention and treatment of epilepsy.
Identification of Multiple Diffusion Rates in Mixed Solvent Anion Exchange Membranes Using High Resolution MAS NMR

High resolution magic angle spinning (HRMAS) 1H NMR in combination with 2D exchange NOESY and pulsed field gradient (PFG) NMR diffusion experiments have been used to characterize 1 N methanol swoll...
Pattern formation techniques in photochemical etching

Abstract The principal techniques for pattern formation in photochemical etching are: (i) image projection; (ii) contact or proximity masking; (iii) direct writing; (iv) optical (holographic) interference; (v) patterned pre-etch substrate modification. The applicability of each for a particular purpose is determined both by the intrinsic optical characteristics of the pattern forming technique and by the characteristics of the specific etching process.
Validated automatic brain extraction of head CT images.

Abstract Background X-ray computed tomography (CT) imaging of the brain is commonly used in diagnostic settings. Although CT scans are primarily used in clinical practice, they are increasingly used in research. A fundamental processing step in brain imaging research is brain extraction — the process of separating the brain tissue from all other tissues. Methods for brain extraction have either been 1) validated but not fully automated, or 2) fully automated and informally proposed, but never formally validated. Aim To systematically analyze and validate the performance of FSL's brain extraction tool (BET) on head CT images of patients with intracranial hemorrhage. This was done by comparing the manual gold standard with the results of several versions of automatic brain extraction and by estimating the reliability of automated segmentation of longitudinal scans. The effects of the choice of BET parameters and data smoothing is studied and reported. Methods All images were thresholded using a 0–100 Hounsfield unit (HU) range. In one variant of the pipeline, data were smoothed using a 3-dimensional Gaussian kernel (σ = 1 mm3) and re-thresholded to 0–100 HU; in the other, data were not smoothed. BET was applied using 1 of 3 fractional intensity (FI) thresholds: 0.01, 0.1, or 0.35 and any holes in the brain mask were filled. For validation against a manual segmentation, 36 images from patients with intracranial hemorrhage were selected from 19 different centers from the MISTIE (Minimally Invasive Surgery plus recombinant-tissue plasminogen activator for Intracerebral Evacuation) stroke trial. Intracranial masks of the brain were manually created by one expert CT reader. The resulting brain tissue masks were quantitatively compared to the manual segmentations using sensitivity, specificity, accuracy, and the Dice Similarity Index (DSI). Brain extraction performance across smoothing and FI thresholds was compared using the Wilcoxon signed-rank test. The intracranial volume (ICV) of each scan was estimated by multiplying the number of voxels in the brain mask by the dimensions of each voxel for that scan. From this, we calculated the ICV ratio comparing manual and automated segmentation: I C V automated I C V manual . To estimate the performance in a large number of scans, brain masks were generated from the 6 BET pipelines for 1095 longitudinal scans from 129 patients. Failure rates were estimated from visual inspection. ICV of each scan was estimated and an intraclass correlation (ICC) was estimated using a one-way ANOVA. Results Smoothing images improves brain extraction results using BET for all measures except specificity (all p In the 1095 longitudinal scans, this pipeline had a low failure rate (5.2%) and the ICC estimate was high (0.929, 95% CI: 0.91, 0.945) for successfully extracted brains. Conclusion BET performs well at brain extraction on thresholded, 1 mm3 smoothed CT images with an FI of 0.01 or 0.1. Smoothing before applying BET is an important step not previously discussed in the literature. Analysis code is provided.
On the Dynamics of Wind-Driven Lake Currents

Abstract Two time-dependent “vertical cross section models” are analyzed and applied to wind-driven currents in Lake Ontario. The models are: 1) a linear frictionless, two-level model, and 2) a numerical model which includes both friction and nonlinear terms. They predict current and temperature under the assumption that all variables except pressure are independent of the longshore coordinate. The longshore pressure gradient is computed from the condition that the volume transport normal to the cross section is zero. First, the quasi-static response of the linear frictionless model is studied to isolate the effects of topography and stratification on the structure of the coastal currents. It predicts that the vertically averaged longshore current is independent of both rotation and stratification, being in the direction of the wind where the water is shallower than average and opposite the wind in the deep water. Under homogeneous conditions, the strongest currents are confined to a thin (∼3 km wide for ...
Upper GI Bleeding in a Post-Liver Transplant Patient

Question: A 45-year-old man presented to the emergency room with large-volume hematochezia and subsequent hematemesis. His medical history is notable for alpha-1 antitrypsin deficiency with eventual liver failure. He underwent orthotopic liver transplantation 9 months prior, which was complicated by ischemic cholangiopathy with recurrent cholangitis and need for serial percutaneous cholangiogram tube exchanges. He underwent retransplantation 2 months before presentation, this time with a relatively uncomplicated postoperative course. The patient was not on aspirin or any nonsteroidal anti-inflammatory drugs. On this presentation, he was afebrile but hemodynamically unstable with a blood pressure of 82/60 mmHg and a heart rate of 110 bpm. Nasogastric lavage returned bright red blood with clot. Laboratory values were as follows: White blood cell count, 8300/ L (neutrophils, 82%); hemoglobin, 8.2 g/dL; platelet count, 92,000/mm3; blood urea nitrogen, 24 mg/dL; creatinine, 1.0 mg/dL; prothrombin time, 12.4 seconds; and International Normalzed Ratio, 1.2. Between admission and intervention, the patient required a total transfusion of 12 U of packed red blood cells for emodynamic support. Upper gastrointestinal endoscopy revealed a normal esophagus. The stomach contained a large amount of blood clot, but no site f active bleeding. Examination of the duodenum showed an adherent blood clot emanating from the ampulla of Vater (Figure A). he patient was referred to interventional radiology for visceral angiography (Figure B). What is the diagnosis? Look on page 1624 for the answer and see the GASTROENTEROLOGY web site (www.gastrojournal.org) for more information n submitting your favorite image to Clinical Challenges and Images in GI.
An integrated approach to the study of polLution transport and waves in the coastal zone - Part II: Modeling

Among the Applications Activities (the application of NASA technological expertise to civil sector problems) at the Langley Research Center are the study of pollution transport in the Coastal Zone and coastal wave conditions. This paper describes the Coastal Zone modeling work being undertaken in support of these Applications Activities. The analytical models described are being developed to provide a predictive capability for pollution transport and wave conditions in the Coastal Zone. The models include: (1) a Continental Shelf circulation model, (2) a North Atlantic circulation model intended for validation of the general ocean circulation models, (3) two pollution dispersal models, and (4) a first-order coastal wave refraction model.
A comparison of methods for studentizing the sample median

Various methods for “Studentizing” the sample median are com-pared on the basis of a Monte Carlo study. Several of the methods do rather poorly while two, the bootstrap and the standardized length of a distribution free confidence interval, behave accept-ably acrors a wide range of sample sizes and several distributions of varying tail length. These two methods seem to agree closely with the distribution free confidence intervals and moreover, un-like these intervals, the methods can be extended to a method of accurate inference for λ1 regreasion.
Domain walls, wakes, and structure formation.

We consider a cosmological domain wall model where the dark matter interacts nongravitationally with the walls. We find that the dark matter is quickly (as early as z ≃ 100) swept up in wakes and voids, with the wakes growing with time in a self-similar manner. The dark matter wakes, of order 5h −1 Mpc thick today, tug on the baryons, which also trail behind in wakes of similar thickness. We find that the peculiar motions induced are of the order of a few hundred km/s, coherent on a scale of order 20h −1 Mpc. The baryon overdensities generated by the domain walls are distributed in a geometry similar to that of galaxy superclusters found in recent surveys
Psychosocial health during pregnancy and self-coherence: Theoretical considerations

A personality characteristic labeled ‘self-coherence’ has been found to be an independent variable in achieving psychosocial health during pregnancy. Psychosocial health is defined as successful resolution of the conflict and change inherent in pregnancy demonstrated by initiation of an affectional tie to the fetus and readiness to take on the mothering role. Pregnancy is widely regarded as a psychosocial developmental stage in which there is an interaction between genetic endowment and environmental influences of the past and present. As with other psychosocial stages, there is an interplay during pregnancy between physical development, self-development, and social development in response to perceived conflict and change. Self-coherence is conceptualized as the facilitator of such an interplay through the development of cognitive schemata which enable the use of non-rational ideation and introspection to ‘cohere’ and experience a self, which in turn enables one to experience and cope with present reality...
High proton polarization achieved with a (Yb, Y) (C/sub 2/H/sub 5/SO/sub 4/)/sub 3/ x 9H/sub 2/O spin refrigerator in a nonuniform magnetic field

Proton polarization of approximately 65% has been achieved with the University of Massachusetts "spin refrigerator" in a nonuniform 1.07-T field at 1.25 K. The free protons in (Yb, Y) ${({\mathrm{C}}_{2}{\mathrm{H}}_{5}\mathrm{S}{\mathrm{O}}_{4})}_{3}$ \ifmmode\cdot\else\textperiodcentered\fi{} 9${\mathrm{H}}_{2}$O are polarized through sample rotation at 100-200 rps. Results represent the first confirmation of high polarization predicted by a single-Yb-ion interaction model since the original proposals of Jeffries and Abragam. The polarized-proton target, with length equivalent to 9 cm of liquid hydrogen, will be utilized in studies of strange particles.
Land observation from geosynchronous earth orbit (LOGEO): Mission concept and preliminary engineering analysis

Abstract We propose an Earth-observation mission Land Observation from Geosynchronous Earth Orbit (LOGEO) to place two spin-scan-stabilized 500-m resolution 9-band VNIR–SWIR imagers in a near-geosynchronous inclined orbit, allowing 15 min observations with a full range of daily sun angles and 30 ∘ variations in view angle. LOGEO drifts westward at about 4 ∘ per day, providing geostationary-style coverage for all points on the globe eight times per year. This unique imaging geometry allows accurate retrievals of daily changes in surface bidirectional reflectance, which in turn enhances direct retrieval of biophysical properties, as well as long term and consistent land surface parameters for modeling studies that seek to understand the Earth system and its interactions. For studies of climate and environmental dynamics, LOGEO provides accurate observations of atmospheric aerosols, clouds, as well as other atmospheric constituents across a diverse number of spatial and temporal scales. This collection of land, atmospheric, and climate data products are directly applicable to seven of the nine GEOSS societal benefits areas, providing great opportunities for international collaboration. We also present an overview of LOGEO's systems architecture, as well as top-level design-trade studies and orbital scenarios.
Vicarious Punishment in a Work Setting: A Failure to Replicate

This research experimentally assessed the effects of vicarious punishment on the affective reactions and behavior of coworkers who observed a peer receive a punishment. In addition, the effects on observers of an emotional, nonaccepting reaction to the punishment by the recipient were examined. While emotional reactions by recipients of punishment exerted a negative effect upon observers' satisfaction with supervision, no main effects were observed for punishment upon output. Results conflict with previous research on the use of punishment in work settings. Explanations of these conflicting findings are suggested.
Distinguishing random and deterministic systems: Abridged version

Abstract This paper attempts to give a mathematically precise version of recent tests on an observed time series {at} for the presence of low dimensional deterministic chaos. Three practical tests for chaos are discussed: (a) the correlation dimension of {at} must be low, (b) the estimated largest Lyapunov exponent must be positive, (c) the residuals {at} of an estimated linear time (or nonlinear) series model (for a large class of such models) must have the same dimension and largest Lyapunov exponent as {at}. Based on (a)-(c) evidence for chaos in post war II, U.S. quarterly real GNP is weak.
Distribution of cytochrome P-450 monoxygenase enzymes in the nasal mucosa of hamster and rat.

Deposition of inhaled particulates onto the respiratory mucosa is relatively great in that portion of the nasal cavity unprotected by ciliated, goblet, or keratinized superficial cells. The cytochrome P-450 system is an important enzyme system involved in the biotransformation of xenobiotics into metabolites that are more readily absorbed. To examine the transitional region caudal to the nasal vestibule, nasal tissues of hamster and rat were prepared for immunocytochemistry. Blocks of tissue representing four levels along the axis of the nasal cavity were examined. Paraffin sections were processed through the avidin-biotin peroxidase procedure, with diaminobenzidine tetrahydrochloride as the chromagen. Enzyme localization was accomplished through the use of antibodies for three rabbit cytochrome P-450 isozymes; 2, 5, and 6 (subfamilies IIB, IVB, and IA, respectively); and for rabbit NADPH-cytochrome P-450 reductase. Enzyme distribution was similar in both hamster and rat nasal tissues except in cells of striated and intercalated ducts of nasal glands and in cells of the nasolacrimal duct where immunoreactivity for reductase and isozyme 2 was intense in nonciliated cells lining the nonolfactory epithelium, in sustentacular cells of the olfactory epithelium, and acinar cells of olfactory glands. Distribution of reaction products to isozyme 5 and 6 were similar to but not so intense as those of reductase an isozyme 2. Reaction products for reductase and isozyme 2 occurred generally in the same cellular and intracellular regions with the following exceptions: isozyme 2 was more concentrated in cells of striated ducts and of the nasolacrimal duct, and reductase was more abundant in intercalated ducts of nasal glands. Ciliated and goblet cells in epithelia lining much of the nasal cavity evidenced little reactivity; those ciliated cells adjacent to olfactory mucosa contained reaction product. It is concluded that the nonciliated epithelium adjacent to the internal ostium of the nose contains enzymes essential for biotransforming extrinsic particles that impinge on it from inhaled air currents.
Studies of transamination.

Abstract 1. 1. In addition to previously described transaminations, it has been found that acetone powders of brain, liver, Escherichia coli , and Aspergillus fumigatus can catalyze the transamination of δ-aminovaleric acid and α,γ-diaminoglutaric acid with α-ketoglutarate. 2. 2. The extent of transamination with α-ketoglutarate of the 3–6-carbon straight-chain ω-amino monocarboxylic acids was compared with the corresponding α,ω-amino acids, and the results were discussed.
Measuring the impact of programs that challenge the public stigma of mental illness.

Public stigma robs people with mental illnesses from rightful opportunities related to work and other important life goals. Advocates have developed anti-stigma programs meant to address the prejudice and discrimination associated with these conditions. Evidence is now needed to make sense of program impact; this paper looks at measurement issues related to stigma change. Community-based participatory research is central to this research and includes the involvement of a diverse collection of stakeholders in all phases of evaluation. Investigators should be cautious about measures vis-a-vis social desirability effects and should directed by social validity of targeted audiences. Conceptual domains with some research support that correspond with assessments include behavior, penetration, psychological perspective, knowledge, and physiological/information processes. These issues are summarized as ten recommendations for evaluation of anti-stigma programs.
Outsourcing of Corporate Information Services: Implications for Redesigning Corporate Library Services.

The current trend in outsourcing of information services threatens the survival of corporate libraries. Outsourcable services seem to demand less case-by-case diagnosis and customization of products than in-house services. Consequently, it is advocated that corporate libraries redesign their services to accentuate those characteristics. Librarians could serve as information counselors on project work teams so as to enhance the responsiveness and flexibility of library services to their clients' needs. The implications of this service model for staffing, and developing service and quality values are discussed.
Hairy roots of Helianthus annuus : A model system to study phytoremediation of tetracycline and oxytetracycline

The release of antibiotics to the environment has to be controlled because of serious threats to human health. Hairy root cultures of Helianthus annuus (sunflower), along with their inherent rhizospheric activity, provide a fast growing, microbe-free environment for understanding plant-pollutant interactions. The root system catalyzes rapid disappearance of tetracycline (TC) and oxytetracycline (OTC) from aqueous media, which suggests roots have potential for phytoremediation of the two antibiotics in vivo. In addition, in vitro modifications of the two antibiotics by filtered, cell- and microbe-free root exudates suggest involvement of root-secreted compounds. The modification is confirmed from changes observed in UV spectra of exudate-treated OTC. Modification appears to be more dominant at the BCD chromophore of the antibiotic molecule. Kinetic analyses dismiss direct enzyme catalysis; the modification rates decrease with increasing OTC concentrations. The rates increase with increasing age of cultures from which root exudates are prepared. The decrease in modification rates upon addition of the antioxidant ascorbic acid (AA) suggests involvement of reactive oxygen species (ROS) in the antibiotic modification process.
An importance sampling scheme for simulating the degradation and failure of complex systems during finite missions

The variance reduction technique of path-splitting is applied to reliability analysis of complex systems. Two approaches are given. In the first, paths are split into a fixed prespecified number of branches. In the second, a sequential procedure is used to estimate the number of branches which will give the maximum variance reduction. The method is illustrated on a simulation of a simplified model of a fault-tolerant computer system. The estimated variance reduction ranged from 36% to 61%.
Conformational differences of oxytocin and vasopressin as observed by fluorescence anisotropy decays and transient effects in collisional quenching of tyrosine fluorescence

We used gigahertz frequency-domain fluorometry to examine the tyrosyl fluorescence intensity and anisotropy decays of the single-tyrosine cyclic peptide hormones oxytocin and vasopressin. Acrylamide quenching and a distance-dependent quenching model for collisional quenching were used to evaluate the extent of tyrosyl exposure to the quencher and to provide increased resolution of the picosecond anisotropy decays. Analysis of the intensity decays using a lifetime distribution model shows different distributions for oxytocin and vasopressin. We found that the tyrosyl fluorescence of lysine-vasopressin, as revealed both by the lifetime Stern-Volmer plots and from the quenching analysis, is quenched more effectively than oxytocin. ForN-acetyltyrosinamide (NATyrA), oxytocin, and lysine-vasopressin, we recovered apparent diffusion coefficients for quenching of 4.7×10−6, 0.44×10−6, and 4.3×10−6 cm2/s, respectively, the lower value for oxytocin suggesting a shielded environment for its tyrosyl residue. Tyrosyl anisotropy decays were recovered by global analysis of progressively quenched samples. Compared with oxytocin, vasopressin displayed a longer correlation time for overall rotational diffusion and a higher amplitude for picosecond segmented motions of its tyrosyl residue. All the data are consistent with a more extended and flexible solution structure for vasopressin than for oxytocin.
Influence of left ventricular function on survival and mode of death after implantable defibrillator therapy (Cleveland Clinic Foundation and Montefiore Medical Center experience)

To determine the influence of left ventricular (LV) function on survival and mode of death in patients with an implantable cardioverter-defibrillator (ICD), sudden death, surgical mortality, total arrhythmia-related death, total cardiac death and total death were retrospectively evaluated in 377 consecutive patients. The outcomes were also compared between patients with an LV ejection fraction > or = 30% (214 patients, group 1) and < 30% (148 patients, group 2). Surgical mortality was 3.9% (1.8% in group 1, 7% in group 2). During the follow-up of 25 +/- 20 months, actuarial survival rates of all patients at 3 years were 96% for sudden deaths, 81% for total cardiac deaths and 74% for total mortality. When the 2 groups were compared, survival rates of groups 1 and 2 at 3 years, respectively, were 99 and 90% for sudden death (p < 0.05), 97 and 84% for sudden death and surgical mortality (p < 0.01), 94 and 80% for the total arrhythmia-related death (p < 0.001), 88 and 68% for total cardiac death (p < 0.0001), and 81 and 62% for total mortality (p < 0.002). In group 2, 73% of total cardiac deaths within 1 year were causally related to the arrhythmia. Thus, in patients with an ICD, sudden death rates were very low. However, total cardiac death and total death rates were relatively higher. The outcomes of patients with an ICD were strongly influenced by the degree of LV dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)
ADC spectral performance measurement uncertainty in DFT method

Spectral performances are important specifications need to be measured for many analog and RF circuits. Measurement errors of these performances are random variables related to additive noise which is normal distributed. Few research results on measurement error can be found in literature. Therefore accuracy or error of measurement is usually estimated by experience. This paper presents rigorous analyses of measurement error of THD and SFDR in DFT testing. Analyses are validated by Matlab simulations and provide useful guidance on how to select number of samples to achieve certain accuracy and confidence level in real testing.
Automatic Visual Inspection Of Metal Surfaces

Applications in automatic visual inspection require careful control of image contrast in the presence of varying part surface conditions. This paper models the part imaging problem as a stochastic light scattering phenomenon. Several equations are presented which provide a relation between a visual image and surface roughness, reflectance, and position.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Can mechanics control pattern formation in plants

Development of the plant body entails many pattern forming events at scales ranging from the cellular level to the whole plant. Recent evidence suggests that mechanical forces play a role in establishing some of these patterns. The development of cellular configurations in glandular trichomes and the rippling of leaf surfaces are discussed in depth to illustrate how intricate patterns can emerge from simple and well-established molecular and cellular processes. The ability of plants to sense and transduce mechanical signals suggests that complex interactions between mechanics and chemistry are possible during plant development. The inclusion of mechanics alongside traditional molecular controls offers a more comprehensive view of developmental processes.
A BOUNDARY CONDITION DISSECTION METHOD FOR THE SOLUTION OF BOUNDARY-VALUE HEAT CONDUCTION PROBLEMS WITH POSITION-DEPENDENT CONVECTIVE COEFFICIENTS

A boundary condition dissection method is developed on the postulation that a condition imposed on the boundary of a heat conduction problem may be realized in practice by using conditions not of the imposed kind. Thus, a Robin condition imposed on the boundary may be dissected as a linear combination of the boundary heal flux and temperature, arid by doing so, heat conduction problems with position-dependent convective coefficients can be solved by the separation-of-variables technique. The method leads to the solution of a Fredholm integral equation of the second kind with a degenerate kernel, and this equation may be solved by using simultaneous algebraic equations. The method is superior to the finite-difference method and the methods of weighted residuals, which have been conventionally used in solving suck problems. Extension of the method to the solution of other heat conduction problems is also possible and mentioned in the paper.
Predicting Fatigue Failures

Engineers who design structures often start at the end: They consider how the materials used will fail. Structures must be overdesigned—a bridge may be able to withstand twice the expected load when it is first built—but over time, repeated cycles of loading and unloading introduce defects in the materials that can ultimately lead to fatigue failure; for example, a paper clip that is bent back and forth until eventually it snaps. Predicting failure is easier for ductile than for brittle materials, and designers can accurately model their response to fatigue loading ( 1 ). However, many relatively brittle materials, such as advanced ceramics, intermetallics, and composites of brittle and ductile materials, are seeing increased use due to their favorable low-density or high-temperature properties. New methods are needed to predict when and how these materials will fail due to cyclic fatigue loading.
Cosmic-Ray Instrumentation in the First U. S. Earth Satellite

The first U. S. satellite, 1958 Alpha (Explorer I) carried instrumentation to measure cosmic‐ray intensity, micrometeorite impacts, and temperatures within the satellite. The instrumentation was designed with emphasis on conservation of electrical power, on stable and reliable operation, on operation over a wide range of temperatures, and on compactness and mechanical ruggedness.The cosmic‐ray instrumentation in 1958 Alpha operated according to expectations, providing several hundred recordings of data received during transits over ground stations. These data led to the discovery of a belt of high‐intensity radiation around the earth.
Estimation of Mobile Velocities and Direction of Movement in Mobile-to-Mobile Wireless Fading Channels

This paper proposes two new estimators, one for mobile velocities and one for the direction of movement in mobile-to-mobile (M-to-M) wireless fading channels. First, we propose a new crossing-based estimator that jointly estimates the velocities of both the transmitter and the receiver in M-to-M communications. Then, using the velocities estimator, we derive a new correlation-based estimator for the relative direction of movement of the transmitter and the receiver. The proposed estimators are designed for narrow-band wireless M-to-M communications. They are evaluated through extensive computer simulations, and the results show that the proposed algorithms provide very good estimation accuracy and perform well in the presence of nonisotropic scattering, line-of-sight (LoS) propagation, and Gaussian noise.
Adherence of neutrophils to hemodialysis membranes : role of complement receptors

Adherence of neutrophils to hemodialysis membranes: Role of complement receptors. Complement activation occurs during hemodialysis using cellulosic dialysis membranes with the consequent deposition of C3 activation and degradation products on the membrane surface. To determine if these complement fragments are functionally active, we examined their capacity to mediate leukocyte adherence to cuprophan membranes. Immunoblotting of proteins eluted from plasma-treated cuprophan membranes confirmed the presence of both C3b and iC3b. Incubation of cuprophan membranes with heparinized whole blood resulted in adherence of leukocytes but not erythrocytes. Neutrophils were the primary cell type bound, with monocytes comprising less than 5% of the adherent cells. Studies using indium-labeled neutrophils demonstrated that the binding was plasma dependent and increased with time up to two hours. Neutrophil binding was inhibited by preincubation of the plasma-treated cuprophan membrane with anti-C3 or preincubation of neutrophils with an antibody directed against the α chain of complement receptor type 3 (CR3). These observations indicate that iC3b deposited on cuprophan membrane surface as a result of complement activation mediates neutrophil adherence via interaction with CR3. They also support the hypothesis that, in addition to the anaphylatoxins released into the fluid phase, complement activation products that remained membrane bound during hemodialysis also stimulate pathophysiological responses.
Estrogen regulates preproenkephalin-A mRNA levels in the rat ventromedial nucleus: temporal and cellular aspects.

Abstract Numerous studies suggest that the ventromedial nucleus of the hypothalamus is a primary locus of control for reproductive behavior in the female rat. The display of lordosis behavior is estrogen dependent and its regulation appears to involve the activity of endogenous opioid circuits in the mediobasal hypothalamus and brainstem. Hypothalamic levels of preproenkephalin-A mRNA and the neuropeptide which it encodes, methionine-enkephalin, are dramatically up-regulated by estrogen. To characterize the temporal and cellular aspects of the effect of an acute exposure to estrogen on preproenkephalin-A mRNA levels in the ventromedial nucleus and arcuate nucleus of the hypothalamus, ovariectomized female rats were injected with 50 μg estradiol benzoate and used for quantitative in situ hybridization histochemistry of preproenkephalin-A mRNA. In the ventromedial nucleus, estrogen treatment caused a biphasic increase in the number of preproenkephalin-A mRNA cells. Maximal numbers of cells expressing preproenkephalin-A mRNA were observed at 1 and 48 h after estrogen injection. At 4 and 96 h after estrogen injection, the numbers of preproenkephalin-A mRNA cells were similar to that which was seen in the ovariectomized female. The induction of preproenkephalin-A mRNA expression in cells of the arcuate nucleus followed a similar pattern that peaked 48 h after exposure to estrogen. Levels of preproenkephalin-A mRNA per cell did not change in either nucleus as a function of estrogen treatment. Thus, acute estrogen treatment induces expression of preproenkephalin-A mRNA in populations of cells in theventromedial hypothalamus and arcuate nucleus in which preproenkephalin-A mRNA expression is undetectable by in situ hybridization in the absence of circulating estrogen.
Kinetic stabilities of bis-terpyridine complexes with iron(II) and cobalt(II) in organic solvent environments

Though 2,2′:6′,2′′-terpyridine is commonly used as a ligand for forming metallo-supramolecular assemblies in a variety of solvent environments, little is known about how the properties of the medium influence its behavior. We have studied the kinetic stabilities of bis terpyridine complexes with iron(II) and cobalt(II), and found variations in decay rate between commonly employed solvents of more than five orders of magnitude for iron, and thirty-fold for cobalt. While numerous factors likely contribute to these effects, a clear correlation between the decay rates of the iron complexes and the solubility of terpyridine suggests that favorable solvent–ligand interactions may lower the activation barrier for dissociation by stabilizing the transition state. These results illustrate the importance of solvent selection when designing metallo-supramolecular assemblies based on terpyridine, and also provide insights for further tuning the dynamic properties of these complexes.
Balanol analogues probe specificity determinants and the conformational malleability of the cyclic 3',5'-adenosine monophosphate-dependent protein kinase catalytic subunit

The protein kinase family is a prime target for therapeutic agents, since unregulated protein kinase activities are linked to myriad diseases. Balanol, a fungal metabolite consisting of four rings, potently inhibits Ser/Thr protein kinases and can be modified to yield potent inhibitors that are selective-characteristics of a desirable pharmaceutical compound. Here, we characterize three balanol analogues that inhibit cyclic 3',5'-adenosine monophosphate-dependent protein kinase (PKA) more specifically and potently than calcium- and phospholipid-dependent protein kinase (PKC). Correlation of thermostability and inhibition potency suggests that better inhibitors confer enhanced protection against thermal denaturation. Crystal structures of the PKA catalytic (C) subunit complexed to each analogue show the Gly-rich loop stabilized in an "intermediate" conformation, disengaged from important phosphoryl transfer residues. An analogue that perturbs the PKA C-terminal tail has slightly weaker inhibition potency. The malleability of the PKA C subunit is illustrated by active site residues that adopt alternate rotamers depending on the ligand bound. On the basis of sequence homology to PKA, a preliminary model of the PKC active site is described. The balanol analogues serve to test the model and to highlight differences in the active site local environment of PKA and PKC. The PKA C subunit appears to tolerate balanol analogues with D-ring modifications; PKC does not. We attribute this difference in preference to the variable B helix and C-terminal tail. By understanding the details of ligand binding, more specific and potent inhibitors may be designed that differentiate among closely related AGC protein kinase family members.