cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluation of the initiation of urine drug screens intended for use in transfer patients

Abstract Objective The objective of this study was to determine if signs of clinical intoxication were present in patients who had transfer urine drug screens (UDS) performed and to determine the proportion of patients with UDS orders who were actually transferred to another facility. Methods Of all emergency department (ED) patient visits who had a transfer UDS ordered from November 19, 2011, to December 31, 2012, 54% of the population was randomly selected for review by 1 of 3 study investigators. For quality assurance, a random sample of 100 patient charts was independently reviewed by all 3 investigators to assure consistency in interpreting data. Demographics, clinical characteristics and history, disposition, and laboratory results were recorded. Results Of the 639 patients included in this study, only 18% were transferred to another psychiatric facility. Pediatric patients and those with presenting with suicidal ideation were more likely to be transferred to an outside facility. Thirty-six percent of the UDS were positive for at least one substance. Marijuana was the most common substance (23%), followed by cocaine (7%) and opiates (7%). There was no evidence that the UDS changed acute management decisions. Conclusions Few (
Psychosocial correlates of hiv-related sexual behavior in an inner city std clinic

Abstract Inner city African Americans suffer a disproportionate share of sexually transmitted disease (STD), including HIV infection. For effective interventions to be planned, variables critical to sexual behavior in this population must be identified. This study introduced and tested a self-report measure of sexual impulse control for its relevance to the risky sexual practices of 83 inner city men and women from three New Jersey public STD clinics. Social cognitive factors, largely derived from Bandura's social cognitive theory (SCT), were also assessed for their influence upon risky inner city sexual practices. Results indicated that difficulty controlling sexual impulse was the variable most strongly linked with unprotected sexual intercourse among the entire sample. However, self-efficacy to negotiate condom use played a significant role in women's sexual behavior but not in men's. Among female STD patients, higher self efficacy to negotiate condom use was linked with less unprotected intercourse.
Cooperative effects in long-range 1,4 DNA-DNA interstrand cross-links formed by polynuclear platinum complexes: an unexpected syn orientation of adenine bases outside the binding sites.

The novel phase II anticancer drug BBR3464 ([{trans-PtCl(NH3)2}2-µ-{trans-Pt(NH3)2(NH2(CH2)6NH2)2}](NO3)4) forms a 1,4-interstrand cross-link adduct with the self-complementary DNA octamer 5′-d(ATG*TACAT)2-3′, with the two platinum atoms coordinated in the major groove at the N7 positions of guanines that are four base pairs apart on opposite DNA strands. The "central" tetraamine linker [trans-H2N(CH2)6NH2Pt(NH3)2NH2(CH2)6NH2] was located in or close to the minor groove. The adduct was characterized and analyzed by MS, UV and NMR spectroscopy. NMR analysis of the adduct shows strong H8/H1′ intraresidue crosspeaks observed for the A1 and A7 resonances, consistent with a syn conformation for these bases which is usually not observed for adenine residues and bases not directly involved in the cross-link in oligonucleotides. The strong intraresidue H8/H1′ crosspeak is also observed for G3. Examination of the structure thus reveals unusual cooperative effects unique to this class of anticancer drugs and is the first demonstration of cooperative effects in solution for an anticancer drug. The significant characteristic of the structure is the lack of severe DNA distortion such as a kink, directed bend or significant unwinding of the helices which are characteristic for DNA adducts of mononuclear complexes. This may contribute to the lack of protein recognition of the cross-link by HMG-domain proteins, a biological consequence significantly different from that of mononuclear complexes such as cisplatin. Since DNA is the principal target in vivo for these Pt cross-linking agents, the unique structural perturbations induced by BBR3464 cross-links are likely related to its increased cytotoxicity and antitumor activity as compared to cisplatin (cis-DDP).Electronic supplementary material is available if you access this article at http://dx.doi.org/10.1007/s00775-002-0383-x. On that page (frame on the left side), a link takes you directly to the supplemtary materials.
Role of lattice registry in the full collapse and twist formation of carbon nanotubes

The effect of interlayer lattice registry on the formation of fully collapsed single wall carbon nanotubes (SWCNTs) was studied via atomistic simulation. It was found that a fully collapsed SWCNT could adopt various structural morphologies, such as a straight ribbon, a warping ribbon, or even a twisted ribbon. Such structural formations depended on the degree of commensurance between the lattice structures of the adhering layers in a collapsed SWCNT, thus the chirality of the SWCNT. The modeling result was further corroborated with a simple analysis of the system energy difference among graphitic double layer structures with different interlayer lattice registry, and with the experimental observation of freestanding, twisted, and collapsed nanotubes.
Splicing of group II introns in spinach chloroplasts (in vivo): analysis of lariat formation.

To investigate the mechanism of chloroplast mRNA splicing in vivo, RNAs from four spinach chloroplast group II intron-containing genes were analyzed. For each of these genes, atpF, rpoC1, petD, and petB, Northern analysis of chloroplast RNAs detected putative lariat-intron/3′ exon-splicing intermediates. Treatment of these RNAs with HeLa cell-debranching extract caused the putative splicing intermediates to disappear, thereby confirming their identities. The lariat-splicing intermediates were further examined by reverse transcriptase extension to determine the branch point location. The in vivo branch points of the atpF and petD introns were found to be eight bases upstream of their respective 3′ intron/exon boundaries. In contrast, no splicing intermediates could be detected by primer-extension analysis of petB and rpoC1. This unexpected result served to demonstrate that the quantity of lariat-intron/3′ exon-splicing intermediates present in the chloroplast RNA population is considerably less in the cases of rpoC1 and petB compared to atpF and petD. The steady-state level of any splicing intermediate is the result of a balance between the splicing kinetics of a particular RNA and the susceptibility of the splicing intermediate to degradation. We conclude that the balance between these two factors varies significantly for chloroplast introns, even for those, such as petB and petD, that are transcribed from the same promoter.
BDNF up-regulates α7 nicotinic acetylcholine receptor levels on subpopulations of hippocampal interneurons

In the hippocampus, brain-derived neurotrophic factor (BDNF) regulates a number of synaptic components. Among these are nicotinic acetylcholine receptors containing alpha7 subunits (alpha7-nAChRs), which are interesting because of their relative abundance in the hippocampus and their high relative calcium permeability. We show here that BDNF elevates surface and intracellular pools of alpha7-nAChRs on cultured hippocampal neurons and that glutamatergic activity is both necessary and sufficient for the effect. Blocking transmission through NMDA receptors with APV blocked the BDNF effect; increasing spontaneous excitatory activity with the GABA(A) receptor antagonist bicuculline replicated the BDNF effect. BDNF antibodies blocked the BDNF-mediated increase but not the bicuculline one, consistent with enhanced glutamatergic activity acting downstream from BDNF. Increased alpha7-nAChR clusters were most prominent on interneuron subtypes known to directly innervate excitatory neurons. The results suggest that BDNF, acting through glutamatergic transmission, can modulate hippocampal output in part by controlling alpha7-nAChR levels.
Simulated climate effects of Southeast Asian deforestation: Regional processes and teleconnection mechanisms

[1] A coupled atmosphere-ocean model is used to examine the climatic effects of Southeast Asian deforestation. On the deforested grid cells surface temperatures rise, and precipitation is reduced after deforestation. Regional moisture convergence and convection increase and lead to strongly enhanced rainfall. The easterlies and associated oceanic surface currents are reduced in the Southeast Asian realm. As a result, the upwelling of cold ocean water weakens, and surface temperatures rise. This acts as a strong positive feedback mechanism for the enhanced regional moisture convergence. Besides the regional effects, we find strong teleconnections to the tropics and to the high latitudes of both hemispheres. The signal from Southeast Asia propagates to the extratropics with the high-level winds in the form of sensible heat and potential energy. Possibly because of strong albedo–sea ice feedbacks, some regions in the high latitudes amplify relatively small initial climate changes and exhibit strong remote effects. The excitation of atmospheric waves (probably Rossby waves) is the underlying mechanism that causes the signal propagation to the extratropics.
Cosmic-ray-induced radioactivities in meteorites—II Al26, Be10 and Co60, aerolites, siderites and tektites

Abstract The long-lived radionuclides Al 26 and Be 10 and the 5 year Co 60 have been detected in stone and iron meteorites. The highest levels observed, in disintegrations per minute per gram of specimen were: in stone, Al 26 , 0.063; Be 10 , 0.0051; Co 60 , 0.0018; in iron, Al 26 , 0.0055; Be 10 , 0.00070; Co 60 , 0.033. The Al 26 and Be 10 were evidently produced by cosmic-ray bombardment of the meteorites before fall. The Co 60 seems to have been produced principally by neutron capture in ordinary cobalt in recent years while the specimens were on earth, although disintegration of the long-lived Fe 60 may contribute some Co 60 . The Be 10 : Al 26 ratio is definitely lower in the Plainview chondrite than in the Richardton chondrite, suggesting that the former may have existed as a small body for only about a million years. The presence of both activities in the Odessa siderite indicates that it and its associated craters are probably less than about a million years old. The absence of these activities in the Canyon Diablo siderite is probably ascribable to a shielded position of the specimen inside the large meteoroid. Al 26 is definitely and Be 10 fairly certainly present in australites, indicating that tektites are glass meteorites and have spent at least a million years or so in space. Both activities are also present in Libyan Desert silica-glass, indicating that it is a variety of tektite. From the Al 26 and Be 10 levels or limits, in comparison with the levels in chondrites, the following approximate terrestrial ages or limits, in millions of years, are calculated: australites, 1.2; moldavites, >3. Measurements of these and other nuclides can give valuable information on the pre-fall and post-fall histories of meteorites and on the past intensity of the cosmic radiation. The average cosmic-ray flux over the past several million years appears not to have been grossly different from the present value. nergy
HUMEAN SUPERVENIENCE AND PERSONAL IDENTITY

Humeans hold that the nomological features of our world, including causal facts, are determined by the global distribution of fundamental properties. Since persistence presupposes causation, it follows that facts about personal identity are also globally determined. I argue that this is unacceptable for a number of reasons, and that the doctrine of Humean supervenience should therefore be rejected.
Outpatient consultation-liaison psychiatry: A valuable addition to the training of advanced psychiatry residents

Abstract With current health care reimbursement conditions and recent research denoting the important relationship between mental health status and poor functioning, especially in medically ill patients, one would think that consultation-liaison (C-L) psychiatry would have an increasingly viable role in the outpatient health care sector. However, only a small number of outpatient C-L clinics are reported and recently several of these have folded. These outpatient C-L clinics can follow different clinical models and have the potential, especially at the residency and fellowship training levels, for interesting and useful educational opportunities. This paper describes a recently founded outpatient C-L clinic—the Medical Illness Clinic—in a university medical center's department of Psychiatry. We highlight the structure of the clinic, the kinds of patients seen, and focus on the unique educational residency training opportunities this setting presents. The results of clinic rotation evaluations by residents are also presented. We conclude with recommendations for more exploration of this clinical model and evaluation of its utility in psychiatric residency education.
Table of nuclear moments

This table is a compilation of experimental data on static nuclear magnetic dipole ane electric quadrupole moments for ground state and excited states of nuclides from {sup 1}H to {sup 254}Es. Listed along with the moments are the associated excitation energy, half-life, spin, and parity of the nuclear state, and the experimental method employed. The literature has been surveyed through early 1988. For those cases for which no new or improved data has been reported since 1977, selected data from the compilation in Appendix VII of the {ital Table} {ital of} {ital Isotopes}, edited by C. M. Lederer and V. S. Shirley (Wiley, New York, 1978), with appropriate revisions, have been included.
Type I interferons inhibit the generation of tumor-associated macrophages.

Tumor-associated macrophages (TAM) are very abundant in tumors and are thought to play a major role in promoting tumor growth. The generation of TAM is positively regulated by several cytokines, including colony stimulating factor-1 (CSF-1) and monocyte chemoattractant protein-1 (CCL2). However, endogenous factors that suppress the generation of TAM within tumors have not been previously identified. An earlier study showed that endogenously produced type I interferons (IFN) suppressed tumor growth via their effects on hematopoietic cells rather than through direct effects on tumor cells. Therefore, we used mouse tumor models to investigate the effects of endogenously produced type I IFNs on the generation of TAM. We found using immunohistochemistry and flow cytometry that TAM density was significantly increased in tumors of mice lacking the type I IFN receptor (IFN-α/βR−/− mice) compared to wild type mice. Moreover, the increase in TAM density was associated with a significant increase in tumor growth rate and angiogenesis. The phenotype of TAM was similar in IFN-α/βR−/− mice and wild type mice and tumors in both mice produced similar amounts of CSF-1 and CCL2. However, in vitro assays indicated that low concentrations of type I IFNs significantly inhibited the generation of bone marrow macrophages in response to CSF-1. These findings indicate that endogenously produced type I IFNs suppress the generation of TAM, which may in turn account for inhibition of tumor growth and angiogenesis.
Advanced Computational Fluid Dynamics Simulations of Proiectiles with Flow Control

This paper describes a computational study undertaken as part of a grand challenge project to determine the aerodynamic effect of flow control in the afterbody regions at subsonic and supersonic speeds using an advanced scalable unstructured flow solver. High parallel efficiency is achieved for both steady and time-accurate unsteady flow field simulations using advanced scalable Navier-Stokes computational techniques on SGI Origin 3000, IBM SP3 and Linux Cluster. Numerical simulations with the unsteady synthetic jet show the jets to substantially alter the flow field both near the jet and the base region of the projectile that in turn affects the forces and moments even at zero degree angle of attack. The results have shown the potential of high performance computing computational fluid dynamics simulations on parallel machines to provide insight into the jet interaction flow fields leading to improved projectile designs and accurate prediction of flight trajectories.
Parallel DC notch filter

In the process of image acquisition, the object of interest may not be evenly illuminated. So an image with shading irregularities would be produced. This type of image is very difficult to analyze. Consequently, a lot of research work concentrates on this problem. In order to remove the light illumination problem, one of the methods is to filter the image. The dc notch filter is one of the spatial domain filters used for reducing the effect of uneven light illumination on the image. Although the dc notch filter is a spatial domain filter, it is still rather time consuming to apply, especially when it is implemented on a microcomputer. To overcome the speed problem, a parallel dc notch filter is proposed. Based on the separability of the algorithm dc of notch filter, image parallelism (parallel image processing model) is used. To improve the performance of the microcomputer, an INMOS IMS B008 Module Mother Board with four IMS T800-17 is installed in the microcomputer. In fact, the dc notch filter is implemented on the transputer network. This parallel dc notch filter creates a great improvement in the computation time of the filter in comparison with the sequential one. Furthermore, the speed-up is used to analyze the performance of the parallel algorithm. As a result, parallel implementation of the dc notch filter on a transputer network gives a real-time performance of this filter.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
PMN-PT single crystal resonators for sensing acetone vapors

This paper compares frequency measurements in lead magnesium niobate-lead titanate (PMN-PT) resonators with conventional quartz crystal microbalance (QCM) resonators when exposed to acetone vapors under identical test conditions. A pumpless mechanism for driving acetone vapors by convection force was developed in our experimental setup. The frequency shift recorded in response to acetone vapor exposure for the PMN-PT resonator was more than 10,000 times larger than for the QCM resonator. Our experimental results reinforce the notion that PMN-PT resonators could be a superior replacement for QCM resonators in a variety of biosensor applications. The experimental setup heated water to produce acetone vapors, a volatile organic chemical, which were delivered to a sensing chamber to interact with the sensing unit. Chemical vapors were driven toward the sensing unit and circulated through the system via a pumpless mechanism by the principle of convection. Both types of resonators displayed a change in frequency as acetone vapors were applied, but PMN-PT showed a more significant change by several orders of magnitude.
Examination of a Measure of Racial Discrimination Among African American Adolescents1

The present study consisted of an empirical examination of the psychometric properties of the Index of Race-Related Stress (IRRS) among 258 African American adolescents. Confirmatory factor analyses supported a 3-component model (i.e., individual, collective/institutional, and cultural) of racial discrimination perceived by African American adolescents. The revised subscales of the IRRS were associated with another measure of racial discrimination as evidence of concurrent validity, and the subscales of the IRRS demonstrated adequate reliability. The results are consistent with previous research indicating that adolescent responses to perceived racial discrimination are distinct from adults'. Future research should consider the assessment of racial discrimination among African American adolescents to understand the relationship between perceptions of racial discrimination and indexes of mental and physical health.
Television viewing practices and obesity among women veterans

BACKGROUND: Obesity is epidemic in the U.S. and has been associated with television viewing.
Photophysics of polycycloalkane xanthenylidene compounds

Abstract The excited state dynamics of a xanthenylidene heptacyclotetradecane have been investigated by steady state and time-resolved fluorescence spectroscopies. In fluid solution, the vertical excited state undergoes a conformational relaxation, resulting in a large fluorescence Stokes shift. The fluorescence quantum yield and the excited state lifetime increase with decreasing temperature and with decreasing solvent polarity. The activation energy of the excited state decay decreases with increasing solvent polarity. The primary decay pathway of the conformationally relaxed, excited state passes over a polar or polarizable transition state. The conventional, one-dimensional potential energy scheme used for stilbenes can also be used to explain most aspects of the photophysics of the xanthenylidene chromophore.
Photobiology and Photomedicine: The Future Is Bright

Important events since 1966 that have helped to advance photobiology in general and photomedicine in particular are reviewed. More formal courses on photobiology are needed so that future photobiologists and photodermatologists will not have to be self-taught about the properties and action of light. The effectiveness of current phototherapies and their future improvement are discussed. Some of the areas of photobiology that will impact on photomedicine in the years to come are ultraviolet (UV) radiation effects on the immune system, the light activation of enzymes as a potential new type of phototherapy, the development of new photosensitizers for phototherapy, the effects of near-UV radiation on cellular membranes, and, of course, the role of DNA damage and repair in mutagenesis and carcinogenesis. The future is bright for photomedicine.
Development of Complex Regional Pain Syndrome after a Cervical Epidural Steroid Injection

THE pathophysiology of the complex regional pain syndrome (CRPS) remains uncertain, and many events have been implicated as causative factors. Events as serious as major trauma and as seemingly innocuous as venipuncture have been incriminated. 1 Trauma to nervous tissue can be a causative factor in CRPS, type II. 2 This report describes a patient in whom a constellation of symptoms consistent with CRPS, type II developed after a cervical epidural steroid injection.
Paradoxical inhibition of nociceptive neurons in the dorsal horn of the rat spinal cord during a nociceptive hindlimb reflex.

Abstract Nociceptive-specific and multireceptive neurons in the lumbar dorsal horn are excited by noxious stimuli applied to the hindpaw and inhibited by noxious stimuli applied to distant body regions. Given that at least a subset of these neurons are part of the circuit for nociceptive reflexes, inhibition of nociceptive-specific and multireceptive neurons should inhibit nociceptive reflexes. Unfortunately, previous attempts to test this hypothesis have been inconclusive because of methodological differences between electrophysiological and behavioral experiments. The present study overcame this problem by recording neural and reflex activity simultaneously. Rats were anesthetized with halothane and surgically prepared for single-unit recording from the lumbar dorsal horn. Hindpaw heat caused a burst of activity that reliably preceded hindpaw withdrawal in 10 nociceptive-specific and 17 multireceptive neurons. A distant noxious stimulus (tail in 50°C water or ear pinch) inhibited the evoked activity of both nociceptive-specific and multireceptive neurons and simultaneously changed the topography of the hindpaw reflex from flexion to extension without altering reflex latency. The present data are consistent with previous reports of inhibition of nociceptive-specific and multireceptive neurons during application of a distant noxious stimulus. However, inhibition of nociceptive-specific and multireceptive neurons concomitant with a shift in the hindlimb reflex from flexion to extension suggests that these neurons are part of the circuit for flexor reflexes specifically. Presumably, lateral inhibition from the flexor to extensor circuit allows for the release of hindlimb extension when neurons in the flexion circuit are inhibited by a distant noxious stimulus. Such a system reduces the chance of injury by allowing for withdrawal reflexes to a single noxious stimulus and escape reactions, such as running and jumping, to multiple noxious stimuli.
Convergence of an efficient local least-squares fitting method for bases with compact support

Abstract The least-squares projection procedure appears frequently in mathematics, science, and engineering. It possesses the well-known property that a least-squares approximation (formed via orthogonal projection) to a given data set provides an optimal fit in the chosen norm. The orthogonal projection of the data onto a finite basis is typically approached by the inversion of a Gram matrix involving the inner products of the basis functions. Even if the basis functions have compact support, so that the Gram matrix is sparse, its inverse will be dense. Thus computing the orthogonal projection is expensive. An efficient local least-squares algorithm for non-orthogonal projection onto smooth piecewise-polynomial basis functions is analyzed. The algorithm runs in optimal time and delivers the same order of accuracy as the standard orthogonal projection. Numerical results indicate that in many computational situations, the new algorithm offers an effective alternative to global least-squares approximation.
Podocyte differentiation in the absence of endothelial cells as revealed in the zebrafish avascular mutant, cloche.

The physiological functions of the zebrafish pronephros are blood plasma filtration and osmoregulation. The pronephric glomerulus is vascularized through a capillary network sprouting from the dorsal aorta. Vascularization of the glomerulus, visualized by flk-1 expression and alkaline phosphatase reactivity, involves the intimate association between podocytes and endothelial cells and the formation of an intervening glomerular basement membrane (GBM). Cell–cell interactions between podocytes and endothelial cells are thought to play an important role in glomerular angiogenesis. In order to determine whether endothelial cell-derived signals were required for podocyte differentiation, we employed in situ hybridization and electron microscopy to investigate glomerulogenesis in the zebrafish mutant cloche (clo), where endothelial cell development is blocked at an early stage. In clo mutants, glomerular epithelial cells expressing the podocyte specific marker wt1 display well-formed foot processes and are able to form a GBM, suggesting podocytes are able to morphologically differentiate in the absence of endothelia or endothelial-derived signals. The presence of irregular aggregates in the clo GBM as well as the apparent effacement of podocyte foot processes implies a role for endothelial cells in the maintenance of the mature glomerular filtration barrier. Dev. Genet. 24:220–229, 1999. © 1999 Wiley-Liss, Inc.
Influence of Adding Malic Acid to Dairy Cattle Rations on Milk Production, Rumen Volatile Acids, Digestibility, and Nitrogen Utilization

Abstract Thirty-two lactating Holstein cows (16 in early and 16 in midlactation) were fed for 100 days either 0, 70, 105, or 140 g of malic acid per day. Rations were corn and corn silage, and 25% of the total nitrogen was urea. Milk persistency was greater for the group fed 140 g malic acid per day. Malic acid increased total volatile fatty acids during early lactation. Intake of dry matter, milk composition, glucose and urea in plasma, and rumen ammonia and pH did not differ among treatments. In another study, six steers with rumen fistulas received 0, 100, or 200 mg/kg body weight of malic acid in a Latin square design. The basal diet was ground shelled corn and corn silage (equal dry matter) supplemented with urea to increase crude protein to 12% (of dry matter) and minerals. Malic acid increased rumen propionate, but digestibilities of nutrients, retained nitrogen, urea and ammonia in plasma, and rumen ammonia did not differ among treatments. In a third trial four rumen-fistulated steers received malic acid at 0 and 200 mg/kg body weight in a 2 × 2 Latin square. In this trial 80% of the dry matter was high moisture corn, and 20% was corn silage. Rumen propionate again tended to be greater for steers fed malic acid. No differences among treatments were shown for other rumen and blood measurements.
A planar elliptical model of cardio-vagal hysteresis.

The state-dependent portion of cardio-vagal baroreflex control is called baroreflex hyteresis: we observe hysteresis when RR interval and carotid diameter depend on both the direction and value of arterial pressure. The elasticity of arterial walls, as well as the responsiveness of central command reset controls the real-time pattern of neural outflow, which is indirectly measured by RR interval in humans. We model the state-dependent relationship among pressure, vessel diameter and heart rate as a three-dimensional planar ellipse. Two-dimensional projections of this ellipse provide motion direction and quantify hysteresis between mechanical (pressure–diameter), neural (diameter–heart rate), and integrated baroreflex (pressure–heart rate) components. A convenient measure for the magnitude of hysteresis is the ratio of the semi-minor and semi-major axes of the best fitting ellipse. This ratio is given a sign according to the direction of its motion. The signed sum of the hysteresis ratio for vessel mechanics and central neural control reliably predicts cardio-vagal hysteresis. Using this relationship, we can quantify the relative importance of neural versus mechanical contributions to integrated baroreflex responses.
Subunit Interactions within an Expressed Regulatory Domain of Chicken Skeletal Myosin LOCATION OF THE NH2 TERMINUS OF THE REGULATORY LIGHT CHAIN BY FLUORESCENCE RESONANCE ENERGY TRANSFER

Abstract The regulatory domain (RD), or neck region of the myosin head, consists of two classes of light chains that stabilize an α-helical segment of the heavy chain. RD from chicken skeletal muscle myosin was prepared in Escherichia coli by coexpression of a 9-kDa heavy chain fragment with the essential light chain. Recombinant regulatory light chain (RLC), wild type or mutant, was added separately to reconstitute the complex. The affinity of RD for divalent cations was determined by measuring the change in fluorescence of a pair of heavy chain tryptophans upon addition of calcium or magnesium. The complex bound divalent cations with high affinity, similar to the association constants determined for native myosin. The intrinsic fluorescence of the tryptophans could be used as a donor to measure the fluorescence resonance energy transfer distance to a single labeled cysteine engineered at position 2 on RLC. Dansylated Cys2 could also serve as a donor by preparing RLC with a second cysteine at position 79 which was labeled with an acceptor probe. These fluorescence resonance energy transfer distances (24–30 A), together with a previous measurement between Cys2 and Cys155 (Wolff-Long, V. L., Tao, T., and Lowey, S. (1995) J. Biol. Chem. 270, 31111–31118) suggest a location for the NH2 terminus of RLC that appears to preclude a direct interaction between the phosphorylatable serine and specific residues in the COOH-terminal domain.
Toward the development of generally applicable models of the microbial loop in aquatic ecosystems

Simulation modeling has been an integral, albeit ad hoc, component of the field of aquatic microbial ecology for the past two decades. One of the most critical steps in simulation modeling is the initial formulation of a clear set of questions and goals. It is doubtful that a single generic model could be constructed to address adequately all questions of interest concerning the microbial loop because of the tremendous range in time scales that define these questions. Progress in the field of aquatic microbial ecology will benefit from an integrated research program including experimental and modeling approaches. A submodel of bacterial utilization of various qualities of organic matter that we have under construction is presented. This submodel will be a component of a larger model to evaluate the effects of quality and quantity of organic matter and inorganic nutrient inputs on estuarine food web structure and efficiency. The overall model will be general enough in its structure that it should be applicable to a wide range of questions concerning the microbial loop, with time scales ranging from hours to days.
Utility of preoperative high-resolution CT and intraoperative image guidance in identification of cerebrospinal fluid leaks for endoscopic repair.

Background Endoscopic repair of cerebrospinal fluid (CSF) leaks is a well-established procedure. The radiological workup and use of intraoperative image guidance (IGS), lumbar drain (LD), and intrathecal fluorescein (IF) are less universally accepted. This study examines endoscopic repair of CSF leaks using preoperative high-resolution CT (HRCT) and intraoperative IGS without IF or LD. Methods Retrospective review was performed of a single surgeon experience between September 2002 and January 2007. Results Forty-two anterior skull base defects in 40 patients were repaired endoscopically. The etiology of CSF leaks was traumatic in 5, spontaneous in 12, and iatrogenic in 25 defects (15 from endoscopic sinus surgeries and 10 from neurosurgical procedures). Fifty-two percent of defects presented with a meningoencephalocele. Defect location was sphenoid sinus (17 defects), ethmoid roof (14 defects), cribriform plate (9 defects), and frontal sinus (2 defects). Defect size ranged from 1x1 mm to 2x2 cm. Follow-up ranged from 8 to 46 months. All defects were identified preoperatively on HRCT with successful intraoperative IGS localization. No patients required IF for identification of CSF leak. Overall successful repair was achieved in 40 (95%) defects after initial repair, and 100% after revision. Seven patients had LD, 6 patients were early in the series. Twenty-three patients were discharged the day after surgery and 6 patients were discharged on day 2. Conclusion Using preoperative HRCT for diagnosis and intraoperative IGS for localization, even small skull base defects can be definitively identified. High success rates and early discharges are achieved without additional procedures such as IF or LD. This is a less invasive and more cost-efficient method of repairing CSF leaks.
Preparation and use of hydantion-based chiral stationary phases

Abstract Starting from α-naphthyl 4-pentenyl ketone, hydantoin-based chiral stationary phase 6a has been prepared. Chiral stationary phase 6a has proven to be quite effective for the separation of the enantiomers of hundreds of 3,5-dinitrobenzamides derived from amino acids, amino esters, amino amides, amino phosphates, amino alcohols and amines. A chiral recognition model involving three simultaneous stereochemically-dependent interactions is advanced to account for the observed elution orders of the enantiomers. On the basis of the chiral recognition model, a rational improvement was made in the design of the hydantoin chiral stationary phase. For example, enahancing the π-basicity of the naphthyl system [chiral stationary phase 6b, derived from (R)-5(6,7-dimethyl-1-naphthyl)-5-(5-triethoxysilyl)hydantoin] has led to significantly imprved performance relative to phase 6a, which lacks the 6,7-dimethyl groups. Ring-alkylated chiral stationary phase 6c has also been prepared and evaluated relative to phase 6a.
Summary of Melting and Transition Temperatures of Pure Substances and Congruent and Incongruent Melting Temperatures of Molecular Addition Compounds

Melting temperatures, along with transition temperatures when they occur, are summarized for 70 pure chemicals used as the components in the study of 112 binary (solid + liquid) phase diagrams reported by us over the past 35 years. The melting temperatures and compositions of 68 solid molecular addition compounds determined as a part of these studies are also reported, and the proposed molecular interactions leading to the formation of these addition compounds are reviewed and discussed. Temperatures were measured with strain-free platinum resistance thermometers (Leeds and Northrup or Rosemount) that were calibrated to conform with the ITS-48 or the IPTS-68 temperature scales. The temperature scale used is estimated to be accurate to ±0.02 K over the temperature range of the measurements. Equations are given to convert temperature from ITS-48 or IPTS-68 to the more recent ITS-90 scale, and used to convert the temperatures reported in the tables to ITS-90.
Using Appreciative Inquiry to Engage the Citizenry: Four Potential Challenges for Public Administrators

In the United States, calls for new citizen engagement strategies have continued to grow at the local government level. One answer is Appreciative Inquiry. As part of a larger study conducted in 2007, the question was posed to public administrators, “What challenges do you see regarding using an Appreciative Inquiry approach to increase citizen participation in local government?” Findings based on a content analysis of the data identified four challenges in particular. Discussion suggests public managers need to be aware of these challenges but depending on local conditions they can be mitigated or overcome.
Higher dietary fructose is associated with impaired hepatic adenosine triphosphate homeostasis in obese individuals with type 2 diabetes

Fructose consumption predicts increased hepatic fibrosis in those with nonalcoholic fatty liver disease (NAFLD). Because of its ability to lower hepatic adenosine triphosphate (ATP) levels, habitual fructose consumption could result in more hepatic ATP depletion and impaired ATP recovery. The degree of ATP depletion after an intravenous (IV) fructose challenge test in low- versus high-fructose consumers was assessed. We evaluated diabetic adults enrolled in the Action for Health in Diabetes Fatty Liver Ancillary Study (n = 244) for whom dietary fructose consumption estimated by a 130-item food frequency questionnaire and hepatic ATP measured by phosphorus magnetic resonance spectroscopy and uric acid (UA) levels were performed (n = 105). In a subset of participants (n = 25), an IV fructose challenge was utilized to assess change in hepatic ATP content. The relationships between dietary fructose, UA, and hepatic ATP depletion at baseline and after IV fructose challenge were evaluated in low- (<15 g/day) versus high-fructose (≥15 g/day) consumers. High dietary fructose consumers had slightly lower baseline hepatic ATP levels and a greater absolute change in hepatic α-ATP/ inorganic phosphate (Pi) ratio (0.08 versus 0.03; P = 0.05) and γ-ATP /Pi ratio after an IV fructose challenge (0.03 versus 0.06; P = 0.06). Patients with high UA (≥5.5 mg/dL) showed a lower minimum liver ATP/Pi ratio postfructose challenge (4.5 versus 7.0; P = 0.04). Conclusions: High-fructose consumption depletes hepatic ATP and impairs recovery from ATP depletion after an IV fructose challenge. Subjects with high UA show a greater nadir in hepatic ATP in response to fructose. Both high dietary fructose intake and elevated UA level may predict more severe hepatic ATP depletion in response to fructose and hence may be risk factors for the development and progression of NAFLD. (HEPATOLOGY 2012;56:952–960)
Effect of Fine Aggregate Angularity on Compaction and Shearing Resistance of Asphalt Mixtures

The effect of fine aggregate angularity (FAA) on the densification characteristics of asphalt mixtures was evaluated with the Superpave® gyratory compactor (SGC). Aggregates from three different sources used in production of Superpave mixtures in Wisconsin were studied. From each source, a fine gradation and a coarse-shaped gradation were included. To vary the FAA values of the fine aggregates, the proportions of the manufactured sand to the natural sand from each source were varied and the same overall gradations were maintained. A range of FAA values between 40 and 48 for the sources was achieved. All other mixture variables were kept constant, and the mixtures were compacted in an SGC equipped with a special device called a gyratory load plate assembly to measure the densification and the shear force required for compaction of each mixture. Densification data were analyzed to estimate the effect of the FAA on densification to 92% of theoretical maximum density (Gmm), which is assumed to represent resis...
A C-terminal domain in KCC2 confers constitutive K+-Cl- cotransport.

The neuron-specific K+-Cl- cotransporter KCC2 plays a crucial role in determining intracellular chloride activity and thus the neuronal response to γ-aminobutyric acid and glycine. Of the four KCCs, KCC2 is unique in mediating constitutive K+-Cl- cotransport under isotonic conditions; the other three KCCs are exclusively swelling-activated, with no isotonic activity. We have utilized a series of chimeric cDNAs to localize the determinant of isotonic transport in KCC2. Two generations of chimeric KCC4-KCC2 cDNAs initially localized this characteristic to within a KCC2-specific expansion of the cytoplasmic C terminus, between residues 929 and 1043. This region of KCC2 is rich in prolines, serines, and charged residues and encompasses two predicted PEST sequences. Substitution of this region in KCC2 with the equivalent sequence of KCC4 resulted in a chimeric KCC that was devoid of isotonic activity, with intact swelling-activated transport. A third generation of chimeras demonstrated that a domain just distal to the PEST sequences confers isotonic transport on KCC4. Mutagenesis of this region revealed that residues 1021-1035 of KCC2 are sufficient for isotonic transport. Swelling-activated K+-Cl- cotransport is abrogated by calyculin A, whereas isotonic transport mediated by KCC chimeras and KCC2 is completely resistant to this serine-threonine phosphatase inhibitor. In summary, a 15-residue C-terminal domain in KCC2 is both necessary and sufficient for constitutive K+-Cl- cotransport under isotonic conditions. Furthermore, unlike swelling-activated transport, constitutive K+-Cl- cotransport mediated by KCC2 is completely independent of serine-threonine phosphatase activity, suggesting that these two modes of transport are activated by distinct mechanisms.
Mechanisms of aortic valve incompetence: Finite-element modeling of Marfan syndrome

Abstract Objectives: Progressive aortic root dilatation and an increased aortic root elastic modulus have been documented in persons with Marfan syndrome. To examine the effect of aortic root dilatation and increased elastic modulus on leaflet stress, strain, and coaptation, we used a finite-element model. Methods: The normal model incorporated the geometry, tissue thickness, and anisotropic elastic moduli of normal human roots and valves. Four Marfan models were evaluated, in which the diameter of the aortic root was dilated by 5%, 15%, 30%, and 50%. Aortic root elastic modulus in the 4 Marfan models was doubled. Under diastolic pressure, regional stresses and strains were evaluated, and the percentage of leaflet coaptation was calculated. Results: Root dilatation and stiffening significantly increased regional leaflet stress and strain compared with normal levels. Stress increases ranged from 80% to 360% and strain increases ranged from 60% to 200% in the 50% dilated Marfan model. Leaflet stresses and strains were disproportionately high at the attachment edge and coaptation area. Leaflet coaptation was decreased by approximately 20% in the 50% root dilatation model. Conclusions: Increasing root dilatation and root elastic modulus to simulate Marfan syndrome significantly increases leaflet stress and strain and reduces coaptation in an otherwise normal aortic valve. These alterations may influence the decision to use valve-sparing aortic root replacement procedures in patients with Marfan syndrome. J Thorac Cardiovasc Surg 2001;122:946-54
The effect of theophylline on adenosine 3′, 5′-monophosphate-dependent protein kinase and ACTH1–24 stimulated steroidogenesis in bovine adrenal cortical cells

Abstract Theophylline (theo), a known phosphodiesterase (PDE) inhibitor, was tested for its effects on ACTH 1–24 regulated steroidogenesis in isolated bovine adrenal cortical cells. Theo produced a dose related inhibition of ACTH 1–24 stimulated cortisol synthesis with half maximal inhibition occuring at 7 mM. Theo enhanced ACTH 1–24 stimulated cellular adenosine 3′, 5′-monophosphate (cAMP) levels above that produced by ACTH 1–24 alone confirming its inhibition of cAMP PDE. When tested on cAMP binding protein and cAMP-dependent protein kinase activities in cytosol prepared from bovine adrenal cortex, theo displaced 3 H-cAMP binding to cAMP binding protein and inhibited cAMP-stimulated protein kinase activity. The half maximal inhibition of cAMP binding and protein kinase activity was observed at 10 and 5 mM, respectively. Inhibition of cAMP-dependent protein kinase by theo provides a possible explanation of its inhibitory effects on adrenal steroidogenesis and further implicates cAMP-dependent protein kinase in mediating ACTH stimulated steroidogenesis. Furthermore these studies suggest a novel mechanism of action for theo in addition to its known action on cAMP PDE.
Why do phosphatidylinositol kinases have so many isoforms

Macromolecules can be transported into the cells by endocytosis, either by phagocytosis or by pinocytosis. Typically, phagocytosis involves the uptake of solid large particles mediated by cell-surface receptors, whereas pinocytosis takes up fluid and solutes. The synthesis of PtdIns(4,5) P 2 and PtdIns(3,4,5) P 3 plays fundamental roles in all forms of endocytosis. Curiously, almost all eukaryotic cells have multiple isoforms of the kinases that synthesize these critical phosphatidylinositols. In this issue of the Biochemical Journal , Namiko Tamura, Osamu Hazeki and co-workers report that the subunit p110α of the type I PI3K (phosphoinositide 3-kinase) is implicated in the phagocytosis and the pinocytosis of large molecules, whereas the receptor-mediated pinocytosis and micropinocytosis of small molecules do not seem to be controlled by this mechanism. The present commentary discusses recent literature that has begun to unravel why cells need so many phosphatidylinositol kinase isoforms, which were previously believed to be redundant.
Conformational subtlety in large polyphenylene molecules

1,3-Bis(nonaphenyl-3-biphenylyl)benzene ( 3 ), a large polyphenylene molecule (C 138 H 94 ), was prepared by the Diels–Alder addition of 2 equiv. of 1-(pentaphenylphenyl)-2-phenylacetylene to 1,3-bis(3-oxo-2,4,5-triphenylcyclopenta-1,4-dienyl)benzene, and its X-ray structure was determined. The experimental structures of decaphenylbiphenyl ( 4 ) and 3 were compared with calculated structures of these molecules obtained by using methods ranging from molecular mechanics to hybrid density functional theory. Surprisingly, none of the computational methods examined correctly predicted the experimentally observed conformations of both 3 and 4 .
Interdiffusion Studies of the System FexO-MgO

The solid-state reaction between Fe,O and MgO is best described as counterdiffusion of the magnesium and iron ions through a relatively rigid oxygen ion lattice of the rock salt structure. A relation between a mutual diffusion coefficient and a controlled cation vacancy concentration was determined by an analysis of the concentration-penetration curve of the Fe,O-MgO solid solution. The diffusion coefficient increased approximately exponentially with a linear increase of the cation vacancy concentration. This may be represented by a linear increase of the entropy of activation with vacancy concentration. The enthalpy of activation for the diffusion reaction, 47.5 kcal per mole, remained independent of vacancy concentration.