cssi/SciSciGPT-SciSciNet huggingface dataset:
Enzymatic and transport characteristics of isolated snake renal brush-border membranes

Brush-border membranes (BBM) of proximal tubules were isolated from the kidney of the garter snake (Thamnophis sirtalis) by a procedure involving hypotonic lysis, Ca precipitation, and differential centrifugation. The isolated membranes were enriched 15-fold in brush-border enzyme activities (alkaline phosphatase, gamma-glutamyl transpeptidase) compared with whole kidney homogenates and were substantially free of other contaminating membranes. The yield of the BBM preparation was 40%. The BBM vesicular transport of several organic solutes was characterized by a rapid filtration technique at 25 degrees C. D-glucose, p-aminohippurate (PAH), and urate entered the same osmotically active space (2-3 microliter/mg protein) and binding was minimal (less than 20% for PAH). An uptake overshoot for 3-O-methyl-D-glucose (20 microM) by reptilian BBM was observed only in the presence of an inwardly directed NaCl gradient and was abolished by 0.1 mM phlorizin. Reptilian BBM exhibited Na-gradient-stimulated uptake of PAH (90 microM) with an overshoot that was inhibited by other organic acids and by 4-acetamido-4'-isothiocyanostilbene-2, 2'-disulfonic acid (SITS). In contrast, urate uptake (30 microM) appeared to be Na independent and not appreciably affected by other organic anions or SITS. The presence of specific transport systems for organic solutes in the isolated membrane preparation distinctly characterizes the BBM of reptilian kidney.
A gimmick to integrate software testing throughout the curriculum

We discuss our experiences in which students of a programming course were asked to submit both an implementation as well as a test set. A portion of a student's grade was then devoted both to the validity of a student's program on others' test sets, as well as how that student's test set performed in uncovering flaws in others' programs. The advantages are many, as this introduces implicit principles of software testing together with a bit of fun competition. The major complication is that such an all-pairs execution of tests grows quadratically with the number of participants, necessitating a fully automated scoring system.
Threads Distribution Effects on Graphics Processing Units Neutron Sensitivity

Graphic Processing Units offer the possibility of executing several threads in parallel, providing the user with higher throughput with respect to traditional multi-core processors. However, the additional resources required to schedule and handle the parallel processes may have the countermeasure of making GPUs more prone to be corrupted by neutrons. The reported experimental results prove that un-optimized thread distribution may exacerbate the device output error rate. As demonstrated, increasing the parallel algorithm block size minimizes the GPU neutron-induced output error rate. The GPU parallelism management is then analyzed as a method to increase reliability.
Analyses of transient capacitance experiments for AuGaAs Schottky barrier diodes in the presence of deep impurities and the interfacial layer

Abstract Transient capacitance experiments have been performed for Au-n-type GaAs Schottky barrier diodes between 285 and 316°K. The GaAs substrates are doped with oxygen and chromium, respectively. From the transient dark-capacitance and photocapacitance measurements, the thermal emission rate, the doping densities and the thermal activation energies of oxygen and chromium impurities are obtained at T = 300°K.
Relational Financial Therapy: An Innovative and Collaborative Treatment Approach

An intervention model for couples reporting both relationship and financial stress was developed and evaluated. The model utilized co-therapy teams of marriage and family therapists and financial planners who employed a five-session treatment approach in working with 12 couples. Findings demonstrated numerous benefits of this collaborative model. A recommendation was made that academic programs and professionals in MFT and Financial Planning develop similar interdisciplinary collaborative efforts.
Oxygenic photosynthesis and the oxidation state of Mars

The oxidation state of the Earth's surface is one of the most obvious indications of the effect of life on this planet. The surface of Mars is highly oxidized, as evidenced by its red color, but the connection to life is less apparent. Two possibilities can be considered. First, the oxidant may be photochemically produced in the atmosphere. In this case the fundamental source of O2 is the loss of H2 to space and the oxidant produced is H2O2. This oxidant would accumulate on the surface and thereby destroy any organic material and other reductants to some depth. Recent models suggest that diffusion limits this depth to a few meters. An alternative source of oxygen is biological oxygen production followed by sequestration of organic material in sediments - as on the Earth. In this case, the net oxidation of the surface was determined billions of years ago when Mars was a more habitable planet and oxidative conditions could persist to great depths, over 100 m. Below this must be a compensating layer of biogenic organic material. Insight into the nature of past sources of oxidation on Mars will require searching for organics in the martian subsurface and sediments.
Finite size effects on the structural progression induced by lithiation of V2O5: a combined diffraction and Raman spectroscopy study

Developing an understanding of the structural changes induced during the insertion of Li-ions into the layered framework of nanostructured V2O5 is necessary to unravel the origin of the dramatically increased power densities characteristic of nanostructured electrodes. In this work, we have contrasted the sequence of structural progressions induced within V2O5 micron-sized powders, hydrothermally grown nanowires, and CVD-grown nanoplatelet arrays as a function of chemical lithiation using powder diffraction and Raman spectroscopy. Raman spectroscopy serves as a powerful and highly sensitive probe for investigating the local structure of the lithiated V2O5 phases. We note a profound size dependence of the structural progression with the kinetics of Li-ion uptake following: CVD-grown nanoplatelet arrays ≫ hydrothermally grown nanowires > micron-sized powders. For bulk powders, Raman spectroscopy indicates conversion to the α-phase at 30 s and to the e-phase at 30 min. The e-phase continues to grow in spatial extent for the remaining 2 h duration. In contrast, the hydrothermally grown nanowires convert to the α-phase after 30 s and have the e-phase as the predominant surface species after just 1 min. The CVD grown nanoplatelets show a much accelerated response with the e-phase nucleated within just 30 s and the Li-rich e′-phase stabilized after 5 min. After 30 min of lithiation, these nanowires convert to the δ/γ phase and are subsequently irreversibly amorphized after 2 h. Chemical delithiation is seen to result in reversion to the α-phase for bulk and hydrothermally grown nanowire powders for chemical lithiations up to 2 h. In contrast, the unlithiated orthorhombic phase is recovered upon delithiation of the δ/γ-phase nanoplatelet arrays.
SU-E-T-215: Tissue Optical Properties Determination in PDT Treated Head & Neck Patients Using a Balloon Diffusing Light Source

Purpose: The main objective of this study was to determine the optical properties(scattering and absorption coefficients) in vivo by interstitial measurements using a light detection device made for this purpose. Methods: Patients were enrolled in a phase I dose escalation study of photodynamic therapy for the treatment of pre‐malignant tumors and superficial microinvasive disease of the head and neck. Patients were given the photosensitizer Levulan&#61650; orally followed by the administration of red light (629–635 nm) to the tumor from a laser to a dose of 50–200 J/cm2. Because of technical challenges, some of the patients were not able to be treated using the classic microlens fiber and instead used a translucent diffusing balloon catheter to deliver the light. Measurements were performed using a light detection device before and after light treatment delivery. The detector is scanned along the length of the light source containing catheter. Scans are done with the device placed on the treatment area and on the normal oral cavity tissue.Optical properties of both the normal and diseased tissue before and after the light treatment were obtained and compared to those measured with a fiber‐optic probe. The fiber‐optic based probe was placed on the tissue surface, and white light was delivered to the tumor surface by one of its source fibers. The diffusely reflected white light was collected by a spectrograph and analyzed to determine the absorption and scatteringspectra of the tissue. Results: A theory based on light source on semi‐infinite medium has been developed to interpret the measured data. Results from both methods were compared for accuracy. This model was also validated by measurements performed in tissue‐simulating. Conclusions: We developed a model for quick and accurate determination of tissueoptical properties in semi‐infinite medium, which is theoretically suitable for determination of optical properties head and neck PDT. Conclusions:
A New LFM Signal Detection Method Based on Empirical Mode Decomposition

A LFM signal detection algorithm based on empirical mode decomposition and Wigner-Hough transform is put forward. The main interference component is found and eliminated through EMD. According to principal signal separation SNR of target component is increased. Through Wigner-Hough transform the energy of LFM signal is concentrated in a peak. Simulation result shows the detection algorithm is effective and target is detected in low SNR.
Electrical coupling differs in the in vitro and in vivo organ of Corti.

Abstract Electrical communication between the supporting cells of the guinea pig organ of Corti was studied. For in vitro experiments, the inner ear was rapidly removed and placed in a heated perfusion chamber. Medium 199 was used. The bony cochlea and the lateral wall (spiral ligament and stria vascularis) were removed to expose the top two coils of the organ of Corti. In vivo experiments were performed upon anesthetized animals whose cochleas were exposed surgically. A tiny fenestra was made in the bony cochlea which permitted the passage of electrodes through the lateral wall and into the organ of Corti of the third turn. Coupling was assessed by impaling neighboring cells with 3 M KC1 electrodes, and noting the spread of intracellularly injected current. Coupling ratios in the in vitro preparation were consistently greater than those obtained in vivo (0.58 ± 0.17 vs. 0.104 ± 0.064). Differences exist between the in vitro and in vivo preparations which might account for these results. In vivo the supporting cells are bathed in two different media, endolymph apically, and perilymph basally. Consequently, on their apical side the supporting cells are exposed to fluid high in K + , low in Ca 2+ and at a potential of 80 mV, the endolymphatic potential. In vitro the cells are bathed on all sides in fluid similar to perilymph. Intermixing the fluids in an in vivo preparation, by tearing away the stria vascularis and Reissner's membrane, increases the magnitude of the coupling ratio (0.455 ± 0.209). Thus the unique microenvironment of the inner ear maintains lower coupling ratios, and smaller space constants for the supporting cells.
Further remarks on line segment curve-fitting using dynamic programming

In a recent paper, Bellman showed how dynamic programming could be used to determine the solution to a problem previously considered by Stone. The problem comprises the determination, given N, of the N points of subdivision of a given interval (a, b and the corresponding line segments, that give the best least squares fit to a function g(x) in the interval. Bellman confined himself primarily to the analytical derivation, suggesting briefly, however, how the solution of the equation derived for each particular point of subdivision ui could be reduced to a discrete search. In this paper, the computational procedure is considered more fully, and the similarities to some of Stone's equations are indicated. It is further shown that an equation for u2 involving no minimization may be found. In addition, it is shown how Bellman's method may be applied to the curve-fitting problem when the additional constraints are added that the ends of the line segments must be on the curve.
Regional metabolism of Met-enkephalin and cholecystokinin on intact rat brain slices : characterization of specific peptidases

The metabolism of Met-enkephalin and cholecystokinin (CCK) 8-(sulfated) by intact microslices was studied in rat brain regions. Incubation of brain slices with Met-enkephalin (400 microM) resulted in a linear rate of disappearance of parent peptide and appearance of metabolic fragments whose rate of accumulation was specific to brain region. The degradative rate (pmol/min/mg of protein) of Met-enkephalin was high in caudate-putamen (5,160 +/- 120) and lower in nucleus accumbens (3,630 +/- 110) and frontal cortex (3,180 +/- 120). Inhibition of aminopeptidases decreased Met-enkephalin degradation (50-97% vs. control) in frontal cortex but was less effective in caudate-putamen (20-34%). Tyr-Gly-Gly and Phe-Met were recovered in caudate-putamen and nucleus accumbens, whereas negligible quantities of these fragments were recovered from frontal cortex. Phosphoramidon, an inhibitor of neutral endopeptidase 24.11, decreased Met-enkephalin degradation in caudate-putamen (14%) but had no effect on that in frontal cortex. A cocktail of bestatin or leuhistin (inhibitors of aminopeptidases), phosphoramidon, and captopril (an inhibitor of angiotensin converting enzyme) protected Met-enkephalin from degradation (recovery > 95%) in caudate-putamen. CCK 8-(sulfated) degradation on slices from caudate-putamen, nucleus accumbens, and frontal cortex was not altered by inhibitors of neutral endopeptidase 24.11, metalloendopeptidase 24.15, angiotensin converting enzyme, or thiol proteases. Inhibitors of either aminopeptidases or serine proteases produced small reductions (13-30%) in CCK degradation in each region. These data provide evidence for regional and structural specificity in terminating the actions of neuropeptides.
A Techno-Economic Approach to U. S. Domestic Satellite Orbit-Spectrum Regulation

The efficiency of orbit-spectrum use is often thought of in units of information rate per unit bandwidth and per unit of satellite spacing. A major problem with using such purely technical measures of use efficiency for policy is that they fail to reflect directly the basic purpose of orbit-spectrum use. It is now possible to accurately include the costs of spectrum-conservation technology in the measure of use efficiency, shedding new light on the nature of the orbit-spectrum conservation measures that should be taken as this resource becomes more crowded.
DENSITY FUNCTIONAL THEORY CALCULATIONS OF THE EFFECT OF FLUORINE SUBSTITUTION ON THE KINETICS OF CYCLOPROPYLCARBINYL RADICAL RING OPENINGS

DFT calculations (B3LYP/6-311+G(2df,2p)//B3LYP/6-31G(d)) indicate a dramatic impact of fluorine substituents on the structure and reactivity of the cyclopropylcarbinyl radical. Stereoelectronic influences are believed to be largely responsible for the predicted reactivity and regiospecificity of fluorinated radicals such as the 2,2-difluorocyclopropyl carbinyl radical, which has a calculated activation barrier of 1.9 kcal/mol, undergoing regiospecific C2−C3 cleavage to form the 2,2-difluoro homoallylic radical. In contrast, calculations indicate that the 2,2-difluorocyclopropylcarbinyl cation will convert regiospecifically to the 1,1-difluoro homoallylic cation.
Asymptotic minimum norm quadrature formulae

The asymptotic limit of minimum norm quadrature formulae for some Hilbert spaces of functions regular and analytic in a domainB is studied, asB expands.
Kinetics of the oxidation of triphenylphosphine by nitric oxide.

The oxidation of PPh3 by NO to N2O and Ph3PO in homogeneous solution occurs by third-order kinetics, d[Ph3P]/dt = k3[Ph3P][NO]2; analysis of solvent and substituent effects suggests formation of a phosphonium diazeniumdiolate intermediate prior to oxygen transfer from nitrogen to phosphorus.
Caribbean pleasure industry: Tourism, sexuality and AIDS in the Dominican Republic

Caribbean pleasure industry: Tourism, sexuality and AIDS in the Dominican Republic, by Mark Padilla, Chicago and London, The University of Chicago Press, 2007, 294 pp., including notes, US$21.00/£1...
ARC syndrome in preterm baby

A preterm female infant born of 32 weeks gestational age was presenting with musculoskeletal abnormalities, and cholestasis that later on resolved. Later on, she developed renal tubular acidosis (RTA), poor weight gain, unexplained intermittent fever and recurrent spontaneous bleeding episodes. ARC is an acronym that stands for arthrogryposis, renal dysfunction and cholestasis. ARC syndrome is a rare disorder that is difficult to diagnose and is associated with poor outcomes. We present a case of ARC syndrome in an infant with a history of failure to thrive, early cholestasis and RTA. There are many unique features about this case that should add to our understanding of this genetic condition. To our knowledge this is the first identified case of ARC syndrome in a preterm infant. Although the specific mutation found in our patient has not been reported previously, the type and location of this mutation is consistent with our genetic understanding of this disorder.
Identification of novel post-transcriptional features in olfactory receptor family mRNAs

Olfactory receptor (Olfr) genes comprise the largest gene family in mice. Despite their importance in olfaction, how most Olfr mRNAs are regulated remains unexplored. Using RNA-seq analysis coupled with analysis of pre-existing databases, we found that Olfr mRNAs have several atypical features suggesting that post-transcriptional regulation impacts their expression. First, Olfr mRNAs, as a group, have dramatically higher average AU-content and lower predicted secondary structure than do control mRNAs. Second, Olfr mRNAs have a higher density of AU-rich elements (AREs) in their 3'UTR and upstream open reading frames (uORFs) in their 5 UTR than do control mRNAs. Third, Olfr mRNAs have shorter 3' UTR regions and with fewer predicted miRNA-binding sites. All of these novel properties correlated with higher Olfr expression. We also identified striking differences in the post-transcriptional features of the mRNAs from the two major classes of Olfr genes, a finding consistent with their independent evolutionary origin. Together, our results suggest that the Olfr gene family has encountered unusual selective forces in neural cells that have driven them to acquire unique post-transcriptional regulatory features. In support of this possibility, we found that while Olfr mRNAs are degraded by a deadenylation-dependent mechanism, they are largely protected from this decay in neural lineage cells.
Analysis of the habituation-like changes in transmission in the temporodentate pathway of the rat.

Abstract Habituation-like decrements in extracellular measures of synaptic activation (population EPSP) and cell discharge (population spike) were analyzed in the dentate gyrus of the rat following repetitive low-frequency stimulation of the medial and lateral entorhinal cortex. Stimulation of either subdivision of the entorhinal projection system resulted in comparable habituation-like response decrements with similar stimulation regimens. However, habituating stimulation of one subdivision did not result in decreased responsiveness to stimulation of the other. Repetitive low-frequency stimulation or even a single pulse delivered to either subdivision did, however, result in a potentiation of granule cell discharge in response to stimulation of the other subdivision (a form of heterosynaptic potentiation). This heterosynaptic potentiation of granule cell discharge was not accompanied by any increase in the extracellular EPSP. Comparisons of the relationship between the population EPSP and population spike before and during habituating stimulation revealed changes in cell discharge in response to the habituating stimulus which could not be accounted for by changes in synaptic activation alone. The results suggest that repetitive activation of the temporodentate pathway alters granule cell output as a result of two processes, a habituation-like decrement in synaptic activation, and a potentiation of granule cell discharge as a consequence of prior activation.
Student explorer: a tool for supporting academic advising at scale

Student Explorer is an early warning system designed to support academic advising that uses learning analytics to categorize students' ongoing academic performance and effort. Advisors use this tool to provide just-in-time assistance to students at risk of underperforming in their classes. Student Explorer is designed to eventually support targeted advising for thousands of undergraduate students.
On the anisotropic elastic properties of woods

In 2003 Nature Materials article, Keckes et al. presented deformation properties of a variety of woods in relation to deformation of their individual wood cells. Their point is “The remarkable mechanical properties of biological materials reside in their complex hierarchical structure…”. This holds for mineral-based biological materials such as bone as well as for wood. Indeed, one of us (J.L.K.) introduced the concept that to explain the material properties of cortical bone, it was necessary to treat it as a complex material/structural hierarchical composite. Calculations to determine anisotropic properties of bone measured using ultrasonic wave propagation techniques, were extended to similar measurements on both soft and hard woods. These anisotropic properties calculations have been extended to include data based on mechanical measurements of orthotropic elastic constants of both soft and hard woods for comparison with both earlier ultrasonic measurements and mechanical testing on other woods. This work illustrates the fact that understanding and modeling the properties of wood is a complex task as the symmetry changes with scale. For example, lignin is isotropic, hemicellulose and cellulose are transversely isotropic, while the cells and microstructure have orthotropic symmetry.
Insights into finding a mismatch through the structure of a mispaired DNA bound by a rhodium intercalator

We report the 1.1-A resolution crystal structure of a bulky rhodium complex bound to two different DNA sites, mismatched and matched in the oligonucleotide 5'-(dCGGAAATTCCCG)2-3'. At the AC mismatch site, the structure reveals ligand insertion from the minor groove with ejection of both mismatched bases and elucidates how destabilized mispairs in DNA may be recognized. This unique binding mode contrasts with major groove intercalation, observed at a matched site, where doubling of the base pair rise accommodates stacking of the intercalator. Mass spectral analysis reveals different photocleavage products associated with the two binding modes in the crystal, with only products characteristic of mismatch binding in solution. This structure, illustrating two clearly distinct binding modes for a molecule with DNA, provides a rationale for the interrogation and detection of mismatches.
Foraging efficacy of the entomopathogenic nematode Steinernema riobrave in different soil types from California citrus groves.

Abstract Entomopathogenic nematodes (EPNs) are lethal insect parasites that develop inside the body of their insect host. The EPN Steinernema riobrave infects many different types of soil insects, including larvae of the invasive citrus root weevil, Diaprepes abbreviatus , which is a key pest in citrus production. Soil characteristics have a great impact on nematode foraging efficacy and therefore on the ability of EPNs to be used successfully in biological control programs. Our specific objectives were to: (1) survey for the presence of native EPNs in California citrus groves; and (2) identify soil parameters that would allow us to predict EPN efficacy. The long-term objective of this study is to develop biological control methods to address the invasion of the citrus root weevil, D. abbreviatus , into California using EPNs. We collected soils from 36 sites in California where citrus is produced commercially, sampled them for native nematode presence and tested the foraging efficacy (movement and host finding) of S. riobrave in these soils at three different soil depths; 100, 250 and 500 mm. Soil textures and physical characteristics were analyzed. We found five isolates of endemic EPNs ( Heterorhabditis spp.) from southern California. Three were identified as Heterorhabditis bacteriophora , and two as Heterorhabditis sonorensis , which were recorded for the first time in California. S. riobrave 's ability to infect hosts varied among soil types and depths. We also found significant correlations between soil characteristics (texture and physical characteristics) and S. riobrave foraging efficacy. Synthesis and applications . Our results and analyses can play a role in the prediction of S. riobrave success in various soil types. Perhaps more importantly, we suggest an approach to predict biological control potential based on soil characters that might be used with other insect pathogens. While soil texture is the main factor that affects EPN efficacy, we found that other parameters like organic matter level and dissolved solids are also important.
Methods For Comparing The Mortality Experience of Heterogeneous Populations

Methods are presented which produce Maximum Likelihood Estimates (MLE) of the degree of heterogeneity in individual mortality risks under a variety of assumptions about the age trajectory of those mortality risks. With these estimates of the degree of population heterogeneity it is possible to adjust comparisons of mortality risks across populations for the effects of population heterogeneity, differential mortality selection, and different age trajectories of the force of mortality. These methods are demonstrated by applying a variety of standard assumptions about the age trajectory of the force of mortality to the analysis of a broad range of cohort mortality data for the U.S. and Swedish populations. The estimates of the degree of heterogeneity, produced under all of the selected force of mortality models, consistently indicated a considerable degree of heterogeneity in mortality risks.
Existence and approximation of solutions of inverse-positive problems

On applique des techniques monotones a des equations du type onde ou biharmonique. On donne une extension du schema iteratif monotone
Space Requirements for Wheeled Mobility Devices

Research on the size of wheeled mobility devices in the UK and Canada suggests that the dimensions for “clear floor area” of wheeled mobility devices as specified in U.S. standards are too small. Anthropometric research was conducted to verify that findings in other countries are relevant for the U.S. Findings support increasing the clear floor area dimensions. To provide universal access to buildings, it is necessary to exceed the current requirements of minimum standards until they are revised to reflect the increased size of wheeled mobility devices.
A modified Newton's method for minimizing factorable functions

Many functions of several variables used in nonlinear programming are factorable, i.e., complicated compositions of transformed sums and products of functions of a single variable. The Hessian matrices of twice-differentiable factorable functions can easily be expressed as sums of outer products (dyads) of vectors. A modified Newton's method for minimizing unconstrained factorable functions which exploits this special form of the Hessian is developed. Computational experience with the method is presented.
The proliferation theory of rejuvenation

A theory concerning the molecular basis of rejuvenation is presented that postulates a central role for cell proliferation. This theory assumes that aging is due to the accumulation of multiple forms of molecular damage and that rejuvenation is due to repair. The advantages of proliferation as a means of repair are described and it is proposed that cell proliferation is required for full rejuvenation. This proliferation theory offers several advantages: a different perspective on the question of which organisms age; an explanation of aging-related phenomena that are not well handled by traditional aging theories; a novel approach to altering the aging rate; and testable implications for the design of new experimental systems and therapeutic interventions.
The problem posed by immigrants married abroad on intermarriage research: the case of Asian Americans.

Cross-sectional and longitudinal variations in rates of intergroup marriage [in the United States] have often been used as indicators of assimilation for minority groups. This article demonstrates that both types of comparisons can give misleading results when census data are used for calculating intermarriage rates without restrictions. Census data include immigrants who married abroad (IMAs) in the enumeration. The inclusion of these individuals in the study of intermarriage inevitably biases the level of minority inmarriage upward making cross-sectional and longitudinal comparisons of intermarriage rates for groups with different levels of IMAs inappropriate. Cumulation of IMAs also inflates the inmarriage rates of older cohorts leading to a misimpression of increasing outmarriage among younger cohorts. These problems are illustrated for several Asian groups using 1980 Public Use Microdata Sample data for California. Alternative approaches for remedying the problem are proposed and their different implications for assimilation theory and research are discussed. (EXCERPT)
Effect of Dissolved Organic Matter Source and Character on Microbial Hg Methylation in Hg–S–DOM Solutions

Dissolved organic matter (DOM) is a key component of fate and transport models for most metals, including mercury (Hg). Utilizing a suite of diverse DOM isolates, we demonstrated that DOM character, in addition to concentration, influences inorganic Hg (Hg(II)i) bioavailability to Hg-methylating bacteria. Using a model Hg-methylating bacterium, Desulfovibrio desulfuricans ND132, we evaluated Hg-DOM-sulfide bioavailability in washed-cell assays at environmentally relevant Hg/DOM ratios (∼1-8 ng Hg/mg C) and sulfide concentrations (1-1000 μM). All tested DOM isolates significantly enhanced Hg methylation above DOM-free controls (from ∼2 to >20-fold for 20 mg C/L DOM solutions), but high molecular weight/highly aromatic DOM isolates and/or those with high sulfur content were particularly effective at enhancing Hg methylation. Because these experiments were conducted under conditions of predicted supersaturation with respect to metacinnabar (β-HgS(s)), we attribute the DOM-dependent enhancement of Hg(II)i bioavailability to steric and specific chemical (e.g., DOM thiols) inhibition of β-HgS(s) growth and aggregation by DOM. Experiments examining the role of DOM across a wide sulfide gradient revealed that DOM only enhances Hg methylation under fairly low sulfide conditions (≲30 μM), conditions that favor HgS nanoparticle/cluster formation relative to dissolved HgS species.
Velocity overshoot effect on a short-gate microwave MESFET

The device parameters of short-gate GaAs and InP FETs have been found to be dependent on the nonequilibrium velocity overshoot phenomenon. Both saturation velocity and critical field are found to be larger for shorter gates. The v-E characteristics of Pucel et al. (1975) are modified. The cutoff frequency and other parameters for GaAs, InP, and Si are given as a function of gate length and bias. The cutoff frequency of InP MESFETs with a doping density of 10 to the 17th per cu cm is only 20% higher than those of equivalent GaAs MESFETs at 300 K. Comparison with other work is also presented.
The psychological characteristics of ambivalent people

Abstract Ambivalence— broadly defined as overlapping approach-avoidance tendencies, manifested behaviorally, cognitively, or affectively, and directed toward a given person or experience— assumes a prominent role in several diverse psychological literatures. It plays a major role in psychoanalytic theories of psychopathology as well as in sociological, cognitive, developmental, and psychometric approaches to normal psychological functioning. A review of the contributions from each of these perspectives suggests that ambivalence may be characteristic of certain normal individuals in addition to particular psychodiagnostic categories. The present paper attempts to identify and describe the characteristics of ambivalent people. Throughout the paper, the clinical implications of these characteristics are discussed. A closing section unifies the earlier sections of the paper by identifying four types of perceived loss that may impede the acknowledgment and resolution of ambivalent conflicts in psychotherapy.
Acromioclavicular joint instability: anatomy, biomechanics and evaluation

Acromioclavicular (AC) joint instability is a common source of pain and disability. The injury is most commonly a result of a direct impact to the AC joint. The AC joint is surrounded by a capsule and has an intra-articular synovium and an articular cartilage interface. An articular disc is usually present in the joint, but this varies in size and shape. The AC joint capsule is quite thin, but has considerable ligamentous support; there are four AC ligaments: superior, inferior, anterior and posterior. The coracoclavicular (CC) ligament complex consists of the conoid and trapezoid ligaments. They insert on the posteromedial and anterolateral region of the undersurface of the distal clavicle, respectively. The coracoid origin of the trapezoid covers the posterior half of the coracoid dorsum; the conoid origin is more posterior on the base of the coracoid. Several biomechanical studies showed that horizontal stability of the AC joint is mediated by the AC ligaments while vertical stability is mediated by the CC ligaments. The radiographic classification of AC joint injuries described by Rockwood includes six types: in type I injuries the AC ligaments are sprained, but the joint is intact; in type II injuries, the AC ligaments are torn, but the CC ligaments are intact; in type III injuries both the AC and the CC ligaments are torn; type IV injuries are characterized by complete dislocation with posterior displacement of the distal clavicle into or through the fascia of the trapezius; type V injuries are characterized by a greater degree of soft tissue damage; type VI injuries are inferior AC joint dislocations into a subacromial or subcoracoid position. The diagnosis of AC joint instability can be based on historical data, physical examination and imaging studies. The cross body adduction stress test has the greatest sensitivity, followed by the AC resisted extension test and the O'Brien test. Proper radiographic evaluation of the AC joint is necessary. The Zanca view is the most accurate view for examining the AC joint. The axial view of the shoulder is important in differentiating a type III AC joint injury from a type IV injury.
Culex pipiens (Diptera: Culicidae) morbidity and mortality associated with Rift Valley fever virus infection.

Experiments were conducted to determine whether infection with Rift Valley fever (RVF) virus resulted in increased morbidity or mortality in infected Egyptian Culex pipiens. Following oral exposure to RVF virus, mosquitoes with disseminated infections showed a 21% reduction in refeeding rate and a 20% reduction in the number of eggs laid compared to uninfected mosquitoes. Mosquitoes with nondisseminated infections had refeeding and egg-laying rates intermediate between those for uninfected and disseminated individuals. All larvae inoculated with RVF virus failed to emerge successfully as adults. However, no increased mortality was observed for larvae inoculated with La Crosse virus compared to those inoculated with diluent. The increased morbidity observed for RVF-virus-infected Cx. pipiens may need to be incorporated in models of the natural history of this virus.
Gender differences in depression: The role of anxiety and generalized negative affect

This study used the tripartite model of depression and anxiety to examine whether gender differences in depression may be accounted for, in part, by the overlap of depression with anxiety and negative affectivity. The tripartite model distinguishes between pure forms of depression and anxiety, co-morbid depression and anxiety, and mixed anxiety-depression. One hundred-six college students completed questionnaires that measured depression, anxiety, and negative and positive affectivity. Results were moderately consistent with hypotheses. Specifically, the proportion of women versus men was significantly higher in the categories of co-morbid depression and anxiety and mixed anxiety-depression, but not in the categories of “specific” (i.e., “pure”) depression or anxiety. It is argued that “specific” depression may be equally prevalent in men and women, but that other depression-related syndromes may be more common among women than men.
An iterative initial-points refinement algorithm for categorical data clustering

The original k-means clustering algorithm is designed to work primarily on numeric data sets. This prohibits the algorithm from being directly applied to categorical data clustering in many data mining applications. The k-modes algorithm [Z. Huang, Clustering large data sets with mixed numeric and categorical value, in: Proceedings of the First Pacific Asia Knowledge Discovery and Data Mining Conference. World Scientific, Singapore, 1997, pp. 21-34] extended the k-means paradigm to cluster categorical data by using a frequency-based method to update the cluster modes versus the k-means fashion of minimizing a numerically valued cost. However, as is the case with most data clustering algorithms, the algorithm requires a pre-setting or random selection of initial points (modes) of the clusters. The differences on the initial points often lead to considerable distinct cluster results. In this paper we present an experimental study on applying Bradley and Fayyad's iterative initial-point refinement algorithm to the k-modes clustering to improve the accurate and repetitiveness of the clustering results [cf. P. Bradley, U. Fayyad, Refining initial points for k-mean clustering, in: Proceedings of the 15th International Conference on Machine Learning, Morgan Kaufmann, Los Altos, CA, 1998]. Experiments show that the k-modes clustering algorithm using refined initial points leads to higher precision results much more reliably than the random selection method without refinement, thus making the refinement process applicable to many data mining applications with categorical data.
Increase in the stoichiometry of the functioning active sites of horse liver aldehyde dehydrogenase in the presence of magnesium ions.

Abstract The V of horse liver aldehyde dehydrogenase is enhanced twofold in the presence of 0.5 m m Mg 2+ ions when assayed in the dehydrogenase reaction. The mechanism of this activation appears to be related to the fact the enzyme changes from functioning with half-of-the-sites reactivity to functioning with all-of-the-sites reactivity. That is, the presteady-state burst magnitude increases from 2 mol NADH formed per mole of tetrameric enzyme to 4 mol formed per mole ( K. Takahashi and H. Weiner, J. Biol. Chem. , 1980 , 255 , 8206–8209). Whether this twofold enhancement correlates, in fact, to a change from half-of-the-sites to all-of-the-sites reactivity of the enzyme by Mg 2+ ions was investigated by determining the Stoichiometry of coenzyme binding by fluorescence quenching and enhancement methods in the absence and presence of the metal ions. The biphasic Scatchard plots for NAD binding to the enzyme were similar in the absence and presence of Mg 2+ ions, while that of NADH binding was monophasic (-Mg 2+ ) and biphasic (+Mg 2+ ). In the presence of p -methoxyacetophenone, a competitive inhibitor for substrate, the stoichiometric titration of coenzyme binding to the ternary complexes (enzyme-NAD(H)-inhibitor) revealed that only 2 mol of NAD or NADH bind in the absence of Mg 2+ ions but 4 bind per mole of tetrameric enzyme in the presence of added metal. The fluorescence intensity of NAD's fluorescent derivative, 1, N 6 -ethenoadenine dinucleotide, bound to the enzyme was also doubled by the addition of Mg 2+ ions. The combined binding data show that the stoichiometry of coenzyme binding to aldehyde dehydrogenase in the ternary complex increases from 2 to 4 mol binding per mole of tetrameric enzyme with the addition of Mg 2+ ions. This increase in stoichiometry corresponds to the observed changes of burst magnitude obtained from the presteady-state and V in the steady-state kinetics assays. From both results of the kinetics and stoichiometry, we show that horse liver aldehyde dehydrogenase exhibits half-of-the-sites reactivity when in the tetrameric state in the absence of Mg 2+ ions, and all-of-the-sites reactivity in the dimeric state in the presence of the metal.
CSTRIP, a Fortran IV Computer Program for Obtaining Initial Polyexponential Parameter Estimates

A new exponential stripping program, CSTRIP, has been developed. This program overcomes the problems associated with the use of previously published techniques and enables the rapid economical calculation of initial polyexponential parameter estimates. Values for the coefficients and exponents of the exponential terms are calculated as well as estimates of lag times. An exhaustive search procedure ensures that the results are comparable to, or better than, those obtained by manual residual methods.
Catch that speeding turtle: latching onto fun graphics in CS1

Graphics are a great way to keep students motivated early in a computer science program. This paper introduces a simple Ada graphics package that simultaneously meets two goals: it provides a easy to understand graphics package that leads to enjoyable projects in CS1, and it is an appropriate tool for teaching fundamental computer science concepts to beginning programmers. The package is an Ada implementation and extension of a Java TutleGraphics package used at a number of universities.
Proton solvation in ternary clusters of water-methanol-acetonitrile. Evidence for cyclic structures

Abstract The distributions of protonated ternary clusters containing water (W), methanol (M) and acetonitrile (A) have been studied as a function of composition using EI ionization of the ternary cluster beam. The cluster distributions show enhanced ion intensities for the sequence H + W n M m A N +2 indicating solvent shell's closing by the blocking groups of acetonitrile molecules. Evidences for cyclic structures in ternary clusters containing five methanol or four water molecules are presented. Cyclic structures in water clusters containing 4–8 molecules are proposed. Implications of the cluster data to the structure of bulk liquid mixtures is discussed. In particular, the cluster model for water—acetonitrile is consistent with the concept of “microheterogeneity” observed in water—acetonitrile liquid mixtures.
Complexity Questionnaires of Visual Displays: A Validation Study of Two Information Complexity Questionnaires of Visual Displays

With the prevalent use of visual interfaces and the increasing demand to display more information, information complexity in human–computer interfaces becomes a major concern for designers. Complex interfaces may adversely affect the effectiveness, efficiency, and even the operational safety of a system. Previously, two questionnaires were developed by researchers at the Federal Aviation Administration to evaluate information complexity of air traffic control displays. This study adapted the questionnaires for commercial visual interfaces and validated them with two types of tasks on three travel websites. The questionnaire measures the information complexity of a visual display based on perceptual, cognitive, and action complexity in terms of three complexity factors: quantity, variety, and relation. The result demonstrates that the questionnaire that uses multiple items for measuring complexity construct has good reliability, validity, and sensitivity. Information complexity is also found to be negatively correlated with usability and positively correlated with mental workload. The contribution of the study includes validating the theoretical framework for the information complexity concept through the use of questionnaires and providing a practical tool for designers to measure information complexity of the visual display for iterative improvement. © 2011 Wiley Periodicals, Inc.
A Methodology for Economic Evaluation of Distribution Automation

A methodology is described for evaluating the economic feasibility of automation of electric utility distribution systems. Approximately 40 distribution automation functions and subfunctions for the distribution substation, feeder primary, and secondary levels are vels are included with provision fortiondistribu- line carrier, radio, and telephone communication systems. The approach followed is determination of the present value and annual revenue requirements for alternative growth plans, with versus without distribution automation, over a study period of future years. Potential benefits of the functions are evaluated for their economic impact at the generation, transmission, and distribution levels of the utility system. Economic evaluation results are presented based on assumed implementation of selected functions.
Fast dilation and erosion of time-varying grey-valued images with uncertainty

Two of the most important basic morphological operations used in image filtering are erosion and dilation. In this paper the authors consider the case when a finite image is part of a pixel display which changes ate discrete times. Taking advantage of the fact that not all pixels will change from time t to time t + 1, they develop two important algorithms for computing the dilation and erosion of such images in o(n2) less time then with brute force. These results hold also for translation and rotation and can be extended to opening and closing of images by structuring elements. These results are also extended to images which contain multi-uncertain values, that is, the extended fuzzy pointing set. The advantages of these fast operations are obvious in on-the-fly image processing schemes such as real-time filtering of images.
Response to Letter Regarding Article, “Outcome of Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy”

We thank Dr ElBardissi for his letter and insightful commentary. In our investigation,1 there were no differences in rates of survival free of severe symptoms between surgical myectomy and septal ablation in the overall population, but patients under the age of 65 years did better with surgery. For patients who underwent septal ablation and then later required myectomy, follow-up was ceased at the time of the occurrence …
Slugging it out: fine tuning the p53-PUMA death connection.

In response to DNA damage, the tumor suppressor p53 elicits a complex cellular response. In this issue of Cell, Wu et al. (2005) show that the transcription factor SLUG is induced by p53 and protects hematopoietic progenitor cells from apoptosis triggered by DNA damage. SLUG exerts this protective role by repressing Puma, a proapoptotic target of p53. PUMA is also a key coordinator of apoptosis mediated by both nuclear and cytoplasmic functions of p53 (Chipuk et al., 2005).