cssi/SciSciGPT-SciSciNet huggingface dataset:
Opportunities and improvisations: a pediatric surgeon's suggestions for successful short-term surgical volunteer work in resource-poor areas.

There is a paucity of trained pediatric surgeons in resource-poor areas, and many children never receive care for debilitating problems that could readily be managed by surgeons with proper training, supplies, and instrumentation. This article, written from the perspective of a surgeon who has been both the recipient of and the provider of volunteer surgical services, is intended to encourage surgeons in technologically advanced locations to volunteer in underserved areas and to assist them in the implementation of such endeavors. Concepts are presented with an emphasis on pediatric surgery, but most are relevant for volunteers in all surgical specialties. Volunteer paradigms include, but are not limited to, the “surgical brigade” model, where a large group of health care professionals take all needed equipment and supplies for the duration of their stint, and the “minimalist” model, where a single volunteer works with local personnel using locally available equipment. For a successful volunteer endeavor the host needs to have a perceived need for the volunteer’s services, and the volunteer must be flexible in adapting to meet overwhelming needs with limited resources. It is suggested that appropriate technology, such as the inexpensive anal stimulator presented herein, should be employed whenever possible. With proper planning, realistic expectations, and a cooperative and helpful attitude, volunteer trips can be rewarding experiences for both volunteers and host physicians and lead to lasting relationships that improve children’s lives globally.
Hydrogen Plasma Removal of Post‐RIE Residue for Backend Processing

Reactive ion etching of a patterned silicon dioxide layer leaves behind a uniform fluorocarbon layer which must subsequently be removed. Both surface and via polymeric residues form during the reactive ion etch step and their removal using H 2 -based plasma clean processes is reported here. X-ray photoelectron spectroscopy was used to determine the composition of the residue. Scanning electron microscope images were taken before and after the dry clean treatment to determine the effectiveness of the residue removal process. A radio-frequency-generated hydrogen plasma was used in the dry clean experiments. Power, temperature, and pressure were varied while gas flow was kept constant at 75 sccm and the process time was 5-10 min. The surface residue (on the oxide) was most efficiently removed at 400 W, 450°C, and 15 mTorr when exposed to the plasma for 10 min. The in-via residue was best removed following a 5 min plasma exposure at 100 W, 450°C and 15 mTorr.
Filaggrin mutations confer susceptibility to atopic dermatitis but not to asthma

Background Loss-of-function mutations in the filaggrin gene ( FLG ) have been strongly associated with atopic dermatitis and allergic phenotypes in multiple populations. The role of these mutations in the development of asthma is less clear, particularly in patients who do not have coincident atopic dermatitis. Objective To determine whether FLG mutations are associated with asthma or asthma-related intermediate phenotypes. Methods We genotyped 2 loss-of-function FLG mutations (R501X and 2282del4) in white children (age 5-12 years) with mild to moderate asthma in the Childhood Asthma Management Program. We assessed the relationship of these mutations to asthma and allergy-related phenotypes in children with and without atopic dermatitis using both population-based and family-based tests of association. Results Nearly 1/3 (185/646) of the participating children had atopic dermatitis. Although strong associations were observed between FLG mutations and atopic dermatitis (odds ratio, 2.4; P = 7.6 × 10 −5 ) and between the mutations and total serum IgE level ( P = .009 in the atopic dermatitis cohort), no association was noted with either asthma or asthma-related phenotypes, including FEV 1 , FEV 1 /forced vital capacity, and methacholine PC 20 ( P > .1 for all tests). Conclusion Although FLG loss-of-function mutations are consistently associated with atopic dermatitis and other allergic phenotypes, these mutations do not appear to influence either susceptibility to asthma or asthma severity phenotypes. Clinical implications Filaggrin mutations that predispose to atopic dermatitis do not modulate the asthma phenotype.
Building Capacity in Election Administration: Local Responses to Complexity and Interdependence

Public administration research has identified networks, professionalization, and collaboration with community interests as potential principles by which public organizations can enhance their capacity and effectiveness. This article explores the implementation of these principles by election administrators at the local level, where their ability to conduct elections is the subject of current scrutiny. Findings indicate that election administrators established networks, professional organizations, professionalization requirements and community collaborations prior to the passage of the Help America Vote Act of 2002. Findings also suggest that local election efforts may become more effective as a result of certain provisions of the act that promote centralization and information dissemination. Local election administrators may also continue to build capacity by applying these public administration principles.
Resveratrol: phytoestrogen effects on reproductive physiology and behavior in female rats.

Resveratrol is a phytoestrogen naturally found in grapes and is a major constituent of wine thought to exert both cardioprotective and chemopreventive activities. Recent studies show that this bioflavonoid binds to and activates gene transcription via the estrogen receptor (ER) subtypes ERalpha and ERbeta. Previous studies have focused primarily on the in vitro effects of resveratrol (RES) in estrogen-sensitive tissues or in carcinogenic cell lines, while frequently neglecting to document its potential effects in animal models with intact neuroendocrine systems. However, the present studies were designed to systematically characterize the in vivo effects of RES on reproductive physiology and behavior in adult female rats. In gonadally intact females, RES consumption reduced body weight, disrupted estrous cyclicity, and induced ovarian hypertrophy. However, in ovariectomized females RES (10-1000 microg) injections did not appear to mimic 17 beta-estradiol benzoate (EB)-induced behavioral responses and had no lasting effects on subsequent estrogen sensitivity or sociosexual behavior. The present studies support recent in vitro findings that RES differs from other phytoestrogens by acting as a possible mixed agonist/antagonist, depending on the availability of specific ER isoforms localized in the reproductive tract and brain of the female rat.
Vibration properties of a percolating cluster

We present for the first time a numerical study of the vibrational modes of a percolating cluster of mass points connected by elastic bonds. The density of states is characterized by a power law behaviour in the fracton frequency regime, while a transition to a Debye type spectrum occurs at lower frequencies. We also find that the fracton states are weakly localized with a wide range of localization lengths while the states in the low frequency regime are extended Presentation d'une etude numerique des modes de vibration pour des amas de percolation constitues de masselottes elastiquement connectees. La densite d'etats est caracterisee par une loi de puissance dans le regime de frequence fracton tandis qu'a plus basse frequence, on observe un spectre de type Debye. Les etats fractals sont faiblement localises, avec une grande dispersion dans les longueurs de localisation. Les etats de basse frequence correspondent a des etats etendus
Exploration of risk factors contributing to the presence of influenza A virus in swine at agricultural fairs.

Influenza A virus infections occurring in exhibition swine populations at agricultural fairs during 2012 served as a source of H3N2 variant influenza A viruses transmitted to humans resulting in more than 300 documented cases. Prior to the outbreak, this investigation was initiated to identify fair-level risk factors contributing to influenza A virus infections in pigs at agricultural fairs. As part of an ongoing active surveillance program, nasal swabs and associated fair-level metadata were collected from pigs at 40 junior fair market swine shows held in Ohio during the 2012 fair season. Analyses of the data show that the adjusted odds of having influenza A virus-infected pigs at a fair were 1.27 (95% confidential interval (CI): 1.04–1.66) higher for every 20 pig increase in the size of the swine show. Additionally, four of the five fairs that hosted breeding swine shows in addition to their junior fair market swine shows had pigs test positive for influenza A virus. While the current study was limited to 40 fairs within one state, the findings provided insight for veterinary and public health officials developing mitigation strategies to decrease the intra- and inter-species transmission of influenza A virus at fairs.
Application of Recent Variance Expressions Associated With Binary Markov Processes for Detecting Changes in Bandwidth and Power With Application to Health Monitoring

Health condition monitoring often entails monitoring and detecting changes in the structure of associated random processes. A common trigger for an alarm is when the process amplitude exceeds a specified threshold for a certain period of time. A less common trigger for an alarm is when the process bandwidth changes significantly. This latter type of change occurs, for example, in EEG just prior to the onset of an epileptic seizure [Sherman (2008)]. One can monitor the process directly, or one can convert the process to a 0/1 process where 0 denotes ‘within’ and 1 denotes ‘outside of’ a specified tolerance. Such a process is given many names. One is a binary process, another is a Bernoulli process. If the underlying process is a Gauss-Markov process, then the associated 0/1 process becomes a Markov 0/1 process. The main parameters associated with such a process are the following probabilities: (i), (ii), and (iii). In this work we use the variance expressions for the estimators of these probabilities that were reported in Sherman (2011), in order to detect changes with specified false alarm probabilities. We demonstrate their value in detecting bandwidth change via zero-crossing estimates, and detecting amplitude change via threshold excursion estimates.Copyright © 2014 by ASME
On Cyclical Phase Transformations in Driven Alloy Systems: A Mass-Action Kinetics Approach

Cyclical phase transformations occurring under externally driven conditions, such as mechanical alloying, are treated in terms of coupled chemical reactions between participant phases. As a conceptual case, microstructural evolution of a driven system is expressed in terms of simplified chemical reaction. By utilizing law of mass action, two independent differential equations are derived for time-dependent phase concentrations. A stability analysis for the rate equations shows that temporal oscillations in phase concentrations result from an interplay of a non-linear autocatalytic reaction. A limit cycle representing sustained, undamped oscillations is also possible with the model.
Information needs of system administrators in information technology service factories

In this paper we describe the results of an empirical study about the information needs of system administrators. This study is based on an electronic survey with more than 200 systems administrators, or sysadmins, working on incident management in a large scale IT service delivery organization. The survey covered their information needs in both complex and routine situations. The results of the survey described in this paper go beyond previous work on system administrators by presenting a much more complex picture, suggesting that sysadmins make low usage of knowledge management tools; largely adopt personal communication and collaboration tools: and finally, need to gather information about customers from a complex set of stakeholders. The system administrators also indicated in our survey that the most useful sources of information in handling complex incidents are: (i) the customer; (ii) the customer account team; and (iii) other employees who were experts both in the customer and in particular aspects of the delivery of services. This study indicates that knowledge management in IT service factories is very challenging and possibly should evolve from the often adopted passive model to a dynamic knowledge management style emphasizing both knowledge reusability through information technologies and knowledge sharing through informal discussions among employees.
Axial-vector currents in finite theories of quantum electrodynamics

We investigate the consequences of assuming that there is an observable axial-vector current ${J}_{5\ensuremath{\mu}}$ in theories of finite quantum electrodynamics (QED). Positivity constraints for the matrix elements of ${J}_{5\ensuremath{\mu}}$ can be neatly formulated for the massive theory via the Schwarz inequality. In order that these requirements be satisfied in the presence of a nonvanishing anomalous constant $S$, it is essential that $d$, the dimension of ${J}_{5\ensuremath{\mu}}$, be greater than 3. In that case, we can explain why the condition ${J}_{\ensuremath{\mu}}|0〉=0$ satisfied by the electromagnetic current ${J}_{\ensuremath{\mu}}$ in the zero-mass theory does not contradict the Adler-Bardeen theorem ($S\ensuremath{\ne}\mathrm{O}$). Further, we explain why the photon-photon scattering subgraphs which cause the anomaly in $d$ are not asymptotically negligible in the Johnson-Baker-Willey (JBW) and Adler versions of finite QED: The argument for $d=3$ fails because it involves the use of an illegal skeleton expansion. The value of $d$ depends on the number of fundamental fermion species in the theory. Vector and axial-vector currents which generate a non-Abelian internal symmetry of the fermions cannot be introduced in the JBW and Adler theories, because the relevant positivity conditions cannot be satisfied. We examine evidence that the infinite perturbative sums are sufficiently irregular to permit this situation. In an appendix, we solve the Callan-Symanzik equations in the asymptotic region when the zero ${\ensuremath{\alpha}}_{e}$ of the Callan-Symanzik function $\ensuremath{\beta}(\ensuremath{\alpha})$ is not simple. In general, violations of asymptotic scale invariance occur if the physical coupling constant is not equal to ${\ensuremath{\alpha}}_{e}$. In the JBW model, this phenomenon can be readily interpreted diagrammatically for matrix elements of ${J}_{5\ensuremath{\mu}}$ and the electron propagator.
Development of a Runge-Kutta Scheme with Total Variation Diminishing for Magnetogasdynamics

A four-stage modified Runge-Kutta scheme augmented with the Davis-Yee symmetric total variation diminishing model in a postprocessing stage has been developed to solve the three-dimensional magnetogasdynamic equations. The spatial discretization is performed using finite difference schemes. To be applicable to complex geometries, the system of governing equations and the system eigenstructure have been expressed in a generalized curvilinear coordinate system. The algorithm is validated by solving benchmark problems and is subsequently used in general applications. The shock-capturing properties are demonstrated by simulation of the magnetic shock tube and comparison with solutions computed with other numerical schemes. The implementation of diffusion terms is validated by solving the Hartmann problem, which admits an analytical solution. The performance of the algorithm in multidimensional problems is illustrated in the simulation of ramp flows and convergent channel flows. The method is shown to be accurate, with the ability to capture the physical phenomena arising in magnetogasdynamic flowfields.
Evaluating the Impact of Six Supplemental Nutrition Assistance Program Education Interventions on Children’s At-Home Diets:

Background. Nutrition education in the Supplemental Nutrition Assistance Program Education (SNAP-Ed) is designed to promote healthy eating behaviors in a low-income target population. Purpose. To evaluate the effectiveness of six SNAP-Ed interventions delivered in child care centers or elementary school settings in increasing participating children’s at-home fruit and vegetable (F/V) consumption by 0.3 cups per day and use of fat-free or low-fat milk instead of whole or reduced-fat milk during the prior week. Method. Clustered randomized or quasi-experimental clustered trials took place in child care centers or elementary schools between 2010 and 2012. Parents of children at intervention and control sites completed baseline and follow-up surveys about their child’s at home F/V consumption and other dietary behaviors. Results. One of the six interventions was successful in meeting the objective of increasing children’s F/V consumption by 0.3 cups per day. For three of the six interventions, there was a sma...
Auditory Acuity and Performance on the Mental Status Questionnaire in the Elderly

: The relationship between auditory acuity and performance on the Mental Status Questionnaire (MSQ, Kahn et al) was investigated in 27 residents of two skilled nursing facilities. Statistically significant correlations between auditory acuity and MSQ total scores were obtained at 500 Hz, 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz, and 6000 Hz, but not at 8000 Hz. The correlations between auditory acuity and individual item scores, however, were statistically significant for only those items for which nursing home personnel believed the opportunity existed for residents to hear the answers. These findings are interpreted as providing strong support for a causal relationship between sensory acuity and test performance, indicating that the cognitive capabilities of elderly persons can be underestimated because of their reduced sensory acuity.
Three stages and two systems of visual processing.

Three stages of visual processing determine how internal noise appears to an external observer: light adaptation, contrast gain control and a postsensory/decision stage. Dark noise occurs prior to adaptation, determines dark-adapted absolute thresholds and mimics stationary external noise. Sensory noise occurs after dark adaptation, determines contrast thresholds for sine gratings and similar stimuli, and mimics external noise that increases with mean luminance. Postsensory noise incorporates perceptual, decision and mnemonic processes. It occurs after contrast-gain control and mimics external noise that increases with stimulus contrast (i.e., multiplicative noise). Dark noise and sensory noise are frequency specific and primarily affect weak signals. Only postsensory noise significantly affects the discriminability of strong signals masked by stimulus noise; postsensory noise has constant power over a wide spatial frequency range in which sensory noise varies enormously. Two parallel perceptual regimes jointly serve human object recognition and motion perception: a first-order linear (Fourier) regime that computes relations directly from stimulus luminance, and a second-order nonlinear (nonFourier) rectifying regime that uses the absolute value (or power) of stimulus contrast. When objects or movements are defined by high spatial frequencies (i.e., texture carrier frequencies whose wavelengths are small compared to the object size), the responses of high-frequency receptors are demodulated by rectification to facilitate discrimination at the higher processing levels. Rectification sacrifices the statistical efficiency (noise resistance) of the first-order regime for efficiency of neural connectivity and computation.
The role of ERK signaling in protein hydrogel remodeling by vascular smooth muscle cells

Collagen type I and fibrin hydrogels have been used for cell-based therapies and tissue engineering. These matrices can be broken down and remodeled by cells, but the effects that these proteins have on cell function are not completely understood. We examined activation of the extracellular signal-regulated kinase (ERK) signaling pathway by vascular smooth muscle cells (VSMC) in response to 2D and 3D matrices of type I collagen, fibrin, or a 1:1 composite mixture of these proteins. After 3 days of culture, ERK phosphorylation, osteopontin secretion, and MMP-2 activation were all markedly increased in 3D matrices, compared with 2D substrates. A strong positive correlation existed between these protein markers of the synthetic phenotype and phosphorylated ERK levels, and this relationship persisted across matrix geometries and compositions. Cell proliferation in 3D matrices was inversely correlated to ERK activation, while on 2D substrates a modest positive correlation was observed. Pharmacologic inhibition of ERK signaling confirmed that this pathway was involved in the observed phenotype shifts. This study suggests that contextual activation of the ERK pathway results in different effects on cell phenotype, depending on the geometry and composition of the ECM. These findings add to our understanding of cell function and remodeling in protein-based hydrogel biomaterials.
Kinetics of electron transfer-induced conformational changes in cytochrome c immobilized on electrodes studied with surface plasmon resonance

Abstract The electron transfer-induced conformational changes in cytochrome c adsorbed on electrodes have been studied with high-resolution surface plasmon resonance spectroscopy. The conformational changes in the native protein follow a stretched exponential function, exp[−( t / τ ) 0.5 ], suggesting a distribution of the activation barrier heights in the process. The measured time constants, τ , are 0.21 and 0.14 s for the oxidation and reduction, respectively. They are much slower than the electron transfer process, due to structural relaxation of the protein layer. As the concentration of guanidine hydrochloride is increased to 3 M, the conformational changes diminish, which indicates that the electron-transfer center is decoupled from the rest of the protein. After replacing the denaturant with buffer, the conformational changes re-appear but occur with much slower time constants. The slowing-down of the conformational changes may be due to the trapping of the protein in an intermediate state.
Transitional cell carcinoma of bladder in pediatric patients

Purpose Only 30 cases of transitional cell carcinoma are reported in children younger then 10 years of age. In “young” patients it is generally a low grade-stage tumour with low recurrence and progression. We report our experience from 1999 to 2006. Material and methods Seven patients (3 males, 4 females, aged 6 to16 years old) presented with gross painless hematuria not trauma related. As an initial screening procedure, bladder-renal ultrasonography showed a bladder lesion. Cystoscopy was performed under general anesthesia. Results A single papillary lesion was observed near the ureteral orefice in all cases. Size ranged from 1.5 to 2 cm. All patients underwent transurethral resection, and superficial biopsies were taken . Pathological grading, using the WHO/ISUP 2004 Classification, revealed 4 urothelial papillomas and 3 papillary urothelial neoplasms of low malignant potential (PUNLMPs). All were superficial to the lamina propria. At follow-up urinalysis and urine cytology were checked monthly, bladder ultrasonography every three months and cystoscopy at six and twelve months for the first year after surgery. Subsequently urinalysis and urine cytology were done every three months, bladder ultrasound every six months and cystoscopy every year. At an average follow-up of 35 months (range 6 to 84 months) no recurrence was detected. Conclusions Transitional cell carcinoma of the bladder is rare in children, and its long term prognosis is still unknown. Routine follow-up with urinary cytology and bladder ultrasound is adeguate. Cystoscopy can be reserved for patients with high grade or potentially highly malignant lesions. Multicenter protocols are required.
Thiazolo-N-hydroxyuracils

The partial Lossen degradation of the hydroxamic acid group at C-4 or C-5 of sodium 4,5-thiazoledicarbohydroxamate (IIIb) and its 2-methyl analog (IIIe) initiated a multicoursed reaction which furnished a mixture of thiazolo[4,5-d]- and thiazolo[5,4-d]-N-hydroxyuracils. The isomer distribution was sensitive to the solvent systems in which these reactions were carried out. The structure of the isomers so obtained was established by chemical and spectral methods.
Hunting on the margins of medieval West African states: a preliminary study of the zooarchaeological record at Diouboye, Senegal

Leather, animal skins and ivory were important components of the economies of medieval West African societies. Despite the prominent role of hunters in diverse oral histories throughout the region, little is known about the actual production of animal products, in particular those derived from wild animals. This paper presents a preliminary examination of the zooarchaeological record of Diouboye, an eleventh- to fourteenth-century AD settlement located along the Faleme River in eastern Senegal. Analyses of a representative sample of the large and diverse faunal assemblage at Diouboye indicate that, in addition to keeping domestic livestock and dogs, the site's occupants hunted large numbers of animals found in riverine ecosystems. In comparison with contemporary West African sites located in similar environmental zones, the economy at Diouboye is particularly focused on medium-sized bovids, animals yielding thick skins and ivory, and carnivores. We argue that this hunting strategy may indicate an emphasis...
Carcinoma Cell Lines Resistant for Growth Inhibition and Apoptosis to Retinoic Acid Are Responsive to 4-Hydroxy-phenyl-retinamide: Correlation with Tissue Transglutaminase

Retinoic acid (RA)-resistant cell lines are highly malignant. To inhibit the growth of the RA-resistant cells we used 4-HPR, a synthetic retinoid, which may act through alternative signal transduction pathways. 4-HPR induced cell growth inhibition and apoptosis in all RA-sensitive as well as -resistant cells, demonstrating a wider spectrum of potency over RA. 4-HPR induced tissue TGase activity. A tight correlation between the induction of tissue TGase, the inhibition of cell growth, and apoptosis was evident in all eight RA-sensitive cell lines. However, basal TGase differed in the different cells, suggesting inducibility rather than basal levels as the relevant parameter. In sharp contrast to the RA-sensitive cells, RA-resistant cells showed sporadic response to 4-HPR for tissue TGase. The wider spectrum of activity of 4-HPR in inhibiting cell growth and inducing apoptosis makes it a good candidate for the treatment of RA-resistant cancer cells.
Mediating self‐hood: exploring the construction and maintenance of identity by mothers of children labeled with autism spectrum disorder

Based on the findings of a qualitative study, this article describes how mothers of children labeled with autism spectrum disorder (ASD) mediate for their children in interactions with those who are unfamiliar with ASD. Data were collected through in‐depth interviews and participant observations. Findings indicate that mothers mediate for their children because they perceive hostility and lack of accommodation for their children on the part of unfamiliars. As they mediate, mothers attempt to construct and maintain positive identities for their children by explaining and reframing their children’s behaviors to influence the interpretations and responses of unfamiliars. I argue that in these interactions mothers function as proxy selves for their children because they are attempting to influence the perceptions others develop of their children, thus shaping their children’s social identity in the process. The findings of this study demonstrate the active, interpretive role that many mothers of children with...
Geometric control of cooperating multiple quadrotor UAVs with a suspended payload

This paper investigates tracking controls for an arbitrary number of cooperating quadrotor unmanned aerial vehicles with a suspended load. Assuming that a point mass is connected to multiple quadrotors by rigid massless links, control systems for quadrotors are constructed such that the point mass asymptotically follows a given desired trajectory and quadrotors maintain a prescribed formation, either relative to the point mass or with respect to the inertial frame. These are developed in a coordinate-free fashion to avoid singularities and complexities associated with local parameterizations. The desirable features are illustrated by several numerical examples, including a flying inverted spherical pendulum on a quadrotor.
The chemistry of the carbon–transition metal double and triple bond: Annual survey covering the year 2009

Abstract This is a review of papers published in the year 2009 that focus on the synthesis, reactivity, or properties of compounds containing a carbon-transition metal double or triple bond.
Phase locking and resetting in human subthalamic neurons

Microelectrode recordings were obtained from human subthalamic nucleus (STN) in parkinsonian patients using a “Ben gun” array of 5 microelectrodes [1] prior to implantation of a deep brain stimulation electrode, and digitized at 25 kHz. Neuronal spikes were threshold extracted (>4SD above baseline). Single units were confirmed using a spike sorting algorithm [2]. Spike trains were then constructed at 1 kHz with unit impulses at each spike time (Fig. ​(Fig.1B)1B) and zeros elsewhere. Episodes of tremor related activity were identified in which the spectral peak in the tremor range (2-6 Hz) was substantially higher than baseline (Fig. ​(Fig.1D).1D). Spike trains corresponding to identified oscillatory activity were then band pass filtered (2 to 6 Hz) to produce a continuous signal (Fig. ​(Fig.1A)1A) corresponding to the envelope of the low frequency activity [3]. The Hilbert transform was used to reconstruct the phase of this signal at each time point. The derivative of this waveform gives the instantaneous frequency (Fig. ​(Fig.1C),1C), and large deviations from the baseline rate of about 4 Hz indicate that the phase of the oscillation has been reset. We identified spontaneous phase advances (Fig. 1A1,B1, and C1) in which the next burst occurred sooner than expected as well as spontaneous phase delays (Fig. 1A2,B2, and C2)in which the next burst occurred later than expected. Our goal is to better understand abnormal synchronization in the STN. Figure 1
Global behavior of solutions of the nonlinear difference equation

We study the global asymptotic behavior of solutions of the nonautonomous difference equation where {p n } is a positive bounded sequence and the initial conditions are positive. We obtain sufficient conditions for the boundedness and persistance of solutions and for the existence of unbounded solutions. In addition, we obtain global attractivity results. The results are applied to the case when {p n } is periodic with prime period k.
Magnetic resonance microimaging of intraaxonal water diffusion in live excised lamprey spinal cord

Anisotropy of water diffusion in axon tracts, as determined by diffusion-weighted MRI, has been assumed to reflect the restriction of water diffusion across axon membranes. Reduction in this anisotropy has been interpreted as degeneration of axons. These interpretations are based primarily on a priori reasoning that has had little empirical validation. We used the experimental advantages of the sea lamprey spinal cord, which contains several very large axons, to determine whether intraaxonal diffusion is isotropic and whether anisotropy is attributable to restriction of water mobility by axon surface membranes. Through the application of magnetic resonance microimaging, we were able to measure the purely intraaxonal diffusion characteristics of the giant reticulospinal axons (20–40 μm in diameter). The intraaxonal apparent diffusion coefficients of water parallel (longitudinal ADC, l-ADC) and perpendicular (transverse ADC, t-ADC) to the long axis were 0.98 ± 0.06 (10−3 mm2/sec) and 0.97 ± 0.11 (10−3 mm2/sec), respectively. In white matter regions that included multiple axons, l-ADCs were almost identical regardless of axon density in the sampled axon tract. By comparison, t-ADCs were reduced and varied inversely with the number of axons (and thus axolemmas) in a fixed cross-sectional area. Thus, diffusion was found to be isotropic when measured entirely within a single axon and anisotropic when measured in regions that included multiple axons. These findings support the hypothesis that the cell membrane is the primary source of diffusion anisotropy in fiber tracts of the central nervous system.
The Near-Calm Stable Boundary Layer

For the near-calm stable boundary layer, nominally 2-m mean wind speed <0.5 ms−1, the time-average turbulent flux is dominated by infrequent mixing events. These events are related to accelerations associated with wave-like motions and other more complex small-scale motions. In this regime, the relationship between the fluxes and the weak mean flow breaks down. Such near-calm conditions are common at some sites. For very weak winds and strong stratification, the characteristics of the fluctuating quantities change slowly with increasing scale and the separation between the turbulence and non-turbulent motions can become ambiguous. Therefore, a new analysis strategy is developed based on the scale dependence of selected flow characteristics, such as the ratio of the fluctuating potential energy to the kinetic energy. In contrast to more developed turbulence, correlations between fluctuating quantities are small, and a significant heat flux is sometimes carried by very weak vertical motions with large temperature fluctuations. The relation of the flux events to small-scale increases of wind speed is examined. Large remaining uncertainties are noted.
The effect of endothelin-1 on nuclear factor kappa B in macrophages.

Abstract Nuclear factor κB (NF-κB) is a transcriptional factor which may be pivotal in the pathogenesis of atherosclerosis. Endothelin-1 (ET-1) is a peptide with proatherogenic properties. We hypothesized that ET-1 may act through activation of NF-κB and degradation of IκB-α, the cytosolic inhibitor of NF-κB activation, to create an atherogenic environment. The human monocytic cell line THP-1 was stimulated with ET-1 ± the ET antagonist, BQ788 and the proteosome inhibitor, PSI. LPS was used as a positive control. Gel shift assays for NF-κB activity and Western blot analysis for IκB-α were performed. Both LPS and ET-1 led to activation of NF-κB in nuclear extracts [3.4 ± 0.45 (LPS) and 2.9 ± 0.26 (ET-1) fold increase in Arbitrary Densitometric Units (ADU) compared with negative control (P
Maximizing Local Control and Organ Preservation in Stage IV Squamous Cell Head and Neck Cancer With Hyperfractionated Radiation and Concurrent Chemotherapy

PURPOSE: Results are reported from an aggressive chemoradiotherapy protocol for advanced squamous cell head and neck cancer. PATIENTS AND METHODS: Patients with advanced squamous cell head and neck cancer were treated with hyperfractionated radiation therapy (72 Gy at 1.2 Gy twice per day) and two courses of concurrent chemotherapy with fluorouracil (1,000 mg/m2/d) and cisplatin (20 mg/m2/d), both given as 96-hour continuous intravenous infusions during weeks 1 and 4 of radiation therapy. Primary-site resection was reserved for residual or recurrent primary-site disease after chemoradiotherapy. Neck dissection was considered for N2 or greater disease, irrespective of clinical response, and for residual or recurrent neck disease after nonoperative treatment. RESULTS: Forty-one patients with stage IV disease were treated. Toxicity was significant, with grade 3 to 4 mucositis in 98%, dysphagia in 88%, and skin reaction in 85%. Neutropenic fever requiring hospitalization occurred in 51%. Despite feeding tube ...
The Anti-angiogenic Activity of rPAI-123 Inhibits Fibroblast Growth Factor-2 Functions

Many angiogenesis inhibitors are breakdown products of endogenous extracellular matrix proteins. Plasmin and matrix metalloproteinase-3 generate breakdown products of matrix-bound plasminogen activator inhibitor-1 (PAI-1). We produced a truncated form of PAI-1, rPAI-123, that possesses significant anti-angiogenic activity and stimulates high levels of apoptosis in quiescent arterial endothelial cells. Quiescent endothelial cells are less susceptible to apoptosis than angiogenic endothelial cells. The present study was designed to determine the mechanism of the rPAI-123 effects in bovine aortic endothelial cells. Apoptosis was measured in annexin V and caspase 3 assays. Expression of death and survival signaling molecules were examined by Western blot and kinase activity. Fibroblast growth factor 2 (FGF2) functions were analyzed in angiogenesis assays. The early response to rPAI-123 was an increase in annexin V-positive cells and phosphorylated (p) JNK isoform expression followed by an increase in p-Akt and p-c-Jun expression. Caspase 3 was activated at 4 h, whereas p-Akt was reduced to control levels. By 6 h of rPAI-123 treatment cell number was reduced by 35%, and p-c-Jun and p-JNK were degraded by proteasomes. Confocal microscopic images showed increased amounts of FGF2 in the extracellular matrix. However, rPAI-123 blocked FGF2 signaling through FGF receptor 1 and syndecan-4, inhibiting cell migration, tubulogenesis, and proliferation. Exogenous FGF2 stimulation could not reverse these effects. We conclude that rPAI-123 stimulation of apoptosis in BAEC triggers a cascade of death versus survival events that includes release of FGF2. The rPAI-123 anti-angiogenic activity inhibits FGF2 pro-angiogenic functions by blocking FGF2 signaling through FGF receptor 1 and syndecan-4 and downstream effectors p-Akt, p-JNK, and p-c-Jun.
The Whimsical Science

Three interviews, fictitious in varying degrees, are used to explore some fundamental questions of economic methodology. The role of mathematics in economic reasoning, the question of truth in assumptions, and whether rigorous arguments will necessarily lead to important results are examined. The use of models in science is usually justified on grounds of prediction or explanation. The general theme of this paper is that many mathematical models in economics fail on both criteria.
Clostridial Neurotoxins in Synaptic Research

Research on clostridial neurotoxins provides a recent illustration of how medical research can spark fundamental breakthroughs in basic science. Clostridia are anaerobic bacilli that live in dust, soil, vegetation, and the gastrointestinal tract of animals and humans. Most are benign, but the pathogenic species produce potent neural toxins. In addition to their involvement in disease and germ warfare, interest in these toxins has increased within the basic research community with the appreciation that these agents can be used as precise experimental tools for dissecting the molecular basis of synaptic transmission, which is without question the most essential process in the nervous system.
Critical review and perspective of macromolecularly imprinted polymers.

Abstract Molecular recognition is a fundamental and ubiquitous process that is the driving force behind life. Natural recognition elements – including antibodies, enzymes, nucleic acids, and cells – exploit non-covalent interactions to bind to their targets with exceptionally strong affinities. Due to this unparalleled proficiency, scientists have long sought to mimic natural recognition pathways. One promising approach is molecularly imprinted polymers (MIPs), which are fully synthetic systems formed via the crosslinking of organic polymers in the presence of a template molecule, which results in stereo-specific binding sites for this analyte of interest. Macromolecularly imprinted polymers, those synthesized in the presence of macromolecule templates (>1500 Da), are of particular importance because they open up the field for a whole new set of robust diagnostic tools. Although the specific recognition of small-molecular-weight analytes is now considered routine, extension of these efficacious procedures to the protein regime has, thus far, proved challenging. This paper reviews the main approaches employed, highlights studies of interest with an emphasis on recent work, and offers suggestions for future success in the field of macromolecularly imprinted polymers.
Serum cholesterol response in man to oral ingestion of arachidonic acid.

I T IS NOW CLEAR that fats in the diet of man have important effects on the concentration of cholesterol and related lipids in the blood. and that the effects are related to the character as well as amount of the fatty acids in the diet. In general, when one fat is isocalorically substituted for another fat or for carbohydrate in the diet of man, the serum cholesterol response is the resultant of the fact that the common saturated fatty acids tend to raise the serum cholesterol, linoleic acid (or polyene in general?) tends to lower it, while oleic acid has substantially no effect. “ The depressant effect of polyene or of linoleic acid upon serum cholesterol has been discussed frequently as being related to the “essentiality” of these fatty acids as demonstrated by other effects in experiments on animals receiving highly artificial diets extremely low in polyunsaturated fats.”4 In view of the fact that arachidonic acid is widely believed to be the most active or effective of the fatty acids in regard to “essentiality,” it is interesting to examine its effect, when provided in the diet, on the serum cholesterol level in man. The present paper is a report of a controlled experiment on men receiving a dietary supplement of arachidonic acid. By inference from the discussions in some of the re
Temperature rise in multimesa devices

Closed form expressions are derived for the temperature of multimesa diodes arranged as trimesas, pentamesas, or N × N arrays.
Antiretroviral Drug Concentrations and HIV RNA in the Genital Tract of HIV-Infected Women Receiving Long-Term Highly Active Antiretroviral Therapy

OBJECTIVE Our objective was to determine antiretroviral drug concentrations and human immunodeficiency virus (HIV) RNA rebound in cervicovaginal fluid (CVF) in relation to blood plasma (BP) in women receiving suppressive highly active antiretroviral therapy (HAART). METHODS Thirty-four HIV-infected women who had plasma HIV RNA levels < or =80 copies/mL for at least 6 months were enrolled. Sixty-eight paired CVF and BP drug concentrations and HIV RNA levels were determined before and 3-4 h after drug administration. For each woman and antiretroviral drug, the CVF:BP drug concentration ratios before and after drug administration were calculated. The nonparametric Wilcoxon rank sum test was used to determine if these ratios were different from 1.0. RESULTS Lamivudine (administered to 20 patients) and tenofovir (administered to 16) had significantly higher concentrations in CVF than in BP before drug administration, with mean CVF:BP concentration ratios of 3.19 (95% confidence interval, 1.2-8.5) and 5.2 (95% confidence interval, 1.2-22.6), respectively. Efavirenz (administered to 13 patients) and lopinavir (administered to 6) had significantly lower concentrations in CVF, with mean CVF:BP concentration ratios of 0.01 (95% confidence interval, 0.00-0.03) and 0.03 (0.01-0.11), respectively. During the study visit (median time after enrollment, 6 months), BP and CVF detectable HIV RNA levels were observed 7 patients (20.6%) and 1 patient (2.9%), respectively. CONCLUSION Despite lower CVF concentrations of key HAART components, such as efavirenz and lopinavir, virologic rebound was rare. The high concentrations of tenofovir and lamivudine in CVF may have implications for the prevention of sexual transmission during HAART and for pre-exposure or postexposure prophylaxis.
Characterization of Pneumococcal Purpura-Producing Principle

Purpura was grossly observable in albino mice 6 to 8 h after the intraperitoneal injection of sterile, deoxyribonuclease-treated, cell-free extracts prepared by sodium deoxycholate-induced lysis, sonic disruption, Parr bomb treatment, autolysis without sodium deoxycholate, or alternate freezing and thawing of washed suspensions of Streptococcus pneumoniae type I. Cell-free extracts obtained from sonically disrupted, heat-killed cells (100 degrees C for 20 min) did not contain purpurogenic activity. The reaction was maximal at approximately 24 h postinjection, started to fade slowly after 24 to 48 h, and usually was not grossly observable by 4 to 6 days postinjection. The purpura-producing principle (PPP) in the cell-free extract was purified by sequential ammonium sulfate precipitation, protamine sulfate precipitation, Sepharose 6B gel filtration, wheat germ lectin-Sepharose 6MB affinity chromatography, ribonuclease and trypsin treatment, and a second Sepharose 6B gel filtration step. The final preparation (i) contained glucosamine (5.6%), muramic acid (8.0%), neutral carbohydrate (12.8%), phosphate (8.0%), orcinol-reactive material (6.0%), and Lowry-reactive material (1.6%), and (ii) was free of detectable amounts of deoxyribonucleic acid, capsular polysaccharide, neuraminidase, cytolysin, and hyaluronidase. The isoelectric point and molecular size of the PPP were approximately pI 3.0 and several million daltons, respectively, and the activity remained in the supernatant fluid after centrifugation for 1 day at 105,000 x g. PPP activity was destroyed by incubation with egg white lysozyme and sodium metaperiodate but was resistant to trypsin, pronase, alpha-amylase, deoxyribonuclease, ribonuclease, alkaline phosphatase, pancreatic lipase, 7% trichloroacetic acid, 6 M urea, autoclaving (121 degrees C) for 30 min, and mild acid and alkali exposure. Our observations indicate that the PPP requires intact beta-1,4-glucosidic linkages for activity and support the working hypothesis that activity is associated with pneumococcal peptidoglycan solubilized by the bacterium's autolysin.
Complement metabolism during membrane plasma separation

: Because it has been found that some plasma separator membranes can activate complement in serum, this study focuses on the behavior of complement during actual membrane plasmapheresis. Complement metabolism in subjects undergoing membrane plasma separation with three different prototypic devices was studied. Complement activation was judged by crossed immunoelectrophoretic analysis of C3 in plasma. A cellulose acetate separator employed with heparin as the anticoagulant caused extensive C3 conversion (up to 50%) in separated plasma. A polysulfone separator used with citrate, and a polyvinylchloride derivative separator employed with heparin plus citrate, caused only small amounts of C3 conversion (0–10%) in separated plasma. C3 conversion in the cellulose acetate separator was reduced when citrate was included in the anticoagulant regimen, whereas C3 conversion in the polyvinylchloride derivative separator was increased when citrate was omitted. Activation of complement by the membrane material may occur during membrane plasma separation. Selection of membranes judged weakly activating by in vitro screening and the use of citrate anticoagulation would appear to minimize complement activation in membrane plasma separators.