cssi/SciSciGPT-SciSciNet huggingface dataset:
Modelling of elastic constants of plasma spray deposits with ellipsoid-shaped voids

Abstract The five independent elastic constants of plasma spray deposits were calculated from constitutive equations and microstructural information (void aspect ratios and porosity) was gained from stereological analysis. The voids within the deposit were assumed to be ellipsoidal in shape. The structure of the deposit was considered to be transversely isotropic with respect to the spray direction, which requires five independent elastic constants of a stiffness tensor. Solid mechanics models containing ellipsoid-shaped voids were applied to obtain the five independent elastic constants of the deposits. The calculated elastic constants were compared to the experimentally determined values.
Diagnosing Climate Feedbacks in Coupled Ocean–Atmosphere Models

We review the methodologies used to quantify climate feedbacks in coupled models. The method of radiative kernels is outlined and used to illustrate the dependence of lapse rate, water vapor, surface albedo, and cloud feedbacks on (1) the length of the time average used to define two projected climate states and (2) the time separation between the two climate states. Except for the shortwave component of water vapor feedback, all feedback processes exhibit significant high-frequency variations and intermodel variability of feedback strengths for sub-decadal time averages. It is also found that the uncertainty of lapse rate, water vapor, and cloud feedback decreases with the increase in the time separation. The results suggest that one can substantially reduce the uncertainty of cloud and other feedbacks with the accumulation of accurate, long-term records of satellite observations; however, several decades may be required.
Layered media green's function approximation in terms of spherical & cylindrical waves

A robust methodology is presented for the derivation of accurate, closed-from expressions for the Green's functions in planar stratified media. The methodology is based on the separation of the spectrum into two parts; the quasi-static and the dynamic part. The quasi-static part is calculated analytically in closed form, both in the spectral and space domain, and translates to a finite sum of spherical waves. The spectrum of the dynamic part is fitted in terms of rational functions and results in a finite sum of cylindrical waves, in the space domain. High accuracy is achieved for both the near field and the far field region due to the fact that both spherical and cylindrical waves are included in the closed form expressions. (4 pages)
Accelerated recovery from irradiation injury by angiotensin peptides.

Purpose: Angiotensin peptides have been shown to affect the proliferation and chemotaxis of multiple cell types. More recent studies in this laboratory have shown that angiotensin II (AII) can increase colony formation and proliferation by hematopoietic progenitors and mesenchymal cells in vitro. As white blood cell (WBC) recovery after bone marrow injury requires progenitor proliferation, the effect of AII and angiotensin (1–7) [A(1–7)], a non-hypertensive fragment of AII, on recovery from total body irradiation was evaluated in C57Bl/6 mice. Materials and methods: The effect of angiotensin peptides on hematopoietic recovery and the number of progenitors in the bone marrow of irradiated C57Bl/6 mice was evaluated. Results: Treatment of animals with angiotensin peptides accelerated hematopoietic recovery and increased the number of hematopoietic progenitors in bone marrow and in the blood. The increase in WBC concentration continued for a longer time after cessation of AII therapy than after treatment with filgrastim. Specifically, the number of WBCs continued to increase 21 days after irradiation with 7 days of angiotensin peptide administration. In contrast, the number of WBCs increased through day 13 with 7 days of filgrastim administration. On day 35 after irradiation (28 days after the last treatment), AII was shown to have increased the number of CFU-GM in the bone marrow of irradiated mice, whereas filgrastim administration had not. Angiotensin peptides also reduced the drop in platelet concentration after irradiation and increased the number of megakaryocyte precursors and megakaryocytes in the bone marrow. Receptor blocking studies indicated that losartan, an antagonist of the angiotensin type 1 receptor, blocked recovery of WBC levels in response to treatment with AII. In contrast, the increase in WBC levels in response to treatment with A(1–7), a ligand for other angiotensin receptors, was not affected by losartan. Conclusions: These findings suggest that these peptides utilize distinct receptors in the stimulation of hematopoietic recovery. In summary, systemic administration of angiotensin peptides led to an acceleration in hematopoietic recovery after irradiation. These peptides act to stimulate the formation of bone marrow progenitors, thereby facilitating recovery after myelosuppressive irradiation.
Expression of two self-enhancing antifreeze proteins from the beetle Dendroides canadensis in Drosophila melanogaster.

Antifreeze proteins (AFPs) lower the freezing point of water without affecting the melting point. This difference between melting point and freezing point has been termed thermal hysteresis. Antifreeze protein genes, dafp-1 and/or dafp-4, from the freeze-avoiding insect, Dendroides canadensis, were transferred to Drosophila melanogaster via P-element-mediated transformation. The Northern and Western blots showed expression of DAFP(s) at both transcript and protein levels. The highest thermal hysteresis activity of 6.78 ± 0.12 °C was detected in 5-day adult flies containing two copies of each of the dafp-1 and dafp-4 genes, while flies with two copies of either dafp-1 or dafp-4 had less activity, 5.52 and 3.24 °C, respectively (measured by nanoliter osmometer). This suggests synergistic enhancement of thermal hysteresis activity between DAFP-1 and DAFP-4 in transgenic D. melanogaster containing both DAFPs. Supercooling points without ice in contact with the insects were lowered in all 5 transgenic lines compared with controls, however, when ice was in contact with the flies, supercooling points were lowered only in the heterozygous + transgenic line. Also, transgenic D. melanogaster exhibited higher survivorship compared with controls when placed at low non-freezing temperatures (0 and 4 °C), however, DAFP-1 and DAFP-4 did not display any synergistic enhancement in these non-freezing survival experiments.
Ultrawideband VHF/UHF dipole array antenna

A linearly-polarized ultrawideband dipole array antenna has been developed for coverage in the VHF/UHF frequency range for communications or radar applications. The antenna design utilizes a horizontally polarized array of thick tubular dipole elements above a ground plane. Numerical electromagnetic simulations were used to analyze and optimize the antenna parameters prior to fabrication. Measurements of a 24-element ultrawideband dipole array prototype in an anechoic chamber demonstrate the antenna's return loss and gain pattern performance over a wide bandwidth.
Validity of computerized diagnoses, procedures, and drugs for inflammatory bowel disease in a northern California managed care organization.

Purpose Resources for studying inflammatory bowel disease (IBD) are needed in evaluations of drug safety including traditional drugs and new biologics agents. We developed an IBD registry, with ascertainment from computerized visit information. Objective We sought to characterize the positive predictive value (PPV) of IBD case-finding using computerized data compared with chart review. Methods We identified 2906 persons aged 89 years or younger with one or more IBD diagnoses in computerized visit data during the period of 1996–2002. The diagnosis of IBD was confirmed through chart review. Adopting chart review as the gold standard, the validity of computerized encounter data to determine IBD was estimated. Results Among the 2906 study subjects with one or more ICD-9 diagnosis codes of 555 or 556 in computerized data, 81% were confirmed as having IBD by chart review. Defining cases as those who underwent two or more visits without regard to diagnostic procedures or drug utilization maximized the correct classification of cases (PPV, 95%). Conclusions The quality of IBD diagnoses in computerized data is adequate to meet the aims of a wide range of research studies. Copyright © 2009 John Wiley & Sons, Ltd.
Endoscopic endonasal odontoidectomy in a child with chronic type 3 atlantoaxial rotatory fixation: case report and literature review

Although the transoral transpharyngeal approach has been the standard approach to decompress the odontoid process, it bears some disadvantages including risk of infection, prolonged intubation or tracheostomy, need for nasogastric tube feeding, extended hospitalization, and possible effects of phonation. The endoscopic transnasal approach is a viable alternative, managing to avoid some of the pitfalls of the more accepted transoral transpharyngeal approach. However, there have only been a handful of adult cases and only three pediatric cases. We present the case of a 10-year-old girl with a chronic type 3 atlantoaxial rotator fixation and significant spinal cord compression from basilar invagination and a displaced odontoid process. We performed an endoscopic endonasal odontoidectomy prior to posterior occiptocervical fusion on the patient. She was neurologically intact with a well-healed wound at 7-month follow-up.
Adding a contributing student pedagogy component to an introductory database course

An introductory database course is well established within computer science curricula. Instructors in this course are challenged to select a subset of possible topics to cover and emphasize and also to design appropriate assignments to help students master those topics. As theories regarding effective educational practice continue to emerge and become known, we also seek to invigorate our courses by including some of these newer techniques.Contributing Student Pedagogy is an umbrella term that refers to a family of techniques that involves finding ways for students to become directly involved in the production of course content utilized by other students. Students not only make use of content provided by other students, but they come to view that content as valuable. This paper reports on initial efforts to incorporate an assignment based on contributing student pedagogy into a standard database course. Several iterations took place, with improvements made between the first and second iterations. Plans for future iterations are included and implications, not only for the database course, but other Computer Science courses, are discussed.
Malposition of central venous catheters outside the central circulation.

Percutaneous insertion of central venous catheters is a common procedure. Although malposition of catheters within the central venous system frequently occurs, positioning of a catheter within a small central vein tributary is rarely reported. Three cases are described in which the central venous catheter was positioned within the venous system, but outside the central venous circulation
Evidence of Key Tinnitus-Related Brain Regions Documented by a Unique Combination of Manganese-Enhanced MRI and Acoustic Startle Reflex Testing

Animal models continue to improve our understanding of tinnitus pathogenesis and aid in development of new treatments. However, there are no diagnostic biomarkers for tinnitus-related pathophysiology for use in awake, freely moving animals. To address this disparity, two complementary methods were combined to examine reliable tinnitus models (rats repeatedly administered salicylate or exposed to a single noise event): inhibition of acoustic startle and manganese-enhanced MRI. Salicylate-induced tinnitus resulted in wide spread supernormal manganese uptake compared to noise-induced tinnitus. Neither model demonstrated significant differences in the auditory cortex. Only in the dorsal cortex of the inferior colliculus (DCIC) did both models exhibit supernormal uptake. Therefore, abnormal membrane depolarization in the DCIC appears to be important in tinnitus-mediated activity. Our results provide the foundation for future studies correlating the severity and longevity of tinnitus with hearing loss and neuronal activity in specific brain regions and tools for evaluating treatment efficacy across paradigms.
Biosynthesis of the pseudobactin chromophore from tyrosine

Abstract Biosynthetic studies have shown the incorporation of DL-[2,3,3- 2 H 3 ]-tyrosine into the chromophore of pseudobactin, a siderophore produced by Pseudomonas flourescens B10. A subsequent feeding using DL-[2′,5′,6′- 2 H 3 ]-3,4-dihydroxyphenylalanine showed no incorporation of the label, suggesting that oxidation of the aryl ring occurs after the incorporation of tyrosine. The 13 C NMR assignments of pseudobactin are also reported herein.
Two craniosynostotic syndrome loci, Crouzon and Jackson-Weiss, map to chromosome 10q23-q26.

Crouzon syndrome (MIM 123500) is a common autosomal dominant form of craniosynostosis with shallow orbits, ocular proptosis, and maxillary hypoplasia. Jackson-Weiss syndrome (MIM 123150) is another autosomal dominant craniosynostosis with highly variable phenotypic expression. Unlike Crouzon syndrome, Jackson-Weiss syndrome is associated with foot anomalies. We performed two point linkage and haplotype analyses using 13 dinucleotide repeat markers on chromosome 10, spanning a genetic distance of 108 cM. The Crouzon syndrome locus (CFD1) maps to the region of chromosome 10q2, with the tightest linkage to locus D10S205 (Z = 3.09, ($) over cap theta = 0.00). The Jackson-Weiss syndrome locus in the large Amish pedigree in which the condition was originally described was also linked to the chromosome 10q23-q26 region between loci D10S190 and D10S186. The D10S209 locus was most strongly linked (Z = 11.29, ($) over cap theta = 0.00), (C) 1994 Academic Press, Inc.
Numerical Issues Associated With the Full-Zone Model of the Optically Heated Floating-Zone Used in Semiconductor Processing

Recent models of the thermocapillary driven liquid bridge or full-zone (FZ) have highlighted numerical difficulties in the system, associated with the large velocity gradients near the free surface and the geometric singularity at r = 0. High resolution spectral solutions have been developed to account for these issues. These result in complex representations and highly specialized numerical procedures. After a brief review of these methods, a simplified formulation for the FZ model with strong form boundary conditions is proposed and discussed. Comparisons are made using base flows and stability analyses. Existing solutions have overcome the geometric singularity either by moving the grid away from the r = 0 axis, or by maintaining the correct Taylor series expansion in the representation of each dependent variable. The former has the weakness that an important constraint is not applied. The later formulation is rigorous, but results in complex expressions for the governing equations. To decrease the load associated with the mathematical manipulation and numerical implementation of this method, here a more general Chebyshev polynomial representation of the stream function is applied to the axisymmetric base flow. This removes the need to maintain the proper expansion and instead offers a set of equations in strong form by treating the axis as a boundary known from the spatial symmetry of the model. However, this does not guarantee that momentum is conserved at the internal symmetry boundaries. Various applications of the other boundary conditions are also studied. In the most accurate representation, all boundary conditions except the thermocapillary condition are cast in the strong form via orthogonality. These strong equations must be chosen carefully to avoid introducing redundant conditions. However, the result is a mathematically simpler representation that mimics the accuracy of previous methods.Copyright © 2008 by ASME
Development and Validation of the Computer Self-Efficacy Scale

A 32-item Computer Self-Efficacy Scale (CSE) was developed to measure perceptions of capability regarding specific computer-related knowledge and skills. Data from 414 individuals engaged in learning to use computers in three settings were used to conduct analyses for assessing the reliability and construct validity of the instrument. A principal factor analysis with oblique rotation produced a conceptually meaningful 3-factor solution with high alpha reliabilities. An additional analysis suggested that the males and females in this study differed in judgments of their computer capability.
Self-management of nutrition

Eleven overweight subjects received a behavioral treatment program for weight loss and a nutritional self-management program during a 10-week treatment period. The nutritional self-management program was evaluated using a multiple-baseline across-groups design. The results indicated that caloric restriction without the nutritional self-management program did not result in the consumption of a well-balanced diet. Introduction of the nutritional self-management program led to improvement of nutritional consumption across six food groups. Self-control of caloric intake within certain food groups, i.e., fruit and vegetable, was better than for others. These findings are discussed in terms of the methodological difficulties involved in managing nutrition and the significance of nutritional self-management for health problems other than obesity.
Methodologic challenges in studying risk factors for progression of knee osteoarthritis

Knee osteoarthritis (OA) is the most common joint disorder among adults in the US and severity of knee radiographic OA (ROA) is strongly associated with knee pain1. Pain from knee OA accounts for a large proportion of limitations with common activities of daily living2, and it is also the main reason for total knee replacement3. Because of the impact of symptoms from knee OA, people with symptomatic knee OA may be more motivated to take steps to prevent disease progression than those without ROA. Thus, investigators and persons with knee OA are particularly interested in risk factors that are associated with ROA progression because such knowledge will provide insightful guidance for secondary prevention4. Over the past few decades, many observational studies have examined risk factors for the occurrence (i.e., incident) and worsening (i.e., progressive) of knee OA. Several risk factors (i.e., female gender, obesity, high bone mineral density (BMD), joint injury, repetitive occupational stress on joints, and certain sports) have been found to be strongly associated with an increased risk for incident knee ROA5, 6. In contrast, findings on risk factors for ROA progression have been inconclusive. Except for the level of serum hyaluronic acid and generalized OA, no other risk factor has been consistently associated with the risk of ROA progression7. Interestingly, some risk factors (e.g., high BMD, low vitamin C) increase the risk of incident knee ROA but are not associated with, or even decrease, the risk of ROA progression8-11. This paradoxical phenomenon is not limited to studies of ROA. Many studies have shown that overweight and obesity increase the risk of cardiovascular disease; however, a number of studies have also reported that among subjects with preexisting cardiovascular disease, those who are overweight or moderately obese have an improved survival and lower risk of major cardiovascular events compared with subjects with normal weight12. These findings have been termed the “obesity paradox”. Similarly, while low body mass index (BMI) is associated with increased incident chronic obstructive pulmonary disease13, it does not, however, increase the risk of recurrent exacerbations of the disease14. While the risk factors for incident events may be biologically different from those for secondary events, there are also compelling methodological explanations behind such discrepancies. In this paper, we provide several explanations that may underlie the discrepancy between findings for knee ROA progression and those for knee ROA incidence. To be consistent with most studies, we consider knees eligible for studies of ROA progression being those that have preexisting mild (K/L=2) or moderate (K/L=3) ROA at baseline. We discuss how study design, study implementation, and outcome measures in studies of ROA progression can potentially bias the effect estimates of risk factors of interest using causal diagrams15. We also present findings from several large prospective studies of ROA progression to facilitate our explanations wherever applicable.
Multinational enterprise competition: grounding the eclectic paradigm of foreign production in resource‐advantage theory

Purpose – This paper seeks to explicate a dynamic theory of competition, i.e. the resource‐advantage theory of competition, with the aim of developing a theoretical foundation for the eclectic paradigm of foreign production.Design/methodology/approach – The paper is conceptual in approach.Findings – The paper develops a set of five criteria that should be met by any theory that attempts to ground the eclectic paradigm. In addition, it demonstrates that the resource‐advantage theory of competition meets all of these criteria.Research limitations/implications – By providing a theoretical foundation for the eclectic paradigm of foreign production, the paper provides researchers with a broader perspective from which to investigate multinational enterprise competition.Originality/value – The usefulness of frameworks, such as the eclectic paradigm of foreign production, is limited when they are not grounded in positive theories. By grounding the eclectic paradigm of foreign production, this paper enhances the p...
Controlled Clinical Trial of Sedative—Anticholinergic Drugs in Patients with the Irritable Bowel Syndrome

We studied 16 patients with long-standing irritable bowel syndrome of moderate severity using a controlled, double-blind crossover method. Five sedative-anticholinergic drug combinations and a placebo were tested. The subjective response was assessed with four subjective methods to include an increasing number of response variables. The patients preferred 30 mg phenobarbital plus 8 mg belladonna (P & B) to placebo (P = 0.02). Five of ten patients were helped "some" or "a lot" with placebo, while ten of 15 were helped "some" or "a lot" with P & B (P = 0.07). The ten prominent-symptoms method revealed that subjective symptoms such as nervousness, sleep difficulties, and tiredness were experienced as greater problems than diarrhea. The factor analysis method documented a strong placebo response. Simpler evaluation methods such as drug preference and a five-choice method appear more likely to show a positive drug effect, while the inclusion of a larger number of variables appears to emphasize the placebo portion of the response. These observations may help explain some of the apparent discrepancies between the conclusions of some controlled clinical trials and subsequent clinical experience.
Machine Translation of Very Close Languages

Using examples of the transfer-based MT system between Czech and Russian RUSLAN and the word-for-word MT system with morphological disambiguation between Czech and Slovak CESILKO we argue that for really close languages it is possible to obtain better translation quality by means of simpler methods. The problem of translation to a group of typologically similar languages using a pivot language is also discussed here.
Photo-, cathodo-, and electroluminescence studies of sputter deposited AlN:Er thin films

Abstract Green cathodoluminescence (CL), photoluminescence (PL) and electroluminescence (EL) have been obtained from Er-doped amorphous AlN thin films, 200 nm thick, prepared by rf magnetron sputtering. All films were activated by annealing at 750°C for 10 min in a nitrogen atmosphere. Three sharp bands at about 479, 538 and 559 nm corresponding to the 4 F 7/2 → 4 I 15/2 , 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 transitions are observed. Fine structure is seen on the major transitions that does not change with temperature indicating that this structure is related to different local environments of the Er3+ ion. The PL spectrum revealed sharp peaks from Er3+ ions and a broad spectral profile that might be from defect states in the amorphous AlN. The results from EL measurements show that Er-doped amorphous AlN films can be used as a phosphor layer in alternating-current thin-film electroluminescent (ACTFEL) devices.
Fluorescence resonance energy transfer study of shape changes in membrane-bound bovine prothrombin and meizothrombin.

Prothrombin activation to thrombin is a key control reaction in blood coagulation. During the process, prothrombin is sequentially cleaved at two peptide bonds (Arg323−Ile and Arg274−Thr) by factor...
Review of Research on the Myers-Briggs Type Indicator:

Research on the Myers-Briggs Type Indicator as a psychometric instrument and as a reflection of Jung's personality typology was reviewed. Its applications in education, business, the artistic world, and in decision-making processes of business have been extensive and well received.
Linear self-adjoint multipoint boundary value problems and related approximation schemes

Linear self-adjoint multipoint boundary value problems are investigated. The case of the homogeneous equation is shown to lead to spline solutions, which are then utilized to construct a Green's function for the case of homogeneous boundary conditions. An approximation scheme is described in terms of the eigen-functions of the inverse of the Green's operator and is shown to be optimal in the sense of then-widths of Kolmogorov. Convergence rates are given and generalizations to more general boundary value problems are discussed.
FORMATION OF CALLOSE AND LIGNIN DURING LEAF ABSCISSION

Deblading of bean leaves promoted the formation of callose and lignin in the abscission zone. The abscission layer became evident three days after deblading. The greatest increase in callose occurred in about two layers of cells during the development of the abscission layer. Four days after deblading, only a few layers of cells on the distal side of the abscission layer showed an increase in lignin. Lignification continued to expand to 8-10 layers of cells at the time of separation. After separation, the lignified cells remained with the petiole. Sieve elements in the abscission zone were covered with callose plugs and the vessels were occluded
Pressure dependent oxidation of Al(111): A photoemission and surface exafs study

Abstract The initial oxidation of Al(111) has been studied with photoemission and surface EXAFS for single crystal surfaces. We find that the oxidation is pressure dependent and that at pressures below 2 × 10-7 Torr molecular oxygen chemisorbs while at pressures above 1 × 10-6 Torr the chemisorption is disassociative. These results are discussed in the context of other LEED and surface EXAFS studies.
Biased paternal transmission of SNAP-25 risk alleles in attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is the most common childhood psychiatric disorder, affecting 5-10% of school-age children. Although the biological basis of this disorder is unknown, twin and family studies provide strong evidence that ADHD has a genetic basis involving multiple genes. A previous study found an association between ADHD and two polymorphisms in the 3' untranslated region (UTR) of SNAP-25, a gene encoding a synaptic vesicle docking protein known to play a role in the hyperactivity observed in the Coloboma mouse strain. In this paper, we test biased transmission of the 3' UTR SNAP-25 haplotype using a larger ADHD sample of 113 families with 207 affected children. Using the transmission disequilibrium test (TDT), we found a trend consistent with biased transmission of the TC haplotype of SNAP-25 in all transmissions and detected a significant distortion (P=0.027) when paternal transmissions were evaluated.
Iron sucrose augments homocysteine-induced endothelial dysfunction in normal subjects

Intravenous iron is commonly used in conjunction with erythropoietic agents to treat anemia in patients with chronic kidney disease. Iron has been proposed to promote oxidative stress and endothelial dysfunction in vascular tissues. We studied the acute effects of intravenous iron sucrose on homocysteine-induced endothelial dysfunction in the brachial artery of normal human subjects. In all, 40 healthy subjects received intravenous iron sucrose 100 mg or placebo over 30 min immediately before ingestion of 100 mg/kg of oral methionine in a double-blind, randomized study. Flow- and nitroglycerin-mediated dilation in the brachial artery, serum markers of iron stores, and homocysteine and nitrotyrosine levels were measured before and after study drug administration. Intravenous iron significantly increased transferrin saturation and non-transferrin-bound iron (NTBI) when compared with placebo. Flow-mediated dilation significantly decreased from baseline 1 h after administration of iron sucrose when compared with placebo (from 6.66±0.47 to 1.93±0.35% after iron sucrose vs from 6.00±0.40 to 5.61±0.46% after placebo, P
The vibrational spectrum of cis N2F2

Abstract The Raman spectrum of cis N 2 F 2 has been measured and the assignment of the inplane fundamentals is now firmly established as follows: ν 1 = 1526 cm −1 , ν 2 = 884 cm −1 , ν = 341 cm −1 , ν 6 = 945 cm −1 , ν 6 = 729 cm −1 . There is a weak feature in the Raman spectrum at ∼550 cm −1 which may be the torsional fundamental. The infrared spectrum has been remeasured and the 341 cm −1 vibration has been located as a type- B band.
A Continuous Flow Input Function Detector for H2 15O Blood Flow Studies in Positron Emission Tomography

A plastic scintillator detection system has been developed for the measurement of arterial blood H2 15O concentrations in positron emission tomographic (PET) local cerebral blood flow (lCBF) studies. The system uses a peristaltic pump to continually pull arterial blood from a radial artery through the plastic scintillator for the detection of the oxygen-15 positrons. To correct for the smearing of the arterial blood curve shape due to laminar flow in the pump tubing, a deconvolution technique has been developed.
CHAOTIC BEHAVIOR IN CERTAIN SINGULARLY PERTURBED EQUATIONS WITH PIECEWISE CONSTANT DELAYS

Conditions for the existence of chaotic behavior of some solutions of an equation of the form ex′(t)= -x(t)+f(x([t]), λ), where e and λ are positive constants and [t] denotes the greatest integer in t, are given. If e→0, it is shown that solutions tend to piecewise constant functions.
OPTESIM, a versatile toolbox for numerical simulation of electron spin echo envelope modulation (ESEEM) that features hybrid optimization and statistical assessment of parameters

Abstract Electron spin echo envelope modulation (ESEEM) is a technique of pulsed-electron paramagnetic resonance (EPR) spectroscopy. The analyis of ESEEM data to extract information about the nuclear and electronic structure of a disordered (powder) paramagnetic system requires accurate and efficient numerical simulations. A single coupled nucleus of known nuclear g value (gN) and spin I = 1 can have up to eight adjustable parameters in the nuclear part of the spin Hamiltonian. We have developed OPTESIM, an ESEEM simulation toolbox, for automated numerical simulation of powder two- and three-pulse one-dimensional ESEEM for arbitrary number (N) and type (I, gN) of coupled nuclei, and arbitrary mutual orientations of the hyperfine tensor principal axis systems for N > 1. OPTESIM is based in the Matlab environment, and includes the following features: (1) a fast algorithm for translation of the spin Hamiltonian into simulated ESEEM, (2) different optimization methods that can be hybridized to achieve an efficient coarse-to-fine grained search of the parameter space and convergence to a global minimum, (3) statistical analysis of the simulation parameters, which allows the identification of simultaneous confidence regions at specific confidence levels. OPTESIM also includes a geometry-preserving spherical averaging algorithm as default for N > 1, and global optimization over multiple experimental conditions, such as the dephasing time (τ) for three-pulse ESEEM, and external magnetic field values. Application examples for simulation of 14N coupling (N = 1, N = 2) in biological and chemical model paramagnets are included. Automated, optimized simulations by using OPTESIM lead to a convergence on dramatically shorter time scales, relative to manual simulations.
Development of a radiometric metabolic viability testing method for human and porcine skin

A radiometric viability assay based upon the conversion of [14C]glucose into 14CO2 by the viable cells on the dermal side of whole skin has been developed. The assay proved to be sensitive, reproducible, and practical, and was based upon the use of a microbiological growth detection system commonly used in many hospitals and laboratories. Relatively small samples of skin (0.25–1.00 g) were used in the test, and it was found that microbiological contamination did not interfere with the assay under normal conditions. The linear proportionality of the assay with both time and amount of skin assayed precluded the difficulties of nonlinear proportionality in other systems, allowing direct comparisons to be made between skin samples of different sizes and different incubation times. The assay could also detect 14CO2 released from many radiolabeled substrates, including glucose, aspartate, glutamate, ornithine, orotic acid, and glycerol. Thus, the method could be used to test a number of cellular functions necessary for viability, including glycolysis, the functioning of the citric acid cycle and the pentose phosphate pathway, sugar and amino acid metabolism, pyrimidine biosynthesis, and cryopreservative agent metabolism. Since any of these tests could be performed in 4 hr, a viability assay based upon glycolysis alone, or in combination with any of the other tested substrates, could be carried out after allograft skin procurement before a decision needed to be made on skin cryopreservation.
Optical Engineering to a 14-Year-Old Girl

I am writing the editorial this month with my daughter, Madison Driggers (otherwise known as Maddie). She is 14 years old, beautiful, makes good grades, has lots of friends, is very popular, and overall, is a great daughter. She really likes Justin Bieber and is going to one of his concerts in a week. I asked her today what she wanted to do after high school. She said she definitely wants to go to college, but her primary interest is medicine. Her reasons are: her mom is an OB/GYN doctor (a big influence), doctors make really good money, and they help people (so it’s satisfying and gratifying). Maddie likes babies, so she is likely to be an OB/GYN doctor.
Spectral emissions and dosimetry of metal tritide particulates.

Inference of intakes and doses from inhalation of metal tritide particles has come under scrutiny because of decommissioning and decontamination of U.S. Department of Energy facilities. Since self-absorption of radiation is very significant for larger particles, interpretation of counting results of metal tritide particles by liquid scintillation requires information about emission spectra. Similarly, inference of dose requires knowledge of charged particle and photon spectra. Using the PENELOPE Monte Carlo radiation transport computer code, we calculated various dosimetric, microdosimetric and spectral emissions from tritides of Sc, Ti, Zr, Er, and Hf. For metal tritide particles with physical diameters in the range from about 0.01 mm to 25 mm, we present energy emission fractions, distributions of microdosimetric quantities, and the emitted spectra of electrons and bremsstrahlung photons. Results characterizing the effects of uncertainties associated with the composition and density of the tritides are also presented. Emission spectra are used to illustrate trends in the relationship between "apparent" and "observed" activity as a function of particle type and size. Emissions from metal tritide particles are weakly penetrating, and the emission spectra tend to "harden" as the particle size increases. Microdosimetric considerations suggest that the radiation emitted by metal tritides can be classified asmore » a low Linear Energy Transfer (LET) radiation source. For cells less than about 7 mm away from the surface of a metal tritide, the primary dose component is due to electrons. However, bremsstrahlung radiation may deposit some energy tens, hundreds or even thousands of micrometers away from the surface of a tritide particle.« less
Extending the sun's magnetic field through the three-dimensional heliosphere

Methods for inferring the interplanetary magnetic field are reviewed. Estimates of the configuration of the field are presented for each phase of the sunspot cycle. The limitations of the methods for predicting it are presented. A contour map of power in the 0.3-0.5 microHz frequency range is presented for various solar latitudes.
Photochemistry of HCl and Other Minor Constituents in the Atmosphere of Venus

Abstract The photodissociation of HCl in the atmosphere of Venus and its various implications are discussed in some detail. From a photochemical steady-state study a new and appealing viewpoint to answer problems associated with Venusian photochemistry emerges. First, the principal source for the hydrogen observed in the Venus thermosphere may be H2 produced from HCl photochemistry low in the atmosphere. Second, the reason Venus has lost most of its water (assuming that Earth and Venus had similar accretion histories), may be because water is converted to the more photo-labile HCl by reactions between the atmosphere and NACl and other minerals at the very hot Venusian surface. This HCl even today is producing H2 above the visible clouds at rates approaching those necessary to deplete H2O over geologic time. Third, the remarkable stability of the predominantly CO2 atmosphere of Venus may be due to the chlorine-atom catalysed-combination of O2, and CO by the cycle of reactions.These Cl atoms are an importan...
ENZYME MANIPULATION: EVALUATION OF ORAL ZnSO 4 SUP-PLEMENTATION IN MANNOSIDOSIS TYPE II

Mannosidosis types I and II (M I/II) have been differentiated by phenotypic (Pediat.Res. 10:985,1976) and now by enzymatic characterization. M I/II variants both showed residual acidic (pH 4.4) α-mannosidase (αM) activity (1-3% of normal (N)), which was cryolablle; intriguingly, decreased neutral (pH 6.0) αM was consistently found in WBC ( 200% of untreated controls after 2d. These in vitro studies suggested that oral ZnSO4 supplementation may increase substrate catabolism in vivo. Four sibs of consanguineous parents with M II participated in a 6 mo controlled (2 treated; 2 untreated) study. The αM activities were unchanged in plasma, WBC and tears in either group. Urinary mannose-rich oligosaccharides appeared to decrease in treated patients. These results indicate 1) genetic heterogeneity of M, 2) a molecular interrelationship among the isozymes, 3) enzyme manipulation by Zn++ in vitro, and finally 4) Zn++ supplementation in M II may stimulate residual tissue αM and increase substrate catabolism.
Hepatic α-tocopherol binding protein in the rat: Absence of an effect of selenium deficiency on binding activity

Selenium deficiency produces no effect on either the total content of or the binding properties of rat liver α-tocopherol binding protein.
Radiometric assay of proteolysis by crude plant extracts

Summary Hydrolysis of bovine serum albumin and [125I]bovine serum albumin by crude plant extracts was measured by the Lowry method and liquid scintillation spectrometry. Measurement of protein hydrolysis by [125I] is faster, more sensitive, and more specific than by the Lowry and probably other colorimetric methods. In addition, the [125I] method can measure hydrolysis by crude extracts of endogenous plant proteins.
Three dimensions of skew deviation.

Are all skew deviations the clinical expressions of central vestibular dysfunction in three dimensional space? Skew means set, placed, or running obliquely; slanting.1 For a century, skew deviation has been the descriptive term for an acquired vertical deviation that slants the interpupillary axis to an oblique orientation.2,3 This condition has traditionally connoted a severe and debilitating neurological injury within the posterior fossa.4, Subsequent investigation has refined our understanding of this disorder and expanded the boundaries of this diagnosis.5 Working over the past two decades, the promethean team of Brandt and Dieterich have established that skew deviation has a clinical localising value within the posterior fossa6,7; that it is a component of the ocular tilt reaction (a triad of skew deviation, binocular torsion, head tilt)7–9; and that it is associated with a tilt in the subjective visual vertical.8–11 These studies have supplanted our basic descriptive definition of skew deviation with a mechanistic understanding of this complex disorder. The underlying mechanism for skew deviation involves a unilateral lesion that inhibits (or occasionally stimulates) central otolithic pathways which run from the medulla to the mesencephalon.10,11 Since a physiological imbalance in central graviceptive tone is normally produced by a head or body tilt in the roll plane, this lesion produces the sensation of body tilt and evokes the same stimulus as is evoked by the Bielschowsky head tilt test.12 By activating prenuclear input to the superior rectus and superior oblique muscles of the ipsilateral eye, and the inferior rectus and oblique muscles of the contralateral eye, and by simultaneously inhibiting their antagonists, a cyclovertical divergence is produced, with intorsion of the higher eye, extorsion of the lower eye, and a corrective head tilt toward the side of the …
Induced moment magnetism in the cooperative Jahn-Teller systems: TbAsO4 and TbVO2☆

Abstract It is suggested that the induced-moment magnetism of the cooperative Jahn-Teller systems TbAsO4 and TbVO4 can be studied in detail, experimentally, by applying an appropriate stress to the crystals. Based on the previous measurements, it is shown to be feasible to apply a stress to vary the crystal-field splitting, and actually induce a magnetic phase transition, even at T = 0 and in the absence of the enhancement effects of a possible further cooperative J-T interaction. The possible cooperative J-T interaction can also be ascertained from such a study.
Internet indiscipline : Two approaches to making a field

This essay outlines two approaches to Internet research as an area of scholarship, the disciplined and the “indisciplined.” The former approach involves departments and curricula and is more stable in the long term but the chances of success are low. The latter approach is more flexible, emphasizing interaction between scholars and innovation without classics and constraints.
Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique

The objective was to investigate the effect of intake before fasting on concentrations of metabolites and hormones, respiratory quotient (RQ) and fasting heat production (HP) using the washed rumen technique and to compare these values with those from the fed state. Six Holstein steers (360±22 kg) were maintained at 21°C and fed three different energy intakes within a replicated 3×3 Latin square design with 21-day periods. Steers were fed alfalfa cubes to provide 1.0, 1.5 and 2.0×NEm during 19 days of each experimental period. Steers were placed in individual metabolism stalls fitted with indirect calorimetry head-boxes on day 20 of each experimental period (FED steers) and fed their normal meal. On day 21 of each period the reticulorumen was emptied, washed and refilled with ruminal buffer (NaCl=96; NaHCO3=24; KHCO3=30; K2HPO4=2; CaCl2=1.5; MgCl2=1.5 mmol/kg of buffer) aerated with 75% N2 and 25% CO2 before introduction to the rumen (steers were not fed; WASHED steers). Each gas exchange was measured over 24 h. HP for 1.0, 1.5 and 2.0×NEm were 479, 597 and 714 kJ/daykg0.75 (s.e.m. =16), respectively. The plateau RQ was 0.756, 0.824 and 0.860 for the 1.0, 1.5 and 2.0×NEm intakes for the FED steers, respectively. After rumen washing, fasting HP was 331, 359 and 400 kJ/daykg0.75 (s.e.m.=13) for 1.0, 1.5, and 2.0×NEm intakes before fasting, respectively. The RQ for WASHED rumen steers was 0.717, 0.710 and 0.719, respectively. Cortisol and β-hydroxybutyrate concentrations in WASHED rumen steers did not exceed threshold levels for severe energy deficit and stress as can be induced from prolonged fasting. This study demonstrates that a fasting state can be emulated using the washed rumen technique, minimizing the time required as opposed to traditional fasting methodologies, without causing a severe energy deficit and stress.
Investigating the mechanism of disease in the RP10 form of retinitis pigmentosa.

Retinitis pigmentosa (RP) is a disease characterized by its vast heterogeneity. Many genes are associated with RP, and the disease causing mutations identified in these genes are even more numerous. To date there are 15 genes that cause autosomal dominant RP (adRP) alone. The role of some of these genes, while complex and not completely understood, is somewhat intuitive in that they are involved in pathways such as phototransduction. However, the role of other genes in retinal disease is not as predictable due to their ubiquitous function and/or expression. One such gene is inosine monophosphate dehydrogenase 1 (IMPDH1) IMPDH1 is a gene involved in de novo purine synthesis and is ubiquitously expressed. IMPDH1 mutations account for 2% of all adRP cases and are a rare cause of Leiber Congenital Amaurosis. Despite its ubiquitous expression missense mutations in this gene cause only retinal degeneration. This paradox of tissue specific disease in the presence of ubiquitous expression has only recently begun to be explained. We have shown in a recent study that novel retinal isoforms of IMPDH1 exist and may account for the tissue specificity of disease. We have gone on to characterize these retinal isoforms both in our laboratory and in collaboration with Dr. Lizbeth Hedstrom’s laboratory at Brandeis University (Waltham, MA) in order to understand more about them. We believe that through clarifying the mechanism of disease in RP10 we will be equipped to consider treatment options for this disease.
A blast of gas in the latest Paleocene: Simulating first-order effects of massive dissociation of oceanic methane hydrate

Carbonate and organic matter deposited during the latest Paleocene thermal maximum is characterized by a remarkable -2.5% excursion in delta 13C that occurred over approximately 10(4) yr and returned to near initial values in an exponential pattern over approximately 2 x 10(5) yr. It has been hypothesized that this excursion signifies transfer of 1.4 to 2.8 x 10(18) g of CH4 from oceanic hydrates to the combined ocean-atmosphere inorganic carbon reservoir. A scenario with 1.12 x 10(18) g of CH4 is numerically simulated here within the framework of the present-day global carbon cycle to test the plausibility of the hypothesis. We find that (1) the delta 13C of the deep ocean, shallow ocean, and atmosphere decreases by -2.3% over 10(4) yr and returns to initial values in an exponential pattern over approximately 2 x 10(5) yr; (2) the depth of the lysocline shoals by up to 400 m over 10(4) yr, and this rise is most pronounced in one ocean region; and (3) global surface temperature increases by approximately 2 degrees C over 10(4) yr and returns to initial values over approximately 2 x 10(6) yr. The first effect is quantitatively consistent with the geologic record; the latter two effects are qualitatively consistent with observations. Thus, significant CH4 release from oceanic hydrates is a plausible explanation for observed carbon cycle perturbations during the thermal maximum. This conclusion is of broad interest because the flux of CH4 invoked during the maximum is of similar magnitude to that released to the atmosphere from present-day anthropogenic CH4 sources.