cssi/SciSciGPT-SciSciNet huggingface dataset:
Helical Secondary Structure of the External S3-S4 Linker of Pacemaker (HCN) Channels Revealed by Site-dependent Perturbations of Activation Phenotype

Abstract If, encoded by the hyperpolarization-activated cyclic nucleotide-modulated channel family (HCN1–4), contributes significantly to neuronal and cardiac pacing. Recently, we reported that the S3-S4 residue Glu-235 of HCN1 influences activation by acting as a surface charge. However, it is uncertain whether other residues of the external S3-S4 linker are also involved in gating. Furthermore, the secondary conformation of the linker is not known. Here we probed the structural and functional role of the HCN1 S3-S4 linker by introducing systematic mutations into the entire linker (defined as 229–237) and studying their effects. We found that the mutations K230A (–62.2 ± 3.4 mV versus –72.2 ± 1.7 mV of wild type (WT)), G231A (–64.4 ± 1.3 mV), M232A (V½ = –63.1 ± 1.1 mV), and E235G (–65.4 ± 1.5 mV) produced depolarizing activation shifts. Although E229A and M232A decelerated gating kinetics ( 0.05). Shortening the linker (EVY235–237ΔΔΔ) caused depolarizing activation shift and slowed kinetics that could not be explained by removing the charge at position 235 alone. Secondary structural predictions by the modeling algorithms SSpro2 and PROF, along with refinements by our experimental data, suggest that part of the S3-S4 linker conforms a helical structure with the functionally important residues Met-232, Glu-235, and Gly-231 (|ΔΔG|>1 kcal/mol) clustered on one side.
What intraoperative monitoring makes sense

The routine practice of monitoring oxygenation, ventilation, circulation, and temperature during surgery is now the standard of care. However, with the possible exception of pulse oximetry and capnography, extensive physiologic monitoring has not been shown to reduce the incidence of adverse anesthestic-related events. Monitors are useful adjuncts, but they alone cannot replace careful observation by a vigilant anesthesiologist.
THE EFFECT OF GOVERNMENT OWNERSHIP AND SUBSIDY ON PERFORMANCE : EVIDENCE FROM THE BUS TRANSIT INDUSTRY

Abstract Several theories have been advanced to predict difference in behavior of government-owned vs private firms, such as theories of bureaucratic growth, inefficiency, and concentration on vote-maximizing service with neglect of other important characteristics of service. This study tests the above theories in a declining industry, the U.S. urban bus transify industry of 1960–1975. The analysis bridges the period before and during the major federal capital grant program which was initiated under the Urban Mass Transportation Act of 1964. The empirical results indicate that subsidy at the federal level is associated with higher costs and lower real price and a redistribution of service toward an expanded area, served less frequently. Local and state subsidy is associated with smaller increases in costs and smaller decreases in frequency of service and ridership. The form of public ownership does affect performance, but the unknown size of inter-agency cross-subsidization and tax benefits makes comparison tenuous without case-level investigation. The conclusion is reached that although the bureaucratic growth, inefficiency and vote-maximization theories are supported, inefficiency and bureaucratic growth are associated with passive sponsorship and large size of firm, rather than with public ownership, per se .
Rotation Students' Perceptions of Clinical Workload Documentation Using a Personal Digital Assistant

Purpose: The main objective of this study was to evaluate whether emphasizing the importance of clinical workload documentation (CWD) throughout the clinical rotation experience would positively impact student views of documentation.Methods: A prospective pre- and postsurvey study design was utilized to evaluate 4th-year pharmacy students’ views of CWD using personal digital assistants while on clinical rotation at an institution during the 2003 to 2004 (Group A) and 2004 to 2005 (Group B) academic years.Results: Student perceptions on the value of CWD improved significantly for both Group A (P = 0.003) and Group B (P = 0.033). Students in both groups also reported they had experience or significant experience with CWD after the rotation experience (P = 0.001).Conclusions: Students’ perception of the value and importance of CWD improved significantly throughout the rotation period with emphasis from the faculty.
The incidence of congenital heart disease

This study was designed to determine the reasons for the variability of the incidence of congenital heart disease (CHD), estimate its true value and provide data about the incidence of specific major forms of CHD. The incidence of CHD in different studies varies from about 4/1,000 to 50/1,000 live births. The relative frequency of different major forms of CHD also differs greatly from study to study. In addition, another 20/1,000 live births have bicuspid aortic valves, isolated anomalous lobar pulmonary veins or a silent patent ductus arteriosus. The incidences reported in 62 studies published after 1955 were examined. Attention was paid to the ways in which the studies were conducted, with special reference to the increased use of echocardiography in the neonatal nursery. The total incidence of CHD was related to the relative frequency of ventricular septal defects (VSDs), the most common type of CHD. The incidences of individual major forms of CHD were determined from 44 studies. The incidence of CHD depends primarily on the number of small VSDs included in the series, and this number in turn depends upon how early the diagnosis is made. If major forms of CHD are stratified into trivial, moderate and severe categories, the variation in incidence depends mainly on the number of trivial lesions included. The incidence of moderate and severe forms of CHD is about 6/1,000 live births (19/1,000 live births if the potentially serious bicuspid aortic valve is included), and of all forms increases to 75/1,000 live births if tiny muscular VSDs present at birth and other trivial lesions are included. Given the causes of variation, there is no evidence for differences in incidence in different countries or times.
The "right to die": a case study in American lawmaking.

In the 20 years that have passed since the Karen Quinlan case exposed a simmering clinical issue to the light of day — more precisely, to the press and to judicial process — a consensus has developed in American law about how end-of-life decisionmaking should occur. To be sure, there are dissenting voices from this consensus, but they are often (though not always) about minor issues. By illustrating how this consensus has evolved, this paper explores how law is made in the American legal system and the roles that different legal and extra-legal institutions play in lawmaking.
Design of supercritical swept wings

Computational fluid dynamics are used to discuss problems inherent to transonic three-dimensional flow past supercritical swept wings. The formulation for a boundary value problem for the flow past the wing is provided, including consideration of weak shock waves and the use of parabolic coordinates. A swept wing code is developed which requires a mesh of 152 x 10 x 12 points and 200 time cycles. A formula for wave drag is calculated, based on the idea that the conservation form of the momentum equation becomes an entropy inequality measuring the drag, expressible in terms of a small-disturbance equation for a potential function in two dimensions. The entropy inequality has been incorporated in a two-dimensional code for the analysis of transonic flow over airfoils. A method of artificial viscosity is explored for optimum pressure distributions with design, and involves a free boundary problem considering speed over only a portion of the wing.
Interpretation of sum frequency generation vibrational spectra of interfacial proteins by the thin film model

To interpret sum frequency generation (SFG) vibrational spectra collected from adsorbed protein molecules using structures of the interfacial proteins, the thin film model has been evaluated both theoretically and experimentally. The calculations indicate that nonlocal contributions to SFG spectra of interfacial proteins usually can be ignored. The experimental results indicate that for some polarization combinations, such as ssp and sps, local field variations across the adsorbed protein layer will not substantially affect SFG signals. Therefore, SFG spectra collected from adsorbed protein molecules are generally dominated by the electric-dipole contribution. From such spectra, quantitative structural or conformation information about interfacial proteins can be deduced using the thin film model. As an example, we analyzed the orientation distribution of the methyl groups of BSA molecules at different interfaces.
A Comparison of Meteorological Sensors Used on the USCGSS Discoverer during the Barbados Experiment.

Abstract Large scale experiments planned for the future as part of the Global Atmospheric Research Project (GARP) will call upon measurements taken from all categories of ocean vessels. During the 1968 Barbados Experiment meteorological measurements were made aboard the USCGSS Discoverer using a variety of sensors and methods typical of many ocean vessels. A comparison of the Discoverer data systems provides an estimate of the inherent error in some shipboard measurements. It is demonstrated that under unstable stratification, wind speed differences from anemometers mounted at separate locations and heights are small while under neutral conditions large differences appear. Unless special precautions are taken, heating of sensors due to solar radiation and ship effects may be as large as 2C. Such an error in dry bulb and wet bulb temperatures with a mean wind speed of 6 m sec−1 yields a 100% error in the sensible heat flux and a 50% error in the latent heat flux calculations. Nomograms of sensible and late...
Bimolecular reactions of positive ions in ammonia-water mixtures☆

Product distribution and rate constants are obtained for the reactions of NH3+ and NH2+ ions with H2O and for the reactions of OH+, H2O+, and H3O+ ions with NH3, by using tandem and trapped-ion ICR methods. A large fraction of NH3+ ions are produced in vibrationally excited states by electron impact ionization above threshold, and these excited ions react by proton transfer to H2O. This latter reaction is endothermic for ground-state NH3+ ions, and slow hydrogen atom abstraction from H2O is observed for reaction of NH3+ ions with less than the required amount of excess internal energy. Proton and charge transfer dominate the reactions of OH+ and H2O+ ions with NH3, and proton transfer dominates the NH2+H2O and H3O+NH3 reactions.
Phosphorus-31 NMR of rat brain in vivo with bloodless perfluorocarbon perfused rat

Abstract Rat brain in vivo has been examined by 31p NMR under conditions of normal blood perfusion (hematocrit 38%) and under conditions in which a perfluorocarbon blood substitute, devoid of any phosphorus containing compounds, largely replaced the animal's normal blood supply (hematocrit 7%). These studies demonstate that 2,3-diphosphoglycerate does not — as has been suggested — contribute to, and thus does not interfere with, the 31p NMR analysis of rat brain in vivo . However, low intensity 31P resonances assigned to choline phosphate, glycerol 3-phosphorylethanolamine, and glycerol 3-phosphorylcholine are observed. “High energy phosphorus” metabolite levels show no marked change over two hours with perfluorocarbon blood substitution from those of the normal blood perfused animal. This supports use of perfluorocarbon media for tissue perfusion in vitro and for 19F NMR vascular imaging in vivo .
GDC: Group Discovery Using Co-location Traces

Smart phones can collect and share Bluetooth co-location traces to identify ad hoc or semi-permanent social groups. This information, known to group members but otherwise unavailable, can be leveraged in applications and protocols, such as recommender systems or delay-tolerant forwarding in ad hoc networks, to enhance the user experience. Group discovery using Bluetooth co-location is practical because:(i) Bluetooth is embedded in nearly every phone and has low battery consumption, (ii) the short wireless transmission range can lead to good group identification accuracy, and (iii) privacy-conscious users are more likely to share co-location data than absolute location data. This paper proposes the Group Discovery using Co-location traces (GDC) algorithm, which leverages user meeting frequency and duration to accurately detect groups. GDC is validated on one month of data collected from 141 smart phones carried by students on our campus. Users rated GDC’s groups 30% better than groups discovered using the K-Clique algorithm. Additionally, GDC lends itself more easily to a distributed implementation, which achieves similar results with the centralized version while improving user’s privacy.
Stressful life events, psychological symptoms, and psychosocial adjustment in Anglo, Black, and Cuban elderly

Abstract The purpose was to compare psychological status between high and low stress groups in Anglo, Black, and Cuban cultures. High and low stress groups were significantly different particularly in regard to symptoms of somatization, depression, and anxiety. Cultural groups differed significantly on social participation and social dysfunction. Controlling for locus of control decreased some of the differences between high and low stress and controlling for social class diminished some of the differences in adjustment between cultures. The fact that symptoms differentiated high and low stress groups similarly in each culture suggests that reactions to such stresses as death and illness, which occurred frequently among these older persons, may be a common response that transcends cultural differences.
Resident Perceptions of the Impact of Work Hour Limitations

BACKGROUND Mandatory work hour limitations for residents began in July 2003. There has been little evaluation of the impact of the new limitations on Internal Medicine residency training.
Collapse Testing and Analysis of a Light-Frame Wood Garage Wall

AbstractLight-frame wood (woodframe) buildings have been tested at full-scale sparingly around the world, primarily due to the cost associated with such testing and a general lack of facilities large enough to test at system level. The data from the tests that have been performed are used to help develop nonlinear time history analysis models that can predict the behavior of woodframe buildings during strong ground shaking. It is difficult to test buildings to the point of collapse because such tests can damage costly test equipment, i.e., the shake table. This paper presents the results of a dynamic collapse test on a light-frame wood garage wall and the results of a numerical model to simulate the wall behavior all the way to the collapse point. The tested wall was heavily damaged as a result of subjecting it to a ground motion recorded during the 1995 Kobe earthquake. Then, 85% of a near-fault ground motion recording from the Northridge earthquake was used, which immediately collapsed the test specimen...
The propeptide of Clostridium septicum alpha toxin functions as an intramolecular chaperone and is a potent inhibitor of alpha toxin‐dependent cytolysis

Clostridium septicum alpha toxin is activated by a proteolytic cleavage at Arg-398 in its carboxy terminus, which yields a 41.3-kDa cytolytically active toxin and a 5.1-kDa propeptide. Studies were performed to determine when the propeptide dissociated from the toxin after proteolytic activation of the protoxin (AT(pro)) and to demonstrate the chaperone activity of the propeptide. The propeptide was found to remain associated with the toxin after activation with trypsin (AT(act)) when analysed by gel filtration or affinity chromatography of a polyhistidine-tagged derivative that contained the polyhistidine tag on the propeptide. The affinity of the propeptide for the toxin was decreased significantly when a mutation was introduced in which Val-400 was converted to a cysteine residue. This mutation destabilized the interaction of the propeptide with the toxin and the propeptide was found to dissociate from the toxin under the same gel-filtration conditions used for the wild-type toxin. The separation of the propeptide in the V400C mutant did not affect the cytolytic activity of the toxin and therefore the propeptide was not necessary for cytolytic activity. These data suggested that the propeptide did not dissociate from the main body of the toxin after proteolysis. Further analysis demonstrated that purified propeptide was a potent inhibitor of alpha toxin activity, which inhibited the oligomerization of alpha toxin into a functional pore. These data suggest that the propeptide does not participate in the final oligomerized complex and that oligomerization appears to displace the propeptide from AT(act). The importance of the propeptide to the solution stability of alpha toxin was also demonstrated. When AT(pro) was activated in solution with trypsin a significant level (approximately 50%) of inactive aggregate formed. This aggregate, which could be removed by centrifugation at 14,000 x g, was made up of both SDS-sensitive and -resistant aggregates, suggesting that a variety of inactive aggregates formed when the monomers interacted in solution. Significantly higher levels of haemolytic activity (approximately 16-fold) were observed when alpha toxin was proteolytically activated after membrane binding instead of in solution. These results support the role of the propeptide as an intramolecular chaperone that stabilizes the monomeric AT(pro) and shuttles it to the membrane where it is activated by protease, oligomerizes into a pre-pore complex and forms a pore. The data suggest that oligomerization of the toxin displaces the propeptide from the monomer form of alpha toxin and that the propeptide does not participate in, and is not necessary to, the final cytolytic complex.
The Subject of Elizabeth: Authority, Gender, and Representation – By Louis Montrose

This is a richly detailed and thoughtfully constructed book. The title has a double meaning and alludes to this author's bifocal approach to Elizabeth I. First, he investigates the queen as a histo...
No Small Problem

It's high time for the United States to get nanotech regulations–and it needs to get them right.
Egg Size, Life History, and Tropical Marine Gastropod Biogeography*

Abstract: Comparative studies of egg size and larval morphological characteristics coupled with estimates of dispersal abilities enabled Kohn and Perron (1994) to predict attributes of geographic distribution patterns of Indo-West Pacific Conus species that vary widely in developmental mode. However, because at that time, no species-level phylogenetic hypothesis had ever been proposed for Conus, we were constrained to treat each species as an independent entity. During the past decade, however, molecular phylogenetics of Conus has progressed to the point where character mapping and the method of phylogenetically independent contrasts can evaluate the importance of phylogenetic relatedness to biogeographic patterns. Analyses of species in two well-supported clades with data on ranges of trait variations suggest that significant evolutionary associations remain among developmental traits that affect dispersal ability after accounting for phylogenetic relationships. These are clades of molluscivorous and pis...
Ekho: realistic and repeatable experimentation for tiny energy-harvesting sensors

Harvesting energy from the environment makes it possible to deploy tiny sensors for long periods of time, with little or no required maintenance; however, this free energy makes testing and experimentation difficult. Environmental energy sources vary widely and are often difficult both to predict and to reproduce in the lab during testing. These variations are also behavior dependent---a factor that leaves application engineers unable to make even simple comparisons between algorithms or hardware configurations, using traditional testing approaches.In this paper, we describe the design and evaluation of Ekho, an emulator capable of recording energy harvesting conditions and accurately recreating those conditions in the lab. This makes it possible to conduct realistic and repeatable experiments involving energy harvesting devices. Ekho is a general-purpose tool that supports a wide range of harvesting technologies. We demonstrate, using a working prototype, that Ekho is capable of reproducing both solar and RF energy harvesting environments accurately and consistently. Our results show that Ekho can recreate harvesting-dependent program behaviors by emulating energy harvesting conditions accurately to within 77.4 μA for solar environments, and can emulate RF energy harvesting conditions significantly more consistently than a programmable RF harvesting environment.
Limits on preserving quantum coherence using multipulse control

We explore the physical limits of pulsed dynamical decoupling methods for decoherence control as determined by finite timing resources. By focusing on a decohering qubit controlled by arbitrary sequences of $\ensuremath{\pi}$ pulses, we establish a nonperturbative quantitative upper bound to the achievable coherence for specified maximum pulsing rate and noise spectral bandwidth. We introduce numerically optimized control ``bandwidth-adapted'' sequences that saturate the performance bound and show how they outperform existing sequences in a realistic excitonic-qubit system where timing constraints are significant. As a by-product, our analysis reinforces the impossibility of fault-tolerance accuracy thresholds for generic open quantum systems under purely reversible error control.
INCREASED WILLOW HEIGHTS ALONG NORTHERN YELLOWSTONE's BLACKTAIL DEER CREEK FOLLOWING WOLF REINTRODUCTION

Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park in 1995-1996. In August 2004 we measured plant architecture of Geyer willow (Salix geyeriana) stems along three 100-m reaches of Blacktail Deer Creek in Yellowstone's northern elk (Cervus elaphus) winter range to evaluate changes in patterns of browsing and height growth following wolf reintroduction. Average browsing intensities (n = 3 stream reaches) of 100% in 1997 decreased to 0%-55% by 2003, whereas average stem heights of 25-74 cm in 1997 increased to 149-268 cm by 2003, indicating that willow height growth was inversely related to browsing intensity. In addition, average willow canopy cover over the streams increased from <5% in 1997 to 14%-73% in 2004. These findings were consistent with a hypoth- esis that increased willow heights following the 1995-1996 wolf reintroduction represent a trophic cascade involving wolves, elk, and deciduous woody vegetation.
The role of leukocytes in the formation and rupture of intracranial aneurysms

Ruptured intracranial aneurysms (IAs) affect a small proportion of the population; however, the morbidity and mortality is disproportionally high. Although little is known about IA formation, progression, and rupture, mounting evidence suggests that inflammation may play an important role in IA pathogenesis. There is emerging evidence to suggest that leukocytes play a key role in generating and maintaining a pathologic inflammatory response that leads to aneurysm formation and rupture. We present the current literature pertaining to the role of leukocytes in aneurysm formation, progression, and rupture. The contributions of individual cell types are detailed, with special attention paid to the cytokine and molecular profiles. The role of magnetic resonance imaging as a means by which to evaluate aneurysm-associated inflammation is reviewed. Finally, we discuss leukocytes as potential targets of pharmacologic intervention.
Earth as viewed in the ultraviolet

Abstract A great variety of atmospheric phenomena on the Earth can be observed in the 300 to 4000 A region. These include simple absorption; Rayleigh scattering; resonance fluorescence from atoms, molecules, and ions; electron impact excitation; recombination radiation; chemiluminescence; and emissions from precipitating ions and neutrals. Observations at these wavelengths from space have been carried out primarily with grating spectrometers and scanning filter photometers. A difficulty with instruments of this type is that they view only a small part of the Earth at any one time and as a result it is difficult to separate temporal and spatial observations. A description of the Earth as it might appear if viewed from a distant spacecraft with imaging capability is extrapolated from available localized data for several optical phenomena. Discussed are variations in reflected sunlight due to ozone absorption, resonant-scattering by geocoronal atoms, resonant-scattering by ions in the plasmasphere, excitation of ultraviolet emissions by electrons in the dayglow and aurora, and the tropical ultraviolet arcs caused by O+ recombination. Particular emphasis is placed on the expected temporal and spatial variability. It is concluded that significant new information could be gathered by ultraviolet-sensitive television systems placed in high Earth orbit, either synchronous or polar.
Purification of β-glucocerebrosidase by preparative-scale high-performance liquid chromatography: The use of ethylene glycol-containing buffers for chromatography of hydrophobic glycoprotein enzymes

Abstract β-Glucocerebrosidase, partially purified by the method of F. S. Furbish et al. (1977, Proc. Natl. Acad. Sci. USA 74, 3560–3563), was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to contain, in addition to the desired enzyme, variable amounts of a very hydrophobic contaminant (apparent M r 45,000). Purification of the enzyme was accomplished by gel-permeation HPLC on a TSK 3000 SW column (0.7 × 60 cm). Adsorptive losses of protein on the column were minimized by using buffers containing up to 50% ethylene glycol. We have examined the effects of varying the ethylene glycol concentration on the elution times and recoveries of the two major proteins in this preparation. The high reproducibility of the individual chromatograms permitted the use of an automatic sampler and fraction collector to perform multiple, continuous runs for the purification of milligram quantities of enzyme. Multiple runs of a preparative-scale column, TSK G3000 SWG (2.15 × 60 cm), permitted gram-scale purification of β-glucocerebrosidase without loss in efficiency of separation. Recovery of enzyme activity is greater than 94% with less than 1% contamination by other proteins. Reaction of enzyme prepared in this fashion with rabbit polyclonal antiserum or mouse monoclonal anti-β-glucocerebrosidase shows the enzyme to be pure and not immunologically related to the 45,000 M r contaminant. The specific activity of enzyme prepared by this means is 1.6 × 10 6 nmol/h/mg protein. Inclusion of ethylene glycol in buffers was shown to overcome hydrophobic protein interactions with TSK 3000 SW column matrices for both the soluble human lysosomal enzyme α-galactosidase A and the plant toxin ricin.
Principal Volatile Components of Raw, Roasted, and Fried Argentinean Peanut Flavors

Volatile components of raw, roasted, and fried Runner peanut seeds from Cordoba (Argentina) were analyzed. The extraction of volatile compounds was performed according to the headspace method. They were separated and identified by GC/MS. Hexanal, 1-methylpyrrole, cyclobutanol, 4-ethyl-2,5-dimethylisoxazolidine, 2,6-dimethylpyrazine, 1-hexanol, and acetic acid were detected. Hexanal and 1-methylpyrrole showed higher concentrations followed by acetic acid. 2,6-Dimethylpyrazine was not found in raw peanuts. Cyclobutanol and 1-hexanol were detected in trace levels in roasted and fried peanuts, respectively. 2,6-Dimethylpyrazine was found in roasted and fried peanuts.
THERMODYNAMICS OF HIGH-PRESSURE AQUEOUS SYSTEMS CONTAINING GASES AND SALTS

This work provides a new method for calculating phase equilibria for systems where conventional activity-coefficient models are not suitable. A procedure is presented for superimposing ionic effects on a conventional equation of state for nonelectrolytes. A modification of Born's equation is used to describe charging the ions; ion-ion interactions are described with the Mean Spherical Approximation, coupled with an adjustable salt/solvent parameter that is obtained from osmotic-coefficient data at room temperature. The equation of state is used to predict gas solubilities in aqueous salt solutions at high pressures. While this method produces qualitative agreement with the experimental solubility data, quantitative agreement requires a salt/ gas parameter obtained from Setchenow-constant data. When Setchenow constants are used, agreement with experiment is good except at high salt concentrations, where salting-out is usually underpredicted. Good results are obtained for phase equilibria in a natural-gas/brine system at high pressures.
A fractal analysis of analyte–estrogen receptor binding and dissociation kinetics using biosensors: environmental and biomedical effects

Abstract A fractal analysis is used to model the binding and dissociation kinetics between analytes in solution and estrogen receptors (ERs) immobilized on a sensor chip of a surface plasmon resonance (SPR) biosensor. The influence of different ligands is also analyzed. A better understanding of the kinetics provides physical insights into the interactions, and suggests means by which appropriate interactions (to promote correct signaling) and inappropriate interactions such as with xenoestrogens (to minimize inappropriate and deleterious to health signaling) may be better controlled. The fractal approach is applied to analyte–ER interaction data available in the literature. The units for the different parameters (rate coefficients and affinities) in fractal-type kinetics are different from those obtained in classical kinetics. Numerical values obtained for the binding and the dissociation rate coefficients are linked to the degree of roughness or heterogeneity (fractal dimension, Df) present on the biosensor chip surface. In general, the binding and the dissociation rate coefficients are very sensitive to the degree of heterogeneity on the surface. A single-fractal analysis is adequate in some cases. In others (that exhibit complexities in the binding or the dissociation curves) a dual-fractal analysis is required to obtain a better fit. This has biomedical and environmental implications in that the dissociation (and the binding) rate coefficient may be used to alleviate (deleterious effects) or enhance (beneficial effects) by selective modulation of the surface. The affinity values obtained in the analysis are consistent with the numbers required to (a) promote signaling between the correct analyte and the estrogen receptor, and (b) minimize the signaling between xenoestrogens and the estrogen receptor.
Synergistic Moments at the Hip and Knee Joints Are Altered in Post-Stroke Hemiplegic Gait

Following stroke, many patients are unable to adequately bend their knee during the swing phase of gait [1,2]. This loss of functional control may be related to an abnormal muscle synergy or torque couple in the lower limb, similar to those reported for the upper extremity [3–5]. For example, several investigators have described a flexor synergy that couples shoulder abduction torque and elbow flexion torque under static, isometric conditions [3–4]. This couple is typically altered following stroke [3–4]. In the lower extremity, hip kinetics in the frontal plane appear to be coupled with knee kinetics in the sagittal plane for static, isometric conditions [6]. It is unknown, however, whether the same relationship holds for hip and knee kinetics under dynamic conditions, such as during the swing phase of gait.Copyright © 2007 by ASME
Iterative Transport-Diffusion Methodology For LWR Core Analysis

This paper presents an update on the development of an advanced methodology for core calculations that uses local heterogeneous solutions for on-the-fly nodal cross-section generation. The Iterative Transport-Diffusion Method is an embedded transport approach that is expected to provide results with near 3D transport accuracy for a fraction of the time required by a full 3D transport method. In this methodology, the infinite environment used for homogenized nodal cross-section generation is replaced with a simulated 3D environment of the diffusion calculation. This update focuses on burnup methodology, axial leakage and 3D modeling.
Mesocortical dopamine neurons: high basal firing frequency predicts tyrosine dependence of dopamine synthesis.

Mesocortical dopamine (DA) neurons projecting to the prefrontal and cingulate cortices possess a faster basal firing rate and exhibit more bursting than other midbrain DA neurons. Thus, we examined whether tyrosine administration could preferentially affect DA synthesis in these DA neurons. Tyrosine administered at doses as low as 25 mg/kg significantly increased in vivo tyrosine hydroxylation in the prefrontal and cingulate cortices without affecting it in other mesocortical, mesolimbic, and nigrostriatal DA terminal fields examined. Further studies in the mesoprefrontal DA neurons showed that tyrosine administered at higher doses of 50 mg/kg initially enhanced tyrosine hydroxylation and elevated endogenous DA levels within 60 min. The resultant increases in DA levels appeared to feedback and normalize prefrontal tyrosine hydroxylase activity. The levels of DA metabolites in the prefrontal cortex were unaltered by doses of tyrosine from 25–200 mg/kg, suggesting that the functional transmitter outflow from these DA neurons is not normally affected by precursor administration under resting conditions. However, when these mesocortical DA neurons were pharmacologically activated following administration of the anxiogenic Β-carboline, FG 7142, tyrosine administration (25 mg/kg) was effective in increasing DA metabolite levels in the prefrontal cortex. These results thus suggest that enhanced activity of the mesoprefrontal DA neurons renders these DA neurons much more dependent up on tyrosine availability for maintenance of transmitter output.
STUDIES ON THE OXIDATION-REDUCTION OF HEMOGLOBIN AND METHEMOGLOBIN : I. THE CHANGES INDUCED BY PNEUMOCOCCI AND BY STERILE ANIMAL TISSUE.

The Pneumococcus is capable of oxidizing hemoglobin to methemoglobin and of reducing the latter to hemoglobin again. Both the living organism and sterile extracts will accomplish the changes; and like systems seem to be involved in them. The type of reaction induced is determined by the presence or absence of molecular oxygen. The oxidation and reduction of the blood pigments are reversible processes. The equilibrium between hemoglobin and methemoglobin in a mixture of blood and pneumococcus cellular substances may be shifted in either direction at will by regulation of the oxygen tension. In the present paper quantitative evidence is presented of the reduction of methemoglobin to hemoglobin by sterile animal tissues. The possible relations of this activity to the disappearance of methemoglobin from the blood stream of the living animal are discussed.
Turbo Codes Based Image Transmission for Channels with Both Random Errors and Packet Loss

In this paper, we propose an unequal error protection (UEP) framework for progressive image transmission over wireless networks with both random errors and packet loss. By sophisticatedly interleaving each coded frame, the packet loss is converted into randomly punctured bits in a turbo code. Therefore, error control of channels with both types of distortions is equivalent to dealing with random bit errors only through turbo codes with reduced rates. To optimally allocate the overall transmission rate between the source and channel codes, a genetic algorithm (GA) based method is proposed which not only largely reduces the optimization complexity but also gives results close to the brute force search in tested scenarios. Then, we extend the UEP to a product code scheme by adding Reed-Solomon (RS) code across the frames. An efficient rate allocation method for this product code with the use of interleaving is further presented. The effectiveness of the proposed schemes is demonstrated with extensive simulation results.
Ischemia induces ligand-independent activation of EGFR in model intestinal epithelia: Role of SHC and GRB2 in stress-induced MAPK response

Abstract Introduction: Ischemic stress activates mitogen-activated protein kinases (MAPKs) in intestinal epithelia, a response that directs cell fate after injury. We reported that ischemic stress triggers ligand-independent activation of the epidermal growth factor receptor (EGFR), an event associated with downstream activation of MAPK. This study examines the role of EGFR-associated adaptor proteins SHC and GRB2 in ischemic activation of MAPK. Methods: Human intestinal T84 cells underwent 60min of ischemic stress (ATP depletion) by substrate withdrawal and chemical inhibition of mitochondrial respiration and glycolysis (glucose-free buffer containing 1mM oligomycin-A plus 10mM 2-deoxyglucose). Ischemic stress was terminated by return to glucose-containing buffer (ATP repletion). SHC activation was assessed by immunoprecipitation of SHC and blotting with phosphotyrosine specific Ab. Blots were probed for total SHC to ensure equal loading. SHC interactions with GRB2 were assessed by immunoprecipitation of SHC followed by blotting for GRB2. Results: ERK 1/2 phosphorylation is maximal and EGFR was activated within 20min of ATP repletion. At this time point, levels of SHC tyrosine phosphorylation (indicative of SHC activation) were increased (131% +/− 23%, n=3) without change in total SHC levels. Additionally, the interaction of SHC with GRB2 increased by nearly 3-fold (291 +/− 63.7%, n=3, p Conclusions: Following ischemic stress in model intestinal epithelia, SHC phosphorylation/activation is increased in parallel with increased association with GRB2. We conclude that ischemic stress induces the recruitment of EGFR adaptor proteins SHC and GRB2. These data further support a role for ligand-independent activation of EGFR in post-ischemic activation of MAPK signaling.
The role of second trimester ultrasound in the diagnosis of placental hypoechoic lesions leading to poor pregnancy outcome

Objective. The purpose of the study was to quantify placental hypoechoic areas without blood flow by means of second trimester high-resolution ultrasound with power color Doppler and to evaluate its relationship to pregnancy outcome.Methods. Patients referred for second trimester ultrasound from January 2001 to December 2003 were eligible for the study. Patients with placental parenchymal hypoechoic areas without blood flow constituted the study group (N = 65). The control group was comprised of 65 patients who had normal placental parenchyma. The groups were similar with regards to maternal age, gestational age, parity, race, and smoking. The mean of the two largest lesion diameters was used for severity classification.Results. Fifty-two patients (80%) had aggregate lesions of ≤5 cm and 13 (20%) had lesions >5 cm. Mean ± standard deviation (SD) gestational age at delivery was 39.1 ± 1.8 weeks for the control group, 37.9 ± 2.8 weeks for those with lesions of ≤5 cm, and 35.2 ± 5.8 weeks for those with lesi...
Phase I Pharmacokinetic and Pharmacodynamic Evaluation of Combined Valproic Acid/Doxorubicin Treatment in Dogs with Spontaneous Cancer

Purpose : Histone deacetylase inhibitors (HDACi) are targeted anticancer agents with a well-documented ability to act synergistically with cytotoxic agents. We recently showed that the HDACi valproic acid sensitizes osteosarcoma cells to doxorubicin in vitro and in vivo . As there are no published reports on the clinical utility of HDACi in dogs with spontaneous cancers, we sought to determine a safe and biologically effective dose of valproic acid administered prior to a standard dose of doxorubicin. Methods: Twenty-one dogs were enrolled into eight cohorts in an accelerated dose-escalation trial consisting of pretreatment with oral valproic acid followed by doxorubicin on a three-week cycle. Blood and tumor tissue were collected for determination of serum valproic acid concentration and evaluation of pharmacodynamic effects by immunofluorescence cytochemistry and immunohistochemistry. Serum and complete blood counts were obtained for determination of changes in doxorubicin pharmacokinetics or hematologic effects. Results: All doses of valproic acid were well tolerated. Serum valproic acid concentrations increased linearly with dose. Doxorubicin pharmacokinetics were comparable with those in dogs receiving doxorubicin alone. A positive correlation was detected between valproic acid dose and histone hyperacetylation in peripheral blood mononuclear cells. No potentiation of doxorubicin-induced myelosuppression was observed. Histone hyperacetylation was documented in tumor and peripheral blood mononuclear cells. Responses included 2 of 21 complete, 3 of 21 partial, 5 of 21 stable disease, and 11 of 21 progressive disease. Conclusions: Valproic acid can be administered to dogs at doses up to 240 mg/kg/day prior to a standard dose of doxorubicin. In addition, we have developed the pharmacokinetic/pharmacodynamic tools necessary for future studies of novel HDACi in the clinical setting of canine cancer. Clin Cancer Res; 16(19); 4832–42. ©2010 AACR.
The role of verbal competence and multiple risk on the internalizing behavior problems of Costa Rican youth.

This longitudinal study examined internalizing behavior problems (anxiety/depression) in early adolescence in relation to adver- sity in early childhood and child verbal competence. We hypothesized that verbal competence would act as a protective factor in the face of early adversity, that is, high verbal IQ would predict relatively lower internal- izing problems in early adolescence primarily for those children who experienced the greatest adversity. The sample was based on 191 Costa Rican children and their mothers, who were recruited in infancy from an urban community and assessed again at 5 and 11-14 years. Families were generally lower-middle to working class. A total of 165 children (94 boys) participated in the early adolescent follow-up (mean age = 12.3 years). Internalizing problems were based on maternal report (Spanish Child Behavior Checklist). Our cumulative risk index (CRI)˙of adversity in early childhood consisted of home environment quality (HOME score), socioeconomic status, maternal depressed mood (CESD), and maternal IQ. Controlling for the effects of age, gender, internalizing problems at 5 years, and verbal IQ at 5 years, there was a significant interaction between early adversity and verbal IQ at age 11-14 years in predicting internalizing problems in early adolescence. Youth with high verbal IQ had comparable levels of internalizing problems regardless of high or low adversity in early childhood. In contrast, youth with low verbal IQ received higher internalizing problem ratings if they experienced high adversity early in life. The results raise the possibility that interventions to improve verbal competence might help lower the risk of internalizing problems in the face of early adversity.
Dystrophin and muscular dystrophy: past, present, and future.

Duchenne muscular dystrophy was described in the medical literature in the early 1850s but the molecular basis of the disease was not determined until the late 1980s. The cloning of dystrophin led to the identification of a large complex of proteins that plays an important, although not yet well understood, role in muscle biology. Concomitant with the elucidation of the function of dystrophin and its associated proteins has been the pursuit of therapeutic options for muscular dystrophy. Although there is still no cure for this disorder, great advances are being made in the areas of gene introduction and cell transplant therapy.
Role of Cognition and Affect in a Functional Behavioral Analysis

Erroneous beliefs, distorted thoughts, and poorly controlled emotional responses to stress contribute to behavior problems as fundamentally as do observable environmental antecedents. The methods of this classical functional behavioral assessment for evaluating high-frequency problem behaviors are insufficient for understanding such low-frequency behavior as drawing a weapon or such covert behavior as possessing drugs. To understand the function of problem behaviors in students' lives, assessment of their social perspectives, beliefs, and feelings is as necessary as assessment of their immediate desires for attention, task avoidance, or escape. The purpose of this article is to present a multidimensional perspective that will lead to psychoeducational interventions in which students are taught to think clearly, solve problems, and self-regulate the intensity of their emotions.
Determining kinks for 980-nm lasers using time-resolved far-field scan

The beam quality of weakly index-guided edge emitting 980nm lasers is investigated via time-resolved far-field measurement technique. A synchronous detection scheme is used to directly measure lasers' far-field pattern, intensity versus divergence angle, as functions of duration and amplitude of injection current pulses. It is shown that the degradation of beam quality, characterized as multiple lateral modes and observed as beam steering of far-field pattern, highly depends on the transient condition associated with the duration of injection current pulses. The beam steering of far-field pattern is well correlated to the kink in power-versus-current curve under the same transient condition. We experimentally found that time constant for the far-field pattern to reach steady state is ~1.4 microsecond. From thermal transience modeling, we conclude that beam steering is the result of local heating, which produces a lateral temperature gradient profile at the laser waveguide region to significantly enhance the lateral index contrast.
Avoiding nostril-cam and postage-stamp people in mobile video conferences

We would like to provide high-quality video conferencing so that people can communicate comfortably with each other anywhere, anytime. This is not a new goal, and there are now several applications such as Skype™ and FaceTime™ on mobile platforms that bring us closer to achieving anywhere, anytime video communications. Alas, these mobile conferences are often of poor quality due to the many challenges presented by mobile devices, such as constrained networks, limited processing power, small displays, and uncontrolled view angles and lighting. These challenges mean that simply porting existing desktop video conferencing solutions to portable devices does not provide the best user experience. Fortunately, these mobile devices also have many advantages that we can exploit to enable better-quality portable video conferences. In this paper we describe how we exploit the devices' mobility and embedded sensors to detect and fix two problems that are often ignored but that adversely affect user experience: bad view angles and too-tiny views of people and content, especially in multi-party conferences. Please note that what we describe is very much an experimental prototype and not a finished project.