cssi/SciSciGPT-SciSciNet huggingface dataset:
Metabolism of selenium in humans

Selenium (Se) metabolism in humans is discussed. More selenium as selenomethionine (Semet) is absorbed than when it is present as selenite (95-97% vs. 44-70%). The selenium content in blood is correlated with GPX activity in selenium-deficient Chinese and in New Zealanders, but it is not correlated in blood of subjects living in the states of Oregon or South Dakota in the United States. Selenium from Semet accumulates in blood at a faster rate than selenate, but there are no differences in the GPX activities. Similarly, no differences occurred in the accumulation of selenium in GPX when Semet was compared to selenate, but a difference was found in the accumulation of selenium in hemoglobin (erythrocytes) and albumin (plasma) in subjects taking these two forms of selenium. The majority of selenium in plasma is usually present in selenoprotein P, but with high intakes of Semet, the amount in albumin predominates. Stable isotopes were used to develop the concept of “selenite exchangeable pool,” which can be employed to assess the body burden of selenium in humans. The renal clearance of selenium is higher for Semet than selenate. Even though the maximum safe intake of selenium for humans was estimated to be 600 μ per day, with use of a safety factor, 400 μ was suggested as the maximum safe intake on a long-term basis. An intake of 40 &mu was suggested as the minimum amount required for humans, and intakes of less than 11 μ will definitely put people at risk of deficiency. J. Trace Elem. Exp. Med. 11:227–240, 1998. © 1998 Wiley-Liss, Inc.
A non‐linear optical chromophore: 2‐[3‐cyano‐4‐((E)‐{5‐[4‐(diethyl­amino)styr­yl]thio­phen‐2‐yl}vin­yl)‐5,5‐dimethyl­furan‐2‐(5H)‐yl­idene]propane­dinitrile

The title compound, C28H26N4OS, is an efficient non-linear optical (NLO) material and features a transoid configuration in contrast to the results of quantum chemical calculations. Mol­ecules associate into layers via C—H⋯N inter­actions.
Endonuclease Activity toward DNA irradiated in vitro by Gamma Rays

MANY biological systems are able to repair ultraviolet damage. One of the more extensively studied repair systems in both prokaryotic and eukaryotic organisms involves the excision of ultraviolet-induced, cyclobutane pyrimidine dimers from irradiated DNA1,2. A number of lines of evidence, reviewed elsewhere, indicate that similar repair systems may also act on alterations to DNA that result from the action of other agents3–5. Although the most readily detectable damage to DNAarising from exposure to ionizing radiation is single-strand breaks, there are indications that an excision repair system also operates on such exposed DNAs. For example, there is a small host-cell reactivating effect on irradiated bacteriophage6, and, as shown by Alper7,8, bacteria that are deficient in the ability to reactivate ultraviolet-irradiated bacteriophage (and therefore presumably lacking a functioning excision system) are also more sensitive to X-irradiation. Alper described two types of ionizing radiation damage to microorganisms: (1) N-type—arising from irradiation carried out anoxically—for which there could be extensive repair and (2) O-type—arising from radiation effects mediated by oxygen–for which there was little repair. Hariharan and Cerutti9,10 have described a radiation product of thymine in γ-irradiated Micrococcus radiodurans and have shown that such a product appears selectively in the acid-soluble fraction of the cells during post-irradiation incubation. The appearance of such a product is analogous to the appearance of pyrimidine dimers in the acid-soluble fraction of cells during excision repair after ultraviolet irradiation.
Determining truth conditions in signaling games

Evolving signaling systems can be said to induce partitions on the space of world states as they approach equilibrium. Formalizing this claim provides a general framework for understanding what it means for language to “cut nature at its seams”. In order to avoid taking our current best science as providing the adaptive target for all evolving systems, the state space of the world must be characterized exclusively in terms of the coincidence of stimuli and payoffs that drives the evolution of cognitive complexity. Cognition exploits the reliable clustering of events in this space. Using this framework to analyze our ordinary concepts of truth and justification, it appears that while justification can be a simple matter of conforming to historically entrenched strategies, truth cannot be fully specified on the basis of the system’s causal history, but requires a robust clustering in the larger world state space.
Effects of DNA adduct structure and distribution on the mutagenicity and genotoxicity of two platinum anticancer drugs

Abstract cis -Diamminedichloroplatinum(II) ( cis -DDP) and cis,trans,cis -ammine(cyclohexylamine)-dibutyratodichloroplatinum(IV) (ACDDP) are anticancer drugs that bind to DNA, forming replication blocking adducts. ACDDP, probably manifests its cytotoxicity through the metabolite cis -ammine(cyclohexylamine)dichloroplatinum(II) (ACDP). The biological effects of ACDP and cis -DDP were compared by studying polymerase inhibition in vitro and mutagenesis and genotoxicity in vivo in the duplex genome of bacteriophage M13mp18 replicated in Escherichia coli, cis -DDP and ACDP adducts were equally genotoxic within the statistical error limits of the analysis. Survival of genomes platinated by either drug, increased by threefold in cells pretreated with u.v. irradiation to induce the SOS functions of the host. In the M13mp18 lacZ' gene fragment, the mutagenicity of ACDP was lower than that of cis -DDP; the difference was approximately twofold at a dose of two adducts per 370 base-pair mutational target. Mutagenesis by both compounds was SOS-dependent. The structural basis for lower mutagenicity of ACDP is proposed to be its reduced reactivity at d(ApG) sites. This effect is attributed to an orientational isomerism that precludes the formation of one of two possible DNA adducts at d(ApG) residues. The types of mutations induced for both drugs were similar, but they occurred with different distributions. Both compounds induced primarily G → T transversions at d(GpG) sites whereas G → A transitions and A → T transversions, many at d(ApG), d(GpNpG), and d(GpG) sites, were also well represented. The mapping of DNA adducts by DNA synthesis inhibition revealed excellent correlation between the location of DNA lesions and the sites of mutations. Analysis of the distribution of mutations and the distribution of potential platination sites revealed no sequence-dependent mutation hotspots; i.e. mutagenesis was random throughout the lacZ' region of the M13mp18 bacteriophage genome. These results offer insights into the molecular mechanism of mutagenicity of platinum anticancer drugs.
Identifying Optimal Chronic Kidney Disease Patient Education Web Sites: Assessing E-Health Technology by Content Area Experts

One in nine adults in the United States has chronic kidney disease (CKD). Randomized studies show electronic health (e-health) systems improve health outcomes in chronic disease. This study describes a systematic evaluation of available CKD Web sites. We evaluated Web sites for educating patients with CKD, focusing on three specific design issues: usability, quality, and content. Thirty Web sites were evaluated between April and July 2004. Cohenâ€™s kappa and intraclass correlation of quartile rankings for two independent evaluators were calculated. Mean score for evaluator 1 was 7.293 (standard error 0.511) and for evaluator 2 was 8.189 (0.413). Cohenâ€™s kappa for the 2 evaluatorsâ€™ total scores for all 30 Web sites is 0.7671, and intraclass correlation is 0.7703. In general, results show that it is possible to identify Web sites more likely to provide a positive educational experience for CKD patients. Further evaluation is needed to investigate the utility of variably ranked Web sites as educational interventions.
Non-linear relationships between oxygen saturation and magnitude of fine structure of ultraviolet oxy versus deoxy difference spectrum in human hemoglobin

Abstract Ultraviolet difference spectra of fully oxygenated hemoglobin vs. successively deoxygenated or reoxygenated hemoglobin were determined in the absence and presence of organic phosphates. Magnitude of fine structure in the difference spectrum around 290 nm, which is considered to be a partial reflection of oxygenation-induced changes in quaternary conformation of hemoglobin, was not linearly related to fractional oxygen saturation of hemoglobin of the reference cell. The non-linear feature was influenced by the organic phosphates as predicted by the allosteric model of Monod et al. The present study suggests that the ultraviolet oxy vs. deoxy difference spectrum measurements provide a useful way to examine the validity of the model.
Magnetic coherence gratings in a high-flux atomic beam

Magnetic coherence gratings have been created in a thermal beam of rubidium atoms. The coherence gratings involve superposition of magnetic sublevels of a single hyperfine ground state. These gratings are created via interaction with a single pulse that drives a two-photon transition between magnetic sublevels of the ground state. After the grating dephases due to the velocity distribution of the atoms, it is revived by the action of a second pulse, an effect that is similar to a photon echo. Such experiment is a first step toward generating periodic atomic structures using a high-flux atomic beam. Here, we present the experimental results and provide a detailed description of the apparatus that produces a high flux beam of thermal rubidium atoms.
Mortality of Overwintering Southwestern Corn Borers in Mississippi

The yellow shafted flicker, Colaptes auratus (L.), was a major factor in the mortality of overwintering Diatraea grandiosella Dyar in Mississippi from 1969 to 1972. However, factors such as low temperatures and possibly diseases also contributed to the overall decline in population. The flicker appeared to be highly efficient in finding stalks that contained larvae and appeared to associate the entrance hole in the infested stalk or girdled stalks with the presence of the larva.
The convex sum of product states for a separable state

Abstract A bipartite separable state ρ can be written as a convex sum of pure product states, we give some results about the minimal number of terms needed in the convex sum. This minimal number s m is close to the rank r of ρ when the rank is small, namely, s m = r when r =1,2, and s m =3 or 4 when r =3. When the rank is greater than 3, the exact relation is not found yet, although a lower bound of s m is the rank r and an upper bound of s m is also available.
Photoinduced reaction of arene singlets with carbon tetrachloride in zeolite Y

Abstract Picosecond fluorescence methodologies combined with nanosecond, laser flash photolysis have been applied to examine the reaction of arene excited singlets with CCl4 in dehydrated, zeolite NaY. Fluorescence quenching by CCl4 was shown to originate mainly from a static process, with a much greater drop in fluorescence intensity than could be accounted for by a random distribution of CCl4 among the anthracene-occupied supercages. A similar effect was observed in a previous study of arene fluorescence quenching by nitroalkanes in NaY, and was explained by a mechanism involving coadsorption of the arene and nitroalkane to conjugate acid–base sites. This places the reactants in close proximity – a requirement for the static quenching. The results of the present study support this quenching mechanism by showing that a different electrophilic species (i.e., CCl4) also behaves like nitroalkanes, while reductive quenching by N,N-dimethylaniline and triethylamine does not. Quenching of pyrene fluorescence by CCl4 produced pyrene radical cations through electron transfer to CCl4, with the cation yield proportional to the level of fluorescence quenching. One-third of these radical cations reacted with the fragmentation products of CCl4 anions to form stable products; the remaining fraction was stable, but reacted with added ferrocene. These results demonstrate that the addition of small quantities of CCl4 to the zeolite leads to efficient charge separation by a single-photon mechanism.
The challenge of obesity treatment: avoiding weight regain.

Although lifestyle-based programs for treatment of obesity are generally associated with weight loss of about 10%, [1][1] avoiding weight regain is a major challenge. [2][2] Most patients regain about 30% of the weight lost in the year following treatment and typically return to their baseline
Industrial research and sources of innovation: A cross-industry analysis of Italian manufacturing firms☆

Abstract This paper deals with sources of innovation in the Italian manufacturing industry. It uses an extensive database on 8,220 firms which developed technological innovations during the period 1981-85. R&D turns out to be a major source of innovation for a limited number of innovating firms. Non-R&D performers mainly rely upon the acquisition of external technology (equipment and machinery). The paper shows that there is not a statistically significant difference between innovation sources in R&D firms versus non-R&D firms. This suggests that the presence of an R&D laboratory does not make any difference in how the overall technological information is gathered by innovating enterprises. The analysis of the role played by R&D activities in innovation development shows that it accounts only for 17.9 percent of costs, while production investment absorbs 51.5 percent of total financial resources. As a conclusion, R&D activity, being only one phase of the innovation process, cannot be an accurate indicator of a firm's commitment to technological innovation. R&D is often a minor source of innovation and policy measures should not concentrate just on R&D support. Encouraging and financing innovative suppliers and users may be more effective than helping manufacturers of final products.
Maximum Likelihood Analysis of Logistic Regression Models with Incomplete Covariate Data and Auxiliary Information

Summary. This article presents a new method for maximum likelihood estimation of logistic regression models with incomplete covariate data where auxiliary information is available. This auxiliary information is extraneous to the regression model of interest but predictive of the covariate with missing data. Ibrahim (1990, Journal of the American Statistical Association85, 765–769) provides a general method for estimating generalized linear regression models with missing covariates using the EM algorithm that is easily implemented when there is no auxiliary data. Vach (1997, Statistics in Medicine16, 57–72) describes how the method can be extended when the outcome and auxiliary data are conditionally independent given the covariates in the model. The method allows the incorporation of auxiliary data without making the conditional independence assumption. We suggest tests of conditional independence and compare the performance of several estimators in an example concerning mental health service utilization in children. Using an artificial dataset, we compare the performance of several estimators when auxiliary data are available.
Uranium in spring water and bryophytes at basin creek in central idaho

Abstract Arkosic sandstones and conglomerates of Tertiary age beneath the Challis Volcanics of Eocene age at Basin Creek, 10 km northeast of Stanley, Idaho, contain uranium-bearing vitrainized carbon fragments. The economic potential of these sandstones and conglomerates is currently being assessed. Springs abound at the contacts of rock units, and water from these springs supports abundant growths of bryophytes (mosses and liverworts). Water from 22 springs and associated bryophytes were sampled; two springs were found to contain apparently anomalous concentrations (normalized) of uranium — as much as 6.5 μg/L (ppb) in water and 1800 μg/g (ppm) in ash of mosses. Moss samples from both springs also contained anomalous concentrations of arsenic, and one contained highly anomalous amounts of beryllium. Water from a third spring contained slightly anomalous amounts of uranium, and two species of mosses at the spring contained anomalous uranium (400 and 700 μg/g) and high levels of both cadmium and lead. Water from a fourth spring was normal for uranium (0.18 μg/L), but the moss from the water contained a moderate uranium level and highly anomalous concentrations of lead, germanium, and thallium. These results suggest that, in the Basin Creek area, moss sampling at springs may give a more reliable indication of uranium occurrence than would water sampling. The reason for this may be the ability of mosses to concentrate uranium and its associated pathfinder elements and to integrate uranium fluctuations that occur in the spring water over any period of time.
Relationship of colonoscopy completion rates and endoscopist features.

The success rate for reaching the cecum has been widely discussed as an indicatorof technical expertise for colonoscopy. However, few studies have addressed the impact of endoscopist-specific parameters on cecal intubation rates. The aim of this study wasto characterize the relationship between endoscopist-specific parameters (age, gender, experience level, annual procedure volume, insertion and withdrawal times) and cecal intubation rates for colonoscopy. Procedural data from all colonoscopies performed by gastroenterologists at the outpatient endoscopy unit of Rochester Methodist Hospital, Minnesota, between January and December 2003 were reviewed. Procedural data of 45 endoscopists who performed 17,100 colonoscopies over the study period were analyzed. The average cecal intubation rate was 93.9% (SD, 2.9%). Higher experience level (> 9 years [median]) was significantly predictive of a cecal intubation rate > 94% (OR = 3.43; 95% CI, 1.03–12.29; P = 0.04). Although higher procedure volume was not predictive of higher colonoscopy completion rates overall, when analysis was confined to the junior faculty members ( 200 per year (92.5%) was significantly higher than for those doing < 200 per year (88.5%; P = 0.04). Our observations suggest that cecal intubation rates increase with increasing endoscopist experience. Moreover, among junior endoscopists, an annual volume of at least 200 procedures appears to be required to maintain adequate competence. Future prospective studies should provide data to support consensus guidelines recommending minimum annual procedure numbers required for maintenance of endoscopic competence among trained endoscopists.
Dietary nucleotides: effects on the immune and gastrointestinal systems

Nucleotides (NT) and their related metabolic products play key roles in many biological processes. NT can be synthesized endogenously and thus are not considered essential nutrients. Studies have demonstrated, however, that dietary NT can have beneficial effects; the term "conditionally essential" has been used to describe their role in human nutrition. These nutrients may become essential when the endogenous supply is insufficient for normal function, even though their absence from the diet does not lead to a classic clinical deficiency syndrome. Most dietary NT are rapidly metabolized and excreted. However, some are incorporated into tissues, particularly at younger ages and with fasting. Under conditions of limited NT intake, rapid growth or certain disease states, dietary NT may spare the cost of de novo NT synthesis and optimize the function of rapidly dividing tissues such as those of the gastrointestinal and immune systems. Animals fed NT-supplemented versus non-NT supplemented diets have enhanced gastrointestinal growth and maturation, and improved recovery following small and large bowel injury. Indices of humoral and cellular immunity are enhanced, and survival rates are higher following infection with pathogens. Infants receive NT in human milk, where they are present as nucleic acids, nucleosides, nucleotides and related metabolic products. The NT content of human milk is significantly higher than most cow's milk-based infant formulae. Dietary NT are reported to enhance the gastrointestinal and immune systems of formula-fed infants. Infants fed NT-supplemented versus non-supplemented formula have a lower incidence of diarrhea, higher antibody titers following Haemophilus influenzae type b vaccination and higher natural killer cell activity. These data suggest that human milk NT may contribute to the superior clinical performance of the breastfed infant.
Quantitative gold nanoparticle analysis methods: A review.

Abstract Research and development in the area of gold nanoparticles’ (AuNPs) preparation, characterization, and applications are burgeoning in recent years. Many of the techniques and protocols are very mature, but two major concerns are with the mass domestic production and the consumption of AuNP based products. First, how many AuNPs exist in a dispersion? Second, where are the AuNPs after digestion by the environment and how many are there? To answer these two questions, reliable and reproducible methods are needed to analyze the existence and the population of AuNP in samples. This review summarized the most recent chemical and particle quantitative analysis methods that have been used to characterize the concentration (in number of moles of gold per liter) or population (in number of particles per mL) of AuNPs. The methods summarized in this review include, mass spectroscopy, electroanalytical methods, spectroscopic methods, and particle counting methods. These methods may count the number of AuNP directly or analyze the total concentration of element gold in an AuNP dispersion.
Role of MerH in mercury resistance in the archaeon Sulfolobus solfataricus

Crenarchaeota include extremely thermoacidophilic organisms that thrive in geothermal environments dominated by sulfidic ores and heavy metals such as mercury. Mercuric ion, Hg(II), inactivates transcription in the crenarchaeote Sulfolobus solfataricus and simultaneously derepresses transcription of a resistance operon, merHAI, through interaction with the MerR transcription factor. While mercuric reductase (MerA) is required for metal resistance, the role of MerH, an adjacent small and predicted product of an ORF, has not been explored. Inactivation of MerH either by nonsense mutation or by in-frame deletion diminished Hg(II) resistance of mutant cells. Promoter mapping studies indicated that Hg(II) sensitivity of the merH nonsense mutant arose through transcriptional polarity, and its metal resistance was restored partially by single copy merH complementation. Since MerH was not required in vitro for MerA-catalysed Hg(II) reduction, MerH may play an alternative role in metal resistance. Inductively coupled plasma-mass spectrometry analysis of the MerH deletion strain following metal challenge indicated that there was prolonged retention of intracellular Hg(II). Finally, a reduced rate of mer operon induction in the merH deletion mutant suggested that the requirement for MerH could result from metal trafficking to the MerR transcription factor.
Accelerated Lifetest Results on Submarine-cable Transistors

A computerized analysis is outlined; it uses a lognormal distribution that is fitted to the observed data by the maximum likelihood method. A typical computer output illustrates the failure levels at operational temperatures. The statistical curve fitting technique aids the analysis of accelerated lifetest data. Failure estimates at junction temperatures, much lower than those under accelerated lifetest, are obtained by extrapolation. However, it is up to user whether such an extrapolation is justified. Due to the quantized nature of the data, an optimum exists for the time of device inspection, whereby statistical information is obtained at minimum testing expense. For example, inspecting the 250°C sample at 80 and 160 hours would be a waste of time since no failures should occur.
Compressive sensing in radar sensor networks using pulse compression waveforms

Inspired by recent advances in compressive sensing (CS), we introduce CS to the radar sensor network (RSN) using the pulse compression technique in order to efficiently compress, restore and recover the radar data. For the sake of simplicity but without losing generality, we study an RSN consisting of a number of transmit sensors and one receive sensor. Our idea is to employ a set of Stepped-Frequency waveforms as pulse compression codes for transmit sensors, and to use the corresponding Stepped-Frequency (SF) waveforms as the sparse matrix in the receive sensor due to the orthogonality of the basis. We conclude that the signal samples along the time domain could be largely compressed so that they could be recovered by a small number of measurements. In addition, a diversity gain could also be obtained at the output of the set of the matched filters in the receive sensor. Simulation results show that even if the signal could not be perfectly reconstructed, the probability of miss detection of target could be kept zero. In the future, the reconstructed signal would further be applied to the study of target recognition.
Numerical Modeling of Flow Control in a Boundary-Layer-Ingesting Offset Inlet Diffuser at Transonic Mach Numbers

This paper will investigate the validation of a NASA developed, Reynolds-averaged Navier-Stokes (RANS) flow solver, OVERFLOW, for a boundary-layer-ingesting (BLI) offset (S-shaped) inlet in transonic flow with passive and active flow control devices as well as the baseline case. Numerical simulations are compared to wind tunnel results of a BLI inlet conducted at the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel. Comparisons of inlet flow distortion, pressure recovery, and inlet wall pressures are performed. The numerical simulations are compared to the BLI inlet data at a freestream Mach number of 0.85 and a Reynolds number of approximately 2 million based on the length of the fan-face diameter. The numerical simulations with and without wind tunnel walls are performed, quantifying effects of the tunnel walls on the BLI inlet flow measurements. The wind tunnel test evaluated several different combinations of jet locations and mass flow rates as well as a vortex generator (VG) vane case. The numerical simulations will be performed on a single jet configuration for varying actuator mass flow rates at a fix inlet mass flow condition. Validation of the numerical simulations for the VG vane case will also be performed for varying inlet mass flow rates. Overall, the numerical simulations were able to predict the baseline circumferential flow distortion, DPCPavg, very well for comparisons made within the designed operating range of the BLI inlet. However the CFD simulations did predict a total pressure recovery that was 0.01 lower than the experiment. Numerical simulations of the baseline inlet flow also showed good agreement with the experimental inlet centerline surface pressures. The vane case showed that the CFD predicted the correct trends in the circumferential distortion for varying inlet mass flow but had a distortion level that was nearly twice as large as the experiment. Comparison to circumferential distortion measurements for a 15 deg clocked 40 probe rake indicated that the circumferential distortion levels are very sensitive to the symmetry of the flow and that a miss alignment of the vanes in the experiment could have resulted in this difference. The numerical simulations of the BLI inlet with jets showed good agreement with the circumferential inlet distortion levels for a range of jet actuator mass flow ratios at a fixed inlet mass flow rate. The CFD simulations for the jet case also predicted an average total pressure recovery that was 0.01 lower than the experiment as was seen in the baseline. Comparison of the flow features the jet case revealed that the CFD predicted a much larger vortex at the engine fan-face when compare to the experiment.
Putting Firms into Optimal Tax Theory

Firms are, for the most part, absent from the modern theory of optimal taxation. Their disappearance dates from the foundational models developed by Peter A. Diamond and James A. Mirrlees (1971) in which firms are simply mechanical vehicles for combining productive inputs into output in cost-minimizing proportions. In contrast, firms play a central role in all modern tax systems, mostly for a reason stated by Richard M. Bird (1996): “The key to effective taxation is information, and the key to information in the modern economy is the corporation.” In most countries, firms remit the majority of tax revenues to the government, either with regard to taxes legally owed by businesses or through withholding of taxes legally owed by employees or other businesses. Even when businesses are not required to remit taxes, they are often required to file information reports that can facilitate monitoring of tax liabilities. The lack of a theoretical framework that features firms impedes rigorous welfare analysis of a number of important policy issues. One such example is the comparative evaluation of a uniform retail sales tax (RST) versus a value added tax (VAT). In the standard model, these two taxes—both remitted entirely by businesses— are equivalent consumption taxes, but most experts consider the VAT to be clearly superior on administrative grounds, a view echoed in the recent report of the President’s Advisory Panel on Federal Tax Reform (2005). We propose a simple framework in which these and other issues can be analyzed. The new framework recognizes that a tax code must be backed up by an administrative and enforcement structure.
Hey, you! The Germans! Using Literary Pragmatics to Teach Language as Culture

In this paper the author outlines a sample lesson that has been developed for second- or third-year German students using the short satirical vignette “Hurra, ich lebe in Deutschland” from the Turkish-German author Sinasi Dikmen's book of the same name. The lesson draws heavily from literary pragmatics, an area of applied linguistics which studies the relationships between literary language use and its users, and which can promote the awareness of language as culture needed in the more advanced levels of language study.
Social influences on androgen levels in the southern leopard frog, Rana sphenocephala.

Social cues play an important role in modulating neuroendocrine and hormonal states in many vertebrates. Social cues in the form of conspecific advertisement calls have been demonstrated to modulate plasma androgen levels in male Rana sphenocephala, the Southern leopard frog. Male R. sphenocephala were captured and brought to the laboratory for testing. Animals were exposed to one of two acoustical environments: a recording of an active conspecific breeding chorus or a recording of the same chorus in which all the spectral frequencies had been digitally shifted 500 Hz higher. Following 12 nights of exposure to either stimulus, plasma androgen levels were assessed by radioimmunoassay and gonadal morphology was examined to compare group differences. Plasma levels of dihydrotestosterone were significantly higher in males exposed to the conspecific chorus, compared with males exposed to the altered version of the chorus. Gonadal morphology did not differ between the two groups. These results suggest that in addition to environmental cues such as rainfall and other seasonal changes, social cues may also serve as environmental synchronizers among anurans to coordinate reproductive effort.
The impact of bottom brightness on spectral reflectance of suspended sediments

Two experiments were conducted outdoors to investigate how bottom brightness impacts the spectral response of a water column under varied suspended sediment concentrations. A white aluminum panel placed at the bottom of the tank was used as the bright bottom, and a flat-black tank liner served as the dark bottom. Sixteen levels of suspended sediment from 25 to 400 mg litre -1 were used in each experiment. Spectral data were collected using a Spectron SE-590 spectroradiometer. The major findings include the following: the bright bottom had the greatest impact at visible wavelengths; when suspended sediment concentrations exceeded 100 mg litre -1, the bright bottom response was found to be negligible; and, substrate brightness has minimal impact between 740 and 900 nm, suggesting that these wavelengths are best for measuring suspended sediment concentrations by means of remote sensing.
Flaming in electronic communication

Communication through computer networks, electronic salons, and virtual communities has its price. Often relatively anonymous and socially detached, electronic communication allows people to write things online that they would seldom consider saying face-to-face, sometimes generating flames. In a study of the motives to flame based upon Uses and Gratifications Theory (UGT), 160 subjects generated comments anonymously in parallel with a group support system (GSS) idea generation program. Results showed that high levels of assertiveness and sensation seeking predicted flaming, and males tended to participate more in the activity than did females.
Cheating in Advantaged High Schools: Prevalence, Justifications, and Possibilities for Change

The current study explored high school student cheating in communities of advantage, gathering survey data from 4,316 high school students in upper middle class communities and qualitative data from a smaller group of students, school leaders, teachers, and parents. Results indicated pervasive cheating among students (93% reported cheating at least once and 26% of upperclassmen indicated cheating in 7 or more of 13 ways listed on the survey). Students described schools as lacking clarity or consequences regarding cheating and expressed feeling forced to cheat in a school culture that promotes getting ahead over learning. The discussion focuses on why advantaged contexts are ripe for student cheating and proposes strategies for change.
North Central Sociological Association Presidential Address. Renewing Sociology: Integral Science, Solidarity, and Loving Kindness

The field of sociology is an ongoing creative process that always requires new energy and new insights. At the same time, in order to remain a collective project, sociology requires solidarity among its practitioners. This article offers reflections on how the discipline might be renewed and revitalized in the context of the still relatively young twenty-first century. Specifically, it calls for an Integral approach to science, for increased bonds among sociological colleagues, and for the development of an explicitly spiritual dimension in teaching, research and service. The discussion also touches on dangers to the sociological enterprise as here conceived, including excesses in both qualitative and quantitative work, segregationist and separatist tendencies, false and misleading dichotomies and an “enemies” mentality. Its overall vision is that of a field characterized by freshness, intellectual excellence, artistry, social relevance, comaraderie, compassion and joyfulness.
Impurity-induced spin-ordering above the Curie temperature

Abstract It is shown that spin impurities in ferromagnets may produce an anomalously large polarization of their environment at temperatures slightly above the Curie temperature.
A national data infrastructure for patient-centered outcomes research

Concerted efforts are underway to improve healthcare decision-making through patient-centered outcomes research. These efforts are supported by the Patient-Centered Outcomes Research Trust Fund, which was established within the Patient Protection and Affordable Care Act. This article focuses on describing national data infrastructure efforts that support patient-centered outcomes research. A national data infrastructure has the potential to decrease research costs and improve research throughput. We describe early and current efforts that demonstrated this potential, how the national effort is utilizing the lessons learned from these predecessor efforts and remaining challenges.
Membrane adhesion and other functions for the myelin basic proteins

The myelin basic proteins are a set of peripheral membrane polypeptides which play an essential role in myelination. Their most well-documented property is the unique ability to 'seal' the cytoplasmic aspects of the myelin membrane, but this is probably not the only function for these highly charged molecules. Despite extensive homology, the individual myelin basic proteins (MBPs) exhibit different expression patterns and biochemical properties, and so it is now believed that the various isoforms are not functionally equivalent in myelinating cells. We now think that while the major MBPs are intracellular adhesion molecules, some of the quantitatively less abundant isoforms that are expressed very early in development may have regulatory effects on the myelination program.
A neurophysiological theory for the pain mechanism of tic douloureux.

Abstract In attempting to understand the mechanism of pain production in tic douloureux, one must account for the myelination pathology seen in the primary afferent fibers, the cases where the trigger is in a different division than the pain, the frequent lack of a fixed neurologic deficit, the effective trigger stimuli corresponding to large caliber axons which would not seem to involve the small axons usually associated with pain production, and similar puzzling features of the disease. We present a theory which satisfactorily predicts, or is consistent with, most known features of tic; it is based upon two mechanistic assumptions, both of which have strong experimental foundations in the literature. The first is the trigeminal dorsal root reflex, and the second is the creation of extra action potentials at sites of altered myelination.
Potentiation of GABAA receptors by neurosteroids: Mechanisms and sites

Abstract Neurosteroids increase the strength of neuronal inhibition by enhancing the activity of GABA-A receptors. The response to lower concentrations of GABA is increased in the presence of these drugs. One question is the nature of the basis for the potentiation — is there a change in the affinity of the receptor for GABA or an increase in the efficacy of activation? The answer for these drugs is that the major change occurs in the efficacy of activation, with no change in channel opening but a decrease in rates for entering states with a closed channel. There are at least 2 sites of action, which can be distinguished by the activity of steroid analogues with different structures. There are at least 3 mechanisms of action. Mutations of GABAA receptor subunits indicate that at least one site for steroid action is likely to be at the extreme carboxyl end of the γ2 subunit. Analysis of data obtained at a low concentration of GABA suggests that the ability of steroids to potentiate the GABAA receptor may be affected by the extent of ligation with GABA.
Fore, Batter Up, Love 15—A Lesson in Bernoulli's Principle

(1986). Fore, Batter Up, Love 15—A Lesson in Bernoulli's Principle. Science Activities: Vol. 23, No. 4, pp. 4-5.
Aortic Tissue as a Niche for Hematopoiesis

The stem cell theory of hematopoiesis predicts that all mature blood cell lineages circulating in the bloodstream or resident in tissues arise via a hierarchy of hematopoietic progenitor cell (HPC) intermediates that are ultimately derived from hematopoietic stem cells (HSC). In the adult human, bone marrow–resident HSC and HPC generate billions of circulating blood cells daily, ranging from the short-lived neutrophils and platelets to long-lived B and T lymphocytes and monocyte macrophages. Recent interest in the roles of macrophages as modulators of angiogenesis1 and as participants in atheroma formation2 highlight the need to better understand the mechanisms of recruitment and retention of macrophages and their progenitor precursors within tissues. In this issue of Circulation , Psaltis and colleagues3 identify clonogenic HPC activity in aortic adventitia (that is enriched in HPC compared with peripheral blood or muscle tissue), which appears skewed toward colony-forming unit-macrophage (CFU-M) differentiation. In addition, stem cell antigen-1–expressing cells in the aortic adventitia coexpressed a variety of HSC antigens, and adoptive transfer of these cells into irradiated recipient mice led to low but sustained multilineage reconstitution, a property of HSC. Although bone marrow (BM)–derived donor hematopoietic cells reconstituted the aorta of lethally irradiated animals, the majority of aorta-derived CFU-M appeared to be constitutive or long term residents of the vessel wall (with sustained but only partial replacement from donor BM cells), suggesting that either the aortic adventitial microenvironment imparts specific differentiation properties to marrow-derived precursors or that a local origin for HSC/HPC exists in the adult vasculature. Is there any evidence to suggest that HSC/HPC may originate and/or migrate through the aortic adventitia? Article see p 592 Hematopoiesis occurs in a site- and tissue-specific pattern that varies throughout mammalian development. The first blood cells (including macrophages) arise in the extraembryonic yolk sac, and the yolk …
Superradiant emission of Smith-Purcell radiation

Smith-Purcell (SP) radiation is emitted when an electron passes close to the surface of a metallic grating. The radiation becomes coherent (fluence proportional to the square of the number of electrons) when the electrons are in bunches whose dimensions are smaller than the wavelength of the radiation. This has been observed in experiments in which the electrons are prebunched by an rf linac. The enhancement of the spectral intensity is accompanied by large changes in the angular and spectral distribution of the radiation when the electrons appear in periodic bunches. This is called superradiance. Recently, superradiant SP radiation has been observed from a so-called Smith-Purcell free-electron laser (SP-FEL) in which the electrons are bunched by the lasing process. As in other slow-wave structures, the electron beam in a SP-FEL interacts with an evanescent wave for which the phase velocity matches the electron velocity and amplifies it. The frequency of this wave lies below the range of SP radiation and the wave is not radiated except from the ends of the grating. However, the bunching of the electrons by the interaction with the evanescent wave enhances the ordinary Smith-Purcell radiation and changes the angular and spectral distribution due to superradiant effects. In this article, we introduce a new method for computing the SP radiation in three dimensions, including the effects of finite grating length and superradiance due to periodic electron bunching at an arbitrary frequency. We show that the SP radiation develops spectrally and angularly narrow peaks at the harmonics of the bunching frequency. In rf linacs, where the bunches are widely spaced, several closely spaced harmonics lie under the spectral envelope of the emission from a single electron. In a SP-FEL the harmonics are widely spaced and the SP radiation appears in narrow cones at the SP angles corresponding to the harmonics of the bunching frequency. Finally, we calculate the angular spectral fluence radiated by an electron passing over a lamellar grating of finite length, examine its coherent enhancement in SP-FELs and rf linacs, and compare the results with numerical simulations and available experimental data.
The effect of small-size habitat disturbances on population density and time to extinction of the prairie vole

Abstract We present a study, based on simulations with SERDYCA, a spatially-explicit individual-based model of rodent dynamics, on the relation between population persistence and the presence of numerous isolated disturbances in the habitat. We are specifically interested in the effect of disturbances that do not fragment the environment on population persistence. Our results suggest that the presence of disturbances in the absence of fragmentation can actually increase the average time to extinction of the modeled population. The presence of disturbances decreases population density but can increase the chance for mating in monogamous species and consequently, the ratio of juveniles in the population. It thus provides a better chance for the population to restore itself after a severe period with critically low population density. We call this the “disturbance-forced localization effect”.
Orbital coupling and superconductivity in the iron pnictides

We demonstrate that strong interorbital interaction is very efficient to achieve superconductivity due to magnetic fluctuations in the iron pnictides. Fermi-surface states that are coupled by the antiferromagnetic wave vector are often of different orbital nature, causing pair-hopping interactions between distinct $\text{Fe-}3d$ orbitals to become important. Performing a self-consistent fluctuation exchange calculation below ${T}_{c}$ we determine the superconducting order parameter as function of intra- and interorbital couplings. We find an ${s}^{\ifmmode\pm\else\textpm\fi{}}$-pairing state with ${T}_{c}\ensuremath{\simeq}80\text{ }\text{K}$ for realistic parameters.
Correlation of myosin isoenzyme alterations with myocardial function in physiologic and pathologic hypertrophy

To explore the interactions of physiologic and pathologic hypertrophy, four groups of hearts were studied in an isolated working rat heart apparatus. Cardiac contractile proteins were also evaluated. The groups were hearts of female control sedentary rats; rats subjected to a 10-week swimming programme; rats with renal hypertension; and hypertensive rats subjected to a 10-week swimming programme. The swimming programme in normotensive female rats caused a 30% cardiac hypertrophy, in hypertensive animals 46% hypertrophy, and in combined hypertension and swimming 70% hypertrophy. Ca2+-myosin ATPase activity and actin-activated myosin ATPase were elevated in hearts of swimmers, depressed in hearts of hypertensive sedentary animals and similar to control values in hearts of hypertensive swimmers. Myosin V1 isoenzyme content was increased in hearts of swimmers, depressed in hearts of hypertensives, but normal in hearts of hypertensive swimmers. Reciprocal relationships were seen with the V3 isoenzyme. Stroke work, mean velocity of circumferential fibre shortening, and per cent fractional shortening at the midwall showed increased values for hearts of swimmers, depressed values for hearts of hypertensives, and normal values or values above the control for hearts of hypertensive swimmers. Myocardial flow measured with microspheres was increased in the left ventricle of swimmers, depressed in hearts of hypertensives and still depressed in hypertensive swimmers, but significantly higher than in the hypertensives alone. The correlation of actin-activated ATPase activity and of fractional shortening was linear among the four groups. These studies demonstrate that physiologic and pathologic hypertrophy in the rat have distinctly opposite effects on contractile proteins and contractile performance. When one type of hypertrophy is superimposed on the other the effects are additive.