cssi/SciSciGPT-SciSciNet huggingface dataset:
Embryonic testicular regression sequence: A part of the clinical spectrum of 46, XY gonadal dysgenesis

We report on a group of 9 subjects who had a 46,XY karyotype, ambiguous genitalia, abnormalities of sexual duct formation, and lack of gonadal tissue on one or both sides. This is sometimes referred to as "embryonic testicular regression." Previous investigators have suggested that this condition results from loss of testes at a critical stage in development. We examined the possibility that the "embryonic testicular regression" is part of the clinical spectrum of 46,XY gonadal dysgenesis. Four subjects totally lacked gonadal tissue, three of them having ambiguous genitalia, and one a micropenis. The development of incongruous sexual ducts (presence of Mullerian ducts in the subject with micropenis, and absence of Mullerian and Wolffian ducts in two subjects with ambiguous genitalia) suggests that the embryonic gonads were intrinsically functionally abnormal before their disappearance. Five subjects had unilateral gonadal tissue, ambiguous genitalia, and a mix of Wolffian and Mullerian structures. The development of incongruous sexual ducts in 3 of them, the presence of ambiguous external genitalia in 5, and the presence of abnormal gonadal histology in 2 patients all indicate an underlying abnormality of gonadal differentiation in these subjects. The occurrence of testicular regression in several subjects in the family of one patient suggests a genetic basis for the condition. The presence of multiple congenital anomalies in other subjects in our study suggests either a mutation in a single gene that functions in several developmental pathways, or a defect of multiple genes that might be the result of a chromosome deletion.(ABSTRACT TRUNCATED AT 250 WORDS)
Changes in the activities of catalase, peroxidase, and polyphenol oxidase in apple buds during bud break induced by thidiazuron

The breaking of dormancy in apple buds (Malus domestica Borkh cv. York Imperial) by thidiazuron (N-phenyl-N′-1,2,3,-thidiazol-5-ylurea) was investigated in relation to catalase, peroxidase, and polyphenol oxidase activities and their isoenzyme patterns. The activity and number of isoenzymic components of catalase increased progressively during bud break, then decreased after buds started to grow. Peroxidase activity was highest during dormancy and declined during bud swell, increased at bud break, and decreased after bud expansion. Several isoperoxidases were observed in gel electrophoresis. Similar patterns were found at different growth stages of apple buds except for one peroxidase isoenzyme, P3, which disappeared 12 days after thidiazuron treatment. There was an inverse relationship between the activities of polyphenol oxidase and peroxidase during the development of apple buds. Apple buds have a very similar polyphenol oxidase isoenzyme pattern throughout bud development. However, the appearance and disappearance of minor isoenzymes were also observed. Phloridzin, rutin, p-coumaric, epicatechin, naringin, chlorogenic acid, and catechol were found in apple buds. Among them, phloridzin, rutin, and p-coumaric were the dominant phenolic compounds. Dormant buds contained a high amount of phenolic substances which decreased after bud break (4 days after thidiazuron treatment) then increased until the start of bud expansion. Phenolic compounds are found to be potent modifiers of catalase, peroxidase, and polyphenol oxidase activity, as both inhibitors and stimulators in apple buds.
Enhancement of tunneling due to resonances in pre-barrier wells in chemical reactions

Abstract I present a model to describe the effect of resonances in a chemical reaction due to van der Waals wells. The basic premise of the model is that quasibound states of such wells have enhanced tunneling through a reaction barrier due to the lifetime of these states, which leads to multiple “collisions” with the reaction barrier. A simple expression for this enhanced tunneling is presented and shown to qualitatively reproduce the enhanced tunneling that was reported recently for the O( 3 P) + HCl reaction [J. Chem. Phys. 116 (2002) 7461].
Interacting with music in a social setting

This paper describes the design of a new system for interacting with music in a social setting. MusiCocktail allows users to influence certain parameters of a pre-composed and pre-recorded piece of music in the way they mix their beverages at a social gathering. This new form of interaction with music enables group participation in the creation of a rich musical environment.
Aligned arrays of single-walled carbon nanotubes generated from random networks by orientationally selective laser ablation

This paper presents results on the selective ablation of individual single-walled carbon nanotubes by use of intense picosecond laser pulses. Linearly polarized pulses ablate only those tubes that are oriented substantially along the polarization direction. When applied to random submonolayer networks of tubes on solid supports, this procedure can produce collections of aligned tubes oriented perpendicular to the polarization direction. Detailed examples highlight essential aspects of the approach and some features of the underlying physics that governs the process. Thin film transistors that use networks of tubes that have been laser processed in this manner show extremely high orientational anisotropy in the effective mobility. The results could be important for transistors that have potential applications as sensors or logic elements in macroelectronic systems or for optical elements with highly anisotropic properties.
Crystal growth and below-bandgap optical absorption studies in InAs for non-linear optic applications

Abstract Indium arsenide (InAs) is a direct bandgap semiconductor ( E g =0.36 eV) and is well suited for non-linear optic (NLO) applications. The NLO applications require high linear optical transmission for below-bandgap energy photons in the material. Due to this stringent criterion, there is a need for understanding the fundamental optical absorption mechanisms in the material as well as correlating them with the presence of native defects and impurities introduced during the crystal growth. In this paper, we will present the experimentally measured and theoretically analyzed infrared absorption in an undoped and Te-doped n-type InAs in the wavelength region of 4–20 μm for horizontal Bridgman grown crystals. Transmission measurements at 300 K were performed on samples of undoped and Te-doped n-type InAs with carrier concentration in the range of 2.6×10 16 –1.7×10 17 cm −3 . The dependences of various absorption mechanisms as a function of wavelength have been presented. Free carrier absorption by electrons is found to be the dominant absorption mechanism at longer wavelengths ( λ >9 μm) for all the samples. At shorter wavelengths ( λ n i =1×10 15 cm −3 ), the inter-valence band transitions by free holes contributes significantly to the total absorption. Unique fitting parameters have been deduced to theoretically explain the infrared absorption mechanism in InAs for the above-mentioned carrier concentration range.
Doubly and triply charged ion production in O+—Si surface scattering

Abstract Significant fractions of the scattered and recoil ions from single collisions of keV O + ions with near surface atoms of amorphous silicon are found to be doubly and triply charged. Definite threshold energies are found for each multicharged ion, suggesting that they are produced in close binary collisions with individual surface atoms and that inner shell vacancies are produced by molecular orbital promotion. Characteristic velocities for the decay of O + , O 2+ , Si + , Si 2+ , and Si 3+ in passing out through the surface are reported.
Noninfectious cerebral vasculitis in children

Abstract The vasculitides are a heterogeneous group of disorders. Vasculitides secondary to infectious diseases are more common than those attributable to noninfectious causes, especially in developing countries. Cerebral vasculitides might be a primary disorder or complicate a systemic disease. We review the clinical presentation, pathology, and treatment of noninfectious vasculitides in children. Henoch-Schonlein purpura and Kawasaki disease are two of the most common vasculitic disorders in children. Noninfectious cerebral vasculitis is a rare cause of stroke in childhood. Mimics of vasculitis (look-alikes) should be considered whenever cerebral vasculitis is suspected.
Women producers of ethnic arts

Abstract Gender dynamics of indigenous ethnic arts production cannot be explained by development theories which predict that either women producers are empowered by economic gain, or exploited by the patriarchal drive of global capitalism epitomized by international tourism. Comparative data on commoditization of ethnicity by indigenous groups indicate that internal (family/community) factors enable women's empowerment, while external (market/state) factors in a stratified gender/class/ ethnicity order limit role options for indigenous women and men to the “same old stuff./rd Whether in homeland or refugee status, the common issue of cultural survival shapes the gender dynamics of “Fourth World” arts production.
Outcome study of stereopsis in relation to duration of misalignment in congenital esotropia.

Abstract Purpose: A recent outcome study of Randot stereopsis in congenital esotropia reported early surgical alignment is associated with a higher percentage of patients with stereopsis and a higher quality of stereopsis because early surgery minimized the duration of misalignment. We compared the Titmus stereopsis with the duration of misalignment and the age of alignment for a group of patients who were surgically aligned by 24 months of age. Methods: The data previously obtained in a study of 90 patients aligned by 2 years of age, examined in a masked, independent evaluation for binocularity was analyzed. The age of alignment and duration of misalignment was correlated with the percentage of patients with stereopsis and quality of the stereopsis result as determined by the Titmus vectograph overlay. Results: Patients aligned by 6 or 12 months of age or within 6 or 12 months of duration of misalignment did not differ in percentage with stereopsis. However, patients aligned after 12 months of age did show a decrease percentage with stereopsis ( P P > .05, power 0.8). The quality of stereopsis, however, was decreased for patients with duration of misalignment greater than 12 months ( P Conclusion: Alignment within 1 year of age or within 12 months of misalignment favorably affects the percentage of patients who develop stereopsis in the treatment of congenital esotropia. The quality of the stereopsis result is affected by the duration of the misalignment, rather, than the age of alignment per se. (J AAPOS 2002;6:3-8)
Comparison of high-energy photon and electron dosimetry for various dosimetry protocols

The American Association of Physicists in Medicine Task Group 51 (TG-51) and the International Atomic Energy Agency (IAEA) published a new high-energy photon and electron dosimetry protocol, in 1999 and 2000, respectively. These protocols are based on the use of an ion chamber having an absorbed-dose to water calibration factor with a 60Co beam. These are different from the predecessors, the TG-21 and IAEA TRS-277 protocols, which require a 60Co exposure or air-kerma calibration factor. The purpose of this work is to present the dose comparison between various dosimetry protocols and the AAPM TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams. The absorbed-dose to water calculated according to the Japanese Association of Radiological Physics (JARP), International Atomic Energy Agency Technical Report Series No. 277 (IAEA TRS-277) and No. 398 (IAEA TRS-398) protocols is compared to that calculated using the TG-51 protocol. For various Farmer-type chambers in photon beams, TG-51 is found to predict 0.6-2.1% higher dose than JARP. Similarly, TG-51 is found to be higher by 0.7-1.7% than TRS-277. For electron beams TG-51 is higher than JARP by 1.5-3.8% and TRS-277 by 0.2-1.9%. The reasons for these differences are presented in terms of the cavity-gas calibration factor, Ngas, and a dose conversion factor, Fw, which converts the absorbed-dose to air in the chamber to the absorbed-dose to water. The ratio of cavity-gas calibration factors based on absorbed-dose to water calibration factors, N60Co(D,w), in TG-51 and cavity-gas calibration factors which are equivalent to absorbed-dose to air chamber factors, N(D,air), based on the IAEA TRS-381 protocol is 1.008 on average. However, the estimated uncertainty of the ratio between the two cavity-gas calibration factors is 0.9% (1 s.d.) and consequently, the observed difference of 0.8% is not significant. The absorbed-dose to water and exposure or air-kerma calibration factors are based on standards traceable to the National Institute of Standards and Technology (NIST). In contrast, the absorbed-dose to water determined with TRS-398 is in good agreement with TG-51 within about 0.5% for photon and electron beams.
Job Socialization: The Carry-Over Effects of Work on Political and Leisure Activities.

A model of job socialization based on the joint effect of decision latitude and psychological demands are developed to predict how behaviors learned on the job would carry over to leisure and political activities out-side of work. The model is tested with a longitudinal national random sample of the Swedish male work force (1:1,000) in 1968 and 1974 (nlongitudinal = 1,508), including both expert and self-reports job data and 92% (1968) and 85% (1968-1974) response rates. Workers with more “active” jobs (high decision latitude and high demands) become more “active” in their political and leisure activity from 1968 to 1974 (p < .001). Cross-sectional analyses and work experience cohort results (1968) are consistent. Associations are unaffected by control for education and father’s education, limiting an alternative explanation via personal background. The content of work may substantially affect political behavior, culture, and the economic equilibrium of service-oriented societies.
PKC-δ inhibits anchorage-dependent and -independent growth, enhances differentiation, and increases apoptosis in CaCo-2 cells

Abstract Background & Aims: Previous studies showed decreased protein kinase C (PKC)-δ expression in azoxymethane-induced rat and sporadic human colonic tumors. To elucidate the role of PKC-δ on the neoplastic phenotype of human colon cancer cells, we established stable transfectants of this isoenzyme in CaCo-2 cells. Methods: Human PKC-δ complementary DNA was subcloned into 2 distinct metallothionein-regulated expression vectors. Polyclonal populations of PKC-δ transfectants were characterized by Western blotting. PKC-δ activity was measured in situ using a PKC-δ–specific substrate. Proliferation was determined by Coulter counter, and cell cycle distribution was analyzed by flow cytometry. In vitro transformation was assessed by growth in soft agar and differentiation by changes in alkaline phosphatase and sucrase isomaltase. Apoptosis was evaluated by 4',6-diamidino-2-phenylindole dihydrochloride and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining. Results: In the presence of Zn 2+ , PKC-δ transfectants expressed a 4-fold increase in the protein and a 2-fold increase in activity of PKC-δ. PKC-δ transfectants exhibited a 30% decrease ( P P P Conclusions: Our studies show that increased expression of PKC-δ inhibits anchorage-dependent and -independent growth, while inducing cellular differentiation and limiting survival of this human colon cancer cell line. GASTROENTEROLOGY 2001;120:1700-1712
On the reduction of α-aminonitriles with sodium

Abstract The reduction of α-aminonitriles with sodium proceeds via an α-aminoradical, which can be engaged in intramolecular cyclization. Reduction does not involve prior dissociation of cyanide to form an iminium species.
Combined effects of allelochemical-fed and scarce prey on the generalist insect predator Podisus maculiventris

1. The simultaneous effects of allelochemicals ingested by herbivorous insect prey and prey scarcity on the performance of a generalist insect predator were examined. 2. Fifth-instar predatory stinkbugs (Podisusmaculiventris: Pentatomidae) were fed caterpillars (Manducasexta: Sphingidae) in three prey scarcity treatments: every day (unlimited amount), one caterpillar every third day, one caterpillar every fifth day. The caterpillars were fed either a plain diet or a diet containing rutin, chlorogenic acid and tomatine, which are three of the major allelochemicals in tomato leaves (Lycopersiconesculentum: Solanaceae), the preferred food of these caterpillars. 3. Food consumed, efficiency of conversion of ingested food to biomass (ECI), biomass gained, stadium duration and relative growth rate (RGR) of predators were negatively affected by prey scarcity. The allelochemicals negatively affected food consumed and ECI. 4. There were prey scarcity by allelochemical interactions for ECI, biomass gained and RGR. For ECI, the allelochemicals had a greater negative impact on the predatory stinkbugs when prey were scarce. When prey diet contained allelochemicals, biomass gained and RGR declined more steeply with increased prey scarcity. There was an allelochemical by predator gender interaction for biomass gained. Allelochemicals had no effect on biomass gained by female stinkbugs, whereas biomass gained declined more steeply with increased prey scarcity for male stinkbugs fed caterpillars containing allelochemicals than for males fed control caterpillars.
Asymmetric synthesis via chiral acetal templates. 8. Reactions with organometallic reagents

Abstract The titanium tetrachloride catalyzed coupling of organometallic reagents with chiral acetals 1 is shown to provide a convenient route for the preparation of a variety of chiral alcohols 4 of high optical purity.
Mild Two-Step Method to Construct DNA-Conjugated Silicon Nanoparticles: Scaffolds for the Detection of MicroRNA-21

We describe a novel two-step method, starting from bulk silicon wafers, to construct DNA conjugated silicon nanoparticles (SiNPs). This method first utilizes reactive high-energy ball milling (RHEBM) to obtain alkene grafted SiNPs. The alkene moieties are subsequently reacted with commercially available thiol-functionalized DNA via thiol–ene click chemistry to produce SiNP DNA conjugates wherein the DNA is attached through a covalent thioether bond. Further, to show the utility of this synthetic strategy, we illustrate how these SiNP ODN conjugates can detect cancer-associated miR-21 via a fluorescence ON strategy. Given that an array of biological molecules can be prepared with thiol termini and that SiNPs are biocompatible and biodegradable, we envision that this synthetic protocol will find utility in salient SiNP systems for potential therapeutic and diagnostic applications.
Plasma enhanced machining of Inconel 718: modeling of workpiece temperature with plasma heating and experimental results

A numerical and experimental analysis of plasma enhanced machining (PEM) of Inconel 718 is presented in this paper. Surface temperatures due to plasma heating are systematically characterized through numerical modeling and experimental investigation using infrared radiation thermometry. A three-dimensional finite difference model is established to determine the temperature distribution in a cylindrical workpiece subjected to intense localized heating. The results are compared with experimental results obtained with a radiation pyrometer. A sensitivity analysis is presented to examine the effects of machining parameters on the temperature distribution. Benefits of PEM are also demonstrated through the reduction of cutting forces and improved surface roughness over a wide range of cutting conditions. In addition, improvement of productivity in machining Inconel with PEM is illustrated.
Recurring Local Sequence Motifs in Proteins

We describe a completely automated approach to identifying local sequence motifs that transcend protein family boundaries. Cluster analysis is used to identify recurring patterns of variation at single positions and in short segments of contiguous positions in multiple sequence alignments for a non-redundant set of protein families. Parallel experiments on simulated data sets constructed with the overall residue frequencies of proteins but not the inter-residue correlations show that naturally occurring protein sequences are significantly more clustered than the corresponding random sequences for window lengths ranging from one to 13 contiguous positions. The patterns of variation at single positions are not in general surprising: chemically similar amino acids tend to be grouped together. More interesting patterns emerge as the window length increases. The patterns of variation for longer window lengths are in part recognizable patterns of hydrophobic and hydrophilic residues, and in part less obvious combinations. A particularly interesting class of patterns features highly conserved glycine residues. The patterns provide a means to abstract the information contained in multiple sequence alignments and may be useful for comparison of distantly related sequences or sequence families and for protein structure prediction.
Rotor Dynamic Synchronous Response: A More Thorough Treatment

Synchronous response can be a very valuable tool for rotor dynamic analysis. It allows the user to determine rotor displacements over a wide speed range without having to perform a transient analysis at every speed increment. The method is typically used to calculate steady state displacements caused by a rotating imbalance force and the location of critical speeds. While the algorithm presented to perform linear synchronous response is straight forward, there are several modifications that can be made to provide the analyst more useful information.Copyright © 1993 by ASME
Toward exploring the location-scale condition: a constant relative risk aversion location-scale objective function

A constant relative risk aversion (CRRA) location-scale function is derived, analysed, and demonstrated for modelling choice under uncertainty. The function contributes to further exploration of the location-scale condition in agricultural economics risk research. Such analysis has been infrequent in recent research because the well-known linear mean-variance function implicitly assumes constant absolute risk aversion (CARA). Examples demonstrate that the CARA meanvariance function produces substantially different results than the CRRA locationscale function. Further, the CRRA location-scale function produces results similar to direct expected utility maximisation with a CRRA utility function and normally distributed returns.
Analysis of crime control strategies

Abstract An important problem in the selection of crime control programs is the choice among broad crime control strategies. This paper presents a Markov approach to the study of one important aspect of the analysis of crime control strategies—the characterization of the criminal population. Results indicate that persons with previous arrest records may commit a somewhat smaller proportion of the common crimes of robbery, burglary, larceny over $50, and assault than is indicated by rearrest data.
Accumulation of Tc-99m phosphonate complexes in metastatic lesions from colon and lung carcinomas

Cases are presented in which Tc-99m methylene diphosphonate accumulated in a lung metastasis from well differentiated adenocarcinoma of the colon, and in a hepatic metastasis from oat cell carcinoma of the lung. To our knowledge, this is the first report of Tc-99m phosphonate complexes concentrated in a pulmonary metastasis of colonic carcinoma or in a hepatic metastasis of oat cell lung carcinoma. The exact mechanism for this non-osseous uptake of bone scanning agents is still unknown.
Characterization of irradiated nuclear fuels by precision gamma scanning

Abstract Gamma scanning is an important nondestructive technique for the characterization of irradiated fuel materials. Techniques and equipment for gross — gamma, isotopic, and two-dimensional scans are discussed. Applications to the determination of mechanical and structural information, neutron flux and burnup profiles, irradiation and cooling information, fission product migration data, and fuel pin failures are discussed.
K+ conduction description from the low frequency impedance and admittance of squid axon.

The form of power spectra of K+ conduction fluctuations in patches of squid axon suggested that K+ conduction kinetics are higher than first order (Fishman, Moore & Poussart, 1975,J. Membrane Biol.24:305). To obtain an alternative description of ion conduction kinetics consistent with spontaneous fluctuations, the complex impedance and admittance of squid (Loligo pealei) axon were measured at low frequencies (1–1000 Hz) with a four electrode system using white Gaussian noise as a stochastic perturbation. As predicted from the spontaneous noise measurements, a low frequency impedance feature is observed between 1 and 30 Hz which is voltage and temperature dependent, disappears after substantial reduction in [K i + ], and is unaffected by the state of Na+ conduction or active transport. These measurements confirm and constitute strong support for the patch noise measurements and interpretations. The linearized Hodgkin-Huxley (HH) equations do not produce the low frequency feature since first order ion conduction kinetics are assumed. Computation of diffusion polarization effects associated with the axon sheath gives a qualitative account of the low frequency feature, but the potential dependence is opposite to that of the data. Thus, K+ conduction kinetics in the axon are not adequately described by a single first order process. In addition, significant changes inHH parameter values were required to describe the usual impedance (resonance) feature inLoligo pealei axon data.
Measuring vertical vorticity in the sea

Abstract Several attempts were made to observe the vertical vorticity in the sea with a neutral buoyant float fitted with either vertical vanes or radial rods. Measurements over periods of several days were made in deep water off the New England coast, in the Gulf Stream, and southwest of Bermuda. The apparent vorticity at all locations from the float rotation, appears to fluctuate with a magnitude of several revolutions per hour in both a cyclonic and anticyclonic sense.
Small time scale fatigue crack growth analysis

A new fatigue crack growth formulation at the small time scale is proposed in this paper. This method is fundamentally different from the classical reversal-based fatigue analysis and is based on the incremental crack growth at any time instant within a cycle. It can be used for fatigue analysis at various time and length scales and is very convenient for the fatigue analysis under random variable-amplitude loadings without cycle-counting. Stress ratio effect is intrinsically considered in the proposed fatigue model since the stress state is directly used instead of using the cyclic stress range. In the proposed methodology, the reverse plastic zone concept is adopted to determine the lower integration limit during the time integral for crack length calculation. Model validation is performed using extensive experimental observations for various metallic materials under both constant amplitude and variable-amplitude loadings. Statistical error analysis is used to compare the proposed model with existing fatigue crack growth codes. Generally, very good correlations are observed between model predictions and experimental observations.
C114 Is a Novel IL-11-inducible Nuclear Double-stranded RNA-binding Protein That Inhibits Protein Kinase R

We have identified a cDNA (named C114) that encodes novel transcripts induced by IL-11 in mouse 3T3 L1 cells. Northern analysis of RNAs from multiple mouse tissues detects two C114 transcripts of ∼1.0 and ∼2.0 kb with the highest expression in liver, testis, brain, and kidney. The C114 cDNA contains an open reading frame of 187 amino acids with a predicted mass of 21 kDa. Three putative nuclear localization signals are predicted at amino acids 83–88, 126–131, and 167–178. Using green fluorescent protein (GFP)-C114 fusion plasmids, amino acids 126–131 are shown to be essential for the nuclear localization of C114. An arginine-rich region (amino acids 98–143) spanning the nuclear localization signals (amino acids 126–131) exhibits a double-stranded RNA (dsRNA) binding activity. Competition experiments with different RNA homopolymers demonstrate that C114 preferentially binds to poly(I·C). Similar to other dsRNA-binding proteins, C114 binds to the dsRNA-activated protein kinase, protein kinase R (PKR), via dsRNA-binding domains of PKR and the N-terminal region of the C114 protein. In vitro kinase assays indicate that C114 inhibits PKR activation via a dsRNA-independent mechanism. Overexpression of C114 protein inhibits the induction of eIF-2α phosphorylation following poly(I·C) treatment. This is the first demonstration of a novel PKR modulator induced by a gp130 superfamily cytokine that may play a role in cytokine-mediated biological functions.
Student socialization in the age of facebook

Most research regarding online social networks such as Facebook, MySpace, Linked-In and Friendster has looked at these networks in terms of activity within the online network, such as profile management and friending behavior. In this paper we are instead focusing on offline socializing structures around an online social network (exemplified by Facebook) and how this can facilitate in-person social life for students. Because students lead nomadic lives, they find Facebook a particularly useful tool for initiating and managing social gatherings, and as they adopt mobile technologies that can access online social networks, their ad-hoc social life is further enabled. We conclude that online social networks are a powerful tool for encouraging peripheral friendships, important in particular to students. We emphasize that the use of online social networks must be viewed from a perspective of use that involves both mobile and stationary platforms and that it is important to relate online and offline social practices.
NONVANISHING OF THE RAMANUJAN TAU FUNCTION IN SHORT INTERVALS

We provide new estimates for the gap function of the Delta function and for the number of nonzero values of the Ramanujan tau function in short intervals.
Feedback interactions between zinc and phytoplankton in seawater

In Zn ion-buffered media, oceanic species (Thalassiosira oceanica and Emiliania hu.xZeyi) grew at near-maximal rates at the lowest free Zn ion concentration ((Zn2+) = lo- 12,3 M), whereas coastal species (Thalassiosira pseudonana and Thalassiosira weissflogii) were limited at (Zn2+) < lo-" M. The ability of the oceanic species to outgrow coastal ones at low (Zn2+) was due almost entirely to a reduced growth requirement for cellular Zn rather than to an increased capability for uptake. All isolates exhibited similar sigmoidal relationships between cellular Zn: C ratios and (Zn2+) with minimal slopes at (Zn2+) of lO-'o.5 to - 1 O-9.5 M and increasing slopes above and below this range. The minimal slopes at intermediate (Zr?+) could be explained by negative feedback regulation of a high-affinity Zn uptake system, while increased slopes at high (Zn2+) appeared to be related to uptake by a low-affinity site. Measured relationships between cellular Zn : C ratios and (Zn'+) agreed well with those computed from a modified Redfield model based on depth profiles for Zn and PO, concentrations and Zn chelation in the nutricline of the North Pacific. This agreement provides evidence that Zn concentrations in the nutricline are controlled by biological uptake and regen- eration as occurs for major nutrients.
Attenuation of a virulent Aeromonas hydrophila with novobiocin and pathogenic characterization of the novobiocin-resistant strain.

Aim To determine whether novobiocin resistance strategy could be used to attenuate a virulent Aeromonas hydrophila AH11P strain and to characterize the growth and pathogenic differences between the novobiocin-resistant strain and its virulent parent strain AH11P. Methods and Results A novobiocin-resistant strain AH11NOVO was obtained from a virulent Aer. hydrophila strain AH11P through selection of resistance to novobiocin. AH11NOVO was found to be avirulent to channel catfish (Ictalurus punctatus), whereas AH11P was virulent. When AH11NOVO vaccinated channel catfish were challenged with AH11P at 14 days postvaccination, relative per cent of survival of vaccinated fish was 100%. The cell proliferation rate of AH11NOVO was found to be significantly (P < 0·05) less than that of AH11P. In vitro motility assay revealed that AH11NOVO was nonmotile, whereas AH11P was motile. AH11NOVO had significantly (P < 0·05) lower in vitro chemotactic response to catfish mucus than that of AH11P. Although the ability of AH11NOVO to attach catfish gill cells was similar to that of AH11P, the ability of AH11NOVO to invade catfish gill cells was significantly (P < 0·05) lower than that of AH11P. Conclusions The novobiocin-resistant AH11NOVO is attenuated and different from its parent AH11P in pathogenicity. Significance and Impact of the Study The significantly lower chemotactic response and invasion ability of AH11NOVO compared with that of its virulent parent strain AH11P might shed light on the pathogenesis of Aer. hydrophila.
SEASONAL PATTERNS AND PLANT‐MEDIATED CONTROLS OF SUBSURFACE WETLAND BIOGEOCHEMISTRY

In tidal marshes, spatial and temporal variability in the importance of mi- crobial metabolic pathways influences ecosystem-level processes such as soil carbon stor- age, the regeneration of inorganic nutrients, and the production of atmospherically important trace gases. We measured seasonal changes in rates of microbial Fe(III) reduction, sulfate reduction, and methanogenesis in tidal freshwater and brackish marshes on the Patuxent River, Maryland, USA, and assessed the ability of plant roots to influence these processes by regenerating electron acceptors and supplying electron donors. In both marshes, the importance of microbial Fe(III) reduction was greatest early in the summer and decreased through the study period. Coincident with the seasonal decline in Fe(III) reduction, me- thanogenesis (freshwater marsh) or sulfate reduction (brackish site) increased in importance. At the brackish marsh, the partitioning of anaerobic carbon metabolism between Fe(III) reduction and sulfate reduction was similar within and below the root zone, suggesting that rhizosphere processes did not control anaerobic metabolism at this site. Instead, seasonal biogeochemical patterns at the brackish marsh were affected by factors such as water table depth and iron-sulfur interactions. At the tidal freshwater site, our results suggest that changes in rates of Fe(III) reduction and methanogenesis were directly affected by plant- mediated processes. In midsummer, Fe(III) reduction accounted for a greater fraction of total anaerobic metabolism in rhizosphere-influenced surface soils than in soils below the root zone. High rates of Fe(III) reduction occurred at the expense of methanogenesis. This study documented strong temporal variations in the outcome of microbial competition for electron donors that ultimately affected the balance between Fe(III) reduction and me- thanogenesis within tidal freshwater marsh soils. Our data suggested that variations in microbial metabolic pathways were regulated by physiochemical factors at the brackish site and plant activity at the freshwater site. Plant regulation of Fe(III) reduction is a largely unstudied mechanism by which plants influence wetland carbon cycling and greenhouse gas production.
CPAP treatment for obstructive sleep apnoea in heart failure: expectations unmet.

Heart failure (HF) is an epidemic, increasing in prevalence as the population ages. The Rotterdam Study shows that persons who live to age 55 have a one in three chance of eventually developing HF.1 The staggering prevalence estimate of more than five million currently living with HF in the United States may underestimate the overall problem, since population-based studies find that a substantial proportion of those with systolic dysfunction are asymptomatic, although still at increased mortality risk.2,3 Despite advances in treatment with drugs, lifestyle modifications, and therapeutic devices, mortality from HF continues to rise, fuelling interest in alternative methods of treatment. One such target of therapy has been obstructive sleep apnoea (OSA). HF and OSA are closely linked by their strong associations with ageing and obesity, and frequently co-exist, with the prevalence of OSA approaching 40% in HF patients referred to a clinical sleep laboratory.4 This relationship may extend beyond that of simple co-morbidity, as mounting data suggest that the cascade of physiological responses to repetitive upper airway closure in OSA may exert deleterious effects on cardiac function, particularly in the already compromised heart. These acute, repetitive stressors include, among others, hypoxemia,5 surges in sympathetic neural output,6 inflammation,7,8 and swings in intrathoracic pressure with respiratory efforts against a collapsed upper airway.9 These effects may conceivably be summative over time, and contribute to the development of myocardial dysfunction. Recent data provide further evidence linking OSA to HF. The Framingham study showed that increasing body mass index (BMI) is directly correlated with incident HF,10 an effect which could potentially be mediated at least in part by … *Corresponding author. Tel: +1 507 255 1144; fax: +1 507 255 7070. E-mail address : somers.virend{at}mayo.edu
Antimolding Agents for Syrups

The antimolding effects of more than two hundred substances were determined using mycophil agar inoculated with microorganisms from deteriorated syrup. Many of these substances were found to equal or exceed the effectiveness of benzoic acid and esters ofp-hydroxybenzoic acid. Certain flavoring and perfumery materials were found to possess antimolding proerties. In comparison with benzoic acid which was effective at a concentration < 1:1, 000, cinnamic aldehyde was effective at 1:10, 000, and oxyquinoline sulfate was effective at 1:100, 000.
THZ radiation source based on two-stream instability

THz radiation straddles microwave and infrared bands (50 GHz – 10 THz), thus combining the penetrating power of lower-frequency waves and imaging capabilities of higher-energy infrared radiation. Since THz radiation is not absorbed by most dry, non-polar materials, it can be used for imaging internal structures. Besides its military uses, THz radiation is employed in such important applications as spectroscopy, industrial bio-medical imaging, and scattering. What also makes THz radiation attractive is its non-ionizing photon energy, which is less than 0.1 eV at 1 THz. Several conventional devices are used presently to generate THz radiation. For example, slow-wave devices require very small structures (mm or sub-mm) in size. This complicates fabrication and alignment and results in merely milliwatts of average output power. Conventional FELs and synchrotrons are bulky and very expensive to operate.
Sorcin modulation of Ca2+ sparks in rat vascular smooth muscle cells

Spontaneous, local Ca2+ release events or Ca2+ sparks by ryanodine receptors (RyRs) are important determinants of vascular tone and arteriolar resistance, but the mechanisms that modulate their properties in smooth muscle are poorly understood. Sorcin, a Ca2+-binding protein that associates with cardiac RyRs and quickly stops Ca2+ release in the heart, provides a potential mechanism to modulate Ca2+ sparks in vascular smooth muscle, but little is known about the functional role of sorcin in this tissue. In this work, we characterized the expression and intracellular location of sorcin in aorta and cerebral artery and gained mechanistic insights into its functional role as a modulator of Ca2+ sparks. Sorcin is present in endothelial and smooth muscle cells, as assessed by immunocytochemical and Western blot analyses. Smooth muscle sorcin translocates from cytosolic to membranous compartments in a Ca2+-dependent manner and associates with RyRs, as shown by coimmunoprecipitation and immunostaining experiments. Ca2+ sparks recorded in saponin-permeabilized vascular myocytes have increased frequency, duration and spatial spread but reduced amplitude with respect to Ca2+ sparks in intact cells, suggesting that permeabilization disrupts the normal organization of RyRs and releases diffusible substances that control Ca2+ spark properties. Perfusion of 2 μm sorcin onto permeabilized myocytes reduced the amplitude, duration and spatial spread of Ca2+ sparks, demonstrating that sorcin effectively regulates Ca2+ signalling in vascular smooth muscle. Together with a dense distribution in the perimeter of the cell along a pool of RyRs, these properties make sorcin a viable candidate to modulate vascular tone in smooth muscle.
Studies on the structure and function of muscle aldolase. IV. The action of dilute alkali on primary structure and its effect on the determination of subunit molecular weight.

Abstract In 0.05 m potassium phosphate buffer (pH 7.0, 20°), native rabbit muscle aldolase has been found to exhibit a molecular weight (Mn ∼ Mw ∼ Mz) close to 160,000, in agreement with previous findings. Upon exposure to cold alkaline borate buffer (pH 12.5, µ = 0.17, 0°), the enzyme spontaneously dissociates into its monomers which subsequently undergo slow hydrolytic degradation. Compensating for electrostatic charge effects and extrapolating the data to zero time in alkali, a subunit molecular weight of 41,400 to 42,000 is obtained. If the native enzyme is exposed to alkaline conditions at 20°, the subunits undergo an initial rapid degradation which eventually yields alkali-resistant material. Similar results are obtained with succinyl aldolase subunits under equivalent conditions. Acrylamide gel electrophoresis of alkali-treated succinyl aldolase (pH 12.5, 30°) results in the appearance of a limited number of electrophoretic bands. This finding suggests that specific alkali-labile peptide bonds are involved in the degradation process. As a further consequence of the action of alkali, native aldolase shows increased solubility properties. Both native and succinyl aldolase manifest new NH2-terminal serine, threonine, and glycine residues after treatment with borate buffer at pH 12.5 and 30°. Prolonged exposure to alkali results in increased liberation of the above end groups, but no evidence is obtained for other NH2-terminal residues except for a small amount of proline.
Alleviating cancer drug toxicity by inhibiting a bacterial enzyme

The dose-limiting side effect of the common colon cancer chemotherapeutic CPT-11 is severe diarrhea caused by symbiotic bacterial β-glucuronidases that reactivate the drug in the gut. We sought to target these enzymes without killing the commensal bacteria essential for human health. Potent bacterial β-glucuronidase inhibitors were identified by high-throughput screening and shown to have no effect on the orthologous mammalian enzyme. Crystal structures established that selectivity was based on a loop unique to bacterial β-glucuronidases. Inhibitors were highly effective against the enzyme target in living aerobic and anaerobic bacteria, but did not kill the bacteria or harm mammalian cells. Finally, oral administration of an inhibitor protected mice from CPT-11-induced toxicity. Thus, drugs may be designed to inhibit undesirable enzyme activities in essential microbial symbiotes to enhance chemotherapeutic efficacy.
Microbial biomass, functional capacity, and community structure after 12 years of soil warming

We examined the effect of chronic soil warming on microbial biomass, functional capacity, and community structure in soil samples collected from the Soil Warming Study located at the Harvard Forest Long-term Ecological Research (LTER) site. Twelve years of chronic soil warming at 5 °C above the ambient temperature resulted in a significant reduction in microbial biomass and the utilization of a suite of C substrates which included amino acids, carbohydrates, and carboxylic acids. Heating significantly reduced the abundance of fungal biomarkers. There was also a shift in the mineral soil microbial community towards gram positive bacteria and actinomycetes.
Towards an integrated model of moral functioning: an overview of the Special Issue

The collection of essays in this Special Issue embodies an aspiration for an integrated, multi‐level model of moral functioning. Our goal in this overview is to draw together some of the salient insights in the six papers in the volume and to suggest some further directions for research about moral functioning. Our observations fall into eight categories, concerning moral cognitive development between paradigms, the importance of early experience, the distinction between implicit/tacit and explicit/deliberative processes in moral cognition, the judgment–action gap, the importance of interaction and perspective‐taking, the mediating role of culture, the not‐so‐menacing spectre of postmodernism and moral relativism and the educational implications of these themes in these papers, with special reference to the Just Community projects. Our observations are a prelude, we hope, to suggest and stimulate further discussions.
Electromechanical Wave Imaging of Normal and Ischemic Hearts In Vivo

Electromechanical wave imaging (EWI) has recently been introduced as a noninvasive, ultrasound-based imaging modality, which could map the electrical activation of the heart in various echocardiographic planes in mice, dogs, and humans in vivo. By acquiring radio-frequency (RF) frames at very high frame rates (390-520 Hz), the onset of small, localized, transient deformations resulting from the electrical activation of the heart, i.e., generating the electromechanical wave (EMW), can be mapped. The correlation between the EMW and the electrical activation speed and pacing scheme has previously been reported. In this study, we pursue the development of EWI using both displacements and strains and analysis of the EMW properties in dogs in vivo for early detection of ischemia. EWI was performed in normal and ischemic open-chest dogs during sinus rhythm. Ischemia of increasing severity was obtained by gradually obstructing the left-anterior descending (LAD) coronary artery flow. We also introduce the novel method of motion-matching that achieves the reconstruction of the full EWI cine-loop at very high frame rates even when the ECG may be irregular or unavailable. Incremental displacements were previously used by our group to map the EMW. This paper focuses on the associated incremental strains, which facilitate the interpretation of the EMW by relating it directly to contraction. Moreover, we define the onset of the EMW as the time, at which the incremental strains change sign after the onset of the QRS complex of the ECG. Based on this definition, isochronal representations of the EMW were generated using a semi-automated method. The isochronal representation of the EMW during sinus rhythm was reproducible and shown similar to electrical activation maps previously reported in the literature. After segmentation using a contour-tracking method, the two- and four-chamber views were imaged and displayed in bi-plane views, allowing a 3-D interpretation of the EMW. EWI was shown to be sensitive to the presence of intermediate ischemia. EWI localized the ischemic region when the LAD flow was obstructed at 60% and beyond and was capable of mapping the increase of the ischemic region size as the LAD occlusion level increased. In conclusion, the activation maps and wave patterns obtained with EWI were similar to the electrical equivalents previously reported in the literature. Moreover, EWI was found to be sensitive enough to detect and map intermediate ischemia. Those results indicate that EWI could be used to assess the conduction properties of the myocardium, and detect its ischemic onset and disease progression entirely noninvasively.