cssi/SciSciGPT-SciSciNet huggingface dataset:
Advances and challenges in phenylketonuria

Phenylketonuria (PKU; OMIM 262600), one of the most common inborn errors of metabolism, is caused by recessively inherited deficiency of the enzyme phenylalanine hydroxylase (PAH; EC 1.14.16.1) (Blau et al. 2010). PAH catalyses the irreversible hydroxylation of phenylalanine (Phe) to tyrosine. PAH is expressed primarily in the liver but also in the kidney and pancreas, and its activity requires the unconjugated pterin co-factor, tetrahydrobiopterin (BH4). PAH deficiency causes hyperphenylalaninaemia, but hyperphenylalaninaemia can also be caused by inherited deficiency of enzymes involved in BH4 synthesis or recycling (Blau et al. 2010). Chronic, untreated, severe hyperphenylalaninaemia in infants and children leads to seizures and mental retardation. Newborn screening and early initiation of PKU therapy has eliminated the major manifestations of the disease, but shortcomings in our current therapeutic approach remain. Contemporary therapy for PKU is centered upon tight restriction of dietary Phe intake and requires supplementation with special medical foods that supply sufficient essential amino acids and energy from fat and carbohydrate. Institution and maintenance of the PKU diet are difficult, and the required medical foods are often unpalatable. Dietary therapy is recommended for life (Anon 2001), but non-compliance with the dietary prescription is commonplace, particularly during adolescence and adulthood. Hyperphenylalaninaemia in adults is often associated with attention problems, mood instability and poor job performance. Chronically elevated Phe may cause a progressive neurodegenerative disorder affecting white matter that leads to seizures and gait disturbance. Finally, untreated maternal hyperphenylalaninaemia during pregnancy is the only teratogen guaranteed to cause birth defects, which include microcephaly, mental retardation and congenital heart disease (Levy et al. 2003), the so-called maternal PKU syndrome. For all these reasons, novel alternative therapies for PKU are being sought. Phe itself, accumulating to extremely high levels, is primarily responsible for the phenotype associated with untreated PKU. Accumulation of Phe in blood (normally less than 150 μM but often over 2,000 μM in untreated patients) severely interferes with growth and maturation of the developing brain, although the exact molecular mechanism by which this occurs has yet to be elucidated. Over 50 years of experience with PKU treatment based upon the restriction of dietary Phe intake have firmly demonstrated the link between clinical outcome and blood Phe levels (Azen et al. 1996). So, any treatment approach that results in decreased blood Phe levels will ameliorate the PKU phenotype. BH4 supplementation is a novel therapeutic approach that is effective in a subset of individuals with PKU (Blau 2010; Harding 2010). In addition to PAH, BH4 is a cofactor Presented in part at the 1st European Phenylketonuria Group Symposium, January, 2009 in Barcelona, Spain (supported by Serono Symposia International Foundation).
Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: The University of Pittsburgh Approach

Anterior cruciate ligament tears are a common occurrence and create significant functional limitations for patients sustaining these injuries. Approximately 100,000 reconstructions are performed each year in the United States. Single-bundle reconstructive techniques have been relatively successful; however, concerns remain over pain, degenerative joint disease, residual instability, and failure to return to prior levels of activity. Traditional single-bundle procedures fail to recreate the native anatomy of the knee and, therefore, the natural kinematics of the knee. Intensive research in these areas has created the opportunity for anatomic double-bundle techniques to improve the outcome of traditional reconstruction.
Precursor effects on SO2 oxidation

Abstract Smog chamber experiments were conducted to determine the relationships between SO 2 oxidation and the gaseous precursors common in polluted air: NO z , NMHC (a mixture of 17 hydrocarbons) and SO 2 . SO 2 oxidation to sulfate aerosols was first-order in SO 2 . The maximum rate of oxidation was strongly related to initial NMHC/NO x ratios, but over 6-h irradiation intervals, the conversion of SO 2 to sulfate aerosol was only weakly related to initial NMHC/NO x ratios. For constant NMHC/NO x ratios. SO 2 conversion was independent of NMHC and NO, concentrations. Typical SO 2 oxidation rates for polluted air ranged from 2–8%/h. but the higher rates were sustained for only a few hours. SO 2 lifetimes > 100 h are predicted from these experiments, in accord with kinetic simulations of photochemical smog and lifetimes derived from tropospheric data.
Momentum and heat transfer in a power-law fluid with arbitrary injection/suction at a moving wall

Abstract The momentum and heat transfer in the laminar boundary layer of a non-Newtonian power-law fluid flowing over a flat plate, which is moving in the direction opposite to the uniform main stream, and with arbitrary fluid injection/suction along the plate surface, are analyzed. The partial differential equations are decomposed into a sequence of ordinary differential equations using the Merk–Chao series to obtain universal velocity and temperature functions that are independent of the fluid injection/suction distribution profile. Results are tabulated as a function of the problem parameters. Friction coefficients and Nusselt numbers are calculated for constant fluid injection/suction along the plate.
Improvement in reporting skills of radiology residents with a structured reporting curriculum.

Rationale and Objectives Radiology residents must acquire dictation and reporting skills to meet Accreditation Council for Graduate Medical Examination requirements and provide optimal patient care. Historically, these skills have been taught informally and vary between institutions and among radiologists. A structured curriculum improves resident report quality when using a quantitative grading scheme. This study describes the implementation of such a curriculum and evaluates its utility in tracking resident progress. Materials and methods We implemented a three-stage reporting curriculum in our diagnostic radiology residency program in 2009. Stages 1 and 2 involve instruction and formative feedback composed of suggestions for improvement in a 360° format from faculty, peers, and others within the resident's sphere of influence. The third stage involves individual, biannual, written feedback with scored reports specifically assessing four categories: succinctness, spelling/grammar, clarity, and responsible referral. Biannual scores were collected from 2009 to 2013, sorted by year of residency training (R1 to R4), and average training level scores were statistically compared. Results Review of 1500 reports over a 4-year period yielded a total of 153 scores: 54, 36, 29, and 34 from R1, R2, R3, and R4 residents, respectively. The mean (standard deviation) scores for R1, R2, R3, and R4 residents were 10.20 (1.06), 10.25 (0.81), 10.5 (0.74), and 10.75 (0.69), respectively. Post hoc analysis identified significant differences between R1 and R4 residents (P = .012) and R2 and R4 residents (P = .009). Conclusions Residents' reporting scores showed significant improvement over the course of their residency training. This indicates that there may be a benefit in using an organized reporting curriculum to track resident progress in producing reports that may improve patient care.
Managing high-acuity-depressed adults in primary care

Purpose: To identify strategies for managing high-acuity-depressed adults in primary care settings. Patients who do not achieve remission with initial treatment, patients at risk for suicide, and patients with co-occurring substance use disorders are specifically addressed. Data sources: Scientific literature and evidence-based practice guidelines. Conclusion: Accurate diagnosis is best accomplished using screening instruments as an adjunct to a thorough history and assessment. The goal of interventions is remission of symptoms as opposed to a partial response. Patient preferences regarding choice of intervention must be considered. Initial pharmacotherapy must include adequate doses and a trial of adequate duration. Patients who do not respond to two medication trials are at risk for suicide and/or have a co-occurring substance use disorder may require: (a) a combination of medications coupled with psychotherapy; or (b) referral to mental health specialists to achieve the best outcomes. Implications for practice: High-acuity patients with mental health needs will continue to be seen in primary care settings. Through educational preparation and a patient-centered focus, advanced practice nurses in primary care settings are in an optimal position to set a high standard of care for complex mental health patients.
Concurrent schedules: a quantitative relation between changeover behavior and its consequences.

Data from several published experiments on concurrent variable-interval schedules were analyzed with respect to the effects of changeover delay on the time spent responding on a schedule before changing to an alternate schedule: i.e., the interchangeover time. Interchangeover time increases as the duration of the changeover delay increases, and the present analysis shows that a power function describes the relation. The power relation applied in spite of numerous differences in the experiments: different variable-interval schedules for the concurrent pairs; equal or unequal reinforcement rates for the schedules of the concurrent pairs; different durations of the changeover delay; response-dependent or response-independent reinforcers; pigeons or rats as subjects; different reinforcers. A power function also described the data in experiments where the changeover incurred a timeout, where a fixed ratio was required to changeover, and also when asymmetrical changeover delays were used.
“Primed” human neutrophils on a standard peripheral blood smear

In the two-event model of end organ injury the first event is the priming of circulating neutrophils (PMNs); the second stressor activates these primed PMNs with subsequent indiscriminate release of cytotoxic reactive oxygen metabolites and proteases into the PMNendothelial microenvironment. After both trauma and cardiopulmonary bypass, circulating PMNs are primed for superoxide release. The first “priming” event in the development of multiple organ failure can be detected with standard light microscopic (100 ) evaluation of routine peripheral blood smears (Wright-Giemsa stain). The resting neutrophil (A) exhibits a smooth, round cell shape with uniform cytoplasmic granularity. After priming (B), with 2 M platelet activating factor, PMNs lose their resting morphology and exhibit an irregular cell shape and membrane, toxic granulation with polarized granularity (white arrowhead), and cytoplasmic vacuolization (black arrowhead).
Flow injection analysis of warfarin sodium with amperometric detection

A flow-injection method for the determination of warfarin sodium and its dosage forms is reported. The method is based on the oxidizability of the drug at the glassy carbon electrode. Applying an electrode potential of +1.5 V versus Ag/AgCl reference electrode, a calibration curve was found to be linear in the 1–40 μg/ml concentration range with minimum detectability of 5 ng/ml (signal-to-noise ratio 2). Although automation was not used in this study, the method could be readily incorporated into automated systems because it employs the technique of continuous analysis in a flowing stream.
Mir-17-3p Controls Spinal Neural Progenitor Patterning by Regulating Olig2/Irx3 Cross-Repressive Loop

Summary Neural patterning relies on transcriptional cross-repressive interactions that ensure unequivocal assignment of neural progenitor identity to proliferating cells. Progenitors of spinal motor neurons (pMN) and V2 interneurons (p2) are specified by a pair of cross-repressive transcription factors, Olig2 and Irx3. Lineage tracing revealed that many p2 progenitors transiently express the pMN marker Olig2 during spinal cord development. Here we demonstrate that the repression of Olig2 in p2 domain is controlled by mir-17-3p microRNA-mediated silencing of Olig2 mRNA. Mice lacking all microRNAs or just the mir-17∼92 cluster manifest a dorsal shift in pMN/p2 boundary and impairment in the production of V2 interneurons. Our findings suggest that microRNA-mediated repression of Olig2 mRNA plays a critical role during the patterning of ventral spinal progenitor domains by shifting the balance of cross-repressive interactions between Olig2 and Irx3 transcription factors.
Analysis of anti-vibration gloves mechanism and evaluation methods

Abstract The primary objectives of the current study are to enhance the understanding of the mechanisms of the anti-vibration gloves and to evaluate the methods for assessing their vibration isolation effectiveness through developing a mechanical-equivalent model of the glove-hand–arm system. The model is developed based on the measured driving-point mechanical impedances distributed at the fingers and the palm of the hand with and without a glove. Six subjects participated in the experiments with two types of anti-vibration gloves (air-bladder glove and gel-filled glove) for measuring the required impedance data. The proposed model is applied to predict the effectiveness of the glove in terms of vibration transmitted to the fingers-glove and palm-glove interfaces, the finger bones, and the wrist. The results show that the gloves could provide some attenuation of the palm-transmitted vibration at frequencies above the fundamental resonant frequency of the gloved hand–arm system, but only little reduction in the finger vibration below the dominant finger resonant frequency. The present standardized methodology based upon the transmissibility measurement at the palm alone would thus be inappropriate for characterizing the overall reduction of the vibration exposure by a glove. Moreover, the palm adapter could introduce some measurement errors because of its mass and misalignment effects and its interference with the glove-palm coupling relationship. Therefore, the standardized method may only be used for general screening tests. On the basis of the model results, several potential improvements in the current standardized methodologies for evaluations of gloves and glove material are proposed and discussed. The proposed model may also serve as a useful tool for further developments of anti-vibration gloves and other anti-vibration devices.
Surface nanopatterning mechanisms by keV ions: Linear instability models and beyond

Abstract Sputtering solid surfaces with low energy ions is well-known to induce a wide array of nanoscale pattern forming behavior (sputter ripples). A simple continuum model originally developed by Bradley and Harper (BH) provides a useful framework that can qualitatively explain multiple types of patterning behavior seen experimentally and their relationship to the ion beam and material parameters. The basis of the model is a dynamic competition between roughening by ion bombardment and smoothing by surface transport that leads to the growth of roughness with a preferred periodicity on the surface. However, there are many experimental results that cannot be accounted for within this framework and additional physical mechanisms are discussed that may close the gap in our understanding.
Vitamin D Deficiency in Adults: When to Test and How to Treat

Recent evidence for the nonskeletal effects of vitamin D, coupled with recognition that vitamin D deficiency is common, has revived interest in this hormone. Vitamin D is produced by skin exposed to ultraviolet B radiation or obtained from dietary sources, including supplements. Persons commonly at risk for vitamin D deficiency include those with inadequate sun exposure, limited oral intake, or impaired intestinal absorption. Vitamin D adequacy is best determined by measurement of the 25-hydroxyvitamin D concentration in the blood. Average daily vitamin D intake in the population at large and current dietary reference intake values are often inadequate to maintain optimal vitamin D levels. Clinicians may recommend supplementation but be unsure how to choose the optimal dose and type of vitamin D and how to use testing to monitor therapy. This review outlines strategies to prevent, diagnose, and treat vitamin D deficiency in adults.
A Unified Approach to Represent Metal Electrode Polarization

A unifying approach based on methods of linear and nonlinear systems engineering theory to conveniently analyze the metal electrode polarization is presented. The polarization phenomenon is modeled in the linear and nonlinear range. The linear model is based on an exentension of Bode's method consisting of a number of time constant distributions of the Davidson?Cole type. In the nonlinear range, the describing function method is used to analyze the interface in terms of a modified saturation element in cascade with a linear part. The linear part of the nonlinear model has the same form as the linear model with shorter "apparent" average time constants than the corresponding linear representation. The applicability of the method is illustrated using the platinum electrode data. However, the methodology is equally appropriate to the study of a wide class of interfacial and dielectric polarization phenomena characterized by a special dispersion behavior.
Action Research: Dance Improvisation as Dance Technique

(2000). Action Research: Dance Improvisation as Dance Technique. Journal of Physical Education, Recreation & Dance: Vol. 71, No. 5, pp. 42-46.
Complex Formation Between Hydroxy Naphthol Blue and First Row Transition Metal Cyanide Complexes

It has been found that cyanide complexes of first row transition metal elements exhibit enhanced binding to hydroxy naphthol blue (HNB) relative to the binding of corresponding aquo-ions. HNB forms...
Examination of some possible biases in double pair comparison estimates of safety belt effectiveness

Biases in double pair comparison estimates of safety belt effectiveness due to two effects (noncoding of some surviving passengers, and driver/passenger impact during crashes) are investigated by calculating effectiveness from fatality frequencies assumed altered by the biases. Noncoding surviving right-front passengers does not affect estimates for drivers, but does overestimate slightly passenger effectiveness. Two biasing driver/passenger contact effects occur for right-side impacts--a "cushioning" effect (risk to unbelted driver is reduced by striking passenger rather than the vehicle interior) and a "missile" effect (passenger risk is increased by being struck by unrestrained driver). Cushioning and missile effects both reduce estimates; their combined effects could cause right-side impact effectiveness to be underestimated by as much as 20% (probably much less). Correcting for all effects increases the overall estimate from 42.6% to 43.2%. Thus, to the nearest percent, the result is still that if all presently unbelted drivers and right-front-seat passengers were to become wearers, fatalities to this group would decline by (43 +/- 3)%.
Chiral conductivities of nanotubes.

Chiral conductivities of nanotubes are examined within the framework of the Boltzmann transport equation. Electron transport along a chiral trajectory is decomposed into current components along the tubule axis and its circumference. Within a constant relaxation time approximation, these components are derived from the expectation values of Fermi velocities by using the appropriate operators and the wave functions at the Fermi level obtained by first-principles calculations. As a typical example, the chiral current of a doped ${\mathrm{BC}}_{2}\mathrm{N}$ tubule is illustrated, and the strength of the induced magnetic field is discussed.
Silicone rubber applied within the eye: a preliminary study

Clear, room temperature vulcanizing silicone rubber (RTV) has already been shown to have well-defined optical and mechanical properties that allow its use as an active optical element. In this work RTV is considered as a possible material for substitution of damaged and/or diseased parts of the human eye, such as the cornea and crystalline lens. The interaction of cured and uncured RTV with eye tissue and eyelike tissue was investigated, and the results support the use of this material in the eye.
THREE-DIMENSIONAL GROUND MOTION SIMULATIONS FOR LARGE EARTHQUAKES ON THE SAN ANDREAS FAULT WITH DYNAMIC AND OBSERVATIONAL CONSTRAINTS

I have simulated 0–0.5 Hz viscoelastic ground motion in Los Angeles from M 7.5 earthquakes on the San Andreas fault using a fourth-order staggered-grid finite-difference method. Two scenarios are considered: (a) a southeast propagating and (b) a northwest propagating rupture along a 170-km long stretch of the fault near Los Angeles in a 3D velocity model. The scenarios use variable slip and rise time distributions inferred from the kinematic inversion results for the 1992 M 7.3 Landers, California, earthquake. The spatially variable static slip distribution used in this study, unlike that modeled in a recent study,1 is in agreement with constraints provided by rupture dynamics. I find peak ground velocities for (a) and (b) of 49 cm/s and 67 cm/s, respectively, near the fault. The near-fault peak motions for scenario (a) are smaller compared to previous estimates from 3D modeling for both rough and smooth faults.1,2 The lower near-fault peak motions are in closer agreements with constraints from precarious rocks located near the fault. Peak velocities in Los Angeles are about 30% larger for (b) 45 cm/s compared to those for (a) 35 cm/s.
The Pauli principle in the center-of-mass system

Abstract The internal states of motion of an arbitrary closed system are studied in terms of a set of 3 N − 3 pairs of internal canonical variables. The complexities involved in constructing states which satisfy the Pauli principle are reduced by expressing these states in terms of ν sets of internal variables which are associated with the ν ways in which one of ν identicals particle may be eliminated. A formalism is set up wherby a simplified expression for the scalar product (and hence matrix elements) is obtained. For purposes of illustration the method is applied to systems of N spinless bosons and fermions interacting through oscillator forces and constrained to move in one dimension. For N identical particles it is shown that the internal Hamiltonian assumes an independent “particle” form only for a system of oscillators. In a section concerned with internal operators, several useful properties of the internal motion of an arbitrary closed system are discussed.
Breakdown probabilities for thin heterostructure avalanche photodiodes

The recurrence theory for the breakdown probability in avalanche photodiodes (APDs) is generalized to heterostructure APDs that may have multiple multiplication layers. The generalization addresses layer-boundary effects such as the initial energy of injected carriers as well as the layer-dependent profile of the dead space in the multiplication region. Reducing the width of the multiplication layer serves to both downshift and sharpen the breakdown probability curve as a function of the applied reverse-bias voltage. In structures where the injected carriers have an initial energy that is comparable to the ionization threshold energy, the transition from linear mode to Geiger-mode is more abrupt than in structures in which such initial energy is negligible. The theory is applied to two recently fabricated Al/sub 0.6/Ga/sub 0.4/As-GaAs heterostructure APDs and to other homostructure thin GaAs APDs and the predictions of the breakdown-voltage thresholds are verified.
Factor XIII binds to the Aα- and Bβ- chains in the D-domain of fibrinogen: An immunoblotting study

The binding sites in fibrinogen for Factor XIII were localized using an immunoblotting technique. Platelet Factor XIII bound to fibrinogen and to plasmin degradation products of fibrin(ogen) including Fragments: X, D1-D3, and D-dimer, but did not bind to Fragment E. Binding of Platelet Factor XIII was independent of calcium ions but could be inhibited by the presence of 0.5 M NaCl. Binding could also be inhibited by preincubating Factor XIII with a 100-fold molar excess of fibrinogen but not by 100-fold molar excess of Fragment E. Binding of Factor XIII to fibrinogen was specific, since several other proteins tested (ovalbumin, bovine serum albumin, alpha 2-macroglobulin, beta-galactosidase, fructose kinase, lactic dehydrogenase, triose phosphate isomerase, fumarase and pyruvate kinase) did not bind Factor XIII. Furthermore, binding was not observed either when Factor XIII was left out or when antiFactor XIII antiserum was substituted with nonimmune serum. When fibrinogen was reduced prior to electrophoresis, Factor XIII bound to the A alpha and B beta chains of fibrinogen and des A,B fibrinogen, the B beta-chain of Fragment X, but not the gamma-chains. Localization of the Factor XIII binding sites to the carboxy terminal segments of the A alpha and B beta chains in the Fragment D-domain of fibrinogen could have important physiological consequences.
Absorption of Semiconductor Nanocrystals by the Aquatic Invertebrate Ceriodaphnia dubia

When incubated with nanomolar concentrations of fluorescent semiconductor nanocrystals in moderately hard water the fluorescence of living Ceriodaphnia dubia increased. Average pixel intensity of exposed animals was greater than that of unexposed animals and increased in a dose and exposure time-dependent-manner. Internal structures were clearly visible in exposed and unexposed animals but fluorescence was most intense in the region of the abdominal appendages of exposed animals. Since these nanoparticles contain significant quantities of the toxic metals cadmium and selenium, their accumulation from aquatic environments by this standard test organism has significant implications about their potential environmental toxicity.
The determination of hafnium in standard reference materials using Bis (2-ethylhexyl) phosphate (HDEHP) with neutron activation analysis

On decrit la methode pour le dosage du hafnium dans des aciers etalons. Cette methode consiste en une combinaison de l'analyse par activation neutronique avec un procede d'extraction par solvant, l'agent d'extraction etant le di (2 ethylhexyl) phosphate. Enfin, on procede a une extraction en retour dans de l'acide fluorhydrique 2N juste avant la mesure d'activite. La mesure est faite au moyen d'un detecteur Ge(Li) 60 cc associe a un analyseur 2048 canaux. La methode d'analyse ainsi decrite permet une determination rapide du hafnium avec, une precision de l'ordre de 3 a 4% pour les dosages de routine.
Pathological gambling: estimating prevalence and group characteristics

A problem which lies in the path of implementing policies designed to address the adverse effects of gambling is the lack of data on the size and composition of the compulsive gambler group. There is a pressing need, therefore, to develop a data base on gambling participation and its consequences. The present study sought to contribute to this goal by identifying the rate of pathological gambling among adults residing in a nine-county area of southeastern Pennsylvania and southern New Jersey. The study was designed as a scientific community survey employing behavioral criteria as the basis for identification of pathological gamblers.
Compact Discs: New tool for competitive analysis

An important part of any strategic competitive analysis has always been access to timely and relevant data that can be pruned into useful information. Some new and still rapidly evolving technology is lowering the cost and simplifying access to huge data banks. This technology is already having an impact on competitive analysis. What once may have been a million‐dollar research effort taking many months, can now be accomplished in a few hours using a well‐equipped desktop PC that can read the new data sources.
Woody Encroachment Removal from Midwestern Oak Savannas Alters Understory Diversity across Space and Time

Recovering biodiversity is a common goal during restoration; however, for many ecosystems, it is not well understood how restoration influences species diversity across space and time. I examined understory species diversity and composition after woody encroachment removal in a large-scale savanna restoration experiment in central Iowa, United States. Over a 4-year time series, restoration had profound effects across space and time, increasing richness at local and site-level scales. Restoration sites had increased a (within sample) Simpson’s diversity and a and g (site level) species richness relative to control sites, although g and b (among sample) Simpson’s diversity, b richness, and a species evenness were not affected. Changes in richness were driven by graminoids at the a and g scales and woody species (and some evidence for forbs) at the a scale. Interestingly, indicator species analysis revealed that at least some species from all functional groups were promoted by restoration, although no species were significant indicators of pre-treatment or control sites. Both savanna and nonsavanna species were indicators of restored sites. Restoration promoted exotic species at both scales, although species with spring phenologies were unaffected. Woody encroachment removal may be a means to promote species establishment in savannas; however, in this study, it resulted in establishment and proliferation of native and exotic and savanna and nonsavanna species. Future work might consider reintroduction of key savanna species to supplement those that have established. Work like this demonstrates the utility of restoration experiments for conducting research on large- and multiscale processes, such as species diversity.
The Lost Phone

Ling considers how the mobile phone has affected our social interactions and how we have come to take it for granted.
Supercoiling of the DNA template during transcription.

Abstract Transcription of a right-handed double-helical DNA requires a relative rotation of the RNA polymerase and its nascent RNA around the DNA. We describe conditions under which the resistance to the rotational motion of the transcription ensemble around the DNA can be large. In such cases, the advancing polymerase generates positive supercoils in the DNA template ahead of it and negative supercoils behind it. Mutual annihilation of the positively and negatively supercoiled regions may be prevented by anchoring points on the DNA to a large structure, or, in the case of an unanchored plasmid, by the presence of two oppositely oriented transcription units. In prokaryotes, DNA topoisomerase I preferentially removes negative supercoils and DNA gyrase (topoisomerase II) removes positive ones. Our model thus provides an explanation for the experimentally observed high degree of negative or positive supercoiling of intracellular pBR322 DNA when DNA topoisomerase I or gyrase is respectively inhibited. We discuss the implications of our model in terms of supercoiling regulation, DNA conformational transitions, and gene regulation in both prokaryotes and eukaryotes.
Piezoresistive in-situ strain sensing of composite laminate structures

Abstract Various methods have been developed to monitor the health and strain state of carbon fiber reinforced polymers, each with a unique set of pros and cons. This research assesses the use of piezoresistive sensors for in situ strain measurement of carbon fiber and other composite structures in multidirectional laminates. The piezoresistive sensor material and the embedded circuitry are both evaluated. For the piezoresistive sensor, a conductive nickel nanocomposite sensor is compared with the piezoresistivity of the carbon fiber itself. For the circuit, the use of carbon fibers already present in the structure is compared with the use of nickel coated carbon fiber. Successful localized strain sensing is demonstrated for several sensor and circuitry configurations. Numerous engineering applications are possible in the ever-growing field of carbon-composites.
Two-Stage, Two-Gap, Light- and Heavy-Ion Cyclotron Study

A detailed study of a separated-magnet two-stage cyclotron has been made. For elements heavier than S, ions are preaccelerated by a 700 keV Cockroft-Walton and then injected into the first stage (lower gap) of the cyclotron. After acceleration, extraction and stripping (from charge Q to 4Q) they are returned to the center of the second stage (upper gap, whose center line is 15 inches above that of the lower gap) and further accelerated. For ions lighter than S, preacceleration takes place in a small cyclotron and the ions are injected directly into the second stage of the large cyclotron. Protons may be accelerated from 4 to 200 MeV, 3He from 12 to 630 MeV and U from 620 to 2130 MeV. The magnitude of external beams of heavy ions is limited by heating and sputtering of the electrostatic deflector extraction system. The turn separation for uranium ions at the final radius is 16 mm, so extraction efficiencies above 90% should be possible. At 90% it is estimated that 1 particle microampere of uranium ions will be obtained.
Memory and "frontal lobe" dysfunction in multiple sclerosis

The characteristics of memory disturbance in multiple sclerosis (MS) are briefly reviewed and the interactions of conceptual and memory dysfunction in MS are considered. Although conceptual functions such as abstraction and problem solving traditionally have been considered to be frontal lobe functions, there is now convincing evidence from studies of patients with focal brain lesions that these capacities are not localized to the frontal lobes. Thus, the concept of frontal lobe dysfunction in MS is without empirical support. Nevertheless, studies examining the relationship between memory and conceptual impairment in MS have value for both basic and clinical neuroscience.
A framework for the study of vocal registers

Summary Register transitions are divided into two classes, periodicity transitions and timbre transitions. Periodicity transitions refer to changes in vocal quality that occur whenever glottal pulses are perceived as individual events rather than as a continuous auditory stimulus. Timbre transitions refer to changes in vocal quality associated with changes in spectral balance. Physiologically, these can be quantified with an abduction quotient. The singing registers appear to be based on timbre transitions resulting from subglottal resonances that interfere with the vocal fold driving pressure. Four of the major singing register shifts are predicted (in frequency and relative importance) on the basis of the first subglottal formant. Strategies for register equalization are proposed on the basis of supraglottal formant tuning (vowel modification) and adjustments in glottal adduction.
The impact of suicide on therapists in training

Abstract This article explores the impact of a patient's suicide during the therapist's training. It is the author's opinion that this subject has received too little attention, and some possible reasons for this are discussed. The scope of the problem is reviewed, including data from a recent study by the author. Also, some general comments about training program responses are offered.
Multilevel Covariance Structure Analysis of Sibling Antisocial Behavior.

Conventional covariance structure analysis, such as factor analysis, is often applied to data that are obtained in a hierarchical fashion, such as siblings observed within families. Multivariate modeling of such data, however, is most frequently done as if the data were obtained as a simple random sample from a single population. An alternative specification is presented that explicitly models the within‐level and between‐level covariance matrices in familial antisocial behavior. Sibling data from the National Youth Survey, a national probability sample of youth, were used to specify a multilevel covariance structure analysis of sibling antisocial behavior. Results demonstrate homogeneity in antisocial behavior within sibling clusters but heterogeneity across families. These analyses highlight potential pitfalls of ignoring issues of independence and demonstrate how conventional covariance structure software can be easily adapted to handle hierarchical models, providing a large set of new analysis possibi...
Multinational information systems (Panel Discussion)

Many organizations today face a unique set of problems and opportunities because they operate across international boundaries. To some extent, the growth of the multinational organization has been made possible by electronic communications. Now, more and more of these organizations are using computers to tie together their far-flung operations. The planning, organizing, and supporting of information systems for the multinational will be the focus of this session.
In vivo 17O NMR approaches for brain study at high field.

O is the only stable oxygen isotope that can be detected by NMR. The quadrupolar moment of 17 Os pin (I ¼ 5/2) can interact with local electric field gradients, resulting in extremely short T1 and T2 relaxation times which are in the range of several milliseconds. One unique NMR property of 17 O spin is the independence of 17 O relaxation times on the magnetic field strength, and this makes it possible to achieve a large sensitivity gain for in vivo 17 O NMR applications at high fields. In vivo 17 O NMR has two major applications for studying brain function and cerebral bioenergetics. The first application is to measure the cerebral blood flow (CBF) through monitoring the washout of inert H2 17 O tracer in the brain tissue following an intravascular bolus injection of the 17 O-labeled water. The second application, perhaps the most important one, is to determine the cerebral metabolic rate of oxygen utilization (CMRO2) through monitoring the dynamic changes of metabolically generated H2 17 O from inhaled 17 O-labeled oxygen gas in the brain tissue. One great merit of in vivo 17 O NMR for the determination of CMRO2 is that only the metabolic H2 17 O is detectable. This merit dramatically simplifies both CMRO2 measurement and quantification compared to other established methods. There are two major NMR approaches for monitoring H2 17 O in vivo, namely direct approach by using 17 O NMR detection (referred as direct in vivo 17 O NMR approach) and indirect approach by using 1 H NMR detection for measuring the changes in T2 -o rT1� -weighted proton NMR signals caused by the 17 O- 1 H scalar coupling and proton chemical exchange (referred as indirect in vivo 17 O NMR approach). Both approaches are suitable for CBF measurements. However, recent studies indicated that the direct in vivo 17 O NMR approach at high/ultrahigh fields appears to offer significant advantages for quantifying and imaging CMRO2 .N ew developments have further demonstrated the feasibility for establishing a completely noninvasive in vivo 17 O NMR approach for imaging CMRO2 in a rat brain during a brief 17 O2 inhalation. This approach should be promising for studying the central role of oxidative metabolism in brain function and neurological diseases. Finally, the similar approach could potentially be applied to image CMRO2 noninvasively in human brain. Copyright # 2005 John Wiley & Sons, Ltd.
Does Prior Abdominal Surgery Influence Conversion Rates and Outcomes of Laparoscopic Right Colectomy in Patients with Neoplasia

Purpose The study investigated the impact of prior abdominal surgery on conversions and outcomes of laparoscopic right colectomy.
In vivo Studies of 111In-Labelled canine Lymphocytes

Abstract [ 111 In]oxine was used to label canine periperal blood lymphocytes from two normal animals and one animal with breast carcinoma. Using 150 μCi of [ 111 In]oxine to label 50 × 106 cells yielded a labeling efficiency between 40 and 75% and a viability of about 95%. Gamma camera images obtained 24–44 h after injection showed uptake in the subcutaneous lymph nodes of the head, neck, axilla, pelvis and popliteal regions. Uptake in the liver, spleen, bowel, and bone marrow was also seen. In the animal bearing breast carcinoma, uptake occurred in the tumor, lungs and in a draining sinus in the left axilla. These results suggest that 111 In labeled lymphocytes are useful in visualizing regional lymph nodes and may be valuable in assessing tumor recognition by these cells in vivo .
Deterministic graph-theoretic algorithm for detecting modules in biological interaction networks

An approach for module identification, Modules of Networks (MoNet), introduced an intuitive module definition and clear detection method using edges ranked by the Girvan-Newman algorithm. Modules from a yeast network showed significant association with biological processes, indicating the method's utility; however, systematic bias leads to varied results across trials. MoNet modules also exclude some network regions. To address these shortcomings, we developed a deterministic version of the Girvan-Newman algorithm and a new agglomerative algorithm, Deterministic Modularization of Networks (dMoNet). dMoNet simultaneously processes structurally equivalent edges while preserving intuitive foundations of the MoNet algorithm and generates modules with full network coverage.
Nuclear Division Without Cytokinesis Followed by Fusion of Pronuclei in Paranotila lata gen. et sp. nov.

SYNOPSIS. Under the influence of ecdysone a uninucleate asexual cell of Paranotila lata gen. et sp. nov. is transformed into a gametocyte in which, as a rule, 8 successive nuclear divisions occur, thus producing 8 male and 8 female pronuclei. No cytokinesis occurs during these divisions. The process should be regarded as a gametogenesis in which only nuclei participate. These gametic pronuclei fuse, male with female, and produce 8 fusion or zygotic nuclei. The cell may now be regarded as a zygote, which soon undergoes plasmotomy, and eventually produces 8 uninucleate, diploid asexual cells. This is the usual course of events. A few exceptions or irregularities have been noted. Throughout gametogenesis, Paranotila is quite indifferent regarding the production of new flagella and axostyles; sometimes they are produced, sometimes they are not.
Response Differences and Preferences for All-Category-Defined and End-Defined Likert Formats

The question as to whether the format of a scale influences results has been examined infrequently and with conflicting answers. Two Likert-type formats, one with all choice points defined and the other with only end-points defined, were administered to 121 subjects. Each subject completed half of the items in the defined and the other half in the end-defined condition. Results were not significantly different between forms, nor did subjects indicate a format preference. Although the end-defined items exhibited greater variability than did the every-point defined items, the results suggest that minor Likert-type format changes do not critically affect outcomes.
Cosmic degenerate matter: a possible solution to the problem of missing mass

Spontaneous symmetry breaking of a neutral scalar field coupled to gravity leads directly to ultra-low mass bosons, with a critical temperature far above the temperature of the Universe, for most of its duration. The particles are therefore expected to condense into a degenerate Bose-Einstein gas, providing a potential candidate for nonbaryonic nonluminous matter.
Experimental studies of oxygen isotope fractionation in the carbonic acid system at 15°, 25°, and 40°C

Abstract In light of recent studies that show oxygen isotope fractionation in carbonate minerals to be a function of HCO3− and CO32− concentrations, the oxygen isotope fractionation and exchange between water and components of the carbonic acid system (HCO3−, CO32−, and CO2(aq)) were investigated at 15°, 25°, and 40°C. To investigate oxygen isotope exchange between HCO3−, CO32−, and H2O, NaHCO3 solutions were prepared and the pH was adjusted over a range of 2 to 12 by the addition of small amounts of HCl or NaOH. After thermal, chemical, and isotopic equilibrium was attained, BaCl2 was added to the NaHCO3 solutions. This resulted in immediate BaCO3 precipitation; thus, recording the isotopic composition of the dissolved inorganic carbon (DIC). Data from experiments at 15°, 25°, and 40°C (1 atm) show that the oxygen isotope fractionation between HCO3− and H2O as a function of temperature is governed by the equation: 1000 ⁢ ln ⁡ α HCO 3 − − H 2 O = 2.59 ± 0.00 ⁢ ( 10 6 T − 2 ) + 1.89 ± 0.04 where α is the fractionation factor and T is in kelvin. The temperature dependence of oxygen isotope fractionation between CO32− and H2O is 1000 ⁢ ln α CO 3 2 − − H 2 O = 2.39 ± 0.04 ⁢ ( 10 6 T − 2 ) − 2.70 ± 0.46 The oxygen isotope fractionation between CO2(aq) and H2O was investigated by acid stripping CO2(aq) from low pH solutions; these data yield the following equation: 1000 ⁢ ln ⁡ α CO 2(aq) − H 2 O = 2.52 ± 0.03 ⁢ ( 10 6 T − 2 ) + 12.12 ± 0.33 These results show that pH can have a significant effect on the δ18O of the DIC, which can vary by as much as 17‰ at a given temperature.
Functional Anatomy of a dsRNA Trigger: Differential Requirement for the Two Trigger Strands in RNA Interference

In RNA-mediated interference (RNAi), externally provided mixtures of sense and antisense RNA trigger concerted degradation of homologous cellular RNAs. We show that RNAi requires duplex formation between the two trigger strands, that the duplex must include a region of identity between trigger and target RNAs, and that duplexes as short as 26 bp can trigger RNAi. Consistent with in vitro observations, a fraction of input dsRNA is converted in vivo to short segments of approximately 25 nt. Interference assays with modified dsRNAs indicate precise chemical requirements for both bases and backbone of the RNA trigger. Strikingly, certain modifications are well tolerated on the sense, but not the antisense, strand, indicating that the two trigger strands have distinct roles in the interference process.
Transport vesicle uncoating: it's later than you think.

Transport vesicle coat proteins play active roles in vesicle cargo sorting as well as membrane deformation and fission during vesicle biogenesis. For years, it was assumed that this was the extent of the coats’ function and that the coats depolymerized immediately after vesicle budding, leaving the exposed fusion machinery free to find, dock, and fuse with the proper target membrane. Recently, however, it has become increasingly clear that the coat remains on transport vesicles during their post-budding life and in fact helps properly pair up the vesicle with its intended target membrane. These data have brought up urgent questions about exactly when vesicles do uncoat and how uncoating is regulated. Here, we summarize the latest round of evidence for post-budding roles for coats, including a few hints about how the uncoating process may be coupled to docking and fusion. We also speculate about the possibility of post-fusion functions for residual coats.