cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular simulation studies of monovalent counterion-mediated interactions in a model RNA kissing loop.

Summary A kissing loop is a highly stable complex formed by loop–loop base-pairing between two RNA hairpins. This common structural motif is utilized in a wide variety of RNA-mediated processes, including antisense recognition, substrate recognition in riboswitches, and viral replication. Recent work has shown that the Tar–Tar⁎ complex, an archetypal kissing loop, can form without Mg2+, so long as high concentrations of alkali chloride salts are present. Interestingly, the stability of the complex is found to decrease with increasing cation size. In this work, we used molecular simulations to develop a molecular-level understanding of the origins of the observed counterion specificity. The ionic atmosphere of the Tar–Tar⁎ complex was examined in the presence of 800 mm (where m denotes molality) NaCl, KCl, or CsCl. We used spatial free-energy density profiles to analyze differences in counterion accumulation at different spatial extents from the RNA molecule. We found that the lowest free-energy levels, which are situated in the vicinity of the loop–loop interface, can accommodate roughly two counterions, irrespective of counterion type. However, as we moved into higher free-energy levels, which are farther from the loop–loop interface, we observed increased differences in the numbers of accumulated counterions, with this number being largest for Na+ and smallest for Cs+. We analyzed the source of these differences and were able to attribute these to two distinct features: The extent of partial dehydration varies based on cation type; the smaller the cation, the greater the degree of dehydration. While smaller ions bind their first-hydration-shell water molecules more tightly than larger ions, they are also able to shed these water molecules for stronger electrostatic interactions with the RNA molecule. Secondly, we observed a distinct asymmetry in the numbers of accumulated cations around each hairpin in the Tar–Tar⁎ complex. We were able to ascribe this asymmetry to the presence of a guanine tract in the Tar hairpin, which facilitates partial dehydration of the counterions. However, the smaller ions compensate for this asymmetry by forming a belt around the loop–loop interface in intermediate free-energy levels. As a result, the degree of asymmetry in counterion accumulation around individual hairpins shows an inverse correlation with the experimentally observed cation specificity for the stability of Tar–Tar⁎ (i.e., the smaller the asymmetry, the greater the experimentally observed stability). This in turn provides a plausible explanation for why the smaller cations help stabilize the Tar–Tar⁎ complex better than the larger cations. These findings suggest that the specific sequence and structural features of the Tar–Tar⁎ complex may be the source of the experimentally observed cation specificity in Tar–Tar⁎ stability. Our results lead to testable predictions for how changes in sequence might alter the observed counterion specificity in kissing loop stability.
Tolerance tests of H2S-laden biogas fuel on solid oxide fuel cells

Abstract Biogas is a variable mixture of methane, carbon dioxide and other gases. It is a renewable resource which comes from numerous sources of plant and animal matter. Ni–YSZ anode-supported solid oxide fuel cell (SOFC) can directly use clean synthesized biogas as fuel. However, trace impurities, such as H2S, Cl2 and F2 in real biogas can cause degradation in cell performance. In this research, both uncoated and coated Ni–YSZ anode-supported cells were exposed to three different compositions of synthesized biogases (syn-biogas) with 20 ppm H2S under a constant current load at 750–850 °C and their performance was evaluated periodically using standard electrochemical methods. Postmortem analysis of the SOFC anode was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results show that H2S causes severe electrochemical degradation of the cell when operating on biogas, leading to both complete electrochemical and mechanical failure. The Ni–CeO2 coated cell showed excellent stability during CH4 reforming and some tolerance to H2S contamination.
Incremental net benefit in randomized clinical trials.

There are three approaches to health economic evaluation for comparing two therapies. These are (i) cost minimization, in which one assumes or observes no difference in effectiveness, (ii) incremental cost-effectiveness, and (iii) incremental net benefit. The latter can be expressed either in units of effectiveness or costs. When analysing data from a clinical trial, expressing incremental net benefit in units of cost allows the investigator to examine all three approaches in a single graph, complete with the corresponding statistical inferences. Furthermore, if costs and effectiveness are not censored, this can be achieved using common two-sample statistical procedures. The above will be illustrated using two examples, one with censoring and one without.
Age-related changes in brain catecholamine responses to a single footshock☆

The responses of forebrain and brainstem catecholamine levels to a single footshock were studied in 70-day, one-year, and two-year-old Fischer-344 rats. Brain catecholamine concentrations were assessed 10 minutes after a single 2 second footshock (0, 0.3, or 2.0 mA). In samples taken from non-footshocked rats, only forebrain dopamine concentrations showed a significant age-related decline. However, because the net weights of both the forebrain and the brainstem samples increased significantly with age, the content of forebrain dopamine did not exhibit a significant decline. Both norepinephrine and dopamine levels showed age-related changes in responsiveness to footshock. Norepinephrine concentrations were reduced in both the forebrain and brainstem samples obtained 10 minutes after the high footshock in both the 70-day and one-year-old animals. In two-year-old rats, however, neither forebrain nor brainstem norepinephrine concentrations were altered in response to footshock. Seventy-day-old rats demonstrated significant footshock-induced increases in brainstem dopamine levels, one-year olds showed no appreciable change, and two-year olds demonstrated a non-significant footshock-induced decrease. Thus, both noradrenergic and dopaminergic systems demonstrated age-related changes in their responsiveness to a single brief footshock. These alterations may contribute to the declining ability of the senescent animals to adapt to stressful situations.
Honey Tokens and Web Bugs: Developing Reactive Techniques for Investigating Phishing Scams

ABSTRACT This article presents a technique for investigating phishing scams. While most anti-phishing efforts focus on preventative measures, or reactive investigation techniques that are not specific to the domain of phishing, this technique applies the concepts of honeytokens and web bugs in a way that may reveal previously unknown information about the phisher. The objective of this work is to develop new ways of addressing phishing scams by exploiting vulnerabilities in the tools and methods used by the phishers. A review of phishing and current anti-phishing techniques is included, along with an introduction to honeytokens and web bugs. The technique is presented with preliminary data to demonstrate promise of the concept.
Public Policies for Information Management: An Overview.

Abstract Three broadly-defined types of public policies for information management are posited and described. The typology is based on the values assigned by society to the desirability of harboring or disseminating certain kinds of knowledge. The policy types are formulated according to secret, private, and public knowledge. It is urged that information scientists recognize their important political role in all three areas.
Ciliary neurotrophic factor regulates nicotinic acetylcholine receptors on human neuroblastoma cells

We have investigated the effects of several neurokine/cytokine family members on the level of α-bungarotoxin-binding to neuronal nicotinic acetylcholine receptors. Exposure of human neuroblastoma cells (SH-SY5Y and IMR-32) to ciliary neurotrophic factor (CNTF), leukemia inhibitory factor or oncostatin-M resulted in a 30–40% decline in α-bungarotoxin receptors on the cells with no decrease seen in either muscarinic acetylcholine receptors or in L-type Ca2+ channels. The level of nicotinic receptor was not affected by the related cytokine, interleukin-6. Treatment of IMR-32 cells with 40 pM CNTF produced a half-maximal decrease of α-bungarotoxin binding which compared well with the affinity estimated from binding of 125I-CNTF (Ki ≈ 40 pM) and the concentration causing c-fos activation in SH-SY5Y cells, as detected by nuclear run-on assays (60–120 pM). Previous results have indicated that the differentiating agents, phorbol esters and retinoic acid, also decrease nicotinic receptor numbers. Here the effects of CNTF, which did not induce neural differentiation, were enhanced by differentiation with 12-O-tetradecanoylphorbol 13-acetate (10 nM) and prevented by retinoic acid (10 μM). Therefore, the response of neuroblastoma cells to cytokines may be under developmental control. These cells offer a system to examine cytokine responses and signal transduction mechanisms during neural development.
Thromboxane A2fails to induce proliferation of smooth muscle cells enriched with eicosapentaenoic acid and docosahexaenoic acid

Thromboxane A2 (TXA2) released from aggregating platelets and injured vessel wall stimulates smooth muscle cell proliferation, which may contribute to the development of vascular lesion formation after percutaneous transluminal coronary angioplasty. Polyunsaturated fatty acids (n-3) present in the fish oils have been shown to have anti-atherosclerotic effects. In view of this, we examined the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the active ingredients of fish oils on TXA2 induced smooth muscle cell proliferation. To find out the specificity of these fatty acids we used gamma-linolenic acid (n-6) and oleic acid (n-9) as controls. It was found that TXA2 failed to stimulate proliferation of smooth muscle cells preloaded with EPA or DHA but not with gamma-linolenic acid or oleic acid. Further, when smooth muscle cells were preloaded with both EPA and DHA, they acted together in preventing the TXA2 induced smooth muscle cell proliferation. These results demonstrate that one of the mechanisms by which fish oils may prevent neointima formation is by making smooth muscle cells less responsive to TXA2 induced proliferation of smooth muscle cells.
Study of Tip-Vortex Formation Using Large-Eddy Simulation

The formation of the tip-vortex from a rectangular NACA 2415 wing-tip at a chord Reynolds number of 10000 has been simulated. The simulations employ a parallelized compressible large-eddy simulation (LES) solver that has been developed to simulate wing and rotor tip-flows. The solver employs an immersed -boundary technique in conjunction with a curvilinear structured grid and the dynamic model is used to model the subgrid-scale (SGS) stress terms. A d etailed discussion of the tip-vortex formation and evolution in the near wake is presented.
Depth and areal extent of sheet and rill erosion based on radionuclides in soils and suspended sediment

Sheetwash and rilling are two important mechanisms of soil erosion by runoff. The relative contribution of each mechanism has been a vexing question because measuring thin sheet erosion is difficult. Fortuitously, various fallout radionuclides have distinct distributions in the soil column; thus, different depths of erosion produce suspended sediment with unique radionuclide signatures. Those signatures can be used to estimate the depth and areal extent of sheet and rill erosion. We developed a model to execute multiple mass balances on soil and radionuclides to quantify these erosion mechanisms. Radionuclide activities (7Be, 137Cs, 210Pb) in the soil of a 6.03 ha agricultural field near Treynor, Iowa, and in suspended sediment washed off the field during thunderstorm runoff were determined by gamma spectroscopy. Using the model, we examined 15.5 million possible combinations of the depth and areal extent of rill and sheet erosion. The best solution to the mass balances corresponded to rills eroding 0.38% of the basin to a depth of 35 mm and sheetwash eroding 37% of the basin to a depth of 0.012 mm. Rill erosion produced 29 times more sediment than sheet erosion.
Potential long-term benefits of no-tillage and organic cropping systems for grain production and soil improvement

There have been few comparisons of the performance of no-tillage cropping systems vs. organic farming systems, particularly on erodible, droughty soils where reduced-tillage systems are recommended. In particular, there is skepticism whether organic farming can improve soils as well as conventional no-tillage systems because of the requirement for tillage associated with many organic farming operations. A 9-yr comparison of selected minimum-tillage strategies for grain production of corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.) was conducted on a sloping, droughty site in Beltsville, MD, from 1994 to 2002. Four systems were compared: (i) a standard mid-Atlantic no-tillage system (NT) with recommended herbicide and N inputs, (ii) a cover crop-based no-tillage system (CC) including hairy vetch (Vicia villosa Roth) before corn, and rye (Secale cereale L.) before soybean, with reduced herbicide and N inputs, (iii) a no-tillage crownvetch (Coronilla varia L.) living mulch system (CV) with recommended herbicide and N inputs, and (iv) a chisel-plow based organic system (OR) with cover crops and manure for nutrients and postplanting cultivation for weed control. After 9 yr, competition with corn by weeds in OR and by the crownvetch living mulch in CV was unacceptable, particularly in dry years. On average, corn yields were 28 and 12% lower in OR and CV, respectively, than in the standard NT, whereas corn yields in CC and NT were similar. Despite the use of tillage, soil combustible C and N concentrations were higher at all depth intervals to 30 cm in OR compared with that in all other systems. A uniformity trial was conducted from 2003 to 2005 with corn grown according to the NT system on all plots. Yield of corn grown on plots with a 9-yr history of OR and CV were 18 and 19% higher, respectively, than those with a history of NT whereas there was no difference between corn yield of plots with a history of NT and CC. Three tests of N availability (corn yield loss in subplots with no N applied in 2003-2005, presidedress soil nitrate test, and corn ear leaf N) all confirmed that there was more N available to corn in OR and CV than in NT. These results suggest that OR can provide greater long-term soil benefits than conventional NT, despite the use of tillage in OR. However, these benefits may not be realized because of difficulty controlling weeds in OR.
TESTS OF NONLINEAR DYNAMICS IN U.S. HOMICIDE TIME SERIES, AND THEIR IMPLICATIONS*

Attempts to explain temporal patterns in U.S. homicide data usually assume that a linear process accounts for the variation. A nonlinear process is an obvious alternative, however, and reasonable arguments suggest that nonlinearity may in part underlie homicide series dynamics. This paper applies tests for nonlinearity to national time series of homicide rates and counts. The results provide relatively little evidence of nonlinear structure; instead, a linear (random walk) process appears to generate most of the change in the series. Although this supports the unstated assumptions of current theories, it also raises questions about why homicides should follow a linear time path in the first place.
Electro‐optical properties of electropolymerized poly(3‐hexylthiophene)/carbon nanotube composite thin films

3-hexylthiophene was electropolymerized on a carbon nanotube (CNT)-laden fluorine-doped tin oxide substrate. Scanning electron microscopy and Raman spectroscopy revealed that the polymer was infused throughout the thickness of the 150-nm thick CNT mat, resulting in a conducting composite film with a dense CNT network. The electropolymerized poly(3-hexylthiophene) (e-P3HT)/CNT composites exhibited photoluminescence intensity quenching by as much as 92% compared to the neat e-P3HT, which provided evidence of charge transfer from the polymer phase to the CNT phase. Through-film impedance and J-V measurements of the composites gave a conductivity (σ) of 1.2 × 10−10 S cm−1 and zero-field mobility (μ0) of 8.5 × 10−4 cm2 V−1 s−1, both of which were higher than those of neat e-P3HT films (σ = 9.9 × 10−12 S cm−1, μ0 = 3 × 10−5 cm2 V−1 s−1). In electropolymerized samples, the thiophene rings were oriented in the (010) direction (thiophene rings parallel to substrate), which resulted in a broader optical absorbance than for spin coated samples, however, the lack of long-range conjugation caused a blueshift in the absorbance maximum from 523 nm for unannealed regioregular P3HT (rr-P3HT) to 470 nm for e-P3HT. Raman spectroscopy revealed that π-π stacking in e-P3HT was comparable to that in rr-P3HT and significantly higher than in regiorandom P3HT (ran-P3HT) as shown by the principal Raman peak shift from 1444 to 1446 cm−1 for e-P3HT and rr-P3HT to 1473 cm−1 for ran-P3HT. This work demonstrates that these polymer/CNT composites may have interesting properties for electro-optical applications. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1269–1275, 2011
Role of Striatum in the Pause and Burst Generation in the Globus Pallidus of 6-OHDA-Treated Rats

Electrophysiological studies in patients and animal models of Parkinson’s disease (PD) often reported increased burst activity of neurons in the basal ganglia. Neurons in the globus pallidus external segment (GPe) in 6-hydroxdopamine (6-OHDA)-treated hemi-parkinsonian rats fire with strong burst interrupted by pauses. This study was to evaluate a hypothesis that DA depletion increases burst firings of striatal (Str) neurons projecting to the GPe and that the increased Str-GPe burst inputs play a significant role in the generation of pauses and bursts in GPe and its projection sites. To evaluate this hypothesis, unitary activity of Str and GPe was recorded from control and 6-OHDA-treated rats anesthetized with 0.5-1% isoflurane. The occurrence of pauses and bursts in the firings of GPe neurons was significantly higher in 6-OHDA than in normal rats. Muscimol injection into the Str of 6-OHDA rats increased the firing rate and greatly reduced the pauses and bursts in GPe. Recording from Str revealed that most of the presumed projection neurons in control rats have very low spontaneous activity and only occasional neurons exhibited spontaneous burst firings with an average rate of less than 2Hz. In DA-depleted Str, neurons having stronger bursts and higher average firing rate were more frequently encountered. Juxtacellular labeling revealed that most of these neurons were medium spiny neurons projecting only to GPe. Injection of a behaviorally effective dose of methyl-L-DOPA into the Str of 6-OHDA rats significantly increased the firing rate and decreased number of pauses of GPe neurons. These data validate the hypothesis that DA depletion increases burst firings of Str neurons projecting to the GPe and that the increased Str-GPe burst inputs play a significant role in the generation of pauses and bursts in GPe. These results suggest that treatment to reduce burst Str-GPe inhibitory inputs may help to restore some of the PD disabilities.
Interaction of Silver, Cesium, and Zinc with Alumina Surfaces: Thermal Desorption and Photoemission Studies

Cs, Ag, and Zn behave in a different way when deposited on surfaces of ultrathin (15−20 A) films of alumina. In the case of Cs/Al2O3, the alkali atoms wet the oxide, forming strong chemisorption bonds. At small coverages of Cs, desorption of the alkali occurred between 600 and 1000 K. As the amount of Cs deposited increased, there was a reduction in the Cs desorption temperature to ∼350 K. This broad range of desorption temperatures reflects a continuous decrease in the Cs adsorption energy from 63 to 18 kcal/mol with increasing Cs coverage. The deposition of small amounts of Cs induced large (0.9−1.1 eV) positive shifts in the binding energies of the O KVV, O 1s, and Al 2p features of the alumina films. This is consistent with a transfer of electrons from Cs into surface states of alumina that produces a transformation similar to a change from p-type to n-type semiconductors. Ag and Zn do not wet the surface of alumina well and form three-dimensional clusters or particles. In these systems, the activatio...
Opportunities and strategies for breast cancer prevention through risk reduction

Due to the high incidence of breast cancer among US females, risk-reduction strategies are essential. Before considering approaches to breast cancer risk reduction, it is important for clinicians to complete individualized qualitative and quantitative assessments of risk for their patients in order to inform physicians' clinical decision making and management and to engage patients collaboratively in a thorough discussion of risks and benefits. This review will summarize information on potential pharmacologic, nutritional, surgical, and behavioral approaches to reducing breast cancer risk. While there is no clear evidence that specific dietary components can effectively reduce breast cancer risk, weight gain and obesity in adulthood are risk factors for the development of postmenopausal breast cancer. Alcohol consumption, even at moderate levels, increases breast cancer risk, although some of the detrimental effects may be reduced by sufficient folate intake. Women at increased risk of breast cancer can opt to reduce their breast cancer risk through the use of tamoxifen or raloxifene; other chemopreventive agents remain under investigation. Surgical approaches to risk reductions are restricted to those patients with a substantially increased risk of developing breast cancer. Patients should be encouraged to maintain a healthy lifestyle for their overall well-being and to remain up to date with recommendations for screening and surveillance.
A Bifunctional Vector Suitable for Both Site-Directed Mutagenesis and Recombinant Expression of Interferon-τ in Escherichia coli

In order to produce workable quantities of a large number of mutant forms of recombinant ovine and bovine interferon-t (IFN-t), a bifunctional vector, pME-2, was developed, which combines a mutant selection system and a strong promoter providing controlled expression. An EcoRI/KpnI fragment containing the complete Trp promoter, a Shine-Dalgarno sequence, and an AT-rich region from the pTrp-2 expression vector was inserted into the large fragment of EcoRI/KpnI-digested pALTER-1 plasmid, which had been modified by eliminating a ClaI site. The pALTER-1 phagemid provides a highly efficient, antibiotic-dependent system for selection of mutant plaques. The existing T7 promoter was then eliminated from the recombinant phagemid to create the pME-2 vector. Ovine and bovine IFN-t genes lacking the coding region for the signal peptide, but with an ATG codon ahead of the open reading frame, were inserted into the multicloning site of pME-2. Following site-directed mutagenesis designed to produce elongations, truncations, and single and multiple amino acid replacements in the protein products, mutant genes were selected in Escherichia coli BMH 71-18 and efficiently expressed in E. coli JM-101 in response to the inducer of the Trp promoter indole acetic acid. The recombinant IFN were solubilized from washed inclusion bodies in guanidinium-HCl and 2-mercaptoethanol and allowed to refold in aerated buffer. The procedure provides high yields of fully active, homogeneous IFN-t and can be accomplished within 1 week.
Evaluating Power and Type 1 Error in Large Pedigree Analyses of Binary Traits

Studying population isolates with large, complex pedigrees has many advantages for discovering genetic susceptibility loci; however, statistical analyses can be computationally challenging. Allelic association tests need to be corrected for relatedness among study participants, and linkage analyses require subdividing and simplifying the pedigree structures. We have extended GenomeSIMLA to simulate SNP data in complex pedigree structures based on an Amish pedigree to generate the same structure and distribution of sampled individuals. We evaluated type 1 error rates when no disease SNP was simulated and power when disease SNPs with recessive, additive, and dominant modes of inheritance and odds ratios of 1.1, 1.5, 2.0, and 5.0 were simulated. We generated subpedigrees with a maximum bit-size of 24 using PedCut and performed two-point and multipoint linkage using Merlin. We also ran MQLS on the subpedigrees and unified pedigree. We saw no inflation of type 1 error when running MQLS on either the whole pedigrees or the sub-pedigrees, and we saw low type 1 error for two-point and multipoint linkage. Power was reduced when running MQLS on the subpedigrees versus the whole pedigree, and power was low for two-point and multipoint linkage analyses of the subpedigrees. These data suggest that MQLS has appropriate type 1 error rates in our Amish pedigree structure, and while type 1 error does not seem to be affected when dividing the pedigree prior to linkage analysis, power to detect linkage is diminished when the pedigree is divided.
Multi-sample scale problem: Unknown location parameters

In continuation of the author’s paper [3], here a class of rank order tests for the homogeneity of scale parameters is proposed and their properties are studied when the location parameters are unknown.
A note on composition factors of Weyl modules

Keywords: simple algebraic group ; reducibility ; Weyl modules Reference CTG-ARTICLE-1989-001doi:10.1080/00927878908823771 Record created on 2008-12-16, modified on 2017-05-12
CDP Binding to Multiple Sites in the Mouse Mammary Tumor Virus Long Terminal Repeat Suppresses Basal and Glucocorticoid-Induced Transcription

Mouse mammary tumor virus (MMTV) is transcribed at high levels in the lactating mammary gland to ensure transmission of virus from the milk of infected female mice to susceptible offspring. We previously have shown that the transcription factor CCAAT displacement protein (CDP) is expressed in high amounts in virgin mammary gland, yet DNA-binding activity for the MMTV long terminal repeat (LTR) disappears as mammary tissue differentiates during lactation. CDP is a repressor of MMTV expression and, therefore, MMTV expression is suppressed during early mammary gland development. In this study, we have shown using DNase I footprinting and electrophoretic mobility shift assays that there are at least five CDP-binding sites in the MMTV LTR upstream of those previously described in the promoter-proximal negative regulatory element (NRE). Single mutations in two of these upstream sites (+691 or +692 and +735 relative to the first base of the LTR) reduced CDP binding to the cognate sites and elevated reporter gene expression from the full-length MMTV LTR. Combination of a mutation in the promoter-distal NRE with a mutation in the proximal NRE gave approximately additive increases in LTR-reporter gene activity, suggesting that these binding sites act independently. Mutations in several different CDP-binding sites allowed elevation of reporter gene activity from the MMTV promoter in the absence and presence of glucocorticoids, hormones that contribute to high levels of MMTV transcription during lactation by activation of hormone receptor binding to the LTR. In addition, overexpression of CDP in transient-transfection assays suppressed both basal and glucocorticoid-induced LTR-mediated transcription in a dose-dependent manner. These data suggest that multiple CDP-binding sites contribute independently to regulate binding of positive factors, including glucocorticoid receptor, to the MMTV LTR during mammary gland development.
Determining Toxicity Trends in the Ozonation of Synthetic Dye Wastewaters Using the Nematode Caenorhabditis elegans

The nematode Caenorhabditis elegans was used in 72-h toxicity tests to evaluate the influence of ozonation on the toxicity of three synthetic azo dye wastewaters (two reactive dyes and one acid-based dye). The two reactive dye wastewaters contained high concentrations of NaCl (89-112 g/L) in addition to potentially toxic dye components. To determine the contribution of NaCl to toxicity, simulated dye wastewater samples with and without NaCl were tested. Samples were collected at various times during ozonation (t = 0, 8, 32, 64 min); nematodes were exposed to the samples for 72 h. The influence of ozonation on toxicity varied between dye wastewater types. For the acid-based dye wastewater, toxicity increased as duration of ozonation increased. For the reactive dyes without NaCl, toxicity did not appear to be influenced by ozonation. For the reactive dyes with NaCl, mortality was 100% with or without ozonation. Range-finding experiments with NaCl in water and NaCl in dye wastewaters suggested an additive toxic interaction between NaCl and the dyes in wastewater to the nematodes. The duration of ozonation for acid-based dyes and the relatively high NaCl concentrations for the reactive dyes appear to influence effluent toxicity in the ozonated dye wastewaters.
Comment on the ``Zero-shift thimble ionization chamber'' [Med. Phys. 37, 1161-1163 (2010)]

To the Editor, The recent publication on a zero-shift thimble ionization chamber by Tessier et al.1 recalls to mind the zero displacement ionization chamber for which a U.S. Patent No. 4,362,940 was issued in 1982. The displacement factor “d” was associated with the 1971 AAPM SCRAD protocol.2 In the TG21 1983 protocol,3 a related, but different factor, the replacement factor “Prepl,” was introduced. This factor corrects for the replacement of a phantom material by the ionization chamber. The genesis of the chamber was in a 1976 paper by Shapiro et al.4 on the displacement correction factor to be used for fast neutron dosimetry in which a computer program was described that calculated, based on geometrical considerations, the net amount of material displaced by an ion chamber in a liquid phantom. The calculated result was described as “missing phantom material” expressed in cm. In 1978 I used this program when commenting in the Communications section of Medical Physics5 on a paper from the Radiological Physics Center (RPC) on “Calibration in water versus calibration in air for cobalt-60 γ rays.”6 The missing phantom material was calculated for seven different chambers which allowed the appropriate displacement factor for the standard Farmer chamber to be determined, which was found to be independent of depth. In doing this study I realized that a chamber could be designed, by adjusting the wall and central electrode dimensions and material, which would yield zero missing phantom material and therefore a displacement factor of 1, effectively making the point of measurement the center of the chamber. This project was assigned to Richard Stark as a master’s degree project7 and was reported at the 1979 AAPM annual meeting.8 At that time, it appeared there might be some commercial application for such a chamber and a U.S. patent was applied for in 1980 and granted in 1982. The chamber was commercially manufactured as a Farmer-type chamber by PTW and sold by them as chamber number 233331 and Nuclear Associates as chamber number 30-36. By then, TG 21 had replaced the old SCRAD protocol and “displacement” had become “replacement,” and the chamber was advertised as a “replacement-free x-ray chamber.” The concept was also explored for x rays in the 6–25 MV range and the results were presented at the 1983 AAPM annual meeting.9 Although the “effective point of measurement” used by Tessier et al.1 is different from displacement and replacement, the factors are not unrelated and results in part from the fact that an ion chamber in a liquid phantom displaces some of the phantom material. Their approach to compensate for this by adjusting the chamber wall thickness is similar to the approach we used 30 years ago.
Cooperative Testing and Analysis: Human-Tool, Tool-Tool and Human-Human Cooperations to Get Work Done

Tool automation to reduce manual effort has been an active research area in various sub fields of software engineering such as software testing and analysis. To maximize the value of software testing and analysis, effective support for cooperation between engineers and tools is greatly needed and yet lacking in state-of-the-art research and practice. In particular, testing and analysis are in a great need of (1) effective ways for engineers to communicate their testing or analysis goals and guidance to tools and (2) tools with strong enough capabilities to accomplish the given testing or analysis goals and with effective ways to communicate challenges faced by them to engineers -- enabling a feedback loop between engineers and tools to refine and accomplish the testing or analysis goals. In addition, different tools have their respective strengths and weaknesses, and there is also a great need of allowing these tools to cooperate with each other. Similarly, there is a great need of allowing engineers (or even users) to cooperate to help tools such as in the form of crowd sourcing. A new research frontier on synergistic co operations between humans and tools, tools and tools, and humans and humans is yet to be explored. This paper presents recent example advances on cooperative testing and analysis.
"Bubbly" duodenal bulb in celiac disease: radiologic-pathologic correlation

Small (1-4 mm) hexagonal filling defects were found on air-contrast studies of the duodenal bulb in three patients with unresponsive (atypical) celiac disease. Multiple biopsies confirmed both celiac disease and peptic duodenitis. Stimulated acid outputs determined in two patients were in the peptic ulcer range. Cimetidine therapy led to improved absorption in all three patients. Repeat upper gastrointestinal series and endoscopy in one patient showed no evidence of nodularity or peptic duodenitis, indicating that these changes may be reversible. Peptic disease may contribute to nodularity in the duodenal bulb and relative lack of response to a gluten-free diet of some patients with celiac disease. The finding of tiny nodules in the duodenal bulb in a patient with malabsorption should lead to consideration of celiac disease as a primary diagnosis with peptic duodenitis as an aggravating factor.
Temporal flux and spatial dynamics of nutrients, fecal indicators, and zoonotic pathogens in anaerobic swine manure lagoon water

Confined animal feeding operations (CAFOs) often use anaerobic lagoons for manure treatment. In the USA, swine CAFO lagoon water is used for crop irrigation that is regulated by farm-specific nutrient management plans (NMPs). Implementation of stricter US environmental regulations in 2013 will set soil P limits; impacting land applications of manure and requiring revision of NMPs. Precise knowledge of lagoon water quality is needed for formulating NMPs, for understanding losses of N and C in ammonia and greenhouse gas emissions, and for understanding risks of environmental contamination by fecal bacteria, including zoonotic pathogens. In this study we determined year-round levels of nutrients and bacteria from swine CAFO lagoon water. Statistical analysis of data for pH, electrical conductivity (EC), inorganic and organic C, total N, water-soluble and total minerals (Ca, Cu, Fe, K, Mg, Mn, P, and Zn) and bacteria (Escherichia coli, enterococci, Clostridium perfringens, Campylobacter spp., Listeria spp., Salmonella spp., and staphylococci) showed that all differed significantly by dates of collection. During the irrigation season, levels of total N decreased by half and the N:P ratio changed from 9.7 to 2.8. Some seasonal differences were correlated with temperature. Total N and inorganic C increased below 19 °C, and decreased above 19 °C, consistent with summer increases in ammonia and greenhouse gas emissions. Water-soluble Cu, Fe, and Zn increased with higher summer temperatures while enterococci and zoonotic pathogens (Campylobacter, Listeria, and Salmonella) decreased. Although their populations changed seasonally, the zoonotic pathogens were present year-round. Increasing levels of E. coli were statistically correlated with increasing pH. Differences between depths were also found. Organic C, total nutrients (C, Ca, Cu, Fe, Mg, Mn, N, P, and Zn) and C. perfringens were higher in deeper samples, indicating stratification of these parameters. No statistical interactions were found between collection dates and depths.
Linking Public Health and the Health of the Chesapeake Bay

The Chesapeake Bay has a profound impact on the lives of all who reside in the 64,000 square miles of its watershed. From crab cakes to sailboats, drinking water to naval ships, the Bay touches virtually every aspect of life in the region. The Bay has inspired literature, driven the regional economy, and shaped political decision making and development patterns for homes, industry, agriculture, and transportation. As population demands increase and urban boundaries expand into pristine landscapes, the sustainability of the Chesapeake Bay and its resources face unprecedented pressures. Consequently, the public's health also is vulnerable to Bay pollution and other stresses stemming from development activities and widespread growth occurring throughout the Chesapeake Bay watershed. This paper will examine the linkages between the environmental quality of the Bay and the population health status, recommend ways to bridge ecological and human health concerns in the context of the Bay, and finally present a framework for developing a public health report card for the Bay.
Oxidative anodic tosylamidation at a vanadium electrode

Abstract Cyclohexene hydroperoxide is converted efficiently to cyclohexenyl tosylamide by electrolysis only at a vanadium anode.
Physician characteristics associated with proficiency in feedback skills.

BACKGROUND: Providing and eliciting high-quality feedback is valuable in medical education. Medical learners’ attainment of clinical competence and professional growth can be facilitated by reliable feedback. This study’s primary objective was to identify characteristics that are associated with physician teachers’ proficiency with feedback. METHODS: A cohort of 363 physicians, who were either past participants of the Johns Hopkins Faculty Development Program or members of a comparison group, were surveyed by mail in July 2002. Survey questions focused on personal characteristics, professional characteristics, teaching activities, self-assessed teaching proficiencies and behaviors, and scholarly activity. The feedback scale, a composite feedback variable, was developed using factor analysis. Logistic regression models were then used to determine which faculty characteristics were independently associated with scoring highly on a dichotomized version of the feedback scale. RESULTS: Two hundred and ninety-nine physicians responded (82%) of whom 262 (88%) had taught medical learners in the prior 12 months. Factor analysis revealed that the 7 questions from the survey addressing feedback clustered together to form the “feedback scale” (Cronbach’s α: 0.76). Six items, representing discrete faculty responses to survey questions, were independently associated with high feedback scores: (i) frequently attempting to detect and discuss the emotional responses of learners (odds ratio [OR]=4.6, 95% confidence interval [CI] 2.2 to 9.6), (ii) proficiency in handling conflict (OR=3.7, 95% CI 1.5 to 9.3), (iii) frequently asking learners what they desire from the teaching interaction (OR=3.5, 95% CI 1.7 to 7.2), (iv) having written down or reviewed professional goals in the prior year (OR=3.2, 95% CI 1.6 to 6.4), (v) frequently working with learners to establish mutually agreed upon goals, objectives, and ground rules (OR=2.2, 95% CI 1.1 to 4.7), and (vi) frequently letting learners figure things out themselves, even if they struggle (OR=2.1, 95% CI 1.1 to 3.9). CONCLUSIONS: Beyond providing training in specific feedback skills, programs that want to improve feedback performance among their faculty may wish to promote the teaching behaviors and proficiencies that are associated with high feedback scores identified in this study.
Acute glucose elevation is highly predictive of infection and outcome in critically injured trauma patients.

Objective(s): To evaluate whether acute glucose elevation (AGE) is predictive of infection and outcome in critically injured trauma patients during the first 14 days of ICU admission. Methods: A prospective study was conducted on 2200 patients admitted to the ICU over a 2 1/2 year period. The diagnosis of infection was made via a multidisciplinary fashion utilizing CDC criteria. After early glucose stabilization occurred (no significant change for 48 hours after admission) monitoring for AGE was performed utilizing a computational and graded algorithmic model. Iatrogenic causes of AGE were excluded. Stepwise regression models were performed controlling for age, gender, mechanism of injury, diabetes, injury severity, and APACHE 2 score. ROC curves were used to evaluate the positive predictive value of the test. Results: Seventy-seven percent of the patients in the cohort were males, and were admitted for blunt injuries (n = 1870 or 85%). The mean age, Injury Severity Score, and APACHE score were 44 ± 20 years, 29 ± 13, and 13 ± 7, respectively. The mean admission serum glucose value was 141 ± 36 mg/dL (range, 64―418 mg/dL). A total of 616 (28%) patients were diagnosed with an infection during the first 14 days of admission. AGE had a 91% positive predictive value for infection diagnosis. In addition, AGE was associated with a significant increase in ventilator, ICU, and hospital days as well as mortality even when adjusted for age, injury severity, APACHE score, and diabetes (P < 0.001). Conclusions: AGE is a highly accurate predictor of infection and should stimulate clinicians to identify a new source of infection.
A behavioral dynamics approach to obstacle detection and avoidance by patients with tunnel vision

Mobility issues are the typical sequelae of "tunnel vision" (severe peripheral visual field loss), and manifest in the difficulty patients have detecting and avoiding obstacles during locomotion. We examined the behavior of seven patients with tunnel vision (6°-27° visual fields) and six normally sighted individuals as they walked toward a visible goal in a virtual environment with or without an obstacle present. Each obstacle was a pole 1.8m tall and either stationary or moving across the path of the participant. Stationary obstacles appeared at a distance of 4 or 6m and an angle of 1° from the path to the goal. The moving obstacles crossed the participant's path at 4 or 6m while moving at a constant speed (50%, 70% or 90% of the participant's preferred walking speed). All obstacles appeared after participants walked 1m, and participants pressed a button when they detected an obstacle. Based on detection rates for short 1.2m obstacles (Kiefer et al., 2012), the patients were divided into two subgroups: (1) a low-detection group and (2) a high-detection group. We simulated individual locomotor trajectories using Fajen & Warren's (2003) steering dynamics model. RMSE between the model and human heading time series revealed no significant differences between the normally sighted (M = 0.28° +/- 0.01°), low-detection (M = 0.36° +/- 0.04°) and high-detection (M = 0.30° +/- 0.03°) groups with stationary obstacles; simulations with moving obstacles are ongoing. There was a trend toward greater variability in RMSE for both patient groups compared to the normally sighted group. The results indicate that tunnel vision patients have different detection strategies (Kiefer et al.), but once an obstacle is detected their locomotor behavior is similar to normally sighted pedestrians. Patients appear to exhibit noisier trajectories, perhaps due to difficulty tracking the obstacle as they fixate and steer toward the goal. Meeting abstract presented at VSS 2013 Language: en
Changes in ocean ventilation during the 21st Century in the CCSM3

Changes in the ventilation rate of the global ocean during the 20th and 21st centuries, as indicated by changes in the distribution of ideal age, are examined in a series of integrations of the Community Climate System Model version 3. The global mean age changes little in the 20th Century relative to pre-industrial conditions, but increases in the 21st Century, by an amount that is independent of the range of climate forcings considered. The increase is primarily due to a decrease in the ventilation rate of Antarctic Bottom Water (AABW), and to a lesser degree, North Atlantic Deep Water (NADW). Changes in a regional volumetric census of age indicate that the changes in AABW are predominantly for waters that are already older than 100 years, so will likely have a moderate direct feedback on oceanic uptake of CO2 and other tracers. On the other hand, the changes in NADW occur most strongly in waters that are a few decades old, so are more likely to have a feedback on the climate system. While the global mean age increases, the age does not increase everywhere in the ocean. Regions newly exposed to strong atmospheric forcing as sea ice retreats experience an increase in convection and decreasing age. Age also decreases over a large volume of the lower thermocline as the rate of upwelling of old deep water decreases with the weakening of the thermohaline circulation. � 2006 Elsevier Ltd. All rights reserved.
Melatonin receptors and their regulation: biochemical and structural mechanisms.

Abstract There is growing evidence demonstrating the complexity of melatonin's role in modulating a diverse number of physiological processes. This complexity could be attributed to the fact that melatonin receptors belong to two distinct classes of proteins, that is, the G-protein coupled receptor superfamily (MT1, MT2) and the quinone reductase enzyme family (MT3) which makes them unique at the molecular level. Also, within the G-protein coupled receptor family of proteins, the MT1 and MT2 receptors can couple to multiple and distinct signal transduction cascades whose activation can lead to unique cellular responses. Also, throughout the 24-hour cycle, the receptors' sensitivity to specific cues fluctuates and this sensitivity can be modulated in a homologous fashion, that is, by melatonin itself, and in a heterologous manner, that is, by other cues including the photoperiod or estrogen. This sensitivity of response may reflect changes in melatonin receptor density that also occurs throughout the 24-hour light/dark cycle but out of phase with circulating melatonin levels. The mechanisms that underlie the changes in melatonin receptor density and function are still not well-understood, but data is beginning to show that transcriptional events and G-protein uncoupling may be involved. Even though this area of research is still in its infancy, great strides are being made everyday in elucidating the mechanisms that underlie melatonin receptor function and regulation. The focus of this review is to highlight some of these discoveries in an attempt to reveal the uniqueness of the melatonin receptor family while at the same time provide thought-provoking ideas to further advance this area of research. Thus, a brief overview of each of the mammalian melatonin receptor subtypes and the signal transduction cascades to which they couple will be discussed with a greater emphasis placed on the mechanisms underlying their regulation and the domains within the receptors essential for proper signaling.