cssi/SciSciGPT-SciSciNet huggingface dataset:
Vinyl epoxide accelerators for the photoinitiated cationic polymerization of oxetane monomers

Abstract Epoxides bearing vinyl groups bonded to one of the carbon atoms of the three-membered ring, exhibit the ability to dramatically increase the rate of the photoinitiated cationic polymerization of 3-mono- and 3,3-disubstuted oxetanes by eliminating or sharply reducing the length of the induction periods. This effect, termed by us as “kick-starting”, results from the ability of the aforementioned epoxides to undergo ring-opening on protonation to yield resonance stabilized allylic carbocations. Several examples are given of “kick-starting” epoxides together with their use in the photopolymerization of various oxetane monomers.
Electrochemical analysis of cell plasma membrane cholesterol at the airway surface of mouse trachea.

Electrochemical detection of plasma membrane cholesterol at the surface of excised mouse trachea tissue is reported. Cholesterol oxidase is covalently linked to an 11-mercaptoundecanoic acid submonolayer on the platinum electrode surface. The cholesterol oxidase-modified electrodes show steady-state responses for cholesterol in solution at physiological temperatures. Experiments for direct contact between the cholesterol oxidase-modified electrode and the surface of excised trachea tissue at 37 °C indicate steady-state responses that are largely independent of the position of contact on the tissue surface. Tissue samples are mounted on a quartz crystal microbalance electrode to gauge contact force between the electrode and the tissue surface, and the steady-state electrode response for tissue cholesterol is shown to be largely independent of the contact force. Trachea tissue excised from a mouse model of cystic fibrosis, which is known to exhibit evaluated cholesterol in airway cells, shows an electrode r...
Estimating Losses of Dry Matter from Wetted Alfalfa–Orchardgrass Mixtures Using Cell Wall Components as Internal Markers

Methods previously used to measure recoveries of dry matter (DM) from forages following natural or simulated rainfall often have relied on simple gravimetric techniques, which yielded inconclusive estimates of DM recovery. Our objective was to evaluate insoluble cell-wall constituents as internal markers for estimating recoveries of DM from alfalfa (Medicago sativa L.) or alfalfa– orchardgrass (Dactylis glomerata L.) mixtures subjected to simulated rainfall. Forage mixtures consisted of 1000, 750, or 500 g kg −1 alfalfa, with the balance comprised of orchardgrass. Regardless of the forage mixture, concentrations of all cell-wall constituents increased (P ≤ 0.053) in response to wetting (0, 70, 140, 280, 420, 560, or 840 mm at 70 mm h −1 ) under a rainfall simulator. Following treatment, recovery of all cell-wall constituents was high ( ≥901 g kg −1 ). Generally, losses were smallest for neutral-detergent fi ber (NDF) markers regardless of analysis method (with alpha-amylase, sodium sulfi te, neither, or both), acid-detergent fi ber (ADF), and cellulose and largest for hemicellulose and lignin. Linear regressions of recoveries of DM by internal markers on values determined gravimetrically were good (r 2 ≥ 0.775) when NDF was used to estimate recovery. In all these cases, neither slopes (P ≥ 0.103) nor intercepts (P ≥ 0.083) differed from one and zero, respectively. Fiber components appear to be suitable internal markers for measuring recoveries of DM following wetting, but this approach depends on complete recovery of shattered leaf particles before conducting laboratory analyses. USDA-ARS, U.S. Dairy Forage Research Center, 8396 Yellowstone Dr., Marshfi eld, WI 54449. Mention of trade names or commercial products is solely for the purpose of providing specifi c information about scientifi c procedures and/or subsequent evaluation of results and does not imply any recommendation or endorsement by the USDA. Received 4 Jan. 2008. *Corresponding author (wayne.coblentz@ars.usda.gov).
Pulsed laser deposition assisted fabrication and characterization of Fe–Co nanoparticles embedded in TiN thin film matrix

Abstract The FeCo material was synthesized in nanoparticle form in a TiN/FeCo/TiN sandwich structure using a pulsed laser deposition (PLD) method. FeCo is significantly cheaper than noble metal based bimetallic materials such as Fe–Pt, Ni–Pd, etc. A Fe0.5 Co0.5 composition was chosen in this study which is based on the local spin-density electronic-structure calculations. The advantage of this structure is in-situ passivation of FeCo nanoparticles by TiN thin films which is highly stable against atmospheric ambient conditions. TiN/FeCo/TiN samples with variable FeCo nanoparticle size were made by changing the number of laser pulses impinging on a chemically synthesized composite FeCo target. By controlling the particle size in the confined layers, it was possible to tune the magnetic properties from superparamagnetic to ferromagnetic in a controlled way. Magnetic hysteresis characteristics below the blocking temperature are consistent with single-domain behavior.
Dehydration of methanol on zeolite-containing catalysts

Conversion of methanol on unmodified industrial cracking catalysts (ICC) containing zeolite Y (KM, Zeocar-2 and KM-R) and NZHS (KM-1 and KM-1R), unmodified and modified with phosphoric acid, was investigated. It was shown that conversion from selective formation of hydrocarbon products whose composition is a function of the temperature to selective formation of dimethyl ether (DME) is observed on KM-1 catalyst as a function of the duration of the experiment. The catalyzates formed on the KM and Zeocar-2 catalysts and hydrocarbons and DME (∼50%) differ from the catalyzates formed on the KM-1 catalyst, with a stable composition for the duration of the experiments. Modified catalysts KM-1R and KM-R provide a stable, highly selective yield of hydrocarbons and DME, respectively. The results obtained demonstrate the promise of using ICC for dehydration of methanol into DME.
Mesopic lightness, brightness, and brightness contrast

At mesopic mean luminances, a fixed luminance contrast produces less brightness contrast than it does at photopic luminances. This suggests that lightnesses of surfaces might also be altered at low luminances. I measured lightness, brightness, and brightness contrast in CRT simulations of achromatic paper patchworks. The illuminance of the standard pattern was fixed, producing 0.12, 1.2, or 12 cd/m2. The illuminance on the test pattern was varied in a lightness constancy paradigm. Constant brightness contrast required more luminance contrast at lower mean luminances. Failures of lightness constancy occurred at the lowest mean luminances, but they were minor in comparison with the loss of brightness contrast in the same pattern. These results have implications for imaging applications. Often, image content falls in both the photopic and the mesopic ranges. Our results indicate that brightness contrast may decrease substantially in low-luminance regions without large changes of surface lightness.
Transonic flutter analysis of aerodynamic surfaces in the presence of structural nonlinearities

Abstract The influence of structural nonlinearities on the transonic aeroelastic behavior of a two-degree-of-freedom system consisting of an airfoil which is plunging and pitching is considered. The preload and freeplay nonlinearity in the spring model are treated using the asymptotic expansion method which takes into account the influence of the higher harmonics. The aerodynamic load vector is obtained by solving the unsteady transonic small-disturbance (TSD) equation using an alternating-direction implicit (ADI) finite-difference algorithm. The frequency domain solution of the aeroelastic equation is obtained using the U-g method, and the aeroelastic response is carried out by applying Newmark-β and Wilson-ϑ methods. A comparison is made between the results obtained from these two solutions. The effects of preload and freeplay magnitudes on the stability of the system and the corresponding reduced frequency and mass density ratio at neutrally stable response are studied.
Reactions of 5-methylcytosine cation radicals in DNA and model systems: thermal deprotonation from the 5-methyl group vs. excited state deprotonation from sugar.

AbstractPurpose: To study the formation and subsequent reactions of the 5-methyl-2′-deoxycytidine cation radical (5-Me-2′-dC•+) in nucleosides and DNA-oligomers and compare to one-electron oxidized thymidine.Materials and methods: Employing electron spin resonance (ESR), cation radical formation and its reactions were investigated in 5-Me-2′-dC, thymidine (Thd) and their derivatives, in fully double-stranded (ds) d[GC*GC*GC*GC*]2 and in the 5-Me-C/A mismatched, d[GGAC*AAGC:CCTAATCG], where C* = 5-Me-C.Results: We report 5-Me-2′-dC•+ production by one-electron oxidation of 5-Me-2′-dC by Cl2•− via annealing in the dark at 155 K. Progressive annealing of 5-Me-2′-dC•+ at 155 K produces the allylic radical (C-CH2•). However, photoexcitation of 5-Me-2′-dC•+ by 405 nm laser or by photoflood lamp leads to only C3′• formation. Photoexcitation of N3-deprotonated thyminyl radical in Thd and its 5′-nucleotides leads to C3′• formation but not in 3′-TMP which resulted in the allylic radical (U-CH2•) and C5′• production...
Picosecond radical kinetics. Alkoxycarbonyl accelerated cyclopropylcarbinyl radical ring openings

Abstract Rate constants and Arrhenius functions for ring openings of the ( trans -2-ethoxycarbonylcyclopropyl)methyl radical and the ( trans -2- tert -butoxycarbonylcyclopropyl)methyl radical were determined by the PTOC-thiol method with PhSeH trapping. At 25°C, these radicals rearrange with rate constants of 7 and 12 × 10 10 s −1 , respectively.
One-year outcomes of Roux-en-Y gastric bypass for morbidly obese adolescents: a multicenter study from the Pediatric Bariatric Study Group

Abstract Background/Purpose Little is known about the metabolic outcomes of adolescent bariatric surgery. We report changes in weight, metabolic profile, and types of complications seen in a multicenter cohort. Methods One-year outcomes were included. For weight loss comparisons, a nonsurgical cohort (n = 12) was used. The primary outcome was weight change (n = 30) and secondary outcomes were metabolic variables (n = 24) and complications (n = 36). Data were analyzed using signed rank or paired t tests. Results Mean body mass index fell 37% (from 56.5 preoperatively to 35.8 kg/m 2 ; P 2 ; P = NS) in nonsurgical patients. Surgical patients showed significant improvements in triglycerides (−65 mg/dL), total cholesterol (−28 mg/dL), fasting blood glucose (−12 mg/dL), and fasting insulin (−21 μ M/mL]). Improvement in high-density lipoprotein cholesterol (−3.9 mg/dL) and low-density lipoprotein cholesterol (−8.8 mg/dL) was not statistically significant. Sixty-one percent of surgical patients had no complications. Of 15 patients with complications, 9 had minor complications with no long-term sequelae, 4 had at least 1 moderate complication with sequelae for at least 1 month and 2 had at least 1 severe medical complication with long-term consequences (including beriberi and death). There were no perioperative deaths or other severe surgical complications in this series. Conclusions Postoperatively, adolescents lose significant weight and realize major metabolic improvements. The complication profile compares favorably to severely obese (body mass index >40 kg/m 2 ) adults; however, small sample size precludes calculation of complication rates. Although there are considerable risks of bariatric surgery, early experience suggests that risks are offset by health benefits.
An Emergent Theory of Structure and Outcomes in Small-Firm Strategic Manufacturing Networks

This article presents the results of a comparative study of two networks of small- to medium-sized manufacturing enterprises in the U.S. wood products industry. Qualitative and survey data were collected from a sample of active participants in each network as well as from a sample of firms that were not network members (market firms) in the same industry. Using both qualitative and network analysis methodologies, we developed a model and testable propositions concerning key aspects of network structure and outcomes.
Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage.

We evaluated mercury (Hg) in five waterbird species representing three foraging guilds in San Francisco Bay, CA. Fish-eating birds (Forster’s and Caspian terns) had the highest Hg concentrations in thier tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. Foraging habitat was important for Hg exposure as illustrated by within-guild differences, where species more associated with marshes and salt ponds had higher concentrations than those more associated with open-bay and tidal mudflats. Importantly, Hg concentrations increased with time spent in the estuary. Surf scoter concentrations tripled over six months, whereas Forster’s terns showed an up to 5-fold increase between estuary arrival and breeding. Breeding waterbirds were at elevated risk of Hg-induced reproductive impairment, particularly Forster’s terns, in which 48% of breeding birds were at high risk due to their Hg levels. Our results highlight the importance of habitat and exposure timing, in addition to trophic position, on waterbird Hg bioaccumulation and risk. Published by Elsevier Ltd.
Toxoplasma gondii: in vivo and in vitro studies of a mutant resistant to arprinocid-N-oxide.

Abstract The anticoccidial drug arprinocid and arprinocid- N -oxide, a metabolite produced in vivo , blocked the growth of Toxoplasma gondii in human fibroblasts. The more potent arprinocid- N -oxide inhibited growth by 50% at 20 ng/ml while arprinocid inhibited at 2 μg/ml. For both drugs, the host cell was less sensitive than was the parasite. Hypoxanthine did not reverse the antitoxoplasma activity of either drug. We isolated a parasite mutant, R-Ano R -1 that was 16- to 20-fold more resistant to arprinocid- N -oxide than was the wild type RH T. gondii . This mutant was not resistant to arprinocid in vitro . Arprinocid in a daily oral dose of 136 μg regularly protected mice against an otherwise fatal infection with RH T. gondii and 55 μg had some protective effect. However, all mice infected with R-Ano R -1 and treated with 360 μg arprinocid per day died. Since this mutant is fully sensitive to arprinocid, the form of the drug that is therapeutically active in vivo cannot be arprinocid and is likely to be arprinocid- N -oxide.
Influence of crystallography upon critical nucleus shapes and kinetics of homogeneous f.c.c.-f.c.c. nucleation—IV. Comparisons between theory and experiment in CuCo alloys

Abstract A discrete lattice point model (Cook, de Fontaine and Hilliard) which incorporates strain energy (Cook and de Fontaine), described in earlier papers, has been used to determine the ranges of temperature and composition at which homogeneous nucleation kinetics of f.c.c. precipitates in Cu Co alloys would be neither too fast nor too slow to be measured. These predictions proved successful and it was possible to measure experimentally nucleation kinetics in Cu Co alloys containing from 0.5 to 1.0 at.% Co within 50°C temperature ranges. Experimental results were compared with theoretical values obtained from the discrete lattice point, the Cahn-Hilliard continuum and the classical theories of homogeneous nucleation. Very good agreement was obtained between the experiments and all three theories. Although surprising at first, the good matching between classical theory and experiments was explained by showing that the calculated concentration profiles of critical nuclei at the temperatures and alloy compositions experimentally studied did show distinct “volumes” and “interfaces” i.e. the solute concentration did not vary continuously throughout the nuclei. In this case, as pointed out in effect by Cahn and Hilliard, classical nucleation theory indeed applies. These findings provide the first strong support for the essential correctness of homogeneous nucleation theory.
Graphics programming independent of interaction techniques and styles

The Information Display Systems project is seeking, among other goals, to apply the principles of top-down design and functional abstraction to the design of interactive systems, particularly those involving interactive computer graphics. An important part of this effort is to develop a methodology and a programming environment to facilitate the functional separation of program modules handling a set of application semantics from program modules handling user interaction.We have developed a model for such an environment, and implemented a prototype version with a number of components:• an interaction language (IL) adapted from augmented transition networks, in which the syntax of interactive dialogs can be written;• an interpreter for the IL;• a set of "style modules" to handle such interaction style-dependent attributes as level of prompting and amount of information to be input in a "transaction";• a library of user profiles to carry information on users' preferred styles of interaction;• a logical-screen handler to handle distribution of different types of output onto logical viewing surfaces;• a library of interaction techniques.Graphics support is provided by a standard device-independent graphics package, in our case the ACM/SIGGRAPH/GSPC Core System. We have called this environment the Abstract Interaction Handler (AIH).This paper provides an overview of our system model, and descriptions of the various components of the current implementation. A number of interesting open questions are raised; proposals for improvements to the system are offered.
In Memoriam Glenn T. Seaborg (1912-1999): Nuclear Pioneer, Educator, and Public Servant

In this section we present articles by leading scientific historians that chronicle the important events, persons, and publications that make up the rich history of chemical science. The history of chemistry, of course, has taken place against the background of world history, and the articles in this section often make that very clear. Chemists and their research are always influenced by current events. These articles are intended to describe the setting in which important discoveries occurred and to humanize their discoverers. —Clifford LeMaster, Editor in Chief
Emission of gaseous carbon dioxide from salt-marsh sediments and its relation to other carbon losses

Rates of CO2 emission from bare salt-marsh sediments in areas of short and tall formSpartina alterniflora were measured monthly for 1 yr. Maximum emission rates, as high as 325 ml CO2m−2h−1, were observed during summer months, while minimum rates, 10.2 ml CO2 m−2h−1, were observed during the winter. An exponential function of inverse soil temperature explained most of the seasonal variability, but other factors are involved in regulating CO2 emissions as demonstrated by rates that were higher in spring than in late summer at equivalent temperatures. Annual CO2 emissions from bare sediments were 27.3 and 18.6 mol C m−2 yr−1 in communities of short and tallS. alterniflora, respectively. It was estimated that losses of dissolved inorganic carbon from the turnover of pore water, up to 14.6 mol C m−2 yr−1 at the creek bank (tall,S. alterniflora) site, and diffusion of CO2 from the root system ofS. alterniflora through the culms, 12.3 to 16.2 mol C m−2 yr−1, could also be important pathways of carbon loss from marsh sediments. If the internal flux of CO2 from the root system through the culm is refixed within the leaves, then the observed rate of 9.8 μI CO2 min−1 cm−2 of culm cross sectional area appears to make a small but significant contribution to total photosynthesis.
STIMULATION OF ISOHEMOLYSINS AND ISOHEMAGGLUTININS BY INFLUENZA VIRUS PREPARATIONS.

Summary Subcutaneous injection of non-dialyzable preparations from commercial chicken egg-grown influenza virus vaccines, corresponding in amount to 3 or more protective doses, and from highly purified egg-grown influenza virus stimulate the production of powerful isoagglutinins with anti-A and cross-reacting anti-B specificity in the majority of humans. Potent isohemolysins are also produced. The relation of these antibodies to cytotoxic Forssman antibodies is considered. Resume L'injection sous-cutanee de preparations non-dialysables de vaccine commerciaux du virus de l'influenza cultive sur œufs de poulet, quantite correspondant a 3 doses protectives ou plus, et de vaccins du virus de l'influenza cultive sur œufs de poulet hautement purifies stimule la production de puissantes iso-agglutinines avec la specificite anti-A et la reactivite croisee anti-B chez la majorite des hommes. De puissantes iso-hemolysines sont egalement produites. Le rapport entre la presence de ces anticorps et les anticorps du type Forssman cytotoxiques est discute. Zusammenfassung Die subkutane Injektion nicht-dialysierbarer Praparationen kommerzieller, auf Huhnereiern gezuchteter Influenza-Virus-Vakzinen, entsprechend der Menge von 3 oder mehr Schutzdosen, sowie von gereinigtem, auf Huhnereiern gezuchtetem Influenza-Virus, bewirkt bei der Mehrzahl der Menschen die Bildung hochaktiver Anti-A- und kreuzreagierender Anti-B-Isoagglutinine. Im weiteren werden kraftige Isohamolysine gebildet. Die Beziehung dieser Antikurper zu den zytotoxischen Forssman-Antikurpern wird diskutiert.
Down-regulation of brain and spinal cord μ-opiate receptors in morphine tolerant-dependent rats

Abstract The effect of chronic administration of morphine and its withdrawal on the characteristics of μ-opiate receptors was determined in male Sprague-Dawley rats. The ligand used for characterizing the receptors was [ 3 H][D-Ala 2 , MePhe 4 ,Gly 5 -ol]enkephalin ([ 3 H]DAMGO). Rats were implanted s.c. under light ether anesthesia with six morphine pellets (each containing 75 mg of morphine free base). Rats serving as controls were implanted similarly with placebo pellets. Two sets of animals were used. In one group of rats, the pellets were left intact (tolerant-dependent) at the time of killing and in the other the pellets had been removed 18 h earlier (abstinent). The spinal cord and brain regions (amygdala, hippocampus, hypothalamus, corpus striatum, midbrain, pons and medulla, and cortex) were dissected. In morphine-abstinent rats, the binding of ligands of μ-opiate receptors to membranes of spinal cord and brain regions did not change. In non-abstinent morphine-tolerant-dependent rats, the binding of [ 3 H]DAMGO to membranes of spinal cord, pons and medulla, and cerebral cortex was found to be decreased. These changes were due to decreases in the B max values rather than K d values for the binding of [ 3 H]DAMGO. The results clearly indicate that morphine-induced tolerance-dependence in the rat is associated with changes in the selected brain regions and spinal cord with μ-opiate receptors being down-regulated in spinal cord, pons and medulla, and cerebral cortex. It is concluded that tolerance to morphine in the rats may be due to down-regulation of central μ-opiate receptors. However, μ-opiate receptors are unaffected in morphine abstinence.
A Default Pathway of Memory CD8 T Cell Differentiation after Dendritic Cell Immunization Is Deflected by Encounter with Inflammatory Cytokines during Antigen-Driven Proliferation

Inflammatory cytokines induced by infection or vaccination with adjuvant act directly or indirectly on CD8 T cells to modulate their expansion, contraction, and acquisition of memory characteristics. Importantly, the initial exposure of naive T cells to inflammatory cytokines may occur before, during, or after their interaction with stimulating dendritic cells (DC) and it is unknown whether and how the timing of cytokine exposure impacts the CD8 T cell response. In this study, we use an immunization strategy with peptide-coated mature DC that, in the absence of inflammatory cytokines, results in a transient effector phase followed by the accelerated acquisition of memory characteristics by the responding CD8 T cells. Induction of inflammatory cytokines by TLR agonists, at the time of DC immunization or 2-4 days after DC immunization, prevented the early acquisition of memory characteristics by the responding CD8 T cells. Interestingly, although induction of inflammatory cytokines at the time of DC immunization increased the effector response, induction of inflammatory cytokines after DC immunization did not promote further expansion of the responding CD8 T cells but still prevented their early acquisition of memory characteristics. In contrast, induction of inflammatory cytokines 2 days before DC immunization did not prevent the CD8 T cells from early acquisition of memory characteristics. Furthermore, TLR ligand-induced inflammatory cytokines had the most significant impact on the phenotype and function of proliferating CD8 T cells. These data suggest that a default pathway of memory CD8 T cell differentiation is deflected toward sustained effector commitment by encounter with inflammatory cytokines during Ag-driven proliferation.
Should Women Care Less? Intrinsic Motivation and Gender Inequality

Gendered values, norms and preferences shape the intrinsic motivation to provide care for others. This article situates an analysis of this motivation within the broader literature on gender inequality, explaining why it has costly consequences for women in both the home and the labour market, even as it provides considerable personal satisfaction and social benefit. Further movement towards gender equality may depend on the success of political and cultural efforts to ‘de‐gender’ normative obligations to care.
Best Practices: Are Financial Incentives and Best Practices Compatible?

thought. In a literature review, Cabana and colleagues (3) identified a number of potential barriers to bringing practice in line with evidencebased recommendations: lack of familiarity with or awareness of recommended practice, lack of belief in or agreement with best-practice guidelines, inconsistency between bestpractices recommendations and past training and current routines, and clinician-acknowledged inability to change their own behaviors.
Pre-Or Postsynaptic Blocking of Glutamatergic Functioning Prevents the Increase in Glucose Utilization Following Concussive Brain Injury

During the first few minutes following an experimental concussive brain injury in the rat, the cerebral cortex and underlying hippocampus are exposed to an increase in extracellular potassium (1). In addition to this ionic flux, these same regions exhibit an increase in glucose metabolism using [14C]2-deoxy-o-glucose (2DG) autoradiography(2). It has been proposed that any ionic flux due to an traumatic brain injury would result in a stimulation of glycolysis, presumably due to the energy demand of cells to activate ionic pumping mechanisms in their effort to restore ionic balance(3).
Pedagogical Approaches Used by Faculty in Holland's Model Environments: The Role of Environmental Consistency

This study examines the extent to which faculty members in the disparate academic environments of Holland's theory devote different amounts of time in their classes to alternative pedagogical approaches and whether such differences are comparable for those in “consistent” and “inconsistent” environments. The findings show wide variations in the use of alternative pedagogical approaches among faculty members in four of the academic environments of Holland's theory based on the level of consistency or inconsistency in the environmental profiles of these environments. The implications of these findings for future research using Holland's theory to understand longitudinal patterns of change and stability in the attitudes, interests, and abilities of college students as well as variability in the patterns of professional attitudes and behaviors of college faculty are discussed. Attention is also devoted to the policy development and practical implications of these findings for careers counselors and other coll...
Fractal analysis of proton exchange kinetics in lysozyme

Abstract Experimental data for the exchange of protons in tritiated lysozyme is reexamined by using a fractal model. The fraction of protons unexchanged, f, is seen to follow a stretched exponential, f infinity exp[(-t/tau)alpha], in the long time limit. Data over a range of temperatures are considered, and accurate fits are obtained with a single, unadjusted scaling exponent, alpha. The time constant, tau, follows an Arrhenius law and gives an activation energy comparable to that obtained for free peptide exchange. A model is proposed where proton exchange occurs as a result of solvent reacting with protein side groups in a restricted volume surrounding the protein. Dynamic fluctuations of the protein allow the protonated groups to enter this volume. Solvent also penetrates this volume, allowing proton exchange to occur. The fluctuations of reactants in this restricted volume dominate the kinetics and result in anomalous behavior. The topology of this reaction volume can be characterized by its fractal dimension. The fractal dimension of the space excluded by the protein is equal to 3-ds, where ds is the fractal dimension of the protein surface. The dimensionality of this "reaction space" can be used to predict the value of the exponent alpha. When the problem is treated as a reaction of the type A + B-->C in a confined region, the exponent is given by alpha = (3-ds)/4. By using the value of 2.17 previously established for the surface dimension of lysozyme [Pfeifer, P., Welz, U. & Wippermann, H. (1985) Chem. Phys. Lett. 113, 535-540], a corresponding alpha of 0.21 is calculated. Data for lysozyme at six different temperatures could be accurately fit by using this unadjusted value for alpha. These results show how the surface morphology of a protein influences diffusional processes of small molecules associating with the protein.
System Identification and Modeling Approach to Characterizing Rigidity in Parkinson's Disease: Neural and Non-Neural Contributions

Rigidity (muscle stiffness) is one of the most disabling symptoms in Parkinson's disease (PD). It is clinically defined as an increased resistance to passive movement of a joint. There is a fundamental gap between mechanistic and applied approaches to understanding this symptom. The objective of the current study was to apply a system identification and modeling approach to differentiating the contributions of neural (enhanced muscle reflex) and non-neural (altered mechanical properties of muscle fibers) factors to rigidity. Six patients participated in the study. The wrist joint torque and muscle activities of the wrist muscles were measured during externally induced movements. Each subject was tested in the Off- and On- medication states. System identification and modeling approach was applied to separate the neural from the non-neural component with respect to the overall stiffness. Results show that both factors are responsible for rigidity in PD. Neural-related reflex component is the predominant factor in overall rigidity. Medication therapy decreased the level of reflex component to overall rigidity.
Urothelial Cultures Support Intracellular Bacterial Community Formation by Uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) causes most community-acquired and nosocomial urinary tract infections (UTI). In a mouse model of UTI, UPEC invades superficial bladder cells and proliferates rapidly, forming biofilm-like structures called intracellular bacterial communities (IBCs). Using a gentamicin protection assay and fluorescence microscopy, we developed an in vitro model for studying UPEC proliferation within immortalized human urothelial cells. By pharmacologic manipulation of urothelial cells with the cholesterol-sequestering drug filipin, numbers of intracellular UPEC CFU increased 8 h and 24 h postinfection relative to untreated cultures. Enhanced UPEC intracellular proliferation required that the urothelial cells, but not the bacteria, be filipin treated prior to infection. However, neither UPEC frequency of invasion nor early intracellular trafficking events to a Lamp1-positive compartment were modulated by filipin. Upon inspection by fluorescence microscopy, cultures with enhanced UPEC intracellular proliferation exhibited large, dense bacterial aggregates within cells that resembled IBCs but were contained with Lamp1-positive vacuoles. While an isogenic fimH mutant was capable of forming these IBC-like structures, the mutant formed significantly fewer than wild-type UPEC. Similar to IBCs, expression of E. coli iron acquisition systems was upregulated by intracellular UPEC. Expression of other putative virulence factors, including hlyA, cnf1, fliC, kpsD, and the biofilm adhesin yfaL also increased, while expression of fimA decreased and that of flu did not change. These results indicate that UPEC differentially regulates virulence factors in the intracellular environment. Thus, immortalized urothelial cultures that recapitulate IBC formation in vitro represent a novel system for the molecular and biochemical characterization of the UPEC intracellular life cycle.
Biology as Politics: The Direct and Indirect Effects of Lewontin and Levins

Lewontin and Levins's contributions are viewed from four angles: a more vigorous culture of science criticism; a visible college of Marxist scientists in the USA; inquiries into the diverse social influences shaping science; and motivating readers who want to pursue their science as a political project. Indirect contributions—influences on and appropriations by other actors in the wider realm of biology as politics—are discussed as well as the more direct effects.
Hotspot Mitigation Using Dynamic Partial Reconfiguration for Improved Performance

As the chips get denser and faster, heat dissipation is fast turning into a major problem in development of ICs. Nonuniform heating of chips due to hotspots is also an area of concern and much research. In this paper, we propose an adaptive method which takes advantage of the self-reconfiguration capability of modern FPGAs to mitigate hotspots. We adapt the floor plan of the IC in response to the current use and ambient conditions on the fly. It is most applicable to paradigms such as Network on Chip (NoC) that allow separation of communication and computation and allow communication between modules to be abstracted away. We achieve a reduction of up to 8 ?C in the maximum temperature of a hotspot using typical power numbers. Alternatively, by increasing the frequency, we achieve a 2-3 times increase in throughput while maintaining the same maximum temperature.
The Efficacy of Text Messaging to Improve Social Connectedness and Team Attitude in Student Technical Communication Projects An Experimental Study

This experimental study investigates the impact of short-messaging service (SMS)—text messaging—on social connectedness and group attitude in student technical communication projects. It also inves...
Extraction of material parameters from a multilayer multi-harmonic thickness shear mode (MTSM) sensor data using genetic algorithm

A novel multi-resonant thickness shear mode (MTSM) sensor has been used to study multi-layer biological processes and to determine mechanical and geometrical properties of the layered structure by using a genetic algorithm for analyzing the sensor data. First, the genetic algorithm was tested theoretically. The Response of MTSM sensor loaded with a model biological system was simulated by using MTSM transmission line model (TLM) representation. Specifically, maximum amplitude and resonant frequency values at the fundamental and odd harmonics (up to 9th harmonic) were calculated. These values then were entered into the genetic algorithm (GA) to extract the properties of the model biological systems. The algorithm was tested with single and multiple layers and was able to provide mechanical and geometrical properties of each layer (up to three layers) with an error of less than 5 percent. Next, the GA algorithm was positively tested with experimental data obtained for multi-layer layer structure of Newtonian fluids. Preliminary results showed that genetic algorithm could accurately extract the properties of real biological layered media. The obtained results demonstrate that the proposed approach, which combines a MTSM sensor and genetic algorithm, could fill the gap in quantification and interpretation of measured multi-layer interfacial processes and provide a comprehensive experimental and modeling foundation, which could lead to the development of quantitative tool for the characterization of a broad range of biological interfacial processes.
Diffusion, Solute Segregations and Interfacial Energies in Some Material: An Overview

We have shown a connection among the three important properties of interfaces, namely, the free energy, diffusion and solute segregation through the conjecture that the interface free energy is the difference between those responsible for diffusion in the lattice and the interface itself. The interface energy is known to decrease upon solute additions. We discuss the methodology and the thermodynamical analysis of the diffusion parameters which enable extraction of the interfacial energies and illustrate them by results obtained in a wide variety of materials. Investigations carried out in pure polycrystalline metals have yielded grain boundary energies comparable to those directly measured. Furthermore, we discuss the role of solute segregation at grain boundaries in alloys in altering diffusion. From the perturbations caused, the solute segregation parameters—the enthalpy and the entropy of binding—have been extracted and levels of solute concentrations estimated. It is shown that similar analyses when applied to complex materials, e.g. the Pb–Sn eutectic alloy, several intermetallic compounds, and oxide systems, also result in acceptable values of interface energies and segregation factors. Finally, some ad-hoc guidelines are provided to alter diffusion in interfaces through solute additions in order to achieve some end use engineering objectives.
An observational study on the epidemiological and mycological profile of Candidemia in ICU patients.

Source of support: Departmental sources Summary Background: This study aimed to analyze the epidemiological and mycological profile of candidemia in inten sive care unit (ICU) patients attending a tertiary care teaching hospital in the Himalayan region of northern India. Material/Methods: A 15-bed medico-surgical ICU and a 5-bed pediatric ICU. Ninety-one consecutively admitted ICU patients were screened for the presence of candidemia by performing blood cultures at periodic intervals. Results: The recovered Candida isolates were speciated and subjected to antifungal susceptibility testing using standard procedures. Forty-one of the recruited patients (45%) were found to be candidemic, with the majority of patients being in the extremes of age (13 neonates and 15 >65 years of age). Four risk factors were found to be significantly associated with the occurrence of candi demia in our patients – a period of hospitalization exceeding 7 days (p=0.0008), previous use of antibiotics (p=0.001), presence of chronic renal failure (p=0.003), and ongoing cancer chemotherapy (p= 0.041). Ninety-six Candida isolates were recovered from the 41 culture-positive patients, with Candida albicans being the commonest isolate recovered (n=75, 78.1%), followed by Candida tropicalis (n=15, 16%), and Candida glabrata (n=6, 6.5%). Fluconazole resistance was observed among 26% of all Candida isolates and 17.3% of C. albicans isolates. Conclusions: Contrary to the majority of recent reports, species shift towards non-albicans candidemia has not been observed in our center, though the prevalence of azole resistance is alarmingly high even among the C. albicans isolates.
A population-based study examining the emergence of community-associated methicillin-resistant Staphylococcus aureus USA300 in New York City

Background Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a serious pathogen in several regions in the United States. It is unclear which populations are at high risk for the emergence of these strains.
EEL'S UNIQUE UREA TRANSPORTER EXPOSED

![Figure][1] Urea transporters are critical to the urinary concentrating mechanism in the mammalian kidney. While the kidney in teleost (bony) fish plays an important role in water balance and ion regulation, urea and other nitrogen wastes are mainly excreted across the gill. Gill urea
Structural investigation of CoMnGe combinatorial epitaxial thin films using microfocused synchrotron X-ray

We discuss important experimental considerations and high-throughput synchrotron-based techniques for structural characterization of binary and ternary composition-spread thin films. We apply these techniques to obtain detailed structural phase diagrams of CoMnGe ternary alloy system.
Partition of Blood Flow to the Cutaneous and Muscular Beds of the Forearm at Rest and during Leg Exercise in Normal Subjects and in Patients with Heart Failure

The purpose of this study was to determine the relative effects of various levels of exercise on blood flow to skin and muscle of the resting extremity of normal subjects and the manner in which this distribution is modified by congestive heart failure. Blood flow to the skin and muscle of the forearm was determined plethysmographically with the aid of epinephrine iontophoresis at rest and during supine leg exercise in 12 normal subjects and in 9 patients with failure. In normal resting subjects, forearm blood flow averaged 6.30 ml/min/100 ml, 52% partitioned to muscle and 48% to skin. In the patients, forearm blood flow averaged 2.94 ml/min/100 ml, with 48% to muscle and 52% to skin. In normal subjects performing mild exercise, forearm muscle flow was not significantly changed, but during moderate and strenuous activity it was significantly reduced. Cutaneous blood flow, however, declined early at all levels of exertion. In the normal subjects, cutaneous hyperemia occurred late during moderate exercise but with strenuous exercise, was delayed until after exercise had been discontinued. In contrast, in the patients, forearm muscle blood flow decreased strikingly during leg exercise, cutaneous flow fell and remained depressed during the entire period of exercise, and no postexercise hyperemia occurred. Thus, in congestive heart failure, both the cutaneous and muscle beds of the forearm are abnormally constricted at rest, there is excessive vasoconstriction in both beds during leg exercise, and postexercise cutaneous vasodilation is abolished.
Functional role of gamma and theta oscillations in episodic memory

The primary aim of this review is to examine evidence for a functional role of gamma and theta oscillations in human episodic memory. It is proposed here that gamma and theta oscillations allow for the transient interaction between cortical structures and the hippocampus for the encoding and retrieval of episodic memories as described by the hippocampal memory indexing theory (Teyler and DiScenna, 1986). Gamma rhythms can act in the cortex to bind perceptual features and in the hippocampus to bind the rich perceptual and contextual information from diverse brain regions into episodic representations. Theta oscillations act to temporally order these individual episodic memory representations. Through feedback projections from the hippocampus to the cortex these gamma and theta patterns could cause the reinstatement of the entire episodic memory representation in the cortex. In addition, theta oscillations could allow for top-down control from the frontal cortex to the hippocampus modulating the encoding and retrieval of episodic memories.
Evaluating a Crosslinguistic Grammar Resource: A Case Study of Wambaya

This paper evaluates the LinGO Grammar Matrix, a cross-linguistic resource for the development of precision broad coverage grammars, by applying it to the Australian language Wambaya. Despite large typological differences between Wambaya and the languages on which the development of the resource was based, the Grammar Matrix is found to provide a significant jump-start in the creation of the grammar for Wambaya: With less than 5.5 person-weeks of development, the Wambaya grammar was able to assign correct semantic representations to 76% of the sentences in a naturally occurring text. While the work on Wambaya identified some areas of refinement for the Grammar Matrix, 59% of the Matrix-provided types were invoked in the final Wambaya grammar, and only 4% of the Matrix-provided types required modification.
Modelling the impacts of the foliar pathogen, Phaeocryptopus gaeumannii, on Douglas-fir physiology: net canopy carbon assimilation, needle abscission and growth

Abstract This paper describes the parameterisation, testing and implementation of needle-level stomatal conductance ( g s ) and net CO 2 assimilation ( A net ) models that include the physiological impacts of the Douglas-fir pathogen, Phaeocryptopus gaeumannii . Hourly estimates of g s were modelled by assuming that stomata regulate water flux such that plant water potential is maintained above a critical threshold, and A net was modelled based on the kinetics of photochemistry. The model was tested using summer field measurements from trees at three western Oregon Douglas-fir ( Pseudotsuga menziesii ) plantations with varying levels of P. gaeumannii , and showed a high degree of accuracy: r 2 =0.777 and 0.792 for g s and A net , respectively. Instantaneous needle-level estimates of g s and A net were also scaled-up to a whole-canopy estimate for a 10-month period (July 1998–April 1999). At all three sites, a significant seasonality in A net was observed, with the highest rates occurring during the summer months (up to 400 g CO 2 m −2 LA) declining to near or below zero during the winter. The presence of P. gaeumannii had a significant impact on needle- and whole-canopy A net , and for the needle age classes where colonisation levels reached 25% pseudothecia density (i.e. percent of stomata with visible fruiting bodies), estimated total carbon budgets were negative. However, at the whole-canopy level all trees maintained a positive carbon budget due to the large contribution from current year needles that remain unaffected by the fungus for the first 6 months of development, or until the emergence of pseudothecia. Furthermore, the abscission of the older, more-heavily diseased foliage, shortly after becoming a carbon sink, has a significant mitigating effect on whole-canopy A net . For example, at the high-disease site, P. gaeumannii -associated reductions in A net per unit leaf were estimated to reduce whole-canopy A net by ca. 110% without needle abscission, but this was reduced to 85% when older, more-heavily diseased needles were abscised.
Kinetic modeling of the Saturn ring-ionosphere plasma environment

A time-independent kinetic plasma model was developed on the basis of the Li et al. (1988) semikinetic plasma model and was used to study the interaction of the Saturnian ionosphere and ring plasma. The model includes the gravitational magnetic mirror and centripetal and ambipolar electric forces, and the effect of the mixing of two plasma populations. The results obtained indicate that the density, temperature, and composition of plasma near the rings changing in the direction from the inner C ring to the outer A ring, due to the fact that the predominant source of plasma changes from the ionosphere to the rings. The model results also suggest that the outflow of hydrogen from the ionosphere to the rings may be shut off for field lines passing through the outer B and A ring, due to the ambipolar electric field set up by the warm ring plasma trapped near the ring plane by the centipetal force. In these regions, there will be a net flux of O(+) ions from the rings to the ionosphere.
Relay Operation During System Oscillations

Discussion of a paper by C. R. Mason published in the July 1937 issue, pages 823–32, and presented for oral discussion at the development of protective equipment session of the Pacific Coast convention, Spokane, Wash., Ausust 31,1937.