OBSERVABLE INDICATORS OF THE SENSITIVITY OF PM 2.5 NITRATE TO EMISSION REDUCTIONS, PART II: SENSITIVITY TO ERRORS IN TOTAL AMMONIA AND TOTAL NITRATE OF THE CMAQ-PREDICTED NONLINEAR EFFECT OF SO 2 EMISSION REDUCTIONS

EPA Science Inventory

The inorganic aerosol system of sulfate, nitrate, and ammonium can respond nonlinearly to changes in precursor sulfur dioxide (SO₂) emissions. The potential increase in nitrate, when sulfate is reduced and the associated ammonia is released, can negate the sulfate mass...

The role of emotions in the reduction of HIV/AIDS stigma among physicians in training.

PubMed

Varas-Díaz, Nelson; Neilands, Torsten B; Rodríguez-Madera, Sheilla L; Padilla, Mark

2016-01-01

Scientific literature has systematically documented the negative effects of social stigma for people living with HIV/AIDS (PLWHA). HIV/AIDS stigma has the potential to negatively impact self-care strategies for those already affected, and simultaneously hinder prevention efforts to deter the emergence of new infections. When health professionals manifest these negative attitudes access to quality health-care and prevention strategies can be seriously affected. Scientifically tested interventions to reduce HIV/AIDS stigma among health professionals are still scarce. Although the number of tested interventions has increased over the past decade, few of them target Latino health professionals or Spanish-speaking populations. Furthermore, although some of those interventions have been reported as effective for stigma reduction, more work is needed to better understand the underlying variables that account for the reduction of stigma attitudes in those efforts. The SPACES intervention has been documented as an effective HIV/AIDS stigma-reduction intervention focusing on health-care professionals in training. The intervention, which is delivered in Spanish, has been previously tested with medical students in Puerto Rico and shown significant results in addressing negative attitudes toward PLWHA. The main objective of this study was to document the underlying variables that fostered reduction of HIV/AIDS stigma due to participation in the SPACES intervention. Results evidence that health professionals in training who participated in the intervention (n = 507) had less stigmatizing attitudes toward PLWHA due to an increase in their positive emotions toward this population. In light of these results, we discuss the importance of engaging health professionals in HIV/AIDS stigma-reduction interventions that go beyond the provision of information and skills for interacting with PLWHA, and address the emotional component of HIV/AIDS stigma.

The role of emotions in the reduction of HIV/AIDS stigma among physicians in training

PubMed Central

Varas-Díaz, Nelson; Neilands, Torsten B.; Rodríguez-Madera, Sheilla L.; Padilla, Mark

2016-01-01

Scientific literature has systematically documented the negative effects of social stigma for people living with HIV/AIDS (PLWHA). HIV/AIDS stigma has the potential to negatively impact self-care strategies for those already affected, and simultaneously hinder prevention efforts to deter the emergence of new infections. When health professionals manifest these negative attitudes access to quality health-care and prevention strategies can be seriously affected. Scientifically tested interventions to reduce HIV/AIDS stigma among health professionals are still scarce. Although the number of tested interventions has increased over the past decade, few of them target Latino health professionals or Spanish-speaking populations. Furthermore, although some of those interventions have been reported as effective for stigma reduction, more work is needed to better understand the underlying variables that account for the reduction of stigma attitudes in those efforts. The SPACES intervention has been documented as an effective HIV/AIDS stigma-reduction intervention focusing on health-care professionals in training. The intervention, which is delivered in Spanish, has been previously tested with medical students in Puerto Rico and shown significant results in addressing negative attitudes toward PLWHA. The main objective of this study was to document the underlying variables that fostered reduction of HIV/AIDS stigma due to participation in the SPACES intervention. Results evidence that health professionals in training who participated in the intervention (n = 507) had less stigmatizing attitudes toward PLWHA due to an increase in their positive emotions toward this population. In light of these results, we discuss the importance of engaging health professionals in HIV/AIDS stigma-reduction interventions that go beyond the provision of information and skills for interacting with PLWHA, and address the emotional component of HIV/AIDS stigma. PMID:26444133

Financial strain and cognitive-based smoking processes: The explanatory role of depressive symptoms among adult daily smokers.

PubMed

Robles, Zuzuky; Anjum, Sahar; Garey, Lorra; Kauffman, Brooke Y; Rodríguez-Cano, Rubén; Langdon, Kirsten J; Neighbors, Clayton; Reitzel, Lorraine R; Zvolensky, Michael J

2017-07-01

Little work has focused on the underlying mechanisms that may link financial strain and smoking processes. The current study tested the hypothesis that financial strain would exert an indirect effect on cognitive-based smoking processes via depressive symptoms. Three clinically significant dependent variables linked to the maintenance of smoking were evaluated: negative affect reduction motives, negative mood abstinence expectancies, and perceived barriers for quitting. Participants included 102 adult daily smokers (M age =33.0years, SD=13.60; 35.3% female) recruited from the community to participate in a self-guided (unaided; no psychological or pharmacological intervention) smoking cessation study. Results indicated that depressive symptoms explain, in part, the relation between financial strain and smoking motives for negative affect reduction, negative mood abstinence expectancies, and perceived barriers for quitting. Results indicate that smoking interventions for individuals with high levels of financial strain may potentially benefit from the addition of therapeutic tactics aimed at reducing depression. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation of the reduction process of dopamine using paired pulse voltammetry

PubMed Central

Kim, Do Hyoung; Oh, Yoonbae; Shin, Hojin; Blaha, Charles D.; Bennet, Kevin E.; Lee, Kendall H.; Kim, In Young; Jang, Dong Pyo

2014-01-01

The oxidation of dopamine (DA) around +0.6V potential in anodic sweep and its reduction around −0.1V in cathodic sweep at a relatively fast scanning rate (300 V/s or greater) have been used for identification of DA oxidation in fast-scan cyclic voltammetry (FSCV). However, compared to the oxidation peak of DA, the reduction peak has not been fully examined in analytical studies, although it has been used as one of the representative features to identify DA. In this study, the reduction process of DA was investigated using paired pulse voltammetry (PPV), which consists of two identical triangle-shaped waveforms, separated by a short interval at the holding potential. Especially, the discrepancies between the magnitude of the oxidation and reduction peaks of DA were investigated based on three factors: (1) the instant desorption of the DA oxidation product (dopamine-o-quinone: DOQ) after production, (2) the effect of the holding potential on the reduction process, and (3) the rate-limited reduction process of DA. For the first test, the triangle waveform FSCV experiment was performed on DA with various scanrates (from 400 to 1000 V/s) and durations of switching potentials of the triangle waveform (from 0.0 to 6.0 ms) in order to vary the duration between the applied oxidation potential at +0.6V and the reduction potential at −0.2V. As a result, the ratio of reduction over oxidation peak current response decreased as the duration became longer. To evaluate the effect of holding potentials during the reduction process, FSCV experiments were conducted with holding potential from 0.0V to −0.8V. We found that more negative holding potentials lead to larger amount of reduction process. For evaluation of the rate-limited reduction process of DA, PPV with a 1Hz repetition rate and various delays (2, 8, 20, 40 and 80ms) between the paired scans were utilized to determine how much reduction process occurred during the holding potential (−0.4V). These tests showed that relatively large amounts of DOQ are reduced to DA during the holding potential. The rate-limited reduction process was also confirmed with the increase of reduction in a lower pH environment. In addition to the mechanism of the reduction process of DA, we found that the differences between the responses of primary and secondary pulses in PPV were mainly dependent on the rate-limited reduction process during the holding potential. In conclusion, the reduction process may be one of the important factors to be considered in the kinetic analysis of DA and other electroactive species in brain tissue and in the design of new types of waveform in FSCV. PMID:24926227

Chemistry and its Role in Sustainability

EPA Science Inventory

As evidenced in literature and practice, the goal of sustainability is being incorporated into the chemical sector. This approach is focused on the reduction of any potential negative effects upon the environment and human health that can be attributed to a chemical. In order to ...

Can older adults resist the positivity effect in neural responding? The impact of verbal framing on event-related brain potentials elicited by emotional images.

PubMed

Rehmert, Andrea E; Kisley, Michael A

2013-10-01

Older adults have demonstrated an avoidance of negative information, presumably with a goal of greater emotional satisfaction. Understanding whether avoidance of negative information is a voluntary, motivated choice or an involuntary, automatic response will be important to differentiate, as decision making often involves emotional factors. With the use of an emotional framing event-related potential (ERP) paradigm, the present study investigated whether older adults could alter neural responses to negative stimuli through verbal reframing of evaluative response options. The late positive potential (LPP) response of 50 older adults and 50 younger adults was recorded while participants categorized emotional images in one of two framing conditions: positive ("more or less positive") or negative ("more or less negative"). It was hypothesized that older adults would be able to overcome a presumed tendency to down-regulate neural responding to negative stimuli in the negative framing condition, thus leading to larger LPP wave amplitudes to negative images. A similar effect was predicted for younger adults, but for positively valenced images, such that LPP responses would be increased in the positive framing condition compared with the negative framing condition. Overall, younger adults' LPP wave amplitudes were modulated by framing condition, including a reduction in the negativity bias in the positive frame. Older adults' neural responses were not significantly modulated, even though task-related behavior supported the notion that older adults were able to successfully adopt the negative framing condition.

The impact of urea-induced unfolding on the redox process of immobilised cytochrome c.

PubMed

Monari, Stefano; Millo, Diego; Ranieri, Antonio; Di Rocco, Giulia; van der Zwan, Gert; Gooijer, Cees; Peressini, Silvia; Tavagnacco, Claudio; Hildebrandt, Peter; Borsari, Marco

2010-11-01

We have studied the effect of urea-induced unfolding on the electron transfer process of yeast iso-1-cytochrome c and its mutant K72AK73AK79A adsorbed on electrodes coated by mixed 11-mercapto-1-undecanoic acid/11-mercapto-1-undecanol self-assembled monolayers. Electrochemical measurements, complemented by surface enhanced resonance Raman studies, indicate two distinct states of the adsorbed proteins that mainly differ with respect to the ligation pattern of the haem. The native state, in which the haem is axially coordinated by Met80 and His18, displays a reduction potential that slightly shifts to negative values with increasing urea concentration. At urea concentrations higher than 6 M, a second state prevails in which the Met80 ligand is replaced by an additional histidine residue. This structural change in the haem pocket is associated with an approximately 0.4 V shift of the reduction potential to negative values. These two states were found for both the wild-type protein and the mutant in which lysine residues 72, 73 and 79 had been substituted by alanines. The analysis of the reduction potentials, the reaction enthalpies and entropies as well as the rate constants indicates that these three lysine residues have an important effect on stabilising the protein structure in the adsorbed state and facilitating the electron transfer dynamics.

Irrigation offsets wheat yield reductions from warming temperatures

NASA Astrophysics Data System (ADS)

Tack, Jesse; Barkley, Andrew; Hendricks, Nathan

2017-11-01

Temperature increases due to climate change are expected to cause substantial reductions in global wheat yields. However, uncertainty remains regarding the potential role for irrigation as an adaptation strategy to offset heat impacts. Here we utilize over 7000 observations spanning eleven Kansas field-trial locations, 180 varieties, and 29 years to show that irrigation significantly reduces the negative impact of warming temperatures on winter wheat yields. Dryland wheat yields are estimated to decrease about eight percent for every one-degree Celsius increase in temperature, yet irrigation completely offsets this negative impact in our sample. As in previous studies, we find that important interactions exist between heat stress and precipitation for dryland production. Here, uniquely, we observe both dryland and irrigated trials side-by-side at the same locations and find that precipitation does not provide the same reduction in heat stress as irrigation. This is likely to be because the timing, intensity, and volume of water applications influence wheat yields, so the ability to irrigate—rather than relying on rainfall alone—has a stronger influence on heat stress. We find evidence of extensive differences of water-deficit stress impacts across varieties. This provides some evidence of the potential for adapting to hotter and drier climate conditions using optimal variety selection. Overall, our results highlight the critical role of water management for future global food security. Water scarcity not only reduces crop yields through water-deficit stress, but also amplifies the negative effects of warming temperatures.

Effects of grassland restoration efforts on mound-building ants in the Chihuahuan Desert

USDA-ARS?s Scientific Manuscript database

Shrub encroachment is a serious problem in arid environments worldwide because of potential reductions in ecosystem services and negative effects on biodiversity. In southwestern USA, Chihuahuan Desert grasslands have experienced long-term encroachment by shrubs including creosotebush (Larrea triden...

Reversal of the asymmetry in a cylindrical coaxial capacitively coupled Ar/Cl 2 plasma

DOE PAGES

Upadhyay, Janardan; Im, Do; Popović, Svetozar; ...

2015-10-08

The reduction of the asymmetry in the plasma sheath voltages of a cylindrical coaxial capacitively coupled plasma is crucial for efficient surface modification of the inner surfaces of concave three-dimensional structures, including superconducting radio frequency cavities. One critical asymmetry effect is the negative dc self-bias, formed across the inner electrode plasma sheath due to its lower surface area compared to the outer electrode. The effect on the self-bias potential with the surface enhancement by geometric modification on the inner electrode structure is studied. The shapes of the inner electrodes are chosen as cylindrical tube, large and small pitch bellows, andmore » disc-loaded corrugated structure (DLCS). The dc self-bias measurements for all these shapes were taken at different process parameters in Ar/Cl 2 discharge. Lastly, the reversal of the negative dc self-bias potential to become positive for a DLCS inner electrode was observed and the best etch rate is achieved due to the reduction in plasma asymmetry.« less

Can Older Adults Resist the Positivity Effect in Neural Responding: The Impact of Verbal Framing on Event-Related Brain Potentials Elicited by Emotional Images

PubMed Central

Rehmert, Andrea E.; Kisley, Michael A.

2014-01-01

Older adults have demonstrated an avoidance of negative information presumably with a goal of greater emotional satisfaction. Understanding whether avoidance of negative information is a voluntary, motivated choice, or an involuntary, automatic response will be important to differentiate, as decision-making often involves emotional factors. With the use of an emotional framing event-related potential (ERP) paradigm, the present study investigated whether older adults could alter neural responses to negative stimuli through verbal reframing of evaluative response options. The late-positive potential (LPP) response of 50 older adults and 50 younger adults was recorded while participants categorized emotional images in one of two framing conditions: positive (“more or less positive”) or negative (“more or less negative”). It was hypothesized that older adults would be able to overcome a presumed tendency to down-regulate neural responding to negative stimuli in the negative framing condition thus leading to larger LPP wave amplitudes to negative images. A similar effect was predicted for younger adults but for positively valenced images such that LPP responses would be increased in the positive framing condition compared to the negative framing condition. Overall, younger adults' LPP wave amplitudes were modulated by framing condition, including a reduction in the negativity bias in the positive frame. Older adults' neural responses were not significantly modulated even though task-related behavior supported the notion that older adults were able to successfully adopt the negative framing condition. PMID:23731435

Exercise attenuates negative effects of abstinence during 72 hours of smoking deprivation.

PubMed

Conklin, Cynthia A; Soreca, Isabella; Kupfer, David J; Cheng, Yu; Salkeld, Ronald P; Mumma, Joel M; Jakicic, John M; Joyce, Christopher J

2017-08-01

Exercise is presumed to be a potentially helpful smoking cessation adjunct reputed to attenuate the negative effects of deprivation. The present study examined the effectiveness of moderate within-session exercise to reduce 4 key symptoms of smoking deprivation during 3 72-hr nicotine abstinence blocks in both male and female smokers. Forty-nine (25 male, 24 female) sedentary smokers abstained from smoking for 3 consecutive days on 3 separate occasions. At each session, smokers' abstinence-induced craving, cue-induced craving, negative mood, and withdrawal symptom severity were assessed prior to and after either exercise (a.m. exercise, p.m. exercise) or a sedentary control activity (magazine reading). Abstinence-induced craving and negative mood differed as a function of condition, F(2, 385) = 21, p < .0001; and, F(2, 385) = 3.38, p = .03. Planned contrasts revealed no difference between a.m. and p.m. exercise, but exercise overall led to greater pre-post reduction in abstinence-induced craving, t(385) = 6.23, p < .0001, effect size Cohen's d = 0.64; and negative mood, t(385) = 2.25, p = .03, d = 0.23. Overall exercise also led to a larger pre-post reduction in cue-induced craving in response to smoking cues, F(2, 387) = 8.94, p = .0002; and withdrawal severity, F(2, 385) = 3.8, p = .02. Unlike the other 3 measures, p.m. exercise reduced withdrawal severity over control, t(385) = 2.64, p = .009, d = 0.27, whereas a.m. exercise did not. The results support the clinical potential of exercise to assist smokers in managing common and robust negative symptoms experienced during the first 3 days of abstinence. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Application of a cognitive neuroscience perspective of cognitive control to late-life anxiety.

PubMed

Beaudreau, Sherry A; MacKay-Brandt, Anna; Reynolds, Jeremy

2013-08-01

Recent evidence supports a negative association between anxiety and cognitive control. Given age-related reductions in some cognitive abilities and the relation of late life anxiety to cognitive impairment, this negative association may be particularly relevant to older adults. This critical review conceptualizes anxiety and cognitive control from cognitive neuroscience and cognitive aging theoretical perspectives and evaluates the methodological approaches and measures used to assess cognitive control. Consistent with behavioral investigations of young adults, the studies reviewed implicate specific and potentially negative effects of anxiety on cognitive control processes in older adults. Hypotheses regarding the role of both aging and anxiety on cognitive control, the bi-directionality between anxiety and cognitive control, and the potential for specific symptoms of anxiety (particularly worry) to mediate this association, are specified and discussed. Published by Elsevier Ltd.

Application of a cognitive neuroscience perspective of cognitive control to late-life anxiety

PubMed Central

Beaudreau, Sherry A.; MacKay-Brandt, Anna; Reynolds, Jeremy

2013-01-01

Recent evidence supports a negative association between anxiety and cognitive control. Given age-related reductions in some cognitive abilities and the relation of late life anxiety to cognitive impairment, this negative association may be particularly relevant to older adults. This critical review conceptualizes anxiety and cognitive control from cognitive neuroscience and cognitive aging theoretical perspectives and evaluates the methodological approaches and measures used to assess cognitive control. Consistent with behavioral investigations of young adults, the studies reviewed implicate specific and potentially negative effects of anxiety on cognitive control processes in older adults. Hypotheses regarding the role of both aging and anxiety on cognitive control, the bi-directionality between anxiety and cognitive control, and the potential for specific symptoms of anxiety (particularly worry) to mediate this association, are specified and discussed. PMID:23602352

An Introductory Lesson to Environmental Health: Media Analysis and Risk Reduction

ERIC Educational Resources Information Center

Ratnapradipa, Dhitinut; Rhodes, Darson L.

2010-01-01

This activity is designed to provide students with an overview of environmental health and to encourage them to think critically about how they can minimize their potential negative health impacts from environmental exposures. Objectives: Students will (a) define environmental health, (b) analyze media wherein environmental health issues are…

Deconstructing the Emotion Regulatory Properties of Mindfulness: An Electrophysiological Investigation

PubMed Central

Lin, Yanli; Fisher, Megan E.; Roberts, Sean M. M.; Moser, Jason S.

2016-01-01

The present study sought to uncover the emotion regulatory properties of mindfulness by examining its effects—differentiated as a meditative practice, state of mind and dispositional trait—on the late positive potential (LPP), an event-related potentials (ERPs) indexing emotional processing. Results revealed that mindfulness as a meditative practice produced a reduction in the difference between the LPP response to negative high arousing and neutral stimuli across time. In contrast, a state mindfulness induction (i.e., instructions to attend to the stimuli mindfully) failed to modulate the LPP. Dispositional mindfulness, however, was related to modulation of the LPP as a function of meditation practice. Dispositional mindfulness was associated with a reduction of the LPP response to negative high arousal stimuli and the difference between negative high arousal and neutral stimuli in participants who listened to a control audio recording but not for those who engaged in the guided meditation practice. Together, these findings provide experimental evidence demonstrating that brief mindfulness meditation, but not deliberate engagement in state mindfulness, produces demonstrable changes in emotional processing indicative of reduced emotional reactivity. Importantly, these effects are akin to those observed in individuals with naturally high dispositional mindfulness, suggesting that the benefits of mindfulness can be cultivated through practice. PMID:27656139

Prosecution of non-disclosure of HIV status: Potential impact on HIV testing and transmission among HIV-negative men who have sex with men.

PubMed

Kesler, Maya A; Kaul, Rupert; Loutfy, Mona; Myers, Ted; Brunetta, Jason; Remis, Robert S; Gesink, Dionne

2018-01-01

Non-disclosure criminal prosecutions among gay, bisexual and other men who have sex with men (MSM) are increasing, even though transmission risk is low when effective antiretroviral treatment (ART) is used. Reduced HIV testing may reduce the impact of HIV "test and treat" strategies. We aimed to quantify the potential impact of non-disclosure prosecutions on HIV testing and transmission among MSM. MSM attending an HIV and primary care clinic in Toronto completed an audio computer-assisted self-interview questionnaire. HIV-negative participants were asked concern over non-disclosure prosecution altered their likelihood of HIV testing. Responses were characterized using cross-tabulations and bivariate logistic regressions. Flow charts modelled how changes in HIV testing behaviour impacted HIV transmission rates controlling for ART use, condom use and HIV status disclosure. 150 HIV-negative MSM were recruited September 2010 to June 2012. 7% (9/124) were less or much less likely to be tested for HIV due to concern over future prosecution. Bivariate regression showed no obvious socio/sexual demographic characteristics associated with decreased willingness of HIV testing to due concern about prosecution. Subsequent models estimated that this 7% reduction in testing could cause an 18.5% increase in community HIV transmission, 73% of which was driven by the failure of HIV-positive but undiagnosed MSM to access care and reduce HIV transmission risk by using ART. Fear of prosecution over HIV non-disclosure was reported to reduce HIV testing willingness by a minority of HIV-negative MSM in Toronto; however, this reduction has the potential to significantly increase HIV transmission at the community level which has important public health implications.

Prosecution of non-disclosure of HIV status: Potential impact on HIV testing and transmission among HIV-negative men who have sex with men

PubMed Central

Kaul, Rupert; Loutfy, Mona; Myers, Ted; Brunetta, Jason; Gesink, Dionne

2018-01-01

Background Non-disclosure criminal prosecutions among gay, bisexual and other men who have sex with men (MSM) are increasing, even though transmission risk is low when effective antiretroviral treatment (ART) is used. Reduced HIV testing may reduce the impact of HIV “test and treat” strategies. We aimed to quantify the potential impact of non-disclosure prosecutions on HIV testing and transmission among MSM. Methods MSM attending an HIV and primary care clinic in Toronto completed an audio computer-assisted self-interview questionnaire. HIV-negative participants were asked concern over non-disclosure prosecution altered their likelihood of HIV testing. Responses were characterized using cross-tabulations and bivariate logistic regressions. Flow charts modelled how changes in HIV testing behaviour impacted HIV transmission rates controlling for ART use, condom use and HIV status disclosure. Results 150 HIV-negative MSM were recruited September 2010 to June 2012. 7% (9/124) were less or much less likely to be tested for HIV due to concern over future prosecution. Bivariate regression showed no obvious socio/sexual demographic characteristics associated with decreased willingness of HIV testing to due concern about prosecution. Subsequent models estimated that this 7% reduction in testing could cause an 18.5% increase in community HIV transmission, 73% of which was driven by the failure of HIV-positive but undiagnosed MSM to access care and reduce HIV transmission risk by using ART. Conclusions Fear of prosecution over HIV non-disclosure was reported to reduce HIV testing willingness by a minority of HIV-negative MSM in Toronto; however, this reduction has the potential to significantly increase HIV transmission at the community level which has important public health implications. PMID:29489890

Cathodic electrodeposition of amorphous elemental selenium from an air- and water-stable ionic liquid.

PubMed

Redman, Daniel W; Murugesan, Sankaran; Stevenson, Keith J

2014-01-14

Electrodeposition of selenium from 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide is reported. In situ UV-vis spectroelectrochemistry was used to investigate the reduction of diethyl selenite to form elemental selenium thin films from an ionic liquid-acetonitrile medium. Three reduction peaks of diethyl selenite were observed via cyclic voltammetry and are attributed to the stepwise reduction of the selenium precursor adsorbed on the electrode. The electrodeposition mechanism is influenced by both potential and time. Electrodeposition at -1.7 V vs Pt QRE resulted in the deposition of elemental selenium nanoparticles that with time coalesced to form a continuous film. At reduction potentials more negative than -1.7 V the morphology of the deposit changed significantly due to the reduction of elemental Se to Se(2-). In addition, p-type photoconductivity of the films was observed during the spectroelectrochemical measurements. X-ray diffraction and Raman spectroscopy confirmed that the deposited selenium films were amorphous. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy confirm the films consisted of pure selenium with minor residual contamination from the precursor and ionic liquid.

Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations.

PubMed

Salvioni, Lucia; Galbiati, Elisabetta; Collico, Veronica; Alessio, Giulia; Avvakumova, Svetlana; Corsi, Fabio; Tortora, Paolo; Prosperi, Davide; Colombo, Miriam

2017-01-01

The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens) and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs) are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases. Water-soluble, negatively charged silver nanoparticles (AgNPs) were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet-visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs. In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells. We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared to currently available colloidal silver, suitable for cosmetic preservatives and pharmaceutical preparations administrable to humans and/or animals as needed.

Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations

PubMed Central

Salvioni, Lucia; Galbiati, Elisabetta; Collico, Veronica; Alessio, Giulia; Avvakumova, Svetlana; Corsi, Fabio; Tortora, Paolo; Prosperi, Davide; Colombo, Miriam

2017-01-01

Background The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens) and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs) are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases. Methods Water-soluble, negatively charged silver nanoparticles (AgNPs) were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet–visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs. Results In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells. Conclusion We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared to currently available colloidal silver, suitable for cosmetic preservatives and pharmaceutical preparations administrable to humans and/or animals as needed. PMID:28408822

Electrochemical reduction of toluene to methylcyclohexane for use as an energy carrier

NASA Astrophysics Data System (ADS)

Matsuoka, Koji; Miyoshi, Kota; Sato, Yasushi

2017-03-01

The electrochemical reduction of liquid toluene to methylcyclohexane (MCH) was investigated using a membrane electrode assembly (MEA) and high active-area catalysts commonly used in proton exchange membrane fuel cells (PEMFC). The current density on Pt/C was higher than on PtRu/C, which was comparable to that of alkaline water electrolysis. The potential of hydrogen evolution was shifted negatively by the presence of toluene and MCH. Therefore, the toluene reduction reaction was almost perfectly separated from the hydrogen evolution reaction. Toluene was perfectly reduced to MCH at around 0 V vs. RHE on PtRu/C and no by-products were detected in the solutions after electrolysis. MCH was produced at a Faradaic efficiency of more than 96% by carefully keeping the potential above -30 mV vs. RHE. Through this electrolytic process, we were able to reduce the concentration of toluene from 100% to 7.6%.

Paying less but harvesting more: the effect of unconscious acceptance in regulating frustrating emotion.

PubMed

Ding, NanXiang; Yang, JieMin; Liu, YingYing; Yuan, JiaJin

2015-08-01

Previous studies indicate that emotion regulation may occur unconsciously, without the cost of cognitive effort, while conscious acceptance may enhance negative experiences despite having potential long-term health benefits. Thus, it is important to overcome this weakness to boost the efficacy of the acceptance strategy in negative emotion regulation. As unconscious regulation occurs with little cost of cognitive resources, the current study hypothesizes that unconscious acceptance regulates the emotional consequence of negative events more effectively than does conscious acceptance. Subjects were randomly assigned to conscious acceptance, unconscious acceptance and no-regulation conditions. A frustrating arithmetic task was used to induce negative emotion. Emotional experiences were assessed on the Positive Affect and Negative Affect Scale while emotion- related physiological activation was assessed by heart-rate reactivity. Results showed that conscious acceptance had a significant negative affective consequence, which was absent during unconscious acceptance. That is, unconscious acceptance was linked with little reduction of positive affect during the experience of frustration, while this reduction was prominent in the control and conscious acceptance groups. Instructed, conscious acceptance resulted in a greater reduction of positive affect than found for the control group. In addition, both conscious and unconscious acceptance strategies significantly decreased emotion-related heart-rate activity (to a similar extent) in comparison with the control condition. Moreover, heart-rate reactivity was positively correlated with negative affect and negatively correlated with positive affect during the frustration phase relative to the baseline phase, in both the control and unconscious acceptance groups. Thus, unconscious acceptance not only reduces emotion-related physiological activity but also better protects mood stability compared with conscious acceptance. This suggests that the clinical practice of acceptance therapy may need to consider using the unconscious priming of an accepting attitude, instead of intentionally instructing people to implement such a strategy, to boost the efficacy of acceptance in emotion regulation.

Role of Health-Promoting Behaviours for On-Campus and Distance Education Students

ERIC Educational Resources Information Center

Beccaria, Lisa; Rogers, Cath; Burton, Lorelle; Beccaria, Gavin

2016-01-01

University students are likely to experience high rates of stress, which has the potential to negatively affect academic performance and their experience of study. Research with on-campus students has found positive benefits of health-promoting behaviours such as stress reduction and academic achievement; yet no research has examined these…

Rating the "Raters": Legal Exposure of Trustmark Authorities in the Context of Consumer Health Informatics

PubMed Central

Terry, Nicolas P

2000-01-01

There are three areas of potential legal exposure for an organization such as a trustmark authority involved in ehealth quality rating. First, an ehealth provider may make a complaint about negative or impliedly negative ratings rendered by the ratings body (false negative). Typically, a negative ratings complaint would rely on defamation or product disparagement causes of action. In some cases such complaints could be defended on the basis of absence of malice (US). Second, the rating body might render a positive rating on ehealth data that a third party allegedly relied upon and suffered injury (false positive). While the primary cause of action would be against the ehealth data provider, questions may arise as to possible liability of the trustmark authority. For example, some US liability exposure is possible based on cases involving the potential liability of product warrantors, trade associations and certifiers or endorsers. Third, a ratings body may face public law liability for its own web misfeasance. Several risk management approaches are possible and would not necessarily be mutually exclusive. These approaches will require careful investigation to assess their risk reduction potential and, in some cases, legislation.

Rating the Raters: Legal Exposure of Trustmark Authorities in the Context of Consumer Health Informatics

PubMed Central

2000-01-01

There are three areas of potential legal exposure for an organization such as a trustmark authority involved in e-health quality rating. First, an e-health provider may make a complaint about negative or impliedly negative ratings rendered by the ratings body (false negative). Typically, a negative ratings complaint would rely on defamation or product disparagement causes of action. In some cases such complaints could be defended on the basis of absence of malice (US). Second, the rating body might render a positive rating on e-health data that a third party allegedly relied upon and suffered injury (false positive). While the primary cause of action would be against the e-health data provider, questions may arise as to the possible liability of the trustmark authority. For example, some US liability exposure is possible based on cases involving the potential liability of product warrantors, trade associations, and certifiers or endorsers. Third, a ratings body may face public law liability for its own web misfeasance. Several risk management approaches are possible and would not necessarily be mutually exclusive. These approaches will require careful investigation to assess their risk reduction potential and, in some cases, the introduction of legislation. PMID:11720941

Rating the raters: legal exposure of trustmark authorities in the context of consumer health informatics.

PubMed

Terry, N P

2000-01-01

There are three areas of potential legal exposure for an organization such as a trustmark authority involved in e-health quality rating. First, an e-health provider may make a complaint about negative or impliedly negative ratings rendered by the ratings body (false negative). Typically, a negative ratings complaint would rely on defamation or product disparagement causes of action. In some cases such complaints could be defended on the basis of absence of malice (US). Second, the rating body might render a positive rating on e-health data that a third party allegedly relied upon and suffered injury (false positive). While the primary cause of action would be against the e-health data provider, questions may arise as to the possible liability of the trustmark authority. For example, some US liability exposure is possible based on cases involving the potential liability of product warrantors, trade associations, and certifiers or endorsers. Third, a ratings body may face public law liability for its own web misfeasance. Several risk management approaches are possible and would not necessarily be mutually exclusive. These approaches will require careful investigation to assess their risk reduction potential and, in some cases, the introduction of legislation.

The predictive utility of drinking refusal self-efficacy and alcohol expectancy: a diary-based study of tension reduction.

PubMed

Young, R M; Oei, T P

2000-01-01

The potential tension reduction effects of alcohol may be most appropriately tested by examining the role of alcohol related beliefs regarding alcohol's anxiolytic properties. The relationship between affective change drinking refusal self-efficacy, tension reduction alcohol expectancies, and ongoing drinking behavior was examined amongst 57 regular drinkers. Alcohol consumption, antecedent, and consequent mood states were monitored prospectively by diary, Social learning theory hypothesizes that low drinking refusal self-efficacy when experiencing a negative mood state should be associated with more frequent drinking when tense. Strong alcohol expectancies of tension reduction were hypothesized to predict subsequent tension reduction. Contrary to this hypothesis, the present study found that alcohol expectancies were more strongly related to antecedent mood states. Only a weak relationship between drinking refusal self-efficacy and predrinking tension, and between alcohol expectancy and subsequent tension reduction, was evident.

Mechanism of electrocatalytic hydrogen production by a di-iron model of iron-iron hydrogenase: a density functional theory study of proton dissociation constants and electrode reduction potentials.

PubMed

Surawatanawong, Panida; Tye, Jesse W; Darensbourg, Marcetta Y; Hall, Michael B

2010-03-28

Simple dinuclear iron dithiolates such as (mu-SCH2CH2CH2S)[Fe(CO)3]2, (1) and (mu-SCH2CH2S)[Fe(CO)3]2 (2) are functional models for diiron-hydrogenases, [FeFe]-H2ases, that catalyze the reduction of protons to H2. The mechanism of H2 production with 2 as the catalyst and with both toluenesulfonic (HOTs) and acetic (HOAc) acids as the H+ source in CH3CN solvent has been examined by density functional theory (DFT). Proton dissociation constants (pKa) and electrode reduction potentials (E(o)) are directly computed and compared to the measured pKa of HOTs and HOAc acids and the experimental reduction potentials. Computations show that when the strong acid, HOTs, is used as a proton source the one-electron reduced species 2- can be protonated to form a bridging hydride complex as the most stable structure. Then, this species can be reduced and protonated to form dihydrogen and regenerate 2. This cycle produces H2 via an ECEC process at an applied potential of -1.8 V vs. Fc/Fc+. A second faster process opens for this system when the species produced at the ECEC step above is further reduced and H2 release returns the system to 2- rather than 2, an E[CECE] process. On the other hand, when the weak acid, HOAc, is the proton source a more negative applied reduction potential (-2.2 V vs. Fc/Fc+) is necessary. At this potential two one-electron reductions yield the dianion 2(2-) before the first protonation, which in this case occurs on the thiolate. Subsequent reduction and protonation form dihydrogen and regenerate 2- through an E[ECEC] process.

Cathodic Corrosion at the Bismuth-Ionic Liquid Electrolyte Interface under Conditions for CO 2 Reduction

DOE PAGES

Medina Ramos, Jonnathan; Zhang, Weiwei; Yoon, Kichul; ...

2018-03-08

Bismuth electrodes undergo distinctive electrochemically induced structural changes in nonaqueous imidazolium ([Im])(+))-based ionic liquid solutions under cathodic polarization. In situ X-ray reflectivity (XR) studies have been undertaken to probe well-ordered Bi (001) films which originally contain a native Bi 2O 3 layer. This oxide layer gets reduced to Bi(0)during the first cyclic voltammetry (CV) scan in acetonitrile solutions containing 1-butyl-3-methylimidazolium ([BMIM](+)) electrolytes. Approximately 60% of the Bi (001) Bragg peak reflectivity is lost during a potential sweep between -1.5 and -1.9 V vs Ag/AgCI due to a similar to 4-10% thinning and a similar to 40% decrease in lateral sizemore » of Bi (001) domains, which are mostly reversed during the anodic scan. Repeated potential cycling enhances the thinning and roughening of the films, suggesting that partial dissolution of Bi ensues during negative polarization. The mechanism of this behavior is understood through molecular dynamics simulations using ReaxFF and density functional theory (DFT) calculations. Both approaches indicate that [Im] + cations bind to the metal surface more strongly than tetrabutylammonium (TBA +) as the potential and the charge on the Bi surface become more negative. ReaxFF simulations predict a higher degree of disorder for a negatively charged Bi (001) slab in the presence of the [Im](+)cations and substantial migration of Bi atoms from the surface. DFT simulations show the formation of Bi center dot center dot center dot[Im] + complexes that lead to the dissolution of Bi atoms from step edges on the Bi (001) surface at potentials between -1.65 and -1.95 V. Bi desorption from a flat terrace requires a potential of approximately -2.25 V. Together, these results suggest the formation of a Bi center dot center dot center dot[Im] + complex through partial cathodic corrosion of the Bi film under conditions (potential and electrolyte composition) that favor the catalytic reduction of CO 2 .« less

Cathodic Corrosion at the Bismuth-Ionic Liquid Electrolyte Interface under Conditions for CO 2 Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina Ramos, Jonnathan; Zhang, Weiwei; Yoon, Kichul

Bismuth electrodes undergo distinctive electrochemically induced structural changes in nonaqueous imidazolium ([Im])(+))-based ionic liquid solutions under cathodic polarization. In situ X-ray reflectivity (XR) studies have been undertaken to probe well-ordered Bi (001) films which originally contain a native Bi 2O 3 layer. This oxide layer gets reduced to Bi(0)during the first cyclic voltammetry (CV) scan in acetonitrile solutions containing 1-butyl-3-methylimidazolium ([BMIM](+)) electrolytes. Approximately 60% of the Bi (001) Bragg peak reflectivity is lost during a potential sweep between -1.5 and -1.9 V vs Ag/AgCI due to a similar to 4-10% thinning and a similar to 40% decrease in lateral sizemore » of Bi (001) domains, which are mostly reversed during the anodic scan. Repeated potential cycling enhances the thinning and roughening of the films, suggesting that partial dissolution of Bi ensues during negative polarization. The mechanism of this behavior is understood through molecular dynamics simulations using ReaxFF and density functional theory (DFT) calculations. Both approaches indicate that [Im] + cations bind to the metal surface more strongly than tetrabutylammonium (TBA +) as the potential and the charge on the Bi surface become more negative. ReaxFF simulations predict a higher degree of disorder for a negatively charged Bi (001) slab in the presence of the [Im](+)cations and substantial migration of Bi atoms from the surface. DFT simulations show the formation of Bi center dot center dot center dot[Im] + complexes that lead to the dissolution of Bi atoms from step edges on the Bi (001) surface at potentials between -1.65 and -1.95 V. Bi desorption from a flat terrace requires a potential of approximately -2.25 V. Together, these results suggest the formation of a Bi center dot center dot center dot[Im] + complex through partial cathodic corrosion of the Bi film under conditions (potential and electrolyte composition) that favor the catalytic reduction of CO 2 .« less

Greenhouse gas mitigation potentials in the livestock sector

NASA Astrophysics Data System (ADS)

Herrero, Mario; Henderson, Benjamin; Havlík, Petr; Thornton, Philip K.; Conant, Richard T.; Smith, Pete; Wirsenius, Stefan; Hristov, Alexander N.; Gerber, Pierre; Gill, Margaret; Butterbach-Bahl, Klaus; Valin, Hugo; Garnett, Tara; Stehfest, Elke

2016-05-01

The livestock sector supports about 1.3 billion producers and retailers, and contributes 40-50% of agricultural GDP. We estimated that between 1995 and 2005, the livestock sector was responsible for greenhouse gas emissions of 5.6-7.5 GtCO2e yr-1. Livestock accounts for up to half of the technical mitigation potential of the agriculture, forestry and land-use sectors, through management options that sustainably intensify livestock production, promote carbon sequestration in rangelands and reduce emissions from manures, and through reductions in the demand for livestock products. The economic potential of these management alternatives is less than 10% of what is technically possible because of adoption constraints, costs and numerous trade-offs. The mitigation potential of reductions in livestock product consumption is large, but their economic potential is unknown at present. More research and investment are needed to increase the affordability and adoption of mitigation practices, to moderate consumption of livestock products where appropriate, and to avoid negative impacts on livelihoods, economic activities and the environment.

Implementation of a biotechnological process for vat dyeing with woad.

PubMed

Osimani, Andrea; Aquilanti, Lucia; Baldini, Gessica; Silvestri, Gloria; Butta, Alessandro; Clementi, Francesca

2012-09-01

The traditional process for vat dyeing with woad (Isatis tinctoria L.) basically relies on microbial reduction of indigo to its soluble form, leucoindigo, through a complex fermentative process. In the 19th century, cultivation of woad went into decline and use of synthetic indigo dye and chemical reduction agents was established, with a consequent negative impact on the environment due to the release of polluting wastewaters by the synthetic dyeing industry. Recently, the ever-growing demand for environmentally friendly dyeing technologies has led to renewed interest in ecological textile traditions. In this context, this study aims at developing an environmentally friendly biotechnological process for vat dyeing with woad to replace use of polluting chemical reduction agents. Two simple broth media, containing yeast extract or corn steep liquor (CSL), were comparatively evaluated for their capacity to sustain the growth and reducing activity of the strain Clostridium isatidis DSM 15098(T). Subsequently, the dyeing capacity of the CSL medium added with 140 g L⁻¹ of woad powder, providing 2.4 g L⁻¹ of indigo dye, was evaluated after fermentation in laboratory bioreactors under anaerobic or microaerophilic conditions. In all fermentations, a sufficiently negative oxidation/reduction potential for reduction of indigo was reached as early as 24 h and maintained up to the end of the monitoring period. However, clearly faster indigo dye reduction was seen in the broth cultures fermented under strict anaerobiosis, thus suggesting the suitability of the N₂ flushing strategy for enhancement of bacterial-driven indigo reduction.

Self-efficacy and dietary fat reduction behaviors in obese African-American and white mothers.

PubMed

Chang, Mei-Wei; Brown, Roger L; Baumann, Linda J; Nitzke, Susan A

2008-05-01

This study examined the influence of weight management and education on five types of fat reduction behaviors mediated through three task-specific domains of self-efficacy among young, low-income obese African-American and white mothers. It also investigated interaction of race with the relationships between weight management, education, self-efficacy, and fat reduction behaviors. A sample of obese African-American and white mothers was recruited from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Wisconsin. Participants reported their weight management status, education, self-efficacy for eating low-fat food, and fat reduction behaviors. For both racial groups, weight management status predicted low-fat food substitution and meat modification behaviors; education predicted meat modification behavior. Three task-specific domains of self-efficacy (negative mood, positive mood, and food availability) predicted different types of fat reduction behaviors and differed by race. Weight management influenced behaviors of low-fat food substitution, meat modification, and fried-food avoidance, mediated partially through self-efficacies of negative mood (African Americans), positive mood (African Americans, whites), and food availability (African Americans). Race affected the relationships between weight management, education, three task-specific domains of self-efficacy, and five types of fat reduction behaviors. Self-efficacies operated differentially for African Americans and whites. Thus, strategies to address specific fat reduction behaviors have the potential to be more effective when tailored to specific individual characteristics such as racial background, history of weight management strategies and task-specific domains of self-efficacy.

Biomass enables the transition to a carbon-negative power system across western North America

NASA Astrophysics Data System (ADS)

Sanchez, Daniel L.; Nelson, James H.; Johnston, Josiah; Mileva, Ana; Kammen, Daniel M.

2015-03-01

Sustainable biomass can play a transformative role in the transition to a decarbonized economy, with potential applications in electricity, heat, chemicals and transportation fuels. Deploying bioenergy with carbon capture and sequestration (BECCS) results in a net reduction in atmospheric carbon. BECCS may be one of the few cost-effective carbon-negative opportunities available should anthropogenic climate change be worse than anticipated or emissions reductions in other sectors prove particularly difficult. Previous work, primarily using integrated assessment models, has identified the critical role of BECCS in long-term (pre- or post-2100 time frames) climate change mitigation, but has not investigated the role of BECCS in power systems in detail, or in aggressive time frames, even though commercial-scale facilities are starting to be deployed in the transportation sector. Here, we explore the economic and deployment implications for BECCS in the electricity system of western North America under aggressive (pre-2050) time frames and carbon emissions limitations, with rich technology representation and physical constraints. We show that BECCS, combined with aggressive renewable deployment and fossil-fuel emission reductions, can enable a carbon-negative power system in western North America by 2050 with up to 145% emissions reduction from 1990 levels. In most scenarios, the offsets produced by BECCS are found to be more valuable to the power system than the electricity it provides. Advanced biomass power generation employs similar system design to advanced coal technology, enabling a transition strategy to low-carbon energy.

The indirect effect of emotion dysregulation in terms of negative affect and smoking-related cognitive processes.

PubMed

Johnson, Adrienne L; McLeish, Alison C

2016-02-01

Although negative affect is associated with a number of smoking-related cognitive processes, the mechanisms underlying these associations have yet to be examined. The current study sought to examine the indirect effect of emotion regulation difficulties in terms of the association between negative affect and smoking-related cognitive processes (internal barriers to cessation, negative affect reduction smoking motives, negative affect reduction smoking outcome expectancies). Participants were 126 daily cigarette smokers (70.4% male, Mage=36.5years, SD=13.0; 69.8% Caucasian) who smoked an average of 18.5 (SD=8.7) cigarettes per day and reported moderate nicotine dependence. Formal mediation analyses were conducted using PROCESS to examine the indirect effect of negative affect on internal barriers to cessation and negative affect reduction smoking motives and outcome expectancies through emotion regulation difficulties. After accounting for the effects of gender, daily smoking rate, and anxiety sensitivity, negative affect was indirectly related to internal barriers to cessation and negative affect reduction smoking motives through emotion regulation difficulties. There was no significant indirect effect for negative affect reduction smoking outcome expectancies. These findings suggest that greater negative affect is associated with a desire to smoke to reduce this negative affect and perceptions that quitting smoking will be difficult due to negative emotions because of greater difficulties managing these negative emotions. Thus, emotion regulation difficulties may be an important target for smoking cessation interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Robust impact of social anxiety in relation to coping motives and expectancies, barriers to quitting, and cessation-related problems.

PubMed

Buckner, Julia D; Zvolensky, Michael J; Jeffries, Emily R; Schmidt, Norman B

2014-08-01

Although social anxiety is related to smoking and nicotine dependence, few researchers have sought to identify factors that contribute to these relations. The current study examined whether social anxiety was associated with cognitive vulnerability factors related to smoking: perceived barriers for quitting, cessation-related problems, negative-affect-reduction-outcome expectancies, and negative-affect-reduction motives. Further, we tested whether social anxiety was robustly related to these factors after controlling for cigarettes smoked per day, gender, alcohol-use frequency, lifetime cannabis-use status, panic attack frequency, anxiety sensitivity, and negative affectivity. The sample consisted of 580 (38.6% female) treatment-seeking smokers. Social anxiety was associated with perceived barriers for quitting, cessation-related problems, negative-affect-reduction-outcome expectancies, and negative-affect-reduction motives. After controlling for covariates, social anxiety was robustly related to perceived barriers for quitting, cessation-related problems, and negative-affect-reduction-outcome expectancies. Social anxiety was robustly related to negative-affect-reduction motives among men, but not women. Results indicate that social anxiety is robustly related to cognitive vulnerability factors associated with poorer cessation outcomes, suggesting that social anxiety may be an important therapeutic target during smoking cessation.

Characterizing use patterns and perceptions of relative harm in dual users of electronic and tobacco cigarettes

PubMed Central

Rass, Olga; Pacek, Lauren R.; Johnson, Patrick S.; Johnson, Matthew W.

2015-01-01

Awareness and use of electronic cigarettes (e-cigarettes) is increasing. Questions regarding positive (e.g., smoking reduction/cessation) and negative (e.g., delay of cessation) potential public health consequences of e-cigarettes may be informed by studying dual users of e-cigarettes and tobacco cigarettes. A cross-sectional online survey assessed demographics, product use patterns, and beliefs about relative product benefits and harms among dual users (n = 350) in the United States using the website Amazon Mechanical Turk (MTurk). Compared to tobacco cigarettes, e-cigarettes were used less often and were associated with lower dependence. Participants reported a 30% reduction in self-reported tobacco cigarette smoking since beginning to use e-cigarettes. Reported primary reasons for e-cigarette use were harm reduction and smoking cessation. E-cigarette use was reported as more likely in settings with smoking restrictions and when others’ health could be adversely affected. Conversely, participants reported having used tobacco cigarettes more often than e-cigarettes in hedonic situations (e.g., after eating, drinking coffee or alcohol, or having sex), outdoors, or when stressed. Participants were twice as likely to report wanting to quit tobacco cigarettes compared to e-cigarettes in the next year and intended to quit tobacco cigarettes sooner. Tobacco cigarettes were described as more harmful and addictive, but also more enjoyable than e-cigarettes. Participants provided evidence consistent with both positive and negative public health consequences of e-cigarettes, highlighting the need for experimental research, including laboratory studies and clinical trials. Policies should consider potential public health benefits of e-cigarettes, in addition to potential harms. PMID:26389638

The Role of Electrode-Catalyst Interactions in Enabling Efficient CO2 Reduction with Mo(bpy)(CO)4 As Revealed by Vibrational Sum-Frequency Generation Spectroscopy.

PubMed

Neri, Gaia; Donaldson, Paul M; Cowan, Alexander J

2017-10-04

Group 6 metal carbonyl complexes ([M(bpy)(CO) 4 ], M = Cr, Mo, W) are potentially promising CO 2 reduction electrocatalysts. However, catalytic activity onsets at prohibitively negative potentials and is highly dependent on the nature of the working electrode. Here we report in situ vibrational SFG (VSFG) measurements of the electrocatalyst [Mo(bpy)(CO) 4 ] at platinum and gold electrodes. The greatly improved onset potential for electrocatalytic CO 2 reduction at gold electrodes is due to the formation of the catalytically active species [Mo(bpy)(CO) 3 ] 2- via a second pathway at more positive potentials, likely avoiding the need for the generation of [Mo(bpy)(CO) 4 ] 2- . VSFG studies demonstrate that the strength of the interaction between initially generated [Mo(bpy)(CO) 4 ] •- and the electrode is critical in enabling the formation of the active catalyst via the low energy pathway. By careful control of electrode material, solvent and electrolyte salt, it should therefore be possible to attain levels of activity with group 6 complexes equivalent to their much more widely studied group 7 analogues.

Combination of cathodic reduction with adsorption for accelerated removal of Cr(VI) through reticulated vitreous carbon electrodes modified with sulfuric acid-glycine co-doped polyaniline.

PubMed

Mo, Xi; Yang, Zhao-hui; Xu, Hai-yin; Zeng, Guang-ming; Huang, Jing; Yang, Xia; Song, Pei-pei; Wang, Li-ke

2015-04-09

Improving the reduction kinetics is crucial in the electroreduction process of Cr(VI). In this study, we developed a novel adsorption-electroreduction system for accelerated removal of Cr(VI) by employing reticulated vitreous carbon electrode modified with sulfuric acid-glycine co-doped polyaniline (RVC/PANI-SA-GLY). Firstly, response surface methodology confirmed the optimum polymerization condition of co-doped polyaniline for modifying electrodes (Aniline, sulfuric acid and glycine, respectively, of 0.2 mol/L, 0.85 mol/L, 0.93 mol/L) when untraditional dopant glycine was added. Subsequently, RVC/PANI-SA-GLY showed higher Cr(VI) removal percentages in electroreduction experiments over RVC electrode modified with sulfuric acid doped polyaniline (RVC/PANI-SA) and bare RVC electrode. In contrast to RVC/PANI-SA, the improvement by RVC/PANI-SA-GLY was more significant and especially obvious at more negative potential, lower initial Cr(VI) concentration, relatively less acidic solution and higher current densities, best achieving 7.84% higher removal efficiency with entire Cr(VI) eliminated after 900 s. Current efficiencies were likewise enhanced by RVC/PANI-SA-GLY under quite negative potentials. Fourier transform infrared (FTIR) and energy dispersive spectrometer (EDS) analysis revealed a possible adsorption-reduction mechanism of RVC/PANI-SA-GLY, which greatly contributed to the faster reduction kinetics and was probably relative to the absorption between protonated amine groups of glycine and HCrO4(-). Eventually, the stability of RVC/PANI-SA-GLY was proven relatively satisfactory. Copyright © 2015 Elsevier B.V. All rights reserved.

Theoretical determination of one-electron redox potentials for DNA bases, base pairs, and stacks.

PubMed

Paukku, Y; Hill, G

2011-05-12

Electron affinities, ionization potentials, and redox potentials for DNA bases, base pairs, and N-methylated derivatives are computed at the DFT/M06-2X/6-31++G(d,p) level of theory. Redox properties of a guanine-guanine stack model are explored as well. Reduction and oxidation potentials are in good agreement with the experimental ones. Electron affinities of base pairs were found to be negative. Methylation of canonical bases affects the ionization potentials the most. Base pair formation and base stacking lower ionization potentials by 0.3 eV. Pairing of guanine with the 5-methylcytosine does not seem to influence the redox properties of this base pair much.

Effect of dissolved oxygen on redox potential and milk acidification by lactic acid bacteria isolated from a DL-starter culture.

PubMed

Larsen, Nadja; Werner, Birgit Brøsted; Vogensen, Finn Kvist; Jespersen, Lene

2015-03-01

Milk acidification by DL-starter cultures [cultures containing Lactococcus lactis diacetylactis (D) and Leuconostoc (L) species] depends on the oxidation-reduction (redox) potential in milk; however, the mechanisms behind this effect are not completely clear. The objective of this study was to investigate the effect of dissolved oxygen on acidification kinetics and redox potential during milk fermentation by lactic acid bacteria (LAB). Fermentations were conducted by single strains isolated from mixed DL-starter culture, including Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Leuconostoc mesenteroides ssp. cremoris, by the DL-starter culture, and by the type strains. High and low levels of oxygen were produced by flushing milk with oxygen or nitrogen, respectively. The kinetics of milk acidification was characterized by the maximum rate and time of acidification (Vamax and Tamax), the maximum rate and time of reduction (Vrmax and Trmax), the minimum redox potential (Eh7 final), and time of reaching Eh7 final (Trfinal). Variations in kinetic parameters were observed at both the species and strain levels. Two of the Lc. lactis ssp. lactis strains were not able to lower redox potential to negative values. Kinetic parameters of the DL-starter culture were comparable with the best acidifying and reducing strains, indicating their additive effects. Acidification curves were mostly diauxic at all oxygen levels, displaying 2 maxima of acidification rate: before (aerobic maximum) and after (anaerobic maximum) oxygen depletion. The redox potential decreased concurrently with oxygen consumption and continued to decrease at slower rate until reaching the final values, indicating involvement of both oxygen and microbiological activity in the redox state of milk. Oxygen flushing had a negative effect on reduction and acidification capacity of tested LAB. Reduction was significantly delayed at high initial oxygen, exhibiting longer Trmax, Trfinal, or both. Concurrently, anaerobic acidification rate maximum Vamax was decreased and Tamax was extended. Fermentation kinetics in nitrogen-flushed milk was not statistically different from that in untreated milk except for Lc. lactis ssp. lactis CHCC D2, which showed faster reduction time after nitrogen flushing. This study clarifies the relationship between the redox state in milk and acidification kinetics of the predominant subspecies in DL-starter cultures. This knowledge is important for dairies to ensure optimized, fast, and controlled milk fermentations, leading to greater standardization of dairy products. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Research progress on ionic plasmas generated in an intense hydrogen negative ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeiri, Y., E-mail: takeiri@nifs.ac.jp; Tsumori, K.; Nagaoka, K.

2015-04-08

Characteristics of ionic plasmas, observed in a high-density hydrogen negative ion source, are investigated with a multi-diagnostics system. The ionic plasma, which consists of hydrogen positive- and negative-ions with a significantly low-density of electrons, is generated in the ion extraction region, from which the negative ions are extracted through the plasma grid. The negative ion density, i.e., the ionic plasma density, as high as the order of 1×10{sup 17}m{sup −3}, is measured with cavity ring-down spectroscopy, while the electron density is lower than 1×10{sup 16}m{sup −3}, which is confirmed with millimeter-wave interferometer. Reduction of the negative ion density is observedmore » at the negative ion extraction, and at that time the electron flow into the ionic plasma region is observed to conserve the charge neutrality. Distribution of the plasma potential is measured in the extraction region in the direction normal to the plasma grid surface with a Langmuir probe, and the results suggest that the sheath is formed at the plasma boundary to the plasma grid to which the bias voltage is applied. The beam extraction should drive the negative ion transport in the ionic plasma across the sheath formed on the extraction surface. Larger reduction of the negative ions at the beam extraction is observed in a region above the extraction aperture on the plasma grid, which is confirmed with 2D image measurement of the Hα emission and cavity ring-down spectroscopy. The electron distribution is also measured near the plasma grid surface. These various properties observed in the ionic plasma are discussed.« less

Photosensitized electron transport across lipid vesicle walls: Enhancement of quantum yield by ionophores and transmembrane potentials

PubMed Central

Laane, Colja; Ford, William E.; Otvos, John W.; Calvin, Melvin

1981-01-01

The photosensitized reduction of heptylviologen in the bulk aqueous phase of phosphatidylcholine vesicles containing EDTA inside and a membrane-bound tris(2,2′-bipyridine)ruthenium(2+) derivative is enhanced by a factor of 6.5 by the addition of valinomycin in the presence of K+. A 3-fold stimulation by gramicidin and carbonyl cyanide m-chlorophenylhydrazone is observed. The results suggest that, under these conditions, the rate of photoinduced electron transfer across vesicle walls in the absence of ion carriers is limited by cotransport of cations. The rate of electron transfer across vesicle walls could be influenced further by generating transmembrane potentials with K+ gradients in the presence of valinomycin. When vesicles are made with transmembrane potentials, interior more negative, the quantum yield of heptylviologen reduction is doubled, and, conversely, when vesicles are made with transmembrane potentials, interior more positive, the quantum yield is decreased and approaches the value found in the absence of valinomycin. PMID:16593002

Catalyst surfaces for the chromous/chromic redox couple

NASA Technical Reports Server (NTRS)

Giner, J. D.; Cahill, K. J. (Inventor)

1981-01-01

An electricity producing cell of the reduction-oxidation (REDOX) type divided into two compartments by a membrane is disclosed. A ferrous/ferric couple in a chloride solution serves as a cathode fluid to produce a positive electric potential. A chromic/chromous couple in a chloride solution serves as an anode fluid to produce a negative potential. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which has been added to the anode fluid. If the REDOX cell is then discharged, the lead deplates from the negative electrode and the metal coating on the electrode acts as a catalyst to increase current density.

Ultramicroelectrode Studies of Self-Terminated Nickel Electrodeposition and Nickel Hydroxide Formation upon Water Reduction.

PubMed

Ritzert, Nicole L; Moffat, Thomas P

2016-12-08

The interaction between electrodeposition of Ni and electrolyte breakdown, namely the hydrogen evolution reaction (HER) via H 3 O + and H 2 O reduction, was investigated under well-defined mass transport conditions using ultramicroelectrodes (UME's) coupled with optical imaging, generation/collection scanning electrochemical microscopy (G/C-SECM), and preliminary microscale pH measurements. For 5 mmol/L NiCl 2 + 0.1 mol/L NaCl, pH 3.0, electrolytes, the voltammetric current at modest overpotentials, i.e. , between -0.6 V and -1.4 V vs. Ag/AgCl, was distributed between metal deposition and H 3 O + reduction, with both reactions reaching mass transport limited current values. At more negative potentials, an unusual sharp current spike appeared upon the onset of H 2 O reduction that was accompanied by a transient increase in H 2 production. The peak potential of the current spike was a function of both [Ni(H 2 O) 6 ] 2+ (aq) concentration and pH. The sharp rise in current was ascribed to the onset of autocatalytic H 2 O reduction, where electrochemically generated OH - species induce heterogeneous nucleation of Ni(OH) 2(ads) islands, the perimeter of which is reportedly active for H 2 O reduction. As the layer coalesces, further metal deposition is quenched while H 2 O reduction continues albeit at a decreased rate as fewer of the most reactive sites, e.g. , Ni/Ni(OH) 2 island edges, are available. At potentials below -1.5 V vs. Ag/AgCl, H 2 O reduction is accelerated, leading to homogeneous precipitation of bulk Ni(OH) 2 · x H 2 O within the nearly hemispherical diffusion layer of the UME.

Simultaneous recording of eeg and direct current (DC) potential makes it possible to assess functional and metabolic state of nervous tissue.

PubMed

Murik, S E; Shapkin, A G

2004-08-01

It has been proposed to assess functional and metabolic state of the brain nervous tissue in terms of bioelectrical parameters. Simultaneous recording of the DC potential level and total slow electrical activity of the nervous tissue was performed in the object of study by nonpolarizable Ag/AgCl electrodes with a DC amplifier. The functional and metabolic state of the brain was determined in terms of enhancement or reduction in the total slow electrical activity and positive or negative shifts in the DC potential level.

Reductive Dissolution of Goethite and Hematite by Reduced Flavins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Zhi; Zachara, John M.; Wang, Zheming

2013-10-02

The abiotic reductive dissolution of goethite and hematite by the reduced forms of flavin mononucleotide (FMNH2) and riboflavin (RBFH2), electron transfer mediators (ETM) secreted by the dissimilatory iron-reducing bacterium Shewanella, was investigated under stringent anaerobic conditions. In contrast to the rapid redox reaction rate observed for ferrihydrite and lepidocrocite (Shi et al., 2012), the reductive dissolution of crystalline goethite and hematite was slower, with the extent of reaction limited by the thermodynamic driving force at circumneutral pH. Both the initial reaction rate and reaction extent increased with decreasing pH. On a unit surface area basis, goethite was less reactive thanmore » hematite between pH 4.0 and 7.0. AH2DS, the reduced form of the well-studied synthetic ETM anthraquinone-2,6-disulfonate (AQDS), yielded higher rates than FMNH2 under most reaction conditions, despite the fact that FMNH2 was a more effective reductant than AH2DS for ferryhydrite and lepidocrocite. Two additional model compounds, methyl viologen and benzyl viologen, were investigated under similar reaction conditions to explore the relationship between reaction rate and thermodynamic properties. Relevant kinetic data from the literature were also included in the analysis to span a broad range of half-cell potentials. Other conditions being equal, the surface area normalized initial reaction rate (ra) increased as the redox potential of the reductant became more negative. A non-linear, parabolic relationship was observed between log ra and the redox potential for eight reducants at pH 7.0, as predicted by Marcus theory for electron transfer. When pH and reductant concentration were fixed, log ra was positively correlated to the redox potential of four Fe(III) oxides over a wide pH range, following a non-linear parabolic relationship as well.« less

Photosensitized electron transfer processes in SiO2 colloids and sodium lauryl sulfate micellar systems: Correlation of quantum yields with interfacial surface potentials

PubMed Central

Laane, Colja; Willner, Itamar; Otvos, John W.; Calvin, Melvin

1981-01-01

The effectiveness of negatively charged colloidal SiO2 particles in controlling photosensitized electron transfer reactions has been studied and compared with that of the negatively charged sodium lauryl sulfate (NaLauSO4) micellar system. In particular, the photosensitized reduction of the zwitterionic electron acceptor propylviologen sulfonate (PVS0) with tris(2,2′-bipyridinium)ruthenium(II) [Ru(bipy)32+] as the sensitizer and triethanolamine as the electron donor is found to have a quantum yield of 0.033 for formation of the radical anion (PVS[unk]) in the SiO2 colloid compared with 0.005 in the homogeneous system and 0.0086 in a NaLauSO4 micellar solution. The higher quantum yields obtained with the SiO2 colloidal system are attributed to substantial stabilization against back reaction of the intermediate photoproducts—i.e., Ru(bipy)33+ and PVS[unk]—by electrostatic repulsion of the reduced electron acceptor from the negatively charged particle surface. The binding properties of the SiO2 particles and NaLauSO4 micelles were investigated by flow dialysis. The results show that the sensitizer binds to both interfaces and that the SiO2 interface is characterized by a much higher surface potential than the micellar interface (≈-170 mV vs. -85 mV). The effect of ionic strength on the surface potential was estimated from the Gouy-Chapman theory, and the measured quantum yields of photosensitized electron transfer were correlated with surface potential at different ionic strengths. This correlation shows that the quantum yield is not affected by surface potentials smaller than ≈-40 mV. At larger potentials, the quantum yield increases rapidly. The quantum yield obtained in the micellar system at different strengths fits nicely on the correlation curve for the colloid SiO2 system. These results indicate that the surface potential is the dominant factor in the quantum yield improvement for PVS0 reduction. PMID:16593095

Tobacco alkaloids reduction by casings added/enzymatic hydrolysis treatments assessed through PLSR analysis.

PubMed

Lin, Shunshun; Zhang, Xiaoming; Song, Shiqing; Hayat, Khizar; Eric, Karangwa; Majeed, Hamid

2016-03-01

Based on encouraged development of potential reduced-exposure products (PREPs) by the US Institute of Medicine, casings (glucose and peptides) added treatments (CAT) and enzymatic (protease and xylanase) hydrolysis treatments (EHT) were developed to study their effect on alkaloids reduction in tobacco and cigarette mainstream smoke (MS) and further investigate the correlation between sensory attributes and alkaloids. Results showed that the developed treatments reduced nicotine by 14.5% and 24.4% in tobacco and cigarette MS, respectively, indicating that both CAT and EHT are potentially effective for developing lower-risk cigarettes. Sensory and electronic nose analysis confirmed the significant influence of treatments on sensory and cigarette MS components. PLSR analysis demonstrated that tobacco alkaloids were positively correlated to the off-taste, irritation and impact attributes, and negatively correlated to the aroma and softness attributes. Additionally, nicotine and anabasine from tobacco leaves positively contributed to the impact attribute, while they negatively contributed to the aroma attribute (P<0.05). Meanwhile, most alkaloids in cigarette MS positively contributed to the impact and irritation attributes (P<0.05). Hence, this study paved a way to better understand the correlation between tobacco alkaloids and sensory attributes. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel molten-salt electrochemical cell for investigating the reduction of uranium dioxide to uranium metal by lithium using in situ synchrotron radiation

PubMed Central

Brown, Leon D.; Abdulaziz, Rema; Jervis, Rhodri; Bharath, Vidal; Mason, Thomas J.; Reinhard, Christina; Connor, Leigh D.; Inman, Douglas; Brett, Daniel J. L.; Shearing, Paul R.

2017-01-01

A novel electrochemical cell has been designed and built to allow for in situ energy-dispersive X-ray diffraction measurements to be made during reduction of UO2 to U metal in LiCl–KCl at 500°C. The electrochemical cell contains a recessed well at the bottom of the cell into which the working electrode sits, reducing the beam path for the X-rays through the molten-salt and maximizing the signal-to-noise ratio from the sample. Lithium metal was electrodeposited onto the UO2 working electrode by exposing the working electrode to more negative potentials than the Li deposition potential of the LiCl–KCl eutectic electrolyte. The Li metal acts as a reducing agent for the chemical reduction of UO2 to U, which appears to proceed to completion. All phases were fitted using Le Bail refinement. The cell is expected to be widely applicable to many studies involving molten-salt systems. PMID:28244437

A novel molten-salt electrochemical cell for investigating the reduction of uranium dioxide to uranium metal by lithium using in situ synchrotron radiation.

PubMed

Brown, Leon D; Abdulaziz, Rema; Jervis, Rhodri; Bharath, Vidal; Mason, Thomas J; Atwood, Robert C; Reinhard, Christina; Connor, Leigh D; Inman, Douglas; Brett, Daniel J L; Shearing, Paul R

2017-03-01

A novel electrochemical cell has been designed and built to allow for in situ energy-dispersive X-ray diffraction measurements to be made during reduction of UO 2 to U metal in LiCl-KCl at 500°C. The electrochemical cell contains a recessed well at the bottom of the cell into which the working electrode sits, reducing the beam path for the X-rays through the molten-salt and maximizing the signal-to-noise ratio from the sample. Lithium metal was electrodeposited onto the UO 2 working electrode by exposing the working electrode to more negative potentials than the Li deposition potential of the LiCl-KCl eutectic electrolyte. The Li metal acts as a reducing agent for the chemical reduction of UO 2 to U, which appears to proceed to completion. All phases were fitted using Le Bail refinement. The cell is expected to be widely applicable to many studies involving molten-salt systems.

The effect of whole-blood donor adverse events on blood donor return rates.

PubMed

Newman, Bruce H; Newman, Daniel T; Ahmad, Raffat; Roth, Arthur J

2006-08-01

Some blood donation-related adverse events (AEs) can negatively impact the blood donor return rate (BDRR) and decrease donor retention. One-thousand randomly selected whole-blood donors were interviewed 3 weeks after a 525-mL index whole-blood donation for seven AEs. The number of return visits and duration of follow-up were recorded for each of the 1000 donors. A negative binomial regression analysis was used to determine the contribution of the four most common AEs to the BDRR, and interactions between these AEs were also evaluated. The four most common AEs were bruise alone (15.1%), sore arm "alone" (7.0%), fatigue "alone" (5.1%), and donor reaction "alone" (4.2%), where "alone" is defined to also include donors who had a bruise but no other AE. The estimated BDRR for donations without AEs was 1.32 visits per year. The estimated BDRRs for the four most common AEs were: bruise alone, 1.32 visits per year; sore arm alone, 1.30 visits per year (2% reduction in BDRR); fatigue alone, 1.06 visits per year (20% reduction in BDRR); and donor reaction alone, 0.87 visits per year (34% reduction in BDRR). The BDRR for donor reaction, fatigue, and sore arm together was 0.20 visits per year (85% reduction in BDRR). Donor reaction had the most negative impact on the BDRR. There appears to be a synergistic effect between donor reaction, fatigue, and sore arm. Theoretically, amelioration of some AEs has the potential to improve BDRRs.

Meditation-induced neuroplastic changes in amygdala activity during negative affective processing.

PubMed

Leung, Mei-Kei; Lau, Way K W; Chan, Chetwyn C H; Wong, Samuel S Y; Fung, Annis L C; Lee, Tatia M C

2018-06-01

Recent evidence suggests that the effects of meditation practice on affective processing and resilience have the potential to induce neuroplastic changes within the amygdala. Notably, literature speculates that meditation training may reduce amygdala activity during negative affective processing. Nonetheless, studies have thus far not verified this speculation. In this longitudinal study, participants (N = 21, 9 men) were trained in awareness-based compassion meditation (ABCM) or matched relaxation training. The effects of meditation training on amygdala activity were examined during passive viewing of affective and neutral stimuli in a non-meditative state. We found that the ABCM group exhibited significantly reduced anxiety and right amygdala activity during negative emotion processing than the relaxation group. Furthermore, ABCM participants who performed more compassion practice had stronger right amygdala activity reduction during negative emotion processing. The lower right amygdala activity after ABCM training may be associated with a general reduction in reactivity and distress. As all participants performed the emotion processing task in a non-meditative state, it appears likely that the changes in right amygdala activity are carried over from the meditation practice into the non-meditative state. These findings suggest that the distress-reducing effects of meditation practice on affective processing may transfer to ordinary states, which have important implications on stress management.

Characterizing use patterns and perceptions of relative harm in dual users of electronic and tobacco cigarettes.

PubMed

Rass, Olga; Pacek, Lauren R; Johnson, Patrick S; Johnson, Matthew W

2015-12-01

Awareness and use of electronic cigarettes (e-cigarettes) is increasing. Questions regarding positive (e.g., smoking reduction/cessation) and negative (e.g., delay of cessation) potential public health consequences of e-cigarettes may be informed by studying dual users of e-cigarettes and tobacco cigarettes. A cross-sectional online survey assessed demographics, product use patterns, and beliefs about relative product benefits and harms among dual users (n = 350) in the United States using the website Amazon Mechanical Turk. Compared to tobacco cigarettes, e-cigarettes were used less often and were associated with lower dependence. Participants reported a 30% reduction in self-reported tobacco cigarette smoking since beginning to use e-cigarettes. Reported primary reasons for e-cigarette use were harm reduction and smoking cessation. E-cigarette use was reported as more likely in settings with smoking restrictions and when others' health could be adversely affected. Conversely, participants reported having used tobacco cigarettes more often than e-cigarettes in hedonic situations (e.g., after eating, drinking coffee or alcohol, or having sex), outdoors, or when stressed. Participants were twice as likely to report wanting to quit tobacco cigarettes compared to e-cigarettes in the next year and intended to quit tobacco cigarettes sooner. Tobacco cigarettes were described as more harmful and addictive, but also as more enjoyable than e-cigarettes. Participants provided evidence consistent with both positive and negative public health consequences of e-cigarettes, highlighting the need for experimental research, including laboratory studies and clinical trials. Policies should consider potential public health benefits of e-cigarettes, in addition to potential harms. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Dose reduction of risperidone and olanzapine can improve cognitive function and negative symptoms in stable schizophrenic patients: A single-blinded, 52-week, randomized controlled study.

PubMed

Zhou, Yanling; Li, Guannan; Li, Dan; Cui, Hongmei; Ning, Yuping

2018-05-01

The long-term effects of dose reduction of atypical antipsychotics on cognitive function and symptomatology in stable patients with schizophrenia remain unclear. We sought to determine the change in cognitive function and symptomatology after reducing risperidone or olanzapine dosage in stable schizophrenic patients. Seventy-five stabilized schizophrenic patients prescribed risperidone (≥4 mg/day) or olanzapine (≥10 mg/day) were randomly divided into a dose-reduction group ( n=37) and a maintenance group ( n=38). For the dose-reduction group, the dose of antipsychotics was reduced by 50%; for the maintenance group, the dose remained unchanged throughout the whole study. The Positive and Negative Syndrome Scale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, and Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery were measured at baseline, 12, 28, and 52 weeks. Linear mixed models were performed to compare the Positive and Negative Syndrome Scale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects and MATRICS Consensus Cognitive Battery scores between groups. The linear mixed model showed significant time by group interactions on the Positive and Negative Syndrome Scale negative symptoms, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, speed of processing, attention/vigilance, working memory and total score of MATRICS Consensus Cognitive Battery (all p<0.05). Post hoc analyses showed significant improvement in Positive and Negative Syndrome Scale negative subscale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, speed of processing, working memory and total score of MATRICS Consensus Cognitive Battery for the dose reduction group compared with those for the maintenance group (all p<0.05). This study indicated that a risperidone or olanzapine dose reduction of 50% may not lead to more severe symptomatology but can improve speed of processing, working memory and negative symptoms in patients with stabilized schizophrenia.

Polyoxometalate-Promoted Electrocatalytic CO2 Reduction at Nanostructured Silver in Dimethylformamide.

PubMed

Guo, Si-Xuan; Li, Fengwang; Chen, Lu; MacFarlane, Douglas R; Zhang, Jie

2018-04-18

Electrochemical reduction of CO 2 is a promising method to convert CO 2 into fuels or useful chemicals, such as carbon monoxide (CO), hydrocarbons, and alcohols. In this study, nanostructured Ag was obtained by electrodeposition of Ag in the presence of a Keggin type polyoxometalate, [PMo 12 O 40 ] 3- (PMo). Metallic Ag is formed upon reduction of Ag + . Adsorption of PMo on the surface of the newly formed Ag lowers its surface energy thus stabilizes the nanostructure. The electrocatalytic performance of this Ag-PMo nanocomposite for CO 2 reduction was evaluated in a CO 2 saturated dimethylformamide medium containing 0.1 M [ n-Bu 4 N]PF 6 and 0.5% (v/v) added H 2 O. The results show that this Ag-PMo nanocomposite can catalyze the reduction of CO 2 to CO with an onset potential of -1.70 V versus Fc 0/+ , which is only 0.29 V more negative than the estimated reversible potential (-1.41 V) for this process and 0.70 V more positive than that on bulk Ag metal. High faradaic efficiencies of about 90% were obtained over a wide range of applied potentials. A Tafel slope of 60 mV dec -1 suggests that rapid formation of *CO 2 •- is followed by the rate-determining protonation step. This is consistent with the voltammetric data which suggest that the reduced PMo interacts strongly with CO 2 (and presumably CO 2 •- ) and hence promotes the formation of CO 2 •- .

Mechanical thinning impacts on runoff, infiltration, and sediment yield following fuel reduction treatments in southwestern dry mixed conifer forest

Treesearch

D.S. Cram; T.T. Baker; A.G. Fernald; A. Madrid; B. Rummer

2007-01-01

Increasing densities of small diameter trees have changed ecological processes and negatively impacted conservation of soil and water resources in western forests. Thinning treatments are commonplace to reduce stem density and potential fire hazard. We evaluated the impacts of using a specialized heavy piece of equipment to reduce he1 loads on intermediate and steep...

Diazonium Functionalisation of Carbon Nanotubes for Specific Orientation of Multicopper Oxidases: Controlling Electron Entry Points and Oxygen Diffusion to the Enzyme.

PubMed

Lalaoui, Noémie; Holzinger, Michael; Le Goff, Alan; Cosnier, Serge

2016-07-18

We report the controlled orientation of bilirubin oxidases (BOD) from Myrothecium verrucaria on multiwalled carbon nanotubes (MWCNTs) functionalised by electrografting of 6-carboxynaphthalenediazonium and 4-(2-aminoethyl)benzenediazonium salts. On negatively charged naphthoate-modified MWCNTs, a high-potential (0.44 V vs. SCE) oxygen reduction electrocatalysis is observed, occurring via the T1 copper centre. On positively charged ammonium-modified MWCNTs, a low-potential (0.15 V) oxygen reduction electrocatalysis is observed, occurring through a partially oxidised state of the T2/T3 trinuclear copper cluster. Finally, chemically modified naphthoate MWCNTs exhibit high bioelectrocatalytic current densities of 3.9 mA cm(-2) under air at gas-diffusion electrode. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Internal ecosystem feedbacks enhance nitrogen-fixing cyanobacteria blooms and complicate management in the Baltic Sea.

PubMed

Vahtera, Emil; Conley, Daniel J; Gustafsson, Bo G; Kuosa, Harri; Pitkänen, Heikki; Savchuk, Oleg P; Tamminen, Timo; Viitasalo, Markku; Voss, Maren; Wasmund, Norbert; Wulff, Fredrik

2007-04-01

Eutrophication of the Baltic Sea has potentially increased the frequency and magnitude of cyanobacteria blooms. Eutrophication leads to increased sedimentation of organic material, increasing the extent of anoxic bottoms and subsequently increasing the internal phosphorus loading. In addition, the hypoxic water volume displays a negative relationship with the total dissolved inorganic nitrogen pool, suggesting greater overall nitrogen removal with increased hypoxia. Enhanced internal loading of phosphorus and the removal of dissolved inorganic nitrogen leads to lower nitrogen to phosphorus ratios, which are one of the main factors promoting nitrogenfixing cyanobacteria blooms. Because cyanobacteria blooms in the open waters of the Baltic Sea seem to be strongly regulated by internal processes, the effects of external nutrient reductions are scale-dependent. During longer time scales, reductions in external phosphorus load may reduce cyanobacteria blooms; however, on shorter time scales the internal phosphorus loading can counteract external phosphorus reductions. The coupled processes inducing internal loading, nitrogen removal, and the prevalence of nitrogen-fixing cyanobacteria can qualitatively be described as a potentially self-sustaining "vicious circle." To effectively reduce cyanobacteria blooms and overall signs of eutrophication, reductions in both nitrogen and phosphorus external loads appear essential.

Note: Rapid reduction of graphene oxide paper by glow discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bo, Zheng; Qian, Jiajing; Duan, Liangping

2015-05-15

This note reports on a novel method for the rapid reduction of graphene oxide (GO) paper using a glow discharge plasma reactor. Glow discharge is produced and sustained between two parallel-plate graphite electrodes at a pressure of 240 mTorr. By exposing GO paper at the junction of negative-glow and Faraday-dark area for 4 min, the oxygen-containing groups can be effectively removed (C/O ratio increases from 2.6 to 7.9), while the material integrality and flexibility are kept well. Electrochemical measurements demonstrate that the as-obtained reduced GO paper can be potentially used for supercapacitor application.

Reductions in negative repetitive thinking and metacognitive beliefs during transdiagnostic internet cognitive behavioural therapy (iCBT) for mixed anxiety and depression.

PubMed

Newby, Jill M; Williams, Alishia D; Andrews, Gavin

2014-08-01

We explored whether transdiagnostic internet-delivered cognitive behavioural therapy (iCBT) for mixed anxiety and depression effectively reduces repetitive negative thinking (RNT), and whether reductions in RNT and positive metacognitive beliefs mediate symptom improvement during iCBT. Participants with generalized anxiety disorder (GAD), major depressive disorder (MDD), or mixed GAD/MDD diagnoses were randomly allocated to a 6-lesson clinician-guided iCBT anxiety and depression program (n = 46) or wait-list control (WLC, n = 53). Depression (PHQ-9), generalized anxiety (GAD-7), RNT (Repetitive Thinking Questionnaire) and positive beliefs about RNT (Positive Beliefs about Rumination Scale) were assessed at pre-, mid-, and post-treatment or matched time points for WLC. Tests of serial indirect effects explored the potential meditating role of RNT and positive belief reductions on the impact of iCBT on depression and anxiety symptoms post-treatment. Results showed that both RNT frequency and positive beliefs about the value of RNT reduced significantly following iCBT compared to WLC, with gains maintained at 3-month follow-up. Reductions between pre- and mid-treatment in positive beliefs and RNT mediated improvements in depression symptoms post-iCBT, and reductions in positive beliefs mediated improvements in GAD symptoms. These findings indicate that iCBT is an effective treatment for RNT and positive metacognitive beliefs. Future dismantling studies are needed to assess the most effective treatment components. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of health/hedonic claims on consumer hedonic and sensory perception of sugar reduction: Case study with orange/passionfruit nectars.

PubMed

Oliveira, Denize; Ares, Gastón; Deliza, Rosires

2018-06-01

Sugar reduction in beverages can contribute to reduce consumption of this nutrient and to improve the health status of the population. However, such reduction can negatively affect consumer perception. Label information can be an effective tool to increase consumer interest in sugar-reduced products. In this context, the aim of the present work was to study the influence of health/hedonic claims on consumer hedonic and sensory perception of sugar reduction in orange/passionfruit nectars under expected and informed conditions. Sugar-reduced orange/passionfruit nectars (20% and 40% reduced in added sugar) featuring different claims (none, health claim or hedonic claim) were evaluated, together with a control product without reduction. Following a between-subjects experimental design, 206 participants evaluated the nectars under two experimental conditions: (a) expected, looking at the packages, and (b) informed, looking at the packages and tasting the nectars. In each experimental condition, participants evaluated their overall liking using a 9-point hedonic scale and answered a check-all-that-apply questions related to the sensory characteristics of the nectars. Results showed that although consumers did not have negative expectations about sugar-reduced nectars, the sensory characteristics of the products were the main determinants of consumers' hedonic reaction towards the nectars. The influence of claims on consumers' perception was modulated by their hedonic sensitivity towards sugar-reduction. The hedonic claim increased overall liking of those consumers with low hedonic sensitivity towards sugar reduction, whereas it had the opposite effect on the most sensitive consumers. Results from the present work suggest that although hedonic claims hold potential for a consumer segment, care must be taken to avoid the generation of unrealistic expectations about the sensory characteristics of sugar-reduced products. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mindfulness-based stress reduction as a stress management intervention for healthy individuals: a systematic review.

PubMed

Sharma, Manoj; Rush, Sarah E

2014-10-01

Stress is a global public health problem with several negative health consequences, including anxiety, depression, cardiovascular disease, and suicide. Mindfulness-based stress reduction offers an effective way of reducing stress by combining mindfulness meditation and yoga in an 8-week training program. The purpose of this study was to look at studies from January 2009 to January 2014 and examine whether mindfulness-based stress reduction is a potentially viable method for managing stress. A systematic search from Medline, CINAHL, and Alt HealthWatch databases was conducted for all types of quantitative articles involving mindfulness-based stress reduction. A total of 17 articles met the inclusion criteria. Of the 17 studies, 16 demonstrated positive changes in psychological or physiological outcomes related to anxiety and/or stress. Despite the limitations of not all studies using randomized controlled design, having smaller sample sizes, and having different outcomes, mindfulness-based stress reduction appears to be a promising modality for stress management. © The Author(s) 2014.

Adolescent smokers' response to reducing the nicotine content of cigarettes: Acute effects on withdrawal symptoms and subjective evaluations.

PubMed

Cassidy, Rachel N; Colby, Suzanne M; Tidey, Jennifer W; Jackson, Kristina M; Cioe, Patricia A; Krishnan-Sarin, Suchitra; Hatsukami, Dorothy

2018-05-15

Mandating a reduction in the nicotine content of cigarettes to a minimally addictive level could dramatically reduce smoking rates in the US. However, little is known about the effects of reduced nicotine content cigarettes in adolescents. Following overnight abstinence, adolescent daily smokers (ages 15-19, n = 50) reported on their craving, withdrawal, and positive and negative affect pre- and post- ad lib smoking of one cigarette containing varying nicotine content (15.8, 5.2, 1.3 and 0.4 mg/g of tobacco) in the laboratory and reported their subjective evaluations of each cigarette. Carbon monoxide (CO) boost from pre- to post-cigarette was calculated to determine if lower-nicotine cigarettes led to differential acute changes in toxicant exposure. All four nicotine cigarette types significantly reduced abstinence-induced craving, withdrawal, and negative affect (all p's < .05). Mixed models evaluating the effect of nicotine content, with nicotine dependence level and gender included as covariates, revealed a significant effect of nicotine content on craving and subjective evaluations: higher nicotine content resulted in greater reductions in craving and increases in both positive and negative subjective evaluations. There were no significant effects of nicotine dose on withdrawal symptoms, negative affect, or CO boost. These results suggest that lower nicotine cigarettes might result in reduced abuse liability compared to higher nicotine content cigarettes due to reduced positive subjective effects, while still reducing withdrawal, in adolescents. These results highlight the potential feasibility of this policy approach and support continued research on how a nicotine reduction policy may affect adolescent smoking patterns. Copyright © 2018 Elsevier B.V. All rights reserved.

A Novel Integrated Cognitive-Behavioral Therapy for Anxiety and Medication Adherence Among Persons Living With HIV/AIDS.

PubMed

Brandt, Charles P; Paulus, Daniel J; Garza, Monica; Lemaire, Chad; Norton, Peter J; Zvolensky, Michael J

2018-02-01

Persons living with HIV/AIDS (PLHIV) are able to live full lifespans after infection, however, rates of anxiety disorders among this population are elevated compared to national samples. Importantly, these anxiety symptoms and disorders have a negative effect on medication adherence, quality of life and other psychological disorders, such as depression. In order to reduce the impact of anxiety among PLHIV, a six-session transdiagnostic CBT-based treatment manual for anxiety among PLHIV named the HIV/Anxiety Management-Reduction Treatment (HAMRT) was developed and implemented. The current manuscript discusses the content of this manual as well as results from three cases examining the impact of HAMRT. Results indicated that HAMRT was effective in reducing symptoms of anxiety, anxiety sensitivity, depression, and negative affect among our sample. Additionally, results indicated that HAMRT was effective in increasing HIV medication adherence as well as quality of life. Results are discussed in terms of the potential utility of an anxiety-reduction therapy program aimed at increasing medication adherence among PLHIV.

Want More? Learn Less: Motivation Affects Adolescents Learning from Negative Feedback.

PubMed

Zhuang, Yun; Feng, Wenfeng; Liao, Yu

2017-01-01

The primary goal of the present study was to investigate how positive and negative feedback may differently facilitate learning throughout development. In addition, the role of motivation as a modulating factor was examined. Participants (children, adolescents, and adults) completed two forms of the guess and application task (GAT). Feedback from the Cool-GAT task has low motivational salience because there are no consequences, while feedback from the Hot-GAT task has high motivational salience as it pertains to receiving a reward. The results indicated that negative feedback leads to a reduction in learning compared to positive feedback. The effect of negative feedback was greater in adolescent participants compared to children and adults in the Hot-GAT task, suggesting an interaction between age and motivation level on learning. Further analysis indicated that greater risk was associated with a greater reduction in learning from negative feedback and again, the reduction was greatest in adolescents. In summary, the current study supports the idea that learning from positive feedback and negative feedback differs throughout development. In a rule-based learning task, when associative learning is primarily in practice, participants learned less from negative feedback. This reduction is amplified during adolescence when task-elicited motivation is high.

Want More? Learn Less: Motivation Affects Adolescents Learning from Negative Feedback

PubMed Central

Zhuang, Yun; Feng, Wenfeng; Liao, Yu

2017-01-01

The primary goal of the present study was to investigate how positive and negative feedback may differently facilitate learning throughout development. In addition, the role of motivation as a modulating factor was examined. Participants (children, adolescents, and adults) completed two forms of the guess and application task (GAT). Feedback from the Cool-GAT task has low motivational salience because there are no consequences, while feedback from the Hot-GAT task has high motivational salience as it pertains to receiving a reward. The results indicated that negative feedback leads to a reduction in learning compared to positive feedback. The effect of negative feedback was greater in adolescent participants compared to children and adults in the Hot-GAT task, suggesting an interaction between age and motivation level on learning. Further analysis indicated that greater risk was associated with a greater reduction in learning from negative feedback and again, the reduction was greatest in adolescents. In summary, the current study supports the idea that learning from positive feedback and negative feedback differs throughout development. In a rule-based learning task, when associative learning is primarily in practice, participants learned less from negative feedback. This reduction is amplified during adolescence when task-elicited motivation is high. PMID:28191003

Growth potential limits drought morphological plasticity in seedlings from six Eucalyptus provenances.

PubMed

Maseda, Pablo H; Fernández, Roberto J

2016-02-01

Water stress modifies plant above- vs belowground biomass allocation, i.e., morphological plasticity. It is known that all species and genotypes reduce their growth rate in response to stress, but in the case of water stress it is unclear whether the magnitude of such reduction is linked to the genotype's growth potential, and whether the reduction can be largely attributed to morphological adjustments such as plant allocation and leaf and root anatomy. We subjected seedlings of six seed sources, three from each of Eucalyptus camaldulensis (potentially fast growing) and E. globulus (inherently slow growing), to three experimental water regimes. Biomass, leaf area and root length were measured in a 6-month glasshouse experiment. We then performed functional growth analysis of relative growth rate (RGR), and aboveground (leaf area ratio (LAR), specific leaf area (SLA) and leaf mass ratio (LMR)) and belowground (root length ratio (RLR), specific root length (SRL) and root mass ratio (RMR)) morphological components. Total biomass, root biomass and leaf area were reduced for all Eucalyptus provenances according to drought intensity. All populations exhibited drought plasticity, while those of greater growth potential (RGRmax) had a larger reduction in growth (discounting the effect of size). A positive correlation was observed between drought sensitivity and RGRmax. Aboveground, drought reduced LAR and LMR; under severe drought a negative correlation was found between LMR and RGRmax. Belowground, drought reduced SRL but increased RMR, resulting in no change in RLR. Under severe drought, a negative correlation was found between RLR, SRL and RGRmax. Our evidence strongly supports the classic ecophysiological trade-off between growth potential and drought tolerance for woody seedlings. It also suggests that slow growers would have a low capacity to adjust their morphology. For shoots, this constraint on plasticity was best observed in partition (i.e., LMR) whereas for roots it was clearest in morphology/anatomy (i.e., SRL). Thus, a low RGRmax would limit plastic response to drought not only at the whole plant level but also at the organ and even the tissue level. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Investigation of the boundary layer during the transition from volume to surface dominated H- production at the BATMAN test facility

NASA Astrophysics Data System (ADS)

Wimmer, C.; Schiesko, L.; Fantz, U.

2016-02-01

BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 1/8 scale H- source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H- production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H- density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H- density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (jH-, je) exists with the Cs emission.

Investigation of the boundary layer during the transition from volume to surface dominated H⁻ production at the BATMAN test facility.

PubMed

Wimmer, C; Schiesko, L; Fantz, U

2016-02-01

BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 18 scale H(-) source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H(-) production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H(-) density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H(-) density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (j(H(-)), j(e)) exists with the Cs emission.

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China.

PubMed

Zhang, Zhennan; Yin, Naiyi; Cai, Xiaolin; Wang, Zhenzhou; Cui, Yanshan

2016-09-01

A mesophilic, Gram-negative, arsenite[As(III)]-oxidizing and arsenate[As(V)]-reducing bacterial strain, Pseudomonas sp. HN-2, was isolated from an As-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri. Under aerobic conditions, this strain oxidized 92.0% (61.4μmol/L) of arsenite to arsenate within 3hr of incubation. Reduction of As(V) to As(III) occurred in anoxic conditions. Pseudomonas sp. HN-2 is among the first soil bacteria shown to be capable of both aerobic As(III) oxidation and anoxic As(V) reduction. The strain, as an efficient As(III) oxidizer and As(V) reducer in Pseudomonas, has the potential to impact arsenic mobility in both anoxic and aerobic environments, and has potential application in As remediation processes. Copyright © 2016. Published by Elsevier B.V.

Developmental changes in neural correlates of cognitive reappraisal: An ERP study using the late positive potential.

PubMed

Van Cauwenberge, Valerie; Van Leeuwen, Karla; Hoppenbrouwers, Karel; Wiersema, Jan R

2017-01-27

The reduction of the amplitude of the late positive potential (LPP) following cognitive reappraisal has been used as a neural marker of emotion regulation. However, studies employing this neural marker in children are scarce and findings are not conclusive, with most studies showing a lack of LPP modulation after reappraisal in children in the age range of 5-12 years. The aim of the current study was therefore to investigate developmental changes in sensitivity of LPP modulation to cognitive reappraisal. To do so, LPP modulation due to cognitive reappraisal of negative pictures was compared between two age groups (8- to 11- versus 12- to 15-year-olds) and regression analyses were applied within the total sample to test whether sensitivity of LPP modulation shows a linear increase with age. In 63 children the LPP was measured after negative pictures that were either combined with a negative story or with a neutral, reappraising story. Although groups did not differ for self-reports on reappraisal, a significant reduction of LPP following cognitive reappraisal was only found in the older children, whereas such an effect was absent in the younger children. Findings were similar for boys and girls. Additional analyses showed a linear increase in sensitivity of LPP modulation with age. The results indicate that LPP modulation as measured in the current paradigm can be used as a valid index of emotion regulation in boys and girls but that caution is recommended using it in younger children. Copyright © 2016 Elsevier Ltd. All rights reserved.

Water Relations, Gas Exchange, and Nutrient Response to a Long Term Constant Water Deficit

NASA Technical Reports Server (NTRS)

Berry, Wade L.; Goldstein, Guillermo; Dreschel, Thomas W.; Wheeler, Raymond M.; Sager, John C.; Knott, William M.

1992-01-01

Wheat plants (Triticum aestivum) were grown for 43 days in a micro-porous tube nutrient delivery system. Roots were unable to penetrate the microporous tube, but grew on the surface and maintained capillary contact with the nutrient solution on the inside of the tube through the 5-micron pores of the porous tube. Water potential in the system was controlled at -0.4, -0.8, and -3.0 kPa by adjusting the applied pressure (hydrostatic head) to the nutrient solution flowing through the microporous tubes. A relatively small decrease in applied water potential from -0.4 to -3.0 kPa resulted in a 34% reduction of shoot growth but only a moderate reduction in the midday leaf water potential from -1.3 to -1.7 MPa. Carbon dioxide assimilation decreased and water use efficiency increased with the more negative applied water potentials, while intercellular CO2 concentration remained constant. This was associated with a decrease in stomatal conductance to water vapor from 1.90 to 0.98 mol/(sq m sec) and a decrease in total apparent hydraulic conductance from 47 to 12 (micro)mol/(sec MPa). Although the applied water potentials were in the -0.4 to -3.0 kPa range, the actual water potential perceived by the plant roots appeared to be in the range of -0.26 to -0.38 MPa as estimated by the leaf water potential of bagged plants. The amount of K, Ca, Mg, Zn, Cu, and B accumulated with each unit of transpired water increased as the applied water potential became less negative. The increase in accumulation ranged from 1.4-fold for K to 2.2-fold for B. The physiological responses observed in this study in response to small constant differences in applied water potentials were much greater than expected from either the applied water potential or the observed plant water potential. Even though the micro-porous tube may not represent natural conditions and could possibly introduce morphological and physiological artifacts, it enables a high degree of control of water potential that facilitates the investigation of many aspects of water relations not practical with other experimental systems.

Three Redox States of Trypanosoma brucei Alternative Oxidase Identified by Infrared Spectroscopy and Electrochemistry

PubMed Central

Maréchal, Amandine; Kido, Yasutoshi; Kita, Kiyoshi; Moore, Anthony L.; Rich, Peter R.

2009-01-01

Electrochemistry coupled with Fourier transform infrared (IR) spectroscopy was used to investigate the redox properties of recombinant alternative ubiquinol oxidase from Trypanosoma brucei, the organism responsible for African sleeping sickness. Stepwise reduction of the fully oxidized resting state of recombinant alternative ubiquinol oxidase revealed two distinct IR redox difference spectra. The first of these, signal 1, titrates in the reductive direction as an n = 2 Nernstian component with an apparent midpoint potential of 80 mV at pH 7.0. However, reoxidation of signal 1 in the same potential range under anaerobic conditions did not occur and only began with potentials in excess of 500 mV. Reoxidation by introduction of oxygen was also unsuccessful. Signal 1 contained clear features that can be assigned to protonation of at least one carboxylate group, further perturbations of carboxylic and histidine residues, bound ubiquinone, and a negative band at 1554 cm−1 that might arise from a radical in the fully oxidized protein. A second distinct IR redox difference spectrum, signal 2, appeared more slowly once signal 1 had been reduced. This component could be reoxidized with potentials above 100 mV. In addition, when both signals 1 and 2 were reduced, introduction of oxygen caused rapid oxidation of both components. These data are interpreted in terms of the possible active site structure and mechanism of oxygen reduction to water. PMID:19767647

Physiological adaptation and plasticity to water stress of coastal and desert populations of Heliotropium curassavicum L.

PubMed

Roy, J; Mooney, H A

1982-01-01

In spite of the ten times higher evaporative demand in a desert versus a coastal habitat, plants of populations of Heliotropium curassavicum from both show similar stomatal conductances in the field as well as under controlled conditions. The desert plants however have a plastic stomatal response to dry air growing conditions which results in a greater photosynthetic performance at negative water potentials. The root and stem resistance to water flow is lower in the desert plants resulting in the maintenance of a high transpiration rate without a large reduction in water potential.

Modeling of Carbon Nanotube Schottky Barrier Reduction for Holes in Air

NASA Technical Reports Server (NTRS)

Yamada, Toshishige

2003-01-01

A model is proposed for the previously reported lower Schottky barrier for holes Phi(sub Bh) in air than in vacuum at a metallic electrode - semiconducting carbon nanotube (CNT) junction. We consider that there is a transition region between the electrode and the CNT, and an appreciable potential can drop there. The role of the oxidation is to increase this potential drop with negatively charged oxygen molecules on the CNT, leading to lower Phi(sub Bh) after oxidation. The mechanism prevails in both p- and n-CNTs, and the model consistently explains the key experimental findings.

Higher-Order Corrections to Earthʼs Ionosphere Shocks

NASA Astrophysics Data System (ADS)

Abdelwahed, H. G.; El-Shewy, E. K.

2017-01-01

Nonlinear shock wave structures in unmagnetized collisionless viscous plasmas composed fluid of positive (negative) ions and nonthermally electron distribution are examined. For ion shock formation, a reductive perturbation technique applied to derive Burgers equation for lowest-order potential. As the shock amplitude decreasing or enlarging, its steepness and velocity deviate from Burger equation. Burgers type equation with higher order dissipation must be obtained to avoid this deviation. Solution for the compined two equations has been derived using renormalization analysis. Effects of higher-order, positive- negative mass ratio Q, electron nonthermal parameter δ and kinematic viscosities coefficient of positive (negative) ions {η }1 and {η }2 on the electrostatic shocks in Earth’s ionosphere are also argued. Supported by the Deanship of Scientific Research at Prince Sattam Bin Abdulaziz University under the Research Project No. 2015/01/4787

Effects of subcallosal cingulate deep brain stimulation on negative self-bias in patients with treatment-resistant depression.

PubMed

Hilimire, Matthew R; Mayberg, Helen S; Holtzheimer, Paul E; Broadway, James M; Parks, Nathan A; DeVylder, Jordan E; Corballis, Paul M

2015-01-01

The cognitive neuropsychological model states that antidepressant treatment alters emotional biases early in treatment, and after this initial change in emotional processing, environmental and social interactions allow for long-term/sustained changes in mood and behavior. Changes in negative self-bias after chronic subcallosal cingulate (SCC) deep brain stimulation (DBS) were investigated with the hypothesis that treatment would lead to changes in emotional biases followed by changes in symptom severity. Patients (N = 7) with treatment-resistant depression were assessed at three time points: pre-treatment; after one month stimulation; and after six months stimulation. The P1, P2, P3, and LPP (late positive potential) components of the event-related potential elicited by positive and negative trait adjectives were recorded in both a self-referential task and a general emotion recognition task. Results indicate that DBS reduced automatic attentional bias toward negative words early in treatment, as indexed by the P1 component, and controlled processing of negative words later in treatment, as indexed by the P3 component. Reduction in negative words endorsed as self-descriptive after six months DBS was associated with reduced depression severity after six months DBS. Change in emotional processing may be restricted to the self-referential task. Together, these results suggest that the cognitive neuropsychological model, developed to explain the time-course of monoamine antidepressant treatment, may also be used as a framework to interpret the antidepressant effects of SCC DBS. Copyright © 2015 Elsevier Inc. All rights reserved.

Voltammetric studies of antimony ions in soda-lime-silica glass melts up to 1873 K.

PubMed

Yamashita, H; Yamaguchi, S; Nishimura, R; Maekawa, T

2001-01-01

The half wave potential of reduction of Sb5+ in 16Na2O x 10CaO x 74SiO2 glass melts was examined by differential pulse voltammetry up to 1873 K. The half wave potential shifted to the positive direction with an increase in temperature. The results indicate that the equilibrium of Sb5+/Sb3+ shifted to negative direction with an increase in temperature. The half wave potential shifted to positive direction (48 mV at 1473 K) when the atmosphere over the melts changed from pure oxygen gas to air, in agreement with the theoretical prediction. The reversibility of Pt:O2 reference electrode is confirmed.

Nonenzymatic Wearable Sensor for Electrochemical Analysis of Perspiration Glucose.

PubMed

Zhu, Xiaofei; Ju, Yinhui; Chen, Jian; Liu, Deye; Liu, Hong

2018-05-25

We report a nonenzymatic wearable sensor for electrochemical analysis of perspiration glucose. Multipotential steps are applied on a Au electrode, including a high negative pretreatment potential step for proton reduction which produces a localized alkaline condition, a moderate potential step for electrocatalytic oxidation of glucose under the alkaline condition, and a positive potential step to clean and reactivate the electrode surface for the next detection. Fluorocarbon-based materials were coated on the Au electrode for improving the selectivity and robustness of the sensor. A fully integrated wristband is developed for continuous real-time monitoring of perspiration glucose during physical activities, and uploading the test result to a smartphone app via Bluetooth.

Inhibition of Return Is Modulated by Negative Stimuli: Evidence from Subliminal Perception.

PubMed

Pan, Fada; Wu, Xiaogang; Zhang, Li; Ou, Yuhong

2017-01-01

Inhibition of return (IOR) is considered as a "blindness mechanism" that emotional stimuli have no impact on it. Most previous studies suggested that IOR was not modulated by emotional cues. However, one key question they ignored was that only supraliminal presentation of emotional stimuli was used in their experiments. The present experiment is aimed at exploring the possible interaction between the IOR effect and subliminal emotional process. We manipulated three different kinds of valence strength of negative stimuli (high negative, HN; moderate negative, MN; low negative, LN) which were presented under the subliminal perception level and an event-related potentials (ERPs) recording was adopted. The results showed that, compared to MN and HN, the IOR effect triggered by peripheral cues was more significant for LN with aspects of behavioral and electrophysiological data (a reduction P1 effect, more negative on cued trials than on uncued trials for both early posterior Nd and Nd components). This indicated that IOR can be modulated by emotionally relevant stimuli. The automatic processing that was triggered by subliminally negative stimuli of peripheral cues had an influence on the shifting of spatial attention that was triggered by IOR. These two mechanisms may occur in the perceptual stage simultaneously.

Charging of dust grains in a plasma with negative ions

NASA Astrophysics Data System (ADS)

Kim, Su-Hyun; Merlino, Robert L.

2006-05-01

The effect of negative ions on the charging of dust particles in a plasma is investigated experimentally. A plasma containing a very low percentage of electrons is formed in a single-ended SF6 is admitted into the vacuum system. The relatively cold (Te≈0.2eV ) readily attach to SF6 molecules to form SF6- negative ions. Calculations of the dust charge indicate that for electrons, negative ions, and positive ions of comparable temperatures, the charge (or surface potential) of the dust can be positive if the positive ion mass is smaller than the negative ion mass and if ɛ, the ratio of the electron to positive ion density, is sufficiently small. The K+ positive ions (mass 39amu) and SF6- negative ions (mass 146amu), and also utilizes a rotating cylinder to dispense dust into the plasma column. Analysis of the current-voltage characteristics of a Langmuir probe in the dusty plasma shows evidence for the reduction in the (magnitude) of the negative dust charge and the transition to positively charged dust as the relative concentration of the residual electrons is reduced. Some remarks are offered concerning experiments that could become possible in a dusty plasma with positive grains.

Big Pile or Small Pile?

NASA Astrophysics Data System (ADS)

Branca, Mario; Quidacciolu, Rossana G.; Soletta, Isabella

2013-10-01

The construction of a voltaic pile (battery) is a simple laboratory activity that commemorates the invention of this important device and is of great help in teaching physics. The voltaic pile is often seen as a scientific toy, with the "pile" being constructed from fruit. These toys use some strips of copper and zinc inserted in a piece of fruit to produce a low-intensity electrical current to power a digital device. In a voltaic pile of this type, the zinc acts as an anode while the copper acts as a cathode. The reduction reaction [i.e.,2H+(aq)+2e⇋H2(g)] occurs on the copper (the cathode). The two electrons that are needed for the reduction are taken from the metal (copper), which remains positively charged, while the anode is the zinc, which is oxidized through the reaction Zn∘(m)⇋Zn+2(aq )+2e, and the two electrons remain on the metal, which is negatively charged. If the two pieces of metal are connected by an external conductor, electrons flow from the zinc to the copper. The electromotive force of this system is about 0.76 V, which is the reduction potential of zinc, as can be found in the table of standard reduction potentials.

Carbon balance in municipal solid waste management--a case study of Nonthaburi municipality, Thailand.

PubMed

Nanthapong, Kampol; Polprasert, Chongchin

2013-12-01

This research aimed to investigate the carbon equivalences associated with the unit processes of municipal solid waste management (MSWM) in Nonthaburi municipality. In addition, factors affecting MSWM's carbon-related activities were determined to find the reduction potential of carbon emissions into the atmosphere. Afield survey was conducted to quantify the amount of resources used in MSWM. Then, they were evaluated in terms of carbon equivalences occurring in the process scheme and categorized into carbon emissions, fixation and reduction,following a carbon-balanced model. From carbon balance analysis of the base-line-scenario MSWM, the carbon emissions were found to be -2,374.56 MTCE/y, resulting in the average carbon unit of-22.98 kg CE/ton solid waste. The negative sign indicates a carbon reduction, instead of an emission,from this MSWM practice, which helps to reduce the concentration of carbon dioxide in the atmosphere. The results of the model reveal that the highest contribution to carbon reduction potential in MSWM is recycling. Accordingly, it is strongly recommended that a policy promoting reuse, recovery, and recycling be pursued in every step of MSWM to assist in, not only extending landfill service life span, but also alleviating the increasing global warming problems.

Predation Efficacy of Bdellovibrio bacteriovorus on Multidrug-Resistant Clinical Pathogens and Their Corresponding Biofilms.

PubMed

Sun, Yao; Ye, Jianzhong; Hou, Yuanbo; Chen, Huale; Cao, Jianming; Zhou, Tieli

2017-09-25

The aim of the present study was to evaluate the predation efficacy of Bdellovibrio bacteriovorus on multidrug-resistant (MDR) or extensive drug resistant (XDR) gram-negative pathogens and their corresponding biofilms. In this study, we examined the ability of B. bacteriovorus to prey on MDR and XDR gram-negative clinical bacteria, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Results showed that B. bacteriovorus was able to prey on all planktonic cultures, among which the most efficient predation was observed for drug-resistant E. coli, with a 3.11 log10 reduction in viability. Furthermore, B. bacteriovorus demonstrated promising efficacy in preventing biofilm formation and dispersing the established biofilm. Reductions in biofilm formation of E. coli, K. pneumoniae, P. aeruginosa, and A. baumannii co-cultured with B. bacteriovorus were 65.2%, 37.1%, 44.7%, and 36.8%, respectively. Meanwhile, the established biofilms of E. coli, K. pneumoniae, P. aeruginosa, and A. baumannii were significantly reduced by 83.4%, 81.8%, 83.1%, and 79.9%, respectively. A visual analysis supported by scanning electron microscopy demonstrated the role of B. bacteriovorus in removing the established biofilms. This study highlights the potential use of B. bacteriovorus as a biological control agent with the capability to prey on MDR/XDR gram-negative pathogens and eradicate biofilms.

Posttraumatic Stress Symptoms and Cognitive-Based Smoking Processes Among Trauma-Exposed Treatment-Seeking Smokers: The Role of Dysphoria

PubMed Central

Garey, Lorra; Bakhshaie, Jafar; Vujanovic, Anka A.; Leventhal, Adam M.; Schmidt, Norman B.; Zvolensky, Michael J.

2014-01-01

Despite the co-occurrence and clinically significant relation between trauma exposure and smoking, there is little understanding of the mechanisms underlying the posttraumatic stress symptoms-smoking relation. The present study examined whether dysphoria (i.e., a psychopathologic symptom dimension that reflects depression’s core affective, cognitive, and psychomotor features) accounted for the covariance between posttraumatic stress symptom severity and an array of smoking processes among trauma-exposed daily smokers. Participants (n = 189; 47.6% female; Mage = 41.15; SD = 12.47) were trauma-exposed, treatment-seeking daily cigarette smokers who completed measures of posttraumatic stress symptom severity, dysphoria, and four cognitive-based smoking processes that interfere with smoking cessation: avoidance/inflexibility to smoking, perceived barriers to smoking cessation, negative affect reduction motivation for smoking, and negative affect reduction/negative reinforcement expectancies from smoking. Dysphoria indirectly and significantly accounted for the relation between posttraumatic stress symptom severity and smoking outcomes. The present results provide initial empirical support that dysphoria accounts for the covariance between posttraumatic symptom severity and a variety of clinically-relevant smoking variables in trauma-exposed, treatment-seeking smokers. The findings suggest the potential importance of targeting dysphoria during smoking cessation among trauma-exposed individuals. PMID:25525942

Distinct structural alterations independently contributing to working memory deficits and symptomatology in paranoid schizophrenia.

PubMed

Zierhut, Kathrin C; Schulte-Kemna, Anna; Kaufmann, Jörn; Steiner, Johann; Bogerts, Bernhard; Schiltz, Kolja

2013-04-01

Schizophrenia is considered a brain disease with a quite heterogeneous clinical presentation. Studies in schizophrenia have yielded a wide array of correlations between structural and functional brain changes and clinical and cognitive symptoms. Reductions of grey matter volume (GMV) in the prefrontal and temporal cortex have been described which are crucial for the development of positive and negative symptoms and impaired working memory (WM). Associations between GMV reduction and positive and negative symptoms as well as WM impairment were assessed in schizophrenia patients (symptomatology in 34, WM in 26) and compared to healthy controls (36 total, WM in 26). GMV was determined by voxel-based morphometry and its relation to positive and negative symptoms as well as WM performance was assessed. In schizophrenia patients, reductions of GMV were evident in anterior cingulate cortex, ventrolateral prefrontal cortex (VLPFC), superior temporal cortex, and insula. GMV reductions in the superior temporal gyrus (STG) were associated with positive symptom severity as well as WM impairment. Furthermore, the absolute GMV of VLPFC was strongly related to negative symptoms. These predicted WM performance as well as processing speed. The present results support the assumption of two distinct pathomechanisms responsible for impaired WM in schizophrenia: (1) GMV reductions in the VLPFC predict the severity of negative symptoms. Increased negative symptoms in turn are associated with a slowing down of processing speed and predict an impaired WM. (2) GMV reductions in the temporal and mediofrontal cortex are involved in the development of positive symptoms and impair WM performance, too. Copyright © 2012 Elsevier Ltd. All rights reserved.

An Electrophysiological Investigation of Emotional Abnormalities in Groups at Risk for Schizophrenia-Spectrum Personality Disorders

PubMed Central

Martin, Elizabeth A.; Karcher, Nicole R.; Bartholow, Bruce D.; Siegle, Greg J.; Kerns, John G.

2017-01-01

Both extreme levels of social anhedonia (SocAnh) and perceptual aberration/magical ideation (PerMag) are associated with risk for schizophrenia-spectrum disorders and with emotional abnormalities. Yet, the nature of any psychophysiological-measured affective abnormality, including the role of automatic/controlled processes, is unclear. We examined the late positive potential (LPP) during passive viewing (to assess automatic processing) and during cognitive reappraisal (to assess controlled processing) in three groups: SocAnh, PerMag, and controls. The SocAnh group exhibited an increased LPP when viewing negative images. Further, SocAnh exhibited greater reductions in the LPP for negative images when told to use strategies to alter negative emotion. Similar to SocAnh, PerMag exhibited an increased LPP when viewing negative images. However, PerMag also exhibited an increased LPP when viewing positive images as well as an atypical decreased LPP when increasing positive emotion. Overall, these results suggest that at-risk groups are associated with shared and unique automatic and controlled abnormalities. PMID:28174121

Tunable thermal expansion in framework materials through redox intercalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jun; Gao, Qilong; Sanson, Andrea

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present, offering a potential route for control. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF 3, doped with 10% Fe to enable reduction. Themore » small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. As a result, redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion.« less

Factors Predicting Internalized Stigma Among Men Who Have Sex with Men Living with HIV in Beijing, China.

PubMed

Xu, Xiaohua; Sheng, Yu; Khoshnood, Kaveh; Clark, Kirsty

Internalized stigma in people living with HIV is associated with negative outcomes including sexual risk behaviors and depression. Little research has focused on internalized stigma in men who have sex with men living with HIV (MSMLWH) in China. We measured internalized stigma and examined its potential predictors in a sample of 277 MSMLWH from two infectious disease specialist hospitals in Beijing, China. Descriptive analysis showed an intermediate high level of internalized stigma in these men. Multiple linear regression revealed that higher levels of stereotypes, negative affect, older age, lower levels of mastery, and limited information and emotional support were significant predictors of internalized stigma. Cognitive reconstruction interventions should be developed to change negative stereotypes and reduce internalized stigma, and information and emotional support should be provided to develop mastery, foster coping skills for internalized stigma, and alleviate negative affect. MSMLWH of older ages need more attention in stigma reduction programs. Copyright © 2016 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Tunable thermal expansion in framework materials through redox intercalation

DOE PAGES

Chen, Jun; Gao, Qilong; Sanson, Andrea; ...

2017-02-09

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present, offering a potential route for control. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF 3, doped with 10% Fe to enable reduction. Themore » small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. As a result, redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion.« less

Water Relations, Gas Exchange, and Nutrient Response to a Long Term Constant Water Deficit

NASA Technical Reports Server (NTRS)

Berry, Wade L.; Goldstein, Guillermo; Dreschel, Thomas W.; Wheeler, Raymond M.; Sager, John C.; Knott, William M.

1992-01-01

Wheat plants (Triticum aestivum) were grown for 43 days in a micro-porous tube nutrient delivery system. Roots were unable to penetrate the microporous tube, but grew on the surface and maintained capillary contact with the nutrient solution on the inside of the tube through the 5-microns pores of the porous tube. Water potential in the system was controlled at -0.4, -0.8, and -3.0 kPa by adjusting the applied pressure (hydrostatic head) to the nutrient solution flowing through the microporous tubes. A relatively small decrease in applied water potential from -0.4 to -3.0 kPa resulted in a 34% reduction of shoot growth but only a moderate reduction in the mid-day leaf water potential from - 1.3 to - 1.7 MPa. Carbon dioxide assimilation decreased and water use efficiency increased with the more negative applied water Potentials, while intercellular C02 concentration remained constant. The physiological responses observed in this study in response to small constant differences in applied water potentials were much greater than expected from either the applied water potential or the observed plant water potential. Even though the micro-porous tube may not represent natural conditions and could possibly introduce morphological and physiological artifacts , it enables a high degree of control of water potential that facilitates the investigation of many aspects of water relations not practical with other experimental systems.

Active sites of ligand-protected Au{sub 25} nanoparticle catalysts for CO{sub 2} electroreduction to CO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alfonso, Dominic R., E-mail: alfonso@netl.doe.gov; Kauffman, Douglas; Matranga, Christopher

2016-05-14

Recent experimental studies have reported the electrochemical reduction of carbon dioxide (CO{sub 2}) into CO at atomically precise negatively charged Au{sub 25}{sup −} nanoclusters. The studies showed CO{sub 2} conversion at remarkably low overpotentials, but the exact mechanisms and nature of the active sites remain unclear. We used first-principles density functional theory and continuum solvation models to examine the role of the cluster during electrochemical CO{sub 2} reduction and analyze the free energies of proposed intermediate species. Contrary to previous assumptions, our results show that the fully ligand protected cluster is not an active CO{sub 2} reduction catalyst because formationmore » of the crucial carboxyl intermediate required very high electrochemical potentials. Instead, our calculations suggest that the reduction process likely occurs on a dethiolated gold site, and adsorbed carboxyl intermediate formation was significantly stabilized at dethiolated gold sites. These findings point to the crucial role of exposed metal sites during electrochemical CO{sub 2} reduction at gold nanocluster catalysts.« less

The potential of land management to decrease global warming from climate change

NASA Astrophysics Data System (ADS)

Mayer, A.; Hausfather, Z.; Jones, A. D.; Silver, W. L.

2016-12-01

Recent evidence suggests that negative emissions (i.e. sequestration) is critical to slow climate change (IPCC, 2013; Gasser et al, 2015). Agricultural (crop and grazing) lands have the potential to act as a significant carbon sink. These ecosystems cover a significant proportion of the global land surface, and are largely degraded with regard to soil carbon due to previous management practices (Bai et al, 2008). However, few studies have examined the required scale of land management interventions that would be required to make a significant contribution to a portfolio of efforts aimed at limiting anthropogenic influences on global mean temperature. To address this, we modelled the quantitative effect of a range of soil carbon sequestration rates on global temperature to 2100. Results showed that by assuming a baseline emissions scenario outlined in RCP 2.6, the sequestration of an additional 0.7 Pg C per year through improved agricultural land management practices would produce a reduction of 0.1 degrees C from predicted global temperatures by the year 2100. We also compiled previous estimates of global carbon sequestration potential of agricultural soils to compare with our theoretical prediction to determine whether carbon sequestration through existing land management practices has potential to significantly reduce global temperatures. Assuming long-term soil carbon uptake, the combined potential of agricultural land management-based mitigation approaches exceeded 0.25 degrees C warming reduction by the year 2100. However, results were highly sensitive to potential carbon saturation, defined as the maximum threshold for carbon storage in soil. Our results suggest that current land management technologies and available land area exist and could make a measureable impact on warming reduction. Results also highlighted potential carbon saturation as a key gap in knowledge.

Sustainable intensive thermal use of the shallow subsurface-a critical view on the status quo.

PubMed

Vienken, T; Schelenz, S; Rink, K; Dietrich, P

2015-01-01

Thermal use of the shallow subsurface for heat generation, cooling, and thermal energy storage is increasingly gaining importance in reconsideration of future energy supplies. Shallow geothermal energy use is often promoted as being of little or no costs during operation, while simultaneously being environmentally friendly. Hence, the number of installed systems has rapidly risen over the last few decades, especially among newly built houses. While the carbon dioxide reduction potential of this method remains undoubted, concerns about sustainability and potential negative effects on the soil and groundwater due to an intensified use have been raised-even as far back as 25 years ago. Nevertheless, consistent regulation and management schemes for the intensified thermal use of the shallow subsurface are still missing-mainly due to a lack of system understanding and process knowledge. In the meantime, large geothermal applications, for example, residential neighborhoods that are entirely dependent up on shallow geothermal energy use or low enthalpy aquifer heat storage, have been developed throughout Europe. Potential negative effects on the soil and groundwater due to an intensive thermal use of the shallow subsurface as well as the extent of potential system interaction still remain unknown. © 2014, National Ground Water Association.

Rising Inequality and Intergenerational Mobility: The Role of Public Investments in Human Capital

PubMed Central

Aizer, Anna

2014-01-01

One consequence of the rise in inequality witnessed over the past 40 years is its potentially negative impact on intergenerational mobility if parents at the bottom of the income distribution invest significantly less in their children's human capital. I consider whether public investments in children can potentially offset the inequality of private investments. Specifically, examining changes in public spending in 25 Organization for Economic Co-operation and Development countries over the period 2000–2009, I find that increases in spending on health are most strongly associated with reductions in the importance of family background and declines in inequality in the production of child human capital as measured by the Program for International Student Assessment test scores among 15-year-olds. Public spending on family support, housing, and education are also moderately related. In contrast, increased spending on the elderly is associated with increases in the importance of parental background and inequality of child test scores. These results suggest that public investments in child human capital have the potential to offset the potentially negative impact of increasing income inequality on intergenerational mobility and inequality of the next generation. Further research firmly establishing a causal relationship is needed. PMID:25419203

Effects of bottom trawling on fish foraging and feeding.

PubMed

Johnson, Andrew Frederick; Gorelli, Giulia; Jenkins, Stuart Rees; Hiddink, Jan Geert; Hinz, Hilmar

2015-01-22

The effects of bottom trawling on benthic invertebrates include reductions of biomass, diversity and body size. These changes may negatively affect prey availability for demersal fishes, potentially leading to reduced food intake, body condition and yield of fishes in chronically trawled areas. Here, the effect of trawling on the prey availability and diet of two commercially important flatfish species, plaice (Pleuronectes platessa) and dab (Limanda limanda), was investigated over a trawling intensity gradient in the Irish Sea. Previous work in this area has shown that trawling negatively affects the condition of plaice but not of dab. This study showed that reductions in local prey availability did not result in reduced feeding of fish. As trawling frequency increased, both fish and prey biomass declined, such that the ratio of fish to prey remained unchanged. Consequently, even at frequently trawled sites with low prey biomass, both plaice and dab maintained constant levels of stomach fullness and gut energy contents. However, dietary shifts in plaice towards energy-poor prey items were evident when prey species were analysed individually. This, together with a potential decrease in foraging efficiency due to low prey densities, was seen as the most plausible cause for the reduced body condition observed. Understanding the relationship between trawling, benthic impacts, fish foraging and resultant body condition is an important step in designing successful mitigation measures for future management strategies in bottom trawl fisheries.

Effects of bottom trawling on fish foraging and feeding

PubMed Central

Johnson, Andrew Frederick; Gorelli, Giulia; Jenkins, Stuart Rees; Hiddink, Jan Geert; Hinz, Hilmar

2015-01-01

The effects of bottom trawling on benthic invertebrates include reductions of biomass, diversity and body size. These changes may negatively affect prey availability for demersal fishes, potentially leading to reduced food intake, body condition and yield of fishes in chronically trawled areas. Here, the effect of trawling on the prey availability and diet of two commercially important flatfish species, plaice (Pleuronectes platessa) and dab (Limanda limanda), was investigated over a trawling intensity gradient in the Irish Sea. Previous work in this area has shown that trawling negatively affects the condition of plaice but not of dab. This study showed that reductions in local prey availability did not result in reduced feeding of fish. As trawling frequency increased, both fish and prey biomass declined, such that the ratio of fish to prey remained unchanged. Consequently, even at frequently trawled sites with low prey biomass, both plaice and dab maintained constant levels of stomach fullness and gut energy contents. However, dietary shifts in plaice towards energy-poor prey items were evident when prey species were analysed individually. This, together with a potential decrease in foraging efficiency due to low prey densities, was seen as the most plausible cause for the reduced body condition observed. Understanding the relationship between trawling, benthic impacts, fish foraging and resultant body condition is an important step in designing successful mitigation measures for future management strategies in bottom trawl fisheries. PMID:25621336

Effect of low water content in protic ionic liquid on ions electrosorption in porous carbon: application to electrochemical capacitors.

PubMed

Gorska, B; Timperman, L; Anouti, M; Béguin, F

2017-05-10

The effect of low water content (<20, 150, 1000, 10 000 ppm) in triethylammonium bis[(trifluoromethyl)sulfonyl]imide - [(C 2 H 5 ) 3 N + H][TFSI - ] - protic ionic liquid (PIL) on the performance of activated carbon (AC) electrodes as well as AC/AC electrochemical capacitors (ECs) is reported. Under negative polarization, hydrogen electrosorption onto carbon is enhanced along with the increase of water content in PIL, whereas the resulting desorption peaks are shifted to lower potential values, evidencing lower sorption energy when hydrogen is stored from moisture containing PIL. Cyclic voltammetry (CV) investigations on PIL-based ECs demonstrated that the evolution of the Stern layer nanostructure at positive and negative potentials is asymmetrical. The results revealed comparable electrochemical performance for PIL containing 150 and 1000 ppm of H 2 O, due to similar operation of the positive electrode, where [TFSI - ] anions are adsorbed in the outer Helmholtz plane, and the negative one, where hydrogen is stored through the reduction of the intermediate hydronium cation. By contrast, a cell with "dry" PIL (<20 ppm of water) displayed a distinctive operation due to hydrogen electrosorption directly through reduction of the protonated cation, and selective adsorption of [TFSI - ] anions, which occurs thanks to the high polarizability and image force (IF) created by their induced charge. Galvanostatic cycling with potential limitation (GCPL) showed comparable capacitance values whatever the water content in PILs up to 1000 ppm, yet electrochemical impedance spectroscopy (EIS) revealed higher capacitance as well as better retention at higher frequencies with the PIL containing 150 ppm of water. Hence, 150 ppm is reasoned to be an optimal value for diffusion and adsorption of ions. The nature of current collectors (aluminum or stainless steel) has a determining role in their polarization behavior, and consequently the potential range of electrodes as well as ion diffusion into the activated carbon porosity, influencing the observed capacitance values (C EIS/2.0V : 170 vs. 128 F g -1 , for Al and SSt, respectively).

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

NASA Astrophysics Data System (ADS)

Irby, Isaac D.; Friedrichs, Marjorie A. M.; Da, Fei; Hinson, Kyle E.

2018-05-01

The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L-1) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

Thinking while drinking: Fear of negative evaluation predicts drinking behaviors of students with social anxiety.

PubMed

Villarosa-Hurlocker, Margo C; Whitley, Robert B; Capron, Daniel W; Madson, Michael B

2018-03-01

College students with social anxiety disorder experience more alcohol-related negative consequences, regardless of the amount of alcohol they consume. Social anxiety refers to psychological distress and physiological arousal in social situations due to an excessive fear of negative evaluation by others. The current study examined within-group differences in alcohol-related negative consequences of students who met or exceeded clinically-indicated social anxiety symptoms. In particular, we tested a sequential mediation model of the cognitive (i.e., fear of negative evaluation) and behavioral (protective behavioral strategies) mechanisms for the link between social anxiety disorder subtypes (i.e., interaction and performance-type) and alcohol-related negative consequences. Participants were 412 traditional-age college student drinkers who met or exceeded the clinically-indicated threshold for social anxiety disorder and completed measures of fear of negative evaluation, protective behavioral strategies (controlled consumption and serious harm reduction), and alcohol-related negative consequences. Fear of negative evaluation and serious harm reduction strategies sequentially accounted for the relationship between interaction social anxiety disorder and alcohol-related negative consequences, such that students with more severe interaction social anxiety symptoms reported more fear of negative evaluation, which was related to more serious harm reduction strategies, which predicted fewer alcohol-related negative consequences. Future directions and implications are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Disturbances in Response Inhibition and Emotional Processing as Potential Pathways to Violence in Schizophrenia: A High-Density Event-Related Potential Study

PubMed Central

Krakowski, Menahem I.; De Sanctis, Pierfilippo; Foxe, John J.; Hoptman, Matthew J.; Nolan, Karen; Kamiel, Stephanie; Czobor, Pal

2016-01-01

Objective: Increased susceptibility to emotional triggers and poor response inhibition are important in the etiology of violence in schizophrenia. Our goal was to evaluate abnormalities in neurophysiological mechanisms underlying response inhibition and emotional processing in violent patients with schizophrenia (VS) and 3 different comparison groups: nonviolent patients (NV), healthy controls (HC) and nonpsychotic violent subjects (NPV). Methods: We recorded high-density Event-Related Potentials (ERPs) and behavioral responses during an Emotional Go/NoGo Task in 35 VS, 24 NV, 28 HC and 31 NPV subjects. We also evaluated psychiatric symptoms and impulsivity. Results: The neural and behavioral deficits in violent patients were most pronounced when they were presented with negative emotional stimuli: They responded more quickly than NV when they made commission errors (ie, failure of inhibition), and evidenced N2 increases and P3 decreases. In contrast, NVs showed little change in reaction time or ERP amplitude with emotional stimuli. These N2 and P3 amplitude changes in VSs showed a strong association with greater impulsivity. Besides these group specific changes, VSs shared deficits with NV, mostly N2 reduction, and with violent nonpsychotic subjects, particularly P3 reduction. Conclusion: Negative affective triggers have a strong impact on violent patients with schizophrenia which may have both behavioral and neural manifestations. The resulting activation could interfere with response inhibition. The affective disruption of response inhibition, identified in this study, may index an important pathway to violence in schizophrenia and suggest new modes of treatment. PMID:26895845

Amygdala response to negative images in postpartum vs nulliparous women and intranasal oxytocin.

PubMed

Rupp, Heather A; James, Thomas W; Ketterson, Ellen D; Sengelaub, Dale R; Ditzen, Beate; Heiman, Julia R

2014-01-01

The neuroendocrine state of new mothers may alter their neural processing of stressors in the environment through modulatory actions of oxytocin on the limbic system. We predicted that amygdala sensitivity to negatively arousing stimuli would be suppressed in postpartum compared to nulliparous women and that this suppression would be modulated by administration of oxytocin nasal spray. We measured brain activation (fMRI) and subjective arousal in response to negatively arousing pictures in 29 postpartum and 30 nulliparous women who received either oxytocin nasal spray or placebo before scanning. Pre- and post-exposure urinary cortisol levels were also measured. Postpartum women (placebo) demonstrated lower right amygdala activation in response to negative images, lower cortisol and lower negative photo arousal ratings to nulliparous women. Nulliparous women receiving oxytocin had lower right amygdala activation compared to placebo. Cortisol levels in the placebo group, and ratings of arousal across all women, were positively associated with right amygdala activation. Together, these findings demonstrate reductions in both amygdala activation and subjective negative arousal in untreated postpartum vs nulliparous women, supporting the hypothesis of an attenuated neural response to arousing stimuli in postpartum women. A causal role of oxytocin and the timing of potential effects require future investigation.

Alcohol effects on performance monitoring and adjustment: affect modulation and impairment of evaluative cognitive control.

PubMed

Bartholow, Bruce D; Henry, Erika A; Lust, Sarah A; Saults, J Scott; Wood, Phillip K

2012-02-01

Alcohol is known to impair self-regulatory control of behavior, though mechanisms for this effect remain unclear. Here, we tested the hypothesis that alcohol's reduction of negative affect (NA) is a key mechanism for such impairment. This hypothesis was tested by measuring the amplitude of the error-related negativity (ERN), a component of the event-related brain potential (ERP) posited to reflect the extent to which behavioral control failures are experienced as distressing, while participants completed a laboratory task requiring self-regulatory control. Alcohol reduced both the ERN and error positivity (Pe) components of the ERP following errors and impaired typical posterror behavioral adjustment. Structural equation modeling indicated that effects of alcohol on both the ERN and posterror adjustment were significantly mediated by reductions in NA. Effects of alcohol on Pe amplitude were unrelated to posterror adjustment, however. These findings indicate a role for affect modulation in understanding alcohol's effects on self-regulatory impairment and more generally support theories linking the ERN with a distress-related response to control failures. PsycINFO Database Record (c) 2012 APA, all rights reserved.

The structure of PccH from Geobactersulfurreducens-a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dantas, Joana; Campelo, Luisa M.; Duke, Norma E. C.

The structure of cytochrome c (GSU3274) designated as PccH from Geobactersulfurreducens was determined at a resolution of 2.0 angstrom. PccH is a small (15kDa) cytochrome containing one c-type heme, found to be essential for the growth of G.sulfurreducens with respect to accepting electrons from graphite electrodes poised at -300mV versus standard hydrogen electrode. with fumarate as the terminal electron acceptor. The structure of PccH is unique among the monoheme cytochromes described to date. The structural fold of PccH can be described as forming two lobes with the heme sandwiched in a cleft between the two lobes. In addition, PccH hasmore » a low reduction potential of -24mV at pH7, which is unusual for monoheme cytochromes. Based on difference in structure, together with sequence phylogenetic analysis, we propose that PccH can be regarded as a first characterized example of a new subclass of class I monoheme cytochromes. The low reduction potential of PccH may enable the protein to be redox active at the typically negative potential ranges encountered by G. sulfurreducens. Because PccH is predicted to be located in the periplasm of this bacterium, it could not be involved in the first step of accepting electrons from the electrode but is very likely involved in the downstream electron transport events in the periplasm.« less

The structure of PccH from Geobacter sulfurreducens  - a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dantas, Joana M.; Campelo, Luísa M.; Duke, Norma E. C.

2015-04-10

The structure of cytochrome-c (GSU3274) designated as PccH from Geobacter sulfurreducens was determined at 2.0 Å resolution. PccH is a small (15 kDa) cytochrome containing one c-type heme, found to be essential for growth of G. sulfurreducens accepting electrons from graphite electrodes poised at -300 mV versus SHE with fumarate as the terminal electron acceptor. The structure of PccH is unique among the monoheme cytochromes described to date. The structural fold of PccH can be described as forming two lobes with the heme sandwiched in a cleft between the two lobes. In addition, PccH has a low reduction potential ofmore » -24 mV at pH 7, which is unusual for monoheme cytochromes. Based on difference in structure together with sequence phylogenetic analysis we propose that PccH can be regarded as a first characterized example of a new subclass of class I monoheme cytochromes. The low reduction potential of PccH may enable the protein to be redox active at the typically negative potential ranges encountered by this bacterium. Because PccH is predicted to be located in the periplasm of G. sulfurreducens, it could not be involved in the first step of accepting electrons from the electrode but very likely involved in the downstream electron transport events in the periplasm.« less

Randomized Controlled Trial of Mindfulness-Based Stress Reduction Versus Aerobic Exercise: Effects on the Self-Referential Brain Network in Social Anxiety Disorder

PubMed Central

Goldin, Philippe; Ziv, Michal; Jazaieri, Hooria; Gross, James J.

2012-01-01

Background: Social anxiety disorder (SAD) is characterized by distorted self-views. The goal of this study was to examine whether mindfulness-based stress reduction (MBSR) alters behavioral and brain measures of negative and positive self-views. Methods: Fifty-six adult patients with generalized SAD were randomly assigned to MBSR or a comparison aerobic exercise (AE) program. A self-referential encoding task was administered at baseline and post-intervention to examine changes in behavioral and neural responses in the self-referential brain network during functional magnetic resonance imaging. Patients were cued to decide whether positive and negative social trait adjectives were self-descriptive or in upper case font. Results: Behaviorally, compared to AE, MBSR produced greater decreases in negative self-views, and equivalent increases in positive self-views. Neurally, during negative self versus case, compared to AE, MBSR led to increased brain responses in the posterior cingulate cortex (PCC). There were no differential changes for positive self versus case. Secondary analyses showed that changes in endorsement of negative and positive self-views were associated with decreased social anxiety symptom severity for MBSR, but not AE. Additionally, MBSR-related increases in dorsomedial prefrontal cortex (DMPFC) activity during negative self-view versus case were associated with decreased social anxiety related disability and increased mindfulness. Analysis of neural temporal dynamics revealed MBSR-related changes in the timing of neural responses in the DMPFC and PCC for negative self-view versus case. Conclusion: These findings suggest that MBSR attenuates maladaptive habitual self-views by facilitating automatic (i.e., uninstructed) recruitment of cognitive and attention regulation neural networks. This highlights potentially important links between self-referential and cognitive-attention regulation systems and suggests that MBSR may enhance more adaptive social self-referential processes in patients with SAD. PMID:23133411

Mechanistic insights into energy conservation by flavin-based electron bifurcation.

PubMed

Lubner, Carolyn E; Jennings, David P; Mulder, David W; Schut, Gerrit J; Zadvornyy, Oleg A; Hoben, John P; Tokmina-Lukaszewska, Monika; Berry, Luke; Nguyen, Diep M; Lipscomb, Gina L; Bothner, Brian; Jones, Anne K; Miller, Anne-Frances; King, Paul W; Adams, Michael W W; Peters, John W

2017-06-01

The recently realized biochemical phenomenon of energy conservation through electron bifurcation provides biology with an elegant means to maximize utilization of metabolic energy. The mechanism of coordinated coupling of exergonic and endergonic oxidation-reduction reactions by a single enzyme complex has been elucidated through optical and paramagnetic spectroscopic studies revealing unprecedented features. Pairs of electrons are bifurcated over more than 1 volt of electrochemical potential by generating a low-potential, highly energetic, unstable flavin semiquinone and directing electron flow to an iron-sulfur cluster with a highly negative potential to overcome the barrier of the endergonic half reaction. The unprecedented range of thermodynamic driving force that is generated by flavin-based electron bifurcation accounts for unique chemical reactions that are catalyzed by these enzymes.

Dyadic Qualitative Analysis of Condom Use Scripts Among Emerging Adult Gay Male Couples.

PubMed

Starks, Tyrel J; Pawson, Mark; Stephenson, Rob; Sullivan, Patrick; Parsons, Jeffrey T

2018-04-03

Sexual risk reduction among gay male couples has received increasing attention in light of evidence that primary partners account for many-and possibly most-new HIV infections. This study examined the content of condom use scripts in interviews conducted with both members of 17 HIV-negative gay male couples. In each couple, at least one partner was an emerging adult (aged 18 to 29). Three scripts were identified: romantic love, unanticipated condomless anal intercourse (CAI), and negotiated safety. Scripts varied in their emphasis on emotional factors versus HIV risk reduction, the salience of sexual agreements, and the presence of an explicit communication goal. Results indicated that condom use may vary for couples as a result of script content and from the fluid adoption of scripts across contexts. Results highlighted potential tensions between emotional closeness and HIV prevention. Condom use cessation and sexual agreements-a potential mechanism for HIV risk reduction-may also serve as expressions of intimacy. This implies interventions that facilitate direct communication about sexual and relational goals-as well as those that expand couples' repertoires for expressing emotional closeness-may enhance sexual health for gay couples, particularly during the period of emerging adulthood.

Electrode reactions of iron oxide-hydroxide colloids.

PubMed

Mahmoudi, Leila; Kissner, Reinhard

2014-11-07

Small-sized FeO(OH) colloids stabilised by sugars, commercially available for the clinical treatment of iron deficiency, show two waves during cathodic polarographic sweeps, or two current maxima with stationary electrodes, in neutral to slightly alkaline aqueous medium. Similar signals are observed with Fe(III) in alkaline media, pH > 12, containing citrate in excess. Voltammetric and polarographic responses reveal a strong influence of fast adsorption processes on gold and mercury. Visible spontaneous accumulation was also observed on platinum. The voltammetric signal at more positive potential is caused by Fe(III)→Fe(II) reduction, while the one at more negative potential has previously been assigned to Fe(II)→Fe(0) reduction. However, the involvement of adsorption phenomena leads us to the conclusion that the second cathodic current is caused again by Fe(III)→Fe(II), of species deeper inside the particles than those causing the first wave. This is further supported by X-ray photoelectron spectra obtained after FeO(OH) particle adsorption and reduction on a gold electrode surface. The same analysis suggests that sucrose stabilising the colloid is still bound to the adsorbed material, despite dilution and rinsing.

Effects of limiter biasing on the ATF torsatron

NASA Astrophysics Data System (ADS)

Uckan, T.; Aceto, S. C.; Baylor, L. R.; Bell, J. D.; Bigelow, T. S.; England, A. C.; Harris, J. H.; Isler, R. C.; Jernigan, T. C.; Lyon, J. F.; Ma, C. H.; Mioduszewski, P. K.; Murakami, M.; Rasmussen, D. A.; Wilgen, J. B.; Zielinski, J. J.

1992-12-01

Positive limiter biasing on the currentless ATF torsatron produces a significant increase in the particle confinement with no improvement in the energy confinement. Experiments have been carried out in 1-T plasmas with ˜400 kW of ECH. Two rail limiters located at the last closed flux surface (LCFS), one at the top and one at the bottom of the device, are biased at positive and negative potentials with respect to the vessel. When the limiters are positively biased at up to 300 V, the density increases sharply to the ECH cutoff value. At the same time, the H α radiation drops, indicating that the particle confinement improves. When the density is kept constant, the H α radiation is further reduced and there is almost no change of plasma stored energy. Under these conditions, the density profiles become peaked and the electric field becomes outward-pointing outside the LCFS and more negative inside the LCFS. In contrast, negative biasing yields some reduction of the density and stored energy at constant gas feed, and the plasma potential profile remains the same. Biasing has almost no effect on the intrinsic impurity levels in the plasma.

Dissolution of Pt during Oxygen Reduction Reaction Produces Pt Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Je Hyun; Brocenschi, Ricardo F.; Kisslinger, Kim

The loss of Pt during the oxygen reduction reaction (ORR) affects the performance and economic viability of fuel cells and sensors. Our group previously observed the dissolution of Pt nanoelectrodes at moderately negative potentials during the ORR. Here we report a more detailed study of this process and identify its product. The nanoporous Pt surface formed during the ORR was visualized by AFM and high-resolution SEM, which also showed ~5 nm sized Pt particles on the glass surface surrounding the electrode. Furthermore, the release of these nanoparticles into the solution was confirmed by monitoring their catalytically amplified collisions with amore » Hg-coated microelectrode used as the tip in the scanning electrochemical microscope (SECM).« less

Dissolution of Pt during Oxygen Reduction Reaction Produces Pt Nanoparticles

DOE PAGES

Bae, Je Hyun; Brocenschi, Ricardo F.; Kisslinger, Kim; ...

2017-11-15

The loss of Pt during the oxygen reduction reaction (ORR) affects the performance and economic viability of fuel cells and sensors. Our group previously observed the dissolution of Pt nanoelectrodes at moderately negative potentials during the ORR. Here we report a more detailed study of this process and identify its product. The nanoporous Pt surface formed during the ORR was visualized by AFM and high-resolution SEM, which also showed ~5 nm sized Pt particles on the glass surface surrounding the electrode. Furthermore, the release of these nanoparticles into the solution was confirmed by monitoring their catalytically amplified collisions with amore » Hg-coated microelectrode used as the tip in the scanning electrochemical microscope (SECM).« less

The effects of vortex like distributed electron in magnetized multi-ion dusty plasmas

NASA Astrophysics Data System (ADS)

Haider, Md. Masum; Ferdous, Tahmina; Duha, Syed S.

2014-09-01

The nonlinear propagation of small but finite amplitude dust-ion-acoustic solitary waves in a magnetized, collisionless dusty plasma is investigated theoretically. It has been assumed that the electrons are trapped following the vortex-like distribution and that the negatively and positively charged ions are mobile with the presence of charge fluctuating stationary dusts, where ions mass provide the inertia and restoring forces are provided by the thermal pressure of hot electrons. A reductive perturbation method was employed to obtain a modified Korteweg-de Vries (mK-dV) equation for the first-order potential and a stationary solution is obtained. The effect of the presence of trapped electrons, negatively and positively charged ions and arbitrary charged dust grains are discussed.

Hydricity, electrochemistry, and excited-state chemistry of Ir complexes for CO 2 reduction

DOE PAGES

Manbeck, Gerald F.; Garg, Komal; Shimoda, Tomoe; ...

2016-12-01

Here, we prepared electron-rich derivatives of [Ir(tpy)(ppy)Cl] + with modification of the bidentate (ppy) or tridentate (tpy) ligands in attempt to increase the reactivity for CO 2 reduction and the ability to transfer hydrides (hydricity). Density functional theory (DFT) calculations reveal that complexes with dimethyl-substituted ppy have similar hydricities to the non-substituted parent complex, and photocatalytic CO 2 reduction studies show selective CO formation. Substitution of tpy for bis(benzimidazole)-phenyl or -pyridine (L3 and L4, respectively) induces changes in the physical properties much more pronounced than addition of methyl groups to ppy. Theoretical data predict [Ir(L3)(ppy)(H)] is the strongest hydride donormore » among complexes studied in this work, but [Ir(L3)(ppy)(NCCH 3)] + cannot be reduced photochemically because the excited state reduction potential is only 0.52 V due to the negative ground state potential of –1.91 V. The excited state [Ir(L4)(ppy)(NCCH 3)] 2+ is the strongest oxidant among complexes studied in this work and the singly reduced species is formed readily upon photolysis in the presence of tertiary amines. Both [Ir(L3)(ppy)(NCCH 3)] + and [Ir(L4)(ppy)(NCCH 3)] 2+ exhibit electrocatalytic current for CO 2 reduction. While a significantly greater overpotential is needed for the L3 complex, a small amount of formate (5-10 %) generation in addition to CO was observed as predicted by the DFT calculations.« less

A-type voltage-gated K+ currents influence firing properties of isolectin B4-positive but not isolectin B4-negative primary sensory neurons.

PubMed

Vydyanathan, Amaresh; Wu, Zi-Zhen; Chen, Shao-Rui; Pan, Hui-Lin

2005-06-01

Voltage-gated K+ channels (Kv) in primary sensory neurons are important for regulation of neuronal excitability. The dorsal root ganglion (DRG) neurons are heterogeneous, and the types of native Kv currents in different groups of nociceptive DRG neurons are not fully known. In this study, we determined the difference in the A-type Kv current and its influence on the firing properties between isolectin B4 (IB4)-positive and -negative DRG neurons. Whole cell voltage- and current-clamp recordings were performed on acutely dissociated small DRG neurons of rats. The total Kv current density was significantly higher in IB+-positive than that in IB(4)-negative neurons. Also, 4-aminopyridine (4-AP) produced a significantly greater reduction in Kv currents in IB4-positive than in IB4-negative neurons. In contrast, IB4-negative neurons exhibited a larger proportion of tetraethylammonium-sensitive Kv currents. Furthermore, IB4-positive neurons showed a longer latency of firing and required a significantly larger amount of current injection to evoke action potentials. 4-AP significantly decreased the latency of firing and increased the firing frequency in IB4-positive but not in IB4-negative neurons. Additionally, IB4-positive neurons are immunoreactive to Kv1.4 but not to Kv1.1 and Kv1.2 subunits. Collectively, this study provides new information that 4-AP-sensitive A-type Kv currents are mainly present in IB4-positive DRG neurons and preferentially dampen the initiation of action potentials of this subpopulation of nociceptors. The difference in the density of A-type Kv currents contributes to the distinct electrophysiological properties of IB4-positive and -negative DRG neurons.

Sex differences in the reduction of arsenic methylation capacity as a function of urinary total and inorganic arsenic in Mexican children.

PubMed

Torres-Sánchez, Luisa; López-Carrillo, Lizbeth; Rosado, Jorge L; Rodriguez, Valentina M; Vera-Aguilar, Eunice; Kordas, Katarzyna; García-Vargas, Gonzalo G; Cebrian, Mariano E

2016-11-01

Chronic arsenic (As) exposure decreases adult and children's ability to methylate inorganic As (iAs); however, few studies have examined children's sex differences. We measured urinary concentrations of iAs, monomethylarsonic (MMA), and dimethylarsinic (DMA) acids, and calculated the primary (PMI: MMA/iAs) and secondary (SMI: DMA/MMA) methylation capacity indexes in 591 children 6-8 years in Torreón, Mexico. We determined iAs, MMA, and DMA by hydride generation cryotrapping AAS. Lineal regression models estimated associations between methylation capacity and total As (TAs) or iAs. Interactions with sex were tested at p<0.10. Boys had significantly higher TAs levels, (58.4µg/L) than girls (46.2µg/L). We observed negative associations between TAs and PMI (β=-0.039; p<0.18) and SMI (β=-0.08; p=0.002) with significant sex differences; PMI reduction was significant in boys (β=-0.09; p=0.02) but not in girls (β=0.021; p=0.63), p for interaction=0.06. In contrast, SMI reduction was significantly more pronounced in girls. Furthermore, negative associations PMI (β=-0.19; p<0.001) and SMI (β=-0.35; p<0.001) were a function of urinary iAs levels, independently of TAs; however, the reduction in PMI was more pronounced in boys (β=-0.24; p<0.001; girls β=-0.15; p<0.001), p for interaction=0.04. A significant negative association was observed between SMI and iAs levels without significant sex differences. TAs and iAs associations with metabolite percentages were in good agreement with those observed with methylation indexes. Our results suggest that iAs plays an important role in reducing As methylation ability and that significant sex differences are present in As metabolism. These differences merit further investigation to confirm our findings and their potential implications for arsenic toxicity in children. Copyright © 2016 Elsevier Inc. All rights reserved.

Lead in hawks, falcons and owls downstream from a mining site on the Coeur D'Alene river, Idaho

USGS Publications Warehouse

Henny, C.J.; Blus, L.J.; Hoffman, D.J.; Grove, R.A.

1994-01-01

Mining and smelting at Kellogg-Smelterville, Idaho, resulted in high concentrations of lead in Coeur d'Alene (CDA) River sediments and the floodplain downstream, where American Kestrels (Falco sparverius), Northern Harriers (Circus cyaneus), Red-tailed Hawks (Buteo jamaicensis), Great Horned Owls (Bubo virginianus), and Western Screech-owls (Otus kennicotti) nested. Nestling American Kestrels contained significantly higher (P=0.0012) blood lead concentrations along the CDA River (0.24 ?g/g, wet wt) than the nearby reference area (0.087 ?g/g). A 35% inhibition of blood *-aminolevulinic acid dehydratase (ALAD) in nestling Northern Harriers (P=0.0001), 55% in nestling American Kestrels (P=0.0001) and 81% in adult American Kestrels (P=0.0004) provided additional evidence of lead exposure in the CDA River population. In nestling American Kestrels and Northern Harriers, ALAD activity was negatively correlated with lead in blood. An earlier report on Ospreys (Pandion haliaetus) showed slightly less inhibition of ALAD than in American Kestrels, but no significant reduction in hemoglobin or hematocrit and no negative influence on production rates. The adult and nestling American Kestrels along the CDA River contained about twice as much blood lead as Ospreys during the same years (adult 0.46 vs. 0.20 ?g/g, and nestling 0.24 vs. 0.09 ?g/g), but adults showed a 7.5% reduction in hemoglobin (P=0.0356) and nestlings an 8.2% reduction in hemoglobin (P=0.0353) and a 5.8% reduction in hematocrit (P=0.0482). We did not observe raptor deaths related to lead, and although the production rate for American Kestrels was slightly lower along the CDA River, we found no significant negative relation between productivity and lead. Limited data on the other raptors provide evidence of exposure to lead along the CDA River. Several traits of raptors apparently reduce their potential for accumulating critical levels of lead which is primarily stored in bones of prey species.

Effects of valence and arousal on emotional word processing are modulated by concreteness: Behavioral and ERP evidence from a lexical decision task.

PubMed

Yao, Zhao; Yu, Deshui; Wang, Lili; Zhu, Xiangru; Guo, Jingjing; Wang, Zhenhong

2016-12-01

We investigated whether the effects of valence and arousal on emotional word processing are modulated by concreteness using event-related potentials (ERPs). The stimuli included concrete words (Experiment 1) and abstract words (Experiment 2) that were organized in an orthogonal design, with valence (positive and negative) and arousal (low and high) as factors in a lexical decision task. In Experiment 1, the impact of emotion on the effects of concrete words mainly resulted from the contribution of valence. Positive concrete words were processed more quickly than negative words and elicited a reduction of N400 (300-410ms) and enhancement of late positive complex (LPC; 450-750ms), whereas no differences in response times or ERPs were found between high and low levels of arousal. In Experiment 2, the interaction between valence and arousal influenced the impact of emotion on the effects of abstract words. Low-arousal positive words were associated with shorter response times and a reduction of LPC amplitudes compared with high-arousal positive words. Low-arousal negative words were processed more slowly and elicited a reduction of N170 (140-200ms) compared with high-arousal negative words. The present study indicates that word concreteness modulates the contributions of valence and arousal to the effects of emotion, and this modulation occurs during the early perceptual processing stage (N170) and late elaborate processing stage (LPC) for emotional words and at the end of all cognitive processes (i.e., reflected by response times). These findings support an embodied theory of semantic representation and help clarify prior inconsistent findings regarding the ways in which valance and arousal influence different stages of word processing, at least in a lexical decision task. Copyright © 2016 Elsevier B.V. All rights reserved.

Reactive oxygen species potentiate the negative inotropic effect of cardiac M2-muscarinic receptor stimulation.

PubMed

Peters, S L; Sand, C; Batinik, H D; Pfaffendorf, M; van Zwieten, P A

2001-08-01

The aim of the present study was to investigate the influence of reactive oxygen species (ROS) on the contractile responses of rat isolated left atria to muscarinic receptor stimulation. ROS were generated by means of electrolysis (30 mA, 75 s) of the organ bath fluid. Twenty minutes after the electrolysis period, the electrically paced atria (3 Hz) were stimulated with the adenylyl cyclase activator forskolin (1 microM). Subsequently, cumulative acetylcholine concentration-response curves were constructed (0.01 nM-10 microM). In addition, phosphoinositide turnover and adenylyl cyclase activity under basal and stimulated conditions were measured. For these biochemical experiments we used the stable acetylcholine analogue carbachol. The atria exposed to reactive oxygen species were influenced more potently (pD2 control: 6.2 vs. 7.1 for electrolysis-treated atria, P<0.05) and more effectively (Emax control: 40% vs. 90% reduction of the initial amplitude, P<0.05) by acetylcholine. In contrast, ROS exposure did not alter the responses to adenosine, whose receptor is also coupled via a Gi-protein to adenylyl cyclase. The basal (40% vs. control, P<0.05) as well as the carbachol-stimulated (-85% vs. control, P<0.05) inositol-phosphate formation was reduced in atria exposed to ROS. The forskolin-stimulated adenylyl cyclase activity was identical in both groups but carbachol stimulation induced a more pronounced reduction in adenylyl cyclase activity in the electrolysis-treated atria. Accordingly we may conclude that ROS enhance the negative inotropic response of isolated rat atria to acetylcholine by both a reduction of the positive (inositide turnover) and increase of the negative (adenylyl cyclase inhibition) inotropic components of cardiac muscarinic receptor stimulation. This phenomenon is most likely M2-receptor specific, since the negative inotropic response to adenosine is unaltered by ROS exposure.

Stimulation and inhibition of enzymatic hydrolysis by organosolv lignins as determined by zeta potential and hydrophobicity.

PubMed

Huang, Yang; Sun, Shaolong; Huang, Chen; Yong, Qiang; Elder, Thomas; Tu, Maobing

2017-01-01

Lignin typically inhibits enzymatic hydrolysis of cellulosic biomass, but certain organosolv lignins or lignosulfonates enhance enzymatic hydrolysis. The hydrophobic and electrostatic interactions between lignin and cellulases play critical roles in the enzymatic hydrolysis process. However, how to incorporate these two interactions into the consideration of lignin effects has not been investigated. We examined the physicochemical properties and the structures of ethanol organosolv lignins (EOL) from hardwood and softwood and ascertained the association between lignin properties and their inhibitory and stimulatory effects on enzymatic hydrolysis. The zeta potential and hydrophobicity of EOL lignin samples, isolated from organosolv pretreatment of cottonwood (CW), black willow (BW), aspen (AS), eucalyptus (EH), and loblolly pine (LP), were determined and correlated with their effects on enzymatic hydrolysis of Avicel. EOLs from CW, BW, and AS improved the 72 h hydrolysis yield by 8-12%, while EOLs from EH and LP decreased the 72 h hydrolysis yield by 6 and 16%, respectively. The results showed a strong correlation between the 72 h hydrolysis yield with hydrophobicity and zeta potential. The correlation indicated that the hydrophobicity of EOL had a negative effect and the negative zeta potential of EOL had a positive effect. HSQC NMR spectra showed that β- O -4 linkages in lignin react with ethanol to form an α -ethoxylated β- O -4' substructure (A') during organosolv pretreatment. Considerable amounts of C 2,6 -H 2,6 correlation in p -hydroxybenzoate (PB) units were observed for EOL-CW, EOL-BW, and EOL-AS, but not for EOL-EH and EOL-LP. This study revealed that the effect of lignin on enzymatic hydrolysis is a function of both hydrophobic interactions and electrostatic repulsions. The lignin inhibition is controlled by lignin hydrophobicity and the lignin stimulation is governed by the negative zeta potential. The net effect of lignin depends on the combined influence of hydrophobicity and zeta potential. This study has potential implications in biomass pretreatment for the reduction of lignin inhibition by increasing lignin negative zeta potential and decreasing hydrophobicity.

Analyses of the genotoxic and mutagenic potential of the products formed after the biotransformation of the azo dye Disperse Red 1.

PubMed

Chequer, Farah Maria Drumond; Lizier, Thiago Mescoloto; de Felício, Rafael; Zanoni, Maria Valnice Boldrin; Debonsi, Hosana Maria; Lopes, Norberto Peporine; Marcos, Ricard; de Oliveira, Danielle Palma

2011-12-01

Azo dyes constitute the largest class of synthetic dyes. Following oral exposure, these dyes can be reduced to aromatic amines by the intestinal microflora or liver enzymes. This work identified the products formed after oxidation and reduction of the dye Disperse Red 1, simulating hepatic biotransformation and evaluated the mutagenic potential of the resultant solution. Controlled potential electrolysis was carried out on dye solution using a Potentiostat/Galvanostat. HPLC-DAD and GC/MS were used to determine the products generated after the oxidation/reduction process. The Salmonella/microsome assay with the strains TA98 and YG1041 without S9, and the mouse lymphoma assay (MLA) using the thymidine kinase (Tk) gene, were used to evaluate the mutagenicity of the products formed. Sulfate 2-[(4-aminophenyl)ethylamino]-ethanol monohydrate, nitrobenzene, 4-nitro-benzamine and 2-(ethylphenylamino)-ethanol were detected. This dye has already being assigned as mutagenic in different cell system. In addition, after the oxidation/reduction process the dye still had mutagenic activity for the Salmonella/microsome assay. Nevertheless, both the original dye Disperse Red 1 and its treated solutions showed negative results in the MLA. The present results suggest that the ingestion of water and food contaminated with this dye may represent human and environmental health problem, due to the generation of harmful compounds after biotransformation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Metsulfuron spray drift reduces fruit yield of hawthorn (Crataegus monogyna L.).

PubMed

Kjaer, Christian; Strandberg, Morten; Erlandsen, Mogens

2006-03-01

This study was carried out to investigate whether spray drift of metsulfuron has a potential to negatively affect hawthorn (Crataegus monogyna) hedgerows near agricultural fields. For this purpose four doses of metsulfuron ranging from 5% to 40% of the field dose (4 g metsulfuron per hectare) were sprayed on trees in seven different hawthorn hedgerows. The actual deposition on the leaves was measured by means of a tracer (glycine). Spraying was conducted both at the bud stage and at early flowering. Leaves, flowers, green berries and mature berries were harvested and the number and weight of each were measured. The spraying at the bud stage caused a highly significant reduction in number and dry weight of berries, whereas it had no effects on leaf and flower production. The berry reduction was close to 100% at actual depositions relevant for spray drift under normal conditions. Spraying at early flowering also significantly reduced berries although the effect was smaller than for the spraying at bud stage. The early flower stage spraying caused no reduction in number and size of leaves. The possible ecological consequence is that metsulfuron spray drift from agricultural fields has a potential to reduce the amount of berries available for frugivorous birds in nearby hedgerows. A potential need for regulatory measures to reduce herbicide spray drift to hedgerows situated near agricultural fields with herbicide use is also indicated.

Interpretation of ambiguous social scenarios in social phobia and depression: evidence from event-related brain potentials.

PubMed

Moser, Jason S; Huppert, Jonathan D; Foa, Edna B; Simons, Robert F

2012-02-01

In the current study, event-related potentials (ERPs) and behavioral responses were measured in individuals meeting diagnostic criteria for social phobia, depression, their combination, or neither in order to examine the unique and combined effects of social phobia and depression on the interpretation of ambiguous social scenarios. ERPs revealed a lack of positive interpretation bias and some suggestion of a negative bias in the semantic expectancy N4 component across all clinical groups. Furthermore, socially phobic and comorbid individuals showed reductions in baseline attention allocation to the task, as indexed by P6 amplitude. RT and accuracy likewise revealed a lack of positive interpretation bias across disordered groups. When considered on a continuum across all samples, social phobia and depression symptoms were related to the N4 interpretation bias effect whereas P6 amplitude reduction and RT interpretation bias appeared uniquely associated with social phobia. Copyright © 2011 Elsevier B.V. All rights reserved.

Catalyst surfaces for the chromous/chromic redox couple

NASA Technical Reports Server (NTRS)

Giner, J. D.; Cahill, K. J. (Inventor)

1980-01-01

An electricity producing cell of the reduction-oxidation (REDOX) type is described. The cell is divided into two compartments by a membrane, each compartment containing a solid inert electrode. A ferrous/ferric couple in a chloride solution serves as a cathode fluid which is circulated through one of the compartments to produce a positive electric potential disposed therein. A chromic/chromous couple in a chloride solution serves as an anode fluid which is circulated through the second compartment to produce a negative potential on an electrode disposed therein. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which was added to the anode fluid. If the REDOX cell is then discharged, the current flows between the electrodes causing the lead to deplate from the negative electrode and the metal coating on the electrode will act as a catalyst to cause increased current density.

The feasibility and effectiveness of Catch It, an innovative CBT smartphone app.

PubMed

Kinderman, Peter; Hagan, Paul; King, Sophie; Bowman, James; Chahal, Jasprit; Gan, Li; McKnight, Rebecca; Waldon, Charlotte; Smith, Matthew; Gilbertson, John; Tai, Sara

2016-05-01

The widespread use of smartphones makes effective therapies such as cognitive-behavioural therapy (CBT) potentially accessible to large numbers of people. This paper reports the usage data of the first trial of Catch It, a new CBT smartphone app. Uptake and usage rates, fidelity of user responses to CBT principles, and impact on reported negative and positive moods were assessed. A relatively modest proportion of people chose to download the app. Once used, the app tended to be used more than once, and 84% of the user-generated content was consistent with the basic concepts of CBT. There were statistically significant reductions in negative mood intensity and increases in positive mood intensity. Smartphone apps have potential beneficial effects in mental health through the application of basic CBT principles. More research with randomised controlled trial designs should be conducted. None. © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.

Anisotropic Negative Differential Resistance in Monolayer Black Phosphorus

NASA Astrophysics Data System (ADS)

Zhang, Wanting; Kang, Peng; Chen, Huahui

2018-01-01

The tremendous potential application in emerging two-dimensional layered materials such as black phosphorus (BP) has attracted great attention as nanoscale devices. In this paper, the effect of anisotropic negative differential resistance (NDR) in monolayer black phosphorus field-effect transistors (FETs) is reported by the first-principles computational study based on the non-equilibrium Green’s function approach combined with density functional theory. The transport properties including current-voltage (I-V) relation and transmission spectrum of monolayer BP are investigated at different gate voltages (Vg). Further studies indicate that NDR occurs at a specific gate voltage in the armchair direction rather than in the zigzag direction. The decrease of current in I-V characteristics can be understood from the generation of non-conducting states region moving towards the Fermi level resulting in a reduction of the integration within corresponding energy range in the transmission spectrum. Our results offer useful guidance for designing FETs and other potential applications in nanoelectronic devices based on BP.

Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

PubMed

Liu, Zhiyuan; Yu, Shuili; Park, Heedeung; Liu, Guicai; Yuan, Qingbin

2016-06-01

Given the increasing discoveries related to the eco-toxicity of titanium dioxide (TiO2) nanoparticles (NPs) in different ecosystems and with respect to public health, it is important to understand their potential effects in drinking water treatment (DWT). The effects of TiO2 NPs on ammonia reduction, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in biological activated carbon (BAC) filters for drinking water were investigated in static and dynamic states. In the static state, both the nitrification potential and AOB were significantly inhibited by 100 μg L(-1) TiO2 NPs after 12 h (p < 0.05), and the threshold decreased to 10 μg L(-1) with prolonged exposure (36 h, p < 0.05). However, AOA were not considerably affected in any of the tested conditions (p > 0.05). In the dynamic state, different amounts of TiO2 NP pulses were injected into three pilot-scale BAC filters. The decay of TiO2 NPs in the BAC filters was very slow. Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation. Furthermore, the TiO2 NP pulses considerably reduced the performance of ammonia reduction. This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction, suggesting a potential threat to DWT by TiO2 NPs.

Germination response of Hylocereus setaceus (Salm-Dyck ex DC: ) Ralf Bauer (Cactaceae) seeds to temperature and reduced water potentials.

PubMed

Simão, E; Takaki, M; Cardoso, V J M

2010-02-01

The germination response of Hylocereus setaceus seeds to isothermic incubation at different water potentials was analysed by using the thermal time and hydrotime models, aiming to describe some germination parameters of the population and to test the validity of the models to describe the response of the seeds to temperature and water potential. Hylocereus setaceus seeds germinated relatively well in a wide range of temperatures and the germination was rate limited from 11 to 20 degrees C interval and beyond 30 degrees C until 40 degrees C, in which the germination rate respectively shifts positively and negatively with temperature. The minimum or base temperature (T(b)) for the germination of H. setaceus was 7 degrees C, and the ceiling temperature varied nearly from 43.5 to 59 degrees C depending on the percent fraction, with median set on 49.8 degrees C. The number of degrees day necessary for 50% of the seeds to germinate in the infra-optimum temperature range was 39.3 degrees C day, whereas at the supra-optimum interval the value of theta = 77 was assumed to be constant throughout. Germination was sensitive to decreasing values of psi in the medium, and both the germinability and the germination rate shift negatively with the reduction of psi, but the rate of reduction changed with temperature. The values of base water potential (psi(b)) shift to zero with increasing temperatures and such variation reflects in the relatively greater effect of low psi on germination in supra optimum range of T. In general, the model described better the germination time courses at lower than at higher water potentials. The analysis also suggest that Tb may not be independent of psi and that psi(b(g)) may change as a function of temperature at the infra-otimum temperature range.

Leaf water relations during summer water deficit: differential responses in turgor maintenance and variation in leaf structure among different plant communities in south-western Australia.

PubMed

Mitchell, Patrick J; Veneklaas, Erik J; Lambers, Hans; Burgess, Stephen S O

2008-12-01

We measured leaf water relations and leaf structural traits of 20 species from three communities growing along a topographical gradient. Our aim was to assess variation in seasonal responses in leaf water status and leaf tissue physiology between sites and among species in response to summer water deficit. Species from a ridge-top heath community showed the greatest reductions in pre-dawn leaf water potentials (Psi(leaf)) and stomatal conductance during summer; species from a valley-floor woodland and a midslope mallee community showed less reductions in these parameters. Heath species also displayed greater seasonal reduction in turgor-loss point (Psi(TLP)) than species from woodland or mallee communities. In general, species that had larger reductions in Psi(leaf) during summer showed significant shifts in either their osmotic potential at full turgor (Psi(pi 100); osmotic adjustment) or in tissue elasticity (epsilon(max)). Psi(pi 100) and epsilon(max) were negatively correlated, during both spring and summer, suggesting a trade-off between these different mechanisms to cope with water stress. Specific leaf area varied greatly among species, and was significantly correlated with seasonal changes in Psi(TLP) and pre-dawn Psi(leaf). These correlations suggest that leaf structure is a prerequisite for cellular mechanisms to be effective in adjusting to water deficit.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vimmerstedt, Laura; Brown, Austin; Newes, Emily

The transportation sector is changing, influenced by concurrent, ongoing, dynamic trends that could dramatically affect the future energy landscape, including effects on the potential for greenhouse gas emissions reductions. Battery cost reductions and improved performance coupled with a growing number of electric vehicle model offerings are enabling greater battery electric vehicle market penetration, and advances in fuel cell technology and decreases in hydrogen production costs are leading to initial fuel cell vehicle offerings. Radically more efficient vehicles based on both conventional and new drivetrain technologies reduce greenhouse gas emissions per vehicle-mile. Net impacts also depend on the energy sources usedmore » for propulsion, and these are changing with increased use of renewable energy and unconventional fossil fuel resources. Connected and automated vehicles are emerging for personal and freight transportation systems and could increase use of low- or non-emitting technologies and systems; however, the net effects of automation on greenhouse gas emissions are uncertain. The longstanding trend of an annual increase in transportation demand has reversed for personal vehicle miles traveled in recent years, demonstrating the possibility of lower-travel future scenarios. Finally, advanced biofuel pathways have continued to develop, highlighting low-carbon and in some cases carbon-negative fuel pathways. We discuss the potential for transformative reductions in petroleum use and greenhouse gas emissions through these emerging transportation-sector technologies and trends and present a Clean Transportation Sector Initiative scenario for such reductions, which are summarized in Table ES-1.« less

Negative Emotions and Suicidal Ideation during Psychosocial Treatments in Older Adults with Major Depression and Cognitive Impairment.

PubMed

Kiosses, Dimitris N; Gross, James J; Banerjee, Samprit; Duberstein, Paul R; Putrino, David; Alexopoulos, George S

2017-06-01

To examine the relationship of negative emotions with suicidal ideation during 12 weeks of Problem Adaptation Therapy (PATH) versus Supportive Therapy of Cognitively Impaired Older Adults (ST-CI), hypothesizing that improved negative emotions are associated with reduced suicidal ideation, PATH improves negative emotions more than ST-CI, and improved negative emotions, rather than other depression symptoms, predict reduction in suicidal ideation. In a randomized controlled trial of two home-delivered psychosocial interventions, 74 older participants (65-95 years old) with major depressive disorder and cognitive impairment were recruited in collaboration with community agencies. The sample reported less intense feelings than suicidal intention. Interventions and assessments were conducted in participants' homes. PATH focuses on improving emotion regulation, whereas ST-CI focuses on nonspecific therapeutic factors, such as understanding and empathy. Improved negative emotions were measured as improvement in Montgomery Asberg's Depression Rating Scales' (MADRS) observer ratings of sadness, anxiety, guilt, hopelessness, and anhedonia. Suicidal ideation was assessed with the MADRS Suicide Item. MADRS Negative Emotions scores were significantly associated with suicidal ideation during the course of treatment (F [1,165]  = 12.73, p = 0.0005). PATH participants had significantly greater improvement in MADRS emotions than ST-CI participants (treatment group by time: F [1,63.2]  = 7.02, p = 0.0102). Finally, improved negative emotions, between lagged and follow-up interview, significantly predicted reduction in suicidal ideation at follow-up interview (F [1, 96]  = 9.95, p = 0.0022). Findings thatimprovement in negative emotions mediates reduction in suicidal ideation may guide the development of psychosocial interventions for reduction of suicidal ideation (clinicaltrials.gov; NCT00368940). Copyright © 2017 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Lack of association between dopaminergic antagonism and negative symptoms in schizophrenia: a positron emission tomography dopamine D2/3 receptor occupancy study

PubMed Central

Fervaha, Gagan; Caravaggio, Fernando; Mamo, David C.; Mulsant, Benoit H.; Pollock, Bruce G.; Nakajima, Shinichiro; Gerretsen, Philip; Rajji, Tarek K.; Mar, Wanna; Iwata, Yusuke; Plitman, Eric; Chung, Jun Ku; Remington, Gary; Graff-Guerrero, Ariel

2016-01-01

Rationale Several pre-clinical studies suggest that antipsychotic medications cause secondary negative symptoms. However, direct evidence for a relationship among antipsychotic medications, their direct effects on neurotransmitter systems, and negative symptoms in schizophrenia remains controversial. Objective The objective of this study was to examine the relationship between antipsychotic-related dopamine D2/3 receptor occupancy and negative symptoms in patients with schizophrenia. Methods Forty-one clinically stable outpatients with schizophrenia participated in this prospective dose reduction positron emission tomography (PET) study. Clinical assessments and [11C]-raclopride PET scans were performed before and after participants underwent gradual dose reduction of their antipsychotic medication by up to 40% from the baseline dose. Results No significant relationship was found between antipsychotic-related dopamine D2/3 receptor occupancy and negative symptom severity at baseline or follow-up. Similar null findings were found for subdomains of negative symptoms (amotivation and diminished expression). Occupancy was significantly lower following dose reduction; however, negative symptom severity did not change significantly, though a trend toward reduction was noted. Examination of change scores between these two variables revealed no systematic relationship. Conclusions Our cross-sectional and longitudinal results failed to find a significant dose-dependent relationship between severity of negative symptoms and antipsychotic-related dopaminergic antagonism in schizophrenia. These findings argue against the notion that antipsychotics necessarily cause secondary negative symptoms. Our results are also in contrast with the behavioural effects of dopaminergic antagonism routinely reported in pre-clinical investigations, suggesting that the role of this variable in the context of chronic treatment and schizophrenia needs to be re-examined. PMID:27557949

Negative Emotions and Suicidal Ideation During Psychosocial Treatments in Older Adults with Major Depression and Cognitive Impairment

PubMed Central

Kiosses, Dimitris N.; Gross, James J.; Banerjee, Samprit; Duberstein, Paul R.; Putrino, David; Alexopoulos, George S.

2017-01-01

Objectives To examine the relationship of negative emotions with suicidal ideation during 12-weeks of Problem Adaptation Therapy (PATH) vs. Supportive Therapy of Cognitively Impaired Older Adults (ST-CI). We hypothesize that: a) improved negative emotions are associated with reduced suicidal ideation; b) PATH improves negative emotions more than ST-CI; and c) improved negative emotions, rather than other depression symptoms, predict reduction in suicidal ideation. Design RCT of two home-delivered psychosocial interventions. Setting Weill-Cornell Institute of Geriatric Psychiatry; interventions and assessments were conducted at participants’ home. Participants 74 older participants (65–95 years old) with MDD and cognitive impairment were recruited in collaboration with community agencies. The sample reported less intense feelings than suicidal intention. Interventions PATH focuses on improving emotion regulation whereas ST-CI focuses on non-specific therapeutic factors, such as understanding and empathy. Measurements Improved negative emotions are measured as improvement in Montgomery Asberg’s Depression Rating Scales’ (MADRS) observer-ratings of sadness, anxiety, guilt, hopelessness and anhedonia. Suicidal ideation was assessed with the MADRS Suicide Item. Results MADRS Negative Emotions scores were significantly associated with suicidal ideation during the course of treatment (F[1, 165]=12.73, p=0.0005). PATH participants had significantly greater improvement in MADRS emotions than ST-CI participants (treatment group by time: F[1,63.2]=7.02, p=0.0102). Finally, improved negative emotions, between lagged and follow-up interview, significantly predicted reduction in suicidal ideation at follow-up interview (F[1, 96]=9.95, p=0.0022). Conclusions Our findings that improvement in negative emotions mediates reduction in suicidal ideation may guide the development of psychosocial interventions for reduction of suicidal ideation. PMID:28223082

Use of negative-pressure dressings and split-thickness skin grafts following penile shaft reduction and reduction scrotoplasty in the management of penoscrotal elephantiasis.

PubMed

Stokes, Tracey H; Follmar, Keith E; Silverstein, Ari D; Weizer, Alon Z; Donatucci, Craig F; Anderson, Everett E; Erdmann, Detlev

2006-06-01

From 1988 to 2005, 8 men who presented with penoscrotal elephantiasis underwent penile shaft degloving and reduction scrotoplasty, followed by transplantation of a split-thickness skin graft (STSG) to the penile shaft. The etiology of elephantiasis in these patients included self-injection of viscous fluid and postsurgical obstructive lymphedema. In the 6 most recent cases, negative-pressure dressings were applied over the STSG to promote graft take, and STSG take rate was 100%. The results of our series corroborate those of a previous report, which showed circumferential negative-pressure dressings to be safe and efficacious in bolstering STSGs to the penile shaft. Furthermore, these results suggest that the use of negative-pressure dressings may improve graft take in this patient population.

Self-Efficacy for Sexual Risk Reduction and Partner HIV Status as Correlates of Sexual Risk Behavior Among HIV-Positive Adolescent Girls and Women

PubMed Central

Boone, Melissa R.; Cherenack, Emily M.

2015-01-01

Abstract Little is known about the correlates of sexual risk behavior among HIV-positive adolescent girls and women in the United States. This study investigates two potential factors related to unprotected vaginal and anal intercourse (UVAI) that have yet to be thoroughly studied in this group: self-efficacy for sexual risk reduction and partner HIV status. Data was analyzed from 331 HIV-positive adolescent girls and women between 12 and 24 years old who reported vaginal and/or anal intercourse with a male partner in the past 3 months at fifteen sites across the United States. Results show that overall self-efficacy (B = −0.15, p=0.01), self-efficacy to discuss safe sex with one's partner (B = −0.14, p=0.01), and self-efficacy to refuse unsafe sex (B = −0.21, p=0.01) are related to UVAI episodes. Participants with only HIV-positive partners or with both HIV-positive and HIV-negative partners showed a trend towards higher percentages of UVAI episodes compared to participants with only HIV-negative partners (F(2, 319)=2.80, p=0.06). These findings point to the importance of including self-efficacy and partner HIV status in risk-reduction research and interventions developed for HIV-positive adolescent girls and young women. PMID:25856632

Self-Efficacy for Sexual Risk Reduction and Partner HIV Status as Correlates of Sexual Risk Behavior Among HIV-Positive Adolescent Girls and Women.

PubMed

Boone, Melissa R; Cherenack, Emily M; Wilson, Patrick A

2015-06-01

Little is known about the correlates of sexual risk behavior among HIV-positive adolescent girls and women in the United States. This study investigates two potential factors related to unprotected vaginal and anal intercourse (UVAI) that have yet to be thoroughly studied in this group: self-efficacy for sexual risk reduction and partner HIV status. Data was analyzed from 331 HIV-positive adolescent girls and women between 12 and 24 years old who reported vaginal and/or anal intercourse with a male partner in the past 3 months at fifteen sites across the United States. Results show that overall self-efficacy (B=-0.15, p=0.01), self-efficacy to discuss safe sex with one's partner (B=-0.14, p=0.01), and self-efficacy to refuse unsafe sex (B=-0.21, p=0.01) are related to UVAI episodes. Participants with only HIV-positive partners or with both HIV-positive and HIV-negative partners showed a trend towards higher percentages of UVAI episodes compared to participants with only HIV-negative partners (F(2, 319)=2.80, p=0.06). These findings point to the importance of including self-efficacy and partner HIV status in risk-reduction research and interventions developed for HIV-positive adolescent girls and young women.

Effects of CO2-induced pH reduction on the exoskeleton structure and biophotonic properties of the shrimp Lysmata californica

PubMed Central

Taylor, Jennifer R. A.; Gilleard, Jasmine M.; Allen, Michael C.; Deheyn, Dimitri D.

2015-01-01

The anticipated effects of CO2-induced ocean acidification on marine calcifiers are generally negative, and include dissolution of calcified elements and reduced calcification rates. Such negative effects are not typical of crustaceans for which comparatively little ocean acidification research has been conducted. Crustaceans, however, depend on their calcified exoskeleton for many critical functions. Here, we conducted a short-term study on a common caridean shrimp, Lysmata californica, to determine the effect of CO2-driven reduction in seawater pH on exoskeleton growth, structure, and mineralization and animal cryptic coloration. Shrimp exposed to ambient (7.99 ± 0.04) and reduced pH (7.53 ± 0.06) for 21 days showed no differences in exoskeleton growth (percent increase in carapace length), but the calcium weight percent of their cuticle increased significantly in reduced pH conditions, resulting in a greater Ca:Mg ratio. Cuticle thickness did not change, indicating an increase in the mineral to matrix ratio, which may have mechanical consequences for exoskeleton function. Furthermore, there was a 5-fold decrease in animal transparency, but no change in overall shrimp coloration (red). These results suggest that even short-term exposure to CO2-induced pH reduction can significantly affect exoskeleton mineralization and shrimp biophotonics, with potential impacts on crypsis, physical defense, and predator avoidance. PMID:26030212

Effects of CO2-induced pH reduction on the exoskeleton structure and biophotonic properties of the shrimp Lysmata californica.

PubMed

Taylor, Jennifer R A; Gilleard, Jasmine M; Allen, Michael C; Deheyn, Dimitri D

2015-06-01

The anticipated effects of CO2-induced ocean acidification on marine calcifiers are generally negative, and include dissolution of calcified elements and reduced calcification rates. Such negative effects are not typical of crustaceans for which comparatively little ocean acidification research has been conducted. Crustaceans, however, depend on their calcified exoskeleton for many critical functions. Here, we conducted a short-term study on a common caridean shrimp, Lysmata californica, to determine the effect of CO2-driven reduction in seawater pH on exoskeleton growth, structure, and mineralization and animal cryptic coloration. Shrimp exposed to ambient (7.99 ± 0.04) and reduced pH (7.53 ± 0.06) for 21 days showed no differences in exoskeleton growth (percent increase in carapace length), but the calcium weight percent of their cuticle increased significantly in reduced pH conditions, resulting in a greater Ca:Mg ratio. Cuticle thickness did not change, indicating an increase in the mineral to matrix ratio, which may have mechanical consequences for exoskeleton function. Furthermore, there was a 5-fold decrease in animal transparency, but no change in overall shrimp coloration (red). These results suggest that even short-term exposure to CO2-induced pH reduction can significantly affect exoskeleton mineralization and shrimp biophotonics, with potential impacts on crypsis, physical defense, and predator avoidance.

Stress-related hormones and genetic diversity in sea otters (Enhydra lutris)

USGS Publications Warehouse

Larson, Shawn E.; Monson, Daniel H.; Ballachey, Brenda E.; Jameson, Ronald J.; Wasser, S.K.

2009-01-01

Sea otters (Enhydra lutris) once ranged throughout the coastal regions of the north Pacific, but were extirpated throughout their range during the fur trade of the 18th and 19th centuries, leaving only small, widely scattered, remnant populations. All extant sea otter populations are believed to have experienced a population bottleneck and thus have lost genetic variation. Populations that undergo severe population reduction and associated inbreeding may suffer from a general reduction in fitness termed inbreeding depression. Inbreeding depression may result in decreased testosterone levels in males, and reduced ability to respond to stressful stimuli associated with an increase in the stress-related adrenal glucocorticoid hormones, cortisol and corticosterone. We investigated correlations of testosterone, cortisol, and corticosterone with genetic diversity in sea otters from five populations. We found a significant negative correlation between genetic diversity and both mean population-level (r2= 0.27, P < 0.001) and individual-level (r2= 0.54, P < 0.001) corticosterone values, as well as a negative correlation between genetic diversity and cortisol at the individual level (r2= 0.17, P= 0.04). No relationship was found between genetic diversity and testosterone (P= 0.57). The strength of the correlations, especially with corticosterone, suggests potential negative consequences for overall population health, particularly for populations with the lowest genetic diversity.

MBSR vs aerobic exercise in social anxiety: fMRI of emotion regulation of negative self-beliefs

PubMed Central

Ziv, Michal; Jazaieri, Hooria; Hahn, Kevin; Gross, James J.

2013-01-01

Mindfulness-based stress reduction (MBSR) is thought to reduce emotional reactivity and enhance emotion regulation in patients with social anxiety disorder (SAD). The goal of this study was to examine the neural correlates of deploying attention to regulate responses to negative self-beliefs using functional magnetic resonance imaging. Participants were 56 patients with generalized SAD in a randomized controlled trial who were assigned to MBSR or a comparison aerobic exercise (AE) stress reduction program. Compared to AE, MBSR yielded greater (i) reductions in negative emotion when implementing regulation and (ii) increases in attention-related parietal cortical regions. Meditation practice was associated with decreases in negative emotion and social anxiety symptom severity, and increases in attention-related parietal cortex neural responses when implementing attention regulation of negative self-beliefs. Changes in attention regulation during MBSR may be an important psychological factor that helps to explain how mindfulness meditation training benefits patients with anxiety disorders. PMID:22586252

B-HT 920, a dopamine D2 agonist, in the treatment of negative symptoms of chronic schizophrenia.

PubMed

Ohmori, T; Koyama, T; Inoue, T; Matsubara, S; Yamashita, I

1993-05-15

A prospective, nonblind 8-week trial of talipexole dihydrochloride (B-HT 920), a dopamine D2 agonist, was conducted in 15 schizophrenic patients with predominantly negative symptoms. B-HT 920 was initiated at 0.15 mg/day and then adjusted at 0.15-2.4 mg/day on the basis of clinical response and side effects. Dosage of concurrent neuroleptics was fixed at least 3 weeks prior to the trial and was unchanged throughout the study period. In addition to clinical assessment, levels of plasma homovanillic acid (pHVA), a potential index of central dopamine turnover, were measured. There was a small but significant (p < 0.01, Wilcoxon test) reduction in total scores of the Scale for the Assessment of Negative Symptoms or in a cluster score of three negative items (Emotional Withdrawal, Blunted Affect, and Psychomotor Retardation) of the Brief Psychiatric Rating Scale (BPRS). No change was observed in cluster scores of positive items of BPRS. There was a weak negative correlation between pHVA levels and the cluster scores of negative items of BPRS both at weeks 0 and 8 of the trial. The clinical results suggest that activation of D2 receptors was related to partial amelioration of the negative symptoms. The clinical and biochemical findings are consistent with a hypothesis that decreased dopaminergic activity may be related to the etiology of negative symptoms of schizophrenia.

Potential negative effects of earthworm prey on damage to turfgrass by omnivorous mole crickets (Orthoptera: Gryllotalpidae).

PubMed

Xu, Yao; Held, David W; Hu, Xing Ping

2012-10-01

The severity of damage to host plants by omnivorous pests can vary according to the availability of plant and animal prey. Two omnivorous mole crickets, Scapteriscus vicinus Scudder and S. borellii Giglio-Tos, were used to determine if the availability of prey influences damage to hybrid bermudagrass by adult mole crickets. Experiments were conducted in arenas with either grass alone (control), grass plus one mole cricket, grass plus earthworms (Eisenia fetida Savigny), or grass with earthworms and a mole cricket. Root growth variables (e.g., volume, dry weight) after 4 wk and weekly measurements of top growth were compared among the treatments. Surprisingly, bermudagrass infested with either mole cricket species caused no significant reduction in root growth and a minimal reduction on top growth with S. vicinus compared with controls. Survival of earthworms with S. borellii was significantly lower than survival in the earthworm-only treatment suggesting predation. Survival of earthworms with S. vicinus, however, was not different from the earthworm-only treatment. The addition of earthworm prey with mole crickets did not significantly impact bermudagrass root or shoot growth relative to grass with only mole crickets. Despite no negative impacts from earthworms or mole crickets separately, earthworms plus mole crickets negatively impact several root parameters (e.g., length) suggesting an interaction between these two soil-dwelling invertebrates. Increased use of more target-selective insecticides in turfgrass may increase available prey. This work suggests that alternative prey, when present, may result in a negative impact on turfgrass roots from foraging omnivorous mole crickets.

Posttraumatic stress symptoms and tobacco abstinence effects in a non-clinical sample: evaluating the mediating role of negative affect reduction smoking expectancies.

PubMed

Langdon, Kirsten J; Leventhal, Adam M

2014-11-01

The relation between posttraumatic stress symptoms and smoking is well documented but poorly understood. The present investigation sought to evaluate the impact of posttraumatic stress symptoms on subjective and behavioral tobacco abstinence effects both directly and indirectly through negative affect reduction smoking outcome expectancies. Participants included 275 (68.7% male; Mage =43.9, 10+ cig/day) adult non-treatment seeking smokers, who attended two counterbalanced laboratory sessions (16 h of smoking deprivation vs ad libitum smoking), during which they completed self-report measures of withdrawal symptoms and mood followed by a smoking lapse task in which they could earn money for delaying smoking and purchase cigarettes to smoke. Results supported a mediational pathway whereby higher baseline symptoms of posttraumatic stress predicted greater endorsement of expectancies that smoking will effectively reduce negative affect, which in turn predicted greater abstinence-provoked exacerbations in nicotine withdrawal symptoms and negative affect. Posttraumatic stress symptoms also predicted number of cigarettes purchased independent of negative affect reduction expectancies, but did not predict delaying smoking for money. Findings highlight tobacco abstinence effects as a putative mechanism underlying posttraumatic stress disorder (PTSD)-smoking comorbidity, indicate an important mediating role of beliefs for smoking-induced negative affect reduction, and shed light on integrated treatment approaches for these two conditions. © The Author(s) 2014.

Effects of a Community-Based HIV Risk Reduction Intervention Among HIV-Positive Individuals: Results of a Quasi-Experimental Study in Nepal.

PubMed

Poudel, Krishna C; Buchanan, David R; Poudel-Tandukar, Kalpana

2015-06-01

We evaluated the efficacy of a sexual risk reduction intervention utilizing protection motivation and social cognitive theories to address knowledge, threat and coping appraisals, and condom use intentions among HIV-positive individuals in Nepal. Using a quasi-experimental research design, we assigned 277 participants to intervention (n=146) and control (n=131) groups. The intervention group received six sessions on sexual risk reduction strategies and the control group six sessions on medication adherence, smoking, and mental health. Data were collected at baseline and immediately after the intervention. Results indicate that the sexual risk reduction intervention produced a significant increase in HIV transmission knowledge, perceived threat and coping appraisals, and intentions to use condoms with regular, HIV-positive, and HIV-negative partners. The positive effects of the intervention remained significant after adjusting for baseline scores and other potential confounders. In conclusion, our theory-based sexual risk reduction intervention was effective in improving HIV transmission knowledge, perceived threat and coping appraisals, and condom use intentions. Further studies are needed to evaluate the long-term efficacy of the intervention in increasing protection motivation and maintaining preventive behaviors.

A strategy for selecting sexual partners believed to pose little/no risks for HIV: serosorting and its implications for HIV transmission.

PubMed

Eaton, Lisa A; Kalichman, Seth C; O'Connell, Daniel A; Karchner, William D

2009-10-01

A common HIV/AIDS risk reduction strategy among men who have sex with men (MSM) is to limit their unprotected sex partners to those who are of the same HIV status, a practice referred to as serosorting. Decisions to serosort for HIV risk reduction are based on personal impressions and beliefs, and there is limited guidance offered on this community derived strategy from public health services. This paper reviews research on serosorting for HIV risk reduction and offers an evidence-based approach to serosorting guidance. Following a comprehensive electronic and manual literature search, we reviewed 51 studies relating to the implications of serosorting. Studies showed that HIV negative MSM who select partners based on HIV status are inadvertently placing themselves at risk for HIV. Infrequent HIV testing, lack of HIV status disclosure, co-occurring sexually transmitted infections, and acute HIV infection impede the potential protective benefits of serosorting. Public health messages should continue to encourage reductions in numbers of sexual partners and increases in condom use. Risk reduction messages should also highlight the limitations of relying on one's own and partner's HIV status in making sexual risk decisions.

The virtues of gossip: reputational information sharing as prosocial behavior.

PubMed

Feinberg, Matthew; Willer, Robb; Stellar, Jennifer; Keltner, Dacher

2012-05-01

Reputation systems promote cooperation and deter antisocial behavior in groups. Little is known, however, about how and why people share reputational information. Here, we seek to establish the existence and dynamics of prosocial gossip, the sharing of negative evaluative information about a target in a way that protects others from antisocial or exploitative behavior. We present a model of prosocial gossip and the results of 4 studies testing the model's claims. Results of Studies 1 through 3 demonstrate that (a) individuals who observe an antisocial act experience negative affect and are compelled to share information about the antisocial actor with a potentially vulnerable person, (b) sharing such information reduces negative affect created by observing the antisocial behavior, and (c) individuals possessing more prosocial orientations are the most motivated to engage in such gossip, even at a personal cost, and exhibit the greatest reduction in negative affect as a result. Study 4 demonstrates that prosocial gossip can effectively deter selfishness and promote cooperation. Taken together these results highlight the roles of prosocial motivations and negative affective reactions to injustice in maintaining reputational information sharing in groups. We conclude by discussing implications for reputational theories of the maintenance of cooperation in human groups.

Can evaluative conditioning decrease soft drink consumption?

PubMed

Shaw, Jena A; Forman, Evan M; Espel, Hallie M; Butryn, Meghan L; Herbert, James D; Lowe, Michael R; Nederkoorn, Chantal

2016-10-01

The present study examined the effect of a picture-picture evaluative conditioning (EC) procedure on soft drink (soda) outcomes, including negative implicit attitudes, consumption during a taste test, and real-world consumption reported during the week after the intervention. In the EC condition (n = 43), soda images were paired with disgust images and water images were paired with pleasant images, whereas in the control condition (n = 41), the same images were viewed without pairing. The EC condition showed a larger reduction in real-world soda consumption across the week following the intervention. However, individuals in the EC condition did not consume less soda during a taste test immediately following the intervention. EC only significantly increased negative implicit attitudes towards soda among individuals who already had relatively higher baseline negative attitudes. These findings generally favored the potential for EC to impact soda drinking habits, but suggest that a brief EC intervention may not be strong enough to change attitudes towards a well-known brand unless negative attitudes are already present. Copyright © 2016 Elsevier Ltd. All rights reserved.

An electrophysiological investigation of emotional abnormalities in groups at risk for schizophrenia-spectrum personality disorders.

PubMed

Martin, Elizabeth A; Karcher, Nicole R; Bartholow, Bruce D; Siegle, Greg J; Kerns, John G

2017-03-01

Both extreme levels of social anhedonia (SocAnh) and perceptual aberration/magical ideation (PerMag) are associated with risk for schizophrenia-spectrum disorders and with emotional abnormalities. Yet, the nature of any psychophysiological-measured affective abnormality, including the role of automatic/controlled processes, is unclear. We examined the late positive potential (LPP) during passive viewing (to assess automatic processing) and during cognitive reappraisal (to assess controlled processing) in three groups: SocAnh, PerMag, and controls. The SocAnh group exhibited an increased LPP when viewing negative images. Further, SocAnh exhibited greater reductions in the LPP for negative images when told to use strategies to alter negative emotion. Similar to SocAnh, PerMag exhibited an increased LPP when viewing negative images. However, PerMag also exhibited an increased LPP when viewing positive images as well as an atypical decreased LPP when increasing positive emotion. Overall, these results suggest that at-risk groups are associated with shared and unique automatic and controlled abnormalities. Copyright © 2017 Elsevier B.V. All rights reserved.

Mice with subtle reduction of NMDA NR1 receptor subunit expression have a selective decrease in mismatch negativity: Implications for schizophrenia prodromal population.

PubMed

Featherstone, Robert E; Shin, Rick; Kogan, Jeffrey H; Liang, Yuling; Matsumoto, Mitsuyuki; Siegel, Steven J

2015-01-01

Reductions in glutamate function are regarded as an important contributory factor in schizophrenia. However, there is a paucity of animal models characterized by developmental and sustained reductions in glutamate function. Pharmacological models using NMDA antagonists have been widely used but these typically produce only transient changes in behavior and brain function. Likewise, mice with homozygous constitutive reductions in glutamate receptor expression show stable brain and behavioral changes, but many of these phenotypes are more severe than the human disease. The current study examines a variety of schizophrenia-related EEG measures in mice with a heterozygous alteration of the NMDA receptor NR1 subunit gene (NR1) that is known to result in reduced NR1 receptor expression in the homozygous mouse (NR1-/-). (NR1+/-) mice showed a 30% reduction in NR1 receptor expression and were reared after weaning in either group or isolated conditions. Outcome measures include the response to paired white noise stimuli, escalating inter-stimulus intervals (ISIs) and deviance-related mismatch negativity (MMN). In contrast to what has been reported in (NR1-/-) mice and mice treated with NMDA antagonists, (NR1+/-) mice showed no change on obligatory Event Related Potential (ERP) measures including the murine P50 and N100 equivalents (P20 and N40), or measures of baseline or evoked gamma power. Alternatively, (NR1+/-) mice showed a marked reduction in response to a deviant auditory tone during MMN task. Data suggest that EEG response to deviant, rather than static, stimuli may be more sensitive for detecting subtle changes in glutamate function. Deficits in these heterozygous NR1 knockdown mice are consistent with data demonstrating MMN deficits among family members of schizophrenia patients and among prodromal patients. Therefore, the current study suggests that (NR1+/-) mice may be among the most sensitive models for increased vulnerability to schizophrenia. Copyright © 2015. Published by Elsevier Inc.

Mechanistic insights into energy conservation by flavin-based electron bifurcation

DOE PAGES

Lubner, Carolyn E.; Jennings, David P.; Mulder, David W.; ...

2017-04-10

The recently realized biochemical phenomenon of energy conservation through electron bifurcation provides biology with an elegant means to maximize utilization of metabolic energy. The mechanism of coordinated coupling of exergonic and endergonic oxidation-reduction reactions by a single enzyme complex has been elucidated through optical and paramagnetic spectroscopic studies revealing unprecedented features. Pairs of electrons are bifurcated over more than 1 volt of electrochemical potential by generating a low-potential, highly energetic, unstable flavin semiquinone and directing electron flow to an iron-sulfur cluster with a highly negative potential to overcome the barrier of the endergonic half reaction. As a result, the unprecedentedmore » range of thermodynamic driving force that is generated by flavin-based electron bifurcation accounts for unique chemical reactions that are catalyzed by these enzymes.« less

Mechanistic insights into energy conservation by flavin-based electron bifurcation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lubner, Carolyn E.; Jennings, David P.; Mulder, David W.

The recently realized biochemical phenomenon of energy conservation through electron bifurcation provides biology with an elegant means to maximize utilization of metabolic energy. The mechanism of coordinated coupling of exergonic and endergonic oxidation-reduction reactions by a single enzyme complex has been elucidated through optical and paramagnetic spectroscopic studies revealing unprecedented features. Pairs of electrons are bifurcated over more than 1 volt of electrochemical potential by generating a low-potential, highly energetic, unstable flavin semiquinone and directing electron flow to an iron-sulfur cluster with a highly negative potential to overcome the barrier of the endergonic half reaction. As a result, the unprecedentedmore » range of thermodynamic driving force that is generated by flavin-based electron bifurcation accounts for unique chemical reactions that are catalyzed by these enzymes.« less

Disturbances in Response Inhibition and Emotional Processing as Potential Pathways to Violence in Schizophrenia: A High-Density Event-Related Potential Study.

PubMed

Krakowski, Menahem I; De Sanctis, Pierfilippo; Foxe, John J; Hoptman, Matthew J; Nolan, Karen; Kamiel, Stephanie; Czobor, Pal

2016-07-01

Increased susceptibility to emotional triggers and poor response inhibition are important in the etiology of violence in schizophrenia. Our goal was to evaluate abnormalities in neurophysiological mechanisms underlying response inhibition and emotional processing in violent patients with schizophrenia (VS) and 3 different comparison groups: nonviolent patients (NV), healthy controls (HC) and nonpsychotic violent subjects (NPV). We recorded high-density Event-Related Potentials (ERPs) and behavioral responses during an Emotional Go/NoGo Task in 35 VS, 24 NV, 28 HC and 31 NPV subjects. We also evaluated psychiatric symptoms and impulsivity. The neural and behavioral deficits in violent patients were most pronounced when they were presented with negative emotional stimuli: They responded more quickly than NV when they made commission errors (ie, failure of inhibition), and evidenced N2 increases and P3 decreases. In contrast, NVs showed little change in reaction time or ERP amplitude with emotional stimuli. These N2 and P3 amplitude changes in VSs showed a strong association with greater impulsivity. Besides these group specific changes, VSs shared deficits with NV, mostly N2 reduction, and with violent nonpsychotic subjects, particularly P3 reduction. Negative affective triggers have a strong impact on violent patients with schizophrenia which may have both behavioral and neural manifestations. The resulting activation could interfere with response inhibition. The affective disruption of response inhibition, identified in this study, may index an important pathway to violence in schizophrenia and suggest new modes of treatment. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

[Effects of warming and precipitation exclusion on soil N2O fluxes in subtropical forests.

PubMed

Tang, Cai di; Zhang, Zheng; Cai, Xiao Zhen; Guo, Jian Fen; Yang, Yu Sheng

2017-10-01

In order to explore how soil warming and precipitation exclusion influence soil N2O fluxes, we used related functional genes as markers, and four treatments were set up, i.e. , control (CT), soil warming (W, 5 ℃ above the ambient temperature of the control), 50% precipitation reduction (P), soil warming plus 50% precipitation reduction (WP). The results showed that precipitation exclusion reduced soil ammonium nitrogen concentration significantly. Soil warming decreased soil N2O flux and soil denitrification potential significantly. Soil microbial biomass nitrogen (MBN) in warming treatment (W) and precipitation exclusion treatment (P) was significantly lower than that in the control. The amoA gene abundance of AOA was negatively correlated with MBN and ammonium nitrogen contents, but neither soil nitrification potential nor soil N2O flux was correlated with the amoA gene abundance of AOA. Path analysis showed that the denitrification potential affected soil N2O flux directly, while microbial biomass phosphorus (MBP) and warming affected soil N2O flux indirectly through their direct effects on denitrification potential. Temperature might be the main driver of N2O flux in subtropical forest soils. Global warming would reduce N2O emissions from subtropical forest soils.

Is psychotherapy for functional somatic syndromes harmful? A mixed methods study on negative effects.

PubMed

Holsting, A F; Pedersen, H F; Rask, M T; Frostholm, L; Schröder, A

2017-07-01

Concern for negative effects of psychotherapy for functional somatic syndromes (FSS) has been expressed by clinicians and some patient associations, which may prevent patients from seeking treatment. Therefore, we sought to explore the occurrence and characteristics of negative effects from group-based psychotherapy as experienced by patients with severe or multiple FSS. An adapted version of the explanatory sequential mixed methods design was applied. We used data from an on-going pilot study on Acceptance and Commitment Therapy and Mindfulness-Based Stress Reduction. Negative effects were measured by Inventory for the assessment of Negative Effects of Psychotherapy (INEP). In addition, telephone interviews were conducted with randomly chosen patients and patients who reported negative effects. The latter were asked to elaborate on their INEP response. Quantitative data were analysed descriptively while interview transcripts were explored by thematic analysis. Eighty patients responded to the questionnaire (89%). Negative effects to different extent (from 'slightly agree' to 'fully agree') were reported by 25 (31%). The most frequent negative effects were dependence on the therapist (12%), feeling down after therapy (6%) and insurance problems (7%). By exploring 27 participants' experiences of negative effects 3 main themes were identified: relations in therapy, outcome and transition from therapy to everyday life. Patients with FSS reported a few specific negative effects, all with low frequency. Generally, therapy was well-received. Some patients did however express negative effects both within and outside the therapeutic context. It is important to inform patients about potential negative effects prior to psychotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Electric potentiation of gravikinesis in Paramecium is possibly mediated by filaments.

PubMed

Machemer, H

1998-01-01

Sensitivity of Paramecium to mechanical stress including gravitational force is organized along two opposing gradients of membrane channel distribution: depolarizing Ca channels and hyperpolarizing K channels. Mechanoreceptor channels reside in the membrane of the cell soma and are activated, when the weight of the cytoplasm deforms the "lower" plasma membrane. Channel distribution is such as to generate ciliary activation which can counteract sedimentation of the cells: a reduction in downward swimming rate and an augmentation in upward swimming rate. Application of weak DC fields does not only induce the well-known cathodal orientation and swimming of Paramecium toward the cathode (galvano-taxis). We document that swimming velocity is augmented up to 175% as a function of the voltage gradient between 0.3 V/cm and 0.8 V/cm (galvanokinesis). A gradient of 0.3 V/cm was highly effective in raising the common negative gravikinesis of downward swimmers threefold. The gravikinesis of upward swimmers reversed polarity under field stimulation inducing cells to augment sedimentation effects (positive gravikinesis). Both effects of electric-field stimulation on ciliary activation are of the depolarizing type: reduction in the frequency of normally beating cilia. Analysis of the data shows that a voltage-sensitivity of gravireceptor channels would not account for the observed potentiation of negative gravikinesis. It is suggested that a previously described voltage-dependent Ca channel of the soma membrane interferes with a Ca(2+)-sensitive, peripheral filament system, which directly connects to gravireceptor channels.

Stable Isotopes of C and N Reveal Habitat Dependent Dietary Overlap between Native and Introduced Turtles Pseudemys rubriventris and Trachemys scripta

PubMed Central

Pearson, Steven H.; Avery, Harold W.; Kilham, Susan S.; Velinsky, David J.; Spotila, James R.

2013-01-01

Habitat degradation and species introductions are two of the leading causes of species declines on a global scale. Invasive species negatively impact native species through predation and competition for limited resources. The impacts of invasive species may be increased in habitats where habitat degradation is higher due to reductions of prey abundance and distribution. Using stable isotope analyses and extensive measurements of resource availability we determined how resource availability impacts the long term carbon and nitrogen assimilation of the invasive red-eared slider turtle (Trachemys scripta elegans) and a native, threatened species, the red-bellied turtle (Pseudemys rubriventris) at two different freshwater wetland complexes in Pennsylvania, USA. At a larger wetland complex with greater vegetative species richness and diversity, our stable isotope analyses showed dietary niche partitioning between species, whereas analyses from a smaller wetland complex with lower vegetative species richness and diversity showed significant dietary niche overlap. Determining the potential for competition between these two turtle species is important to understanding the ecological impacts of red-eared slider turtles in wetland habitats. In smaller wetlands with increased potential for competition between native turtles and invasive red-eared slider turtles we expect that when shared resources become limited, red-eared slider turtles will negatively impact native turtle species leading to long term population declines. Protection of intact wetland complexes and the reduction of introduced species populations are paramount to preserving populations of native species. PMID:23675437

Stable isotopes of C and N reveal habitat dependent dietary overlap between native and introduced turtles Pseudemys rubriventris and Trachemys scripta.

PubMed

Pearson, Steven H; Avery, Harold W; Kilham, Susan S; Velinsky, David J; Spotila, James R

2013-01-01

Habitat degradation and species introductions are two of the leading causes of species declines on a global scale. Invasive species negatively impact native species through predation and competition for limited resources. The impacts of invasive species may be increased in habitats where habitat degradation is higher due to reductions of prey abundance and distribution. Using stable isotope analyses and extensive measurements of resource availability we determined how resource availability impacts the long term carbon and nitrogen assimilation of the invasive red-eared slider turtle (Trachemys scripta elegans) and a native, threatened species, the red-bellied turtle (Pseudemys rubriventris) at two different freshwater wetland complexes in Pennsylvania, USA. At a larger wetland complex with greater vegetative species richness and diversity, our stable isotope analyses showed dietary niche partitioning between species, whereas analyses from a smaller wetland complex with lower vegetative species richness and diversity showed significant dietary niche overlap. Determining the potential for competition between these two turtle species is important to understanding the ecological impacts of red-eared slider turtles in wetland habitats. In smaller wetlands with increased potential for competition between native turtles and invasive red-eared slider turtles we expect that when shared resources become limited, red-eared slider turtles will negatively impact native turtle species leading to long term population declines. Protection of intact wetland complexes and the reduction of introduced species populations are paramount to preserving populations of native species.

On the interpretation of quantitative structure–function activity relationship data for lactate oxidase

PubMed Central

Yorita, Kazuko; Misaki, Hideo; Palfey, Bruce A.; Massey, Vincent

2000-01-01

The native flavin, FMN, has been removed from the l-lactate oxidase of Aerococcus viridans, and the apoprotein reconstituted with 12 FMN derivatives with various substituents at the flavin 6- and 8-positions. Impressive linear relationships are exhibited between the sum of the Hammett σpara and σortho parameters and the redox potentials of the free flavins, and between the redox potentials of the free and enzyme-bound flavins. Rapid reaction kinetics studies of the reconstituted enzymes with the substrates l-lactate and l-mandelate show an increase in the reduction rate constant with increasing redox potential, except that, with lactate, a limiting rate constant of ≈700 s−1 is obtained with flavins of high potential. Similar breakpoints are found in plots of the rate constants for flavin N5-sulfite adduct formation and for the reaction of the reduced enzymes with molecular oxygen. These results are interpreted in terms of a two-step equilibrium preceding the chemical reaction step, in which the second equilibrium step provides an upper limit to the rate with which the particular substrate or ligand is positioned with the flavin in the correct fashion for the observed chemical reaction to occur. The relationship of rate constants for flavin reduction and N5-sulfite adduct formation with flavin redox potential below the observed breakpoint indicate development of significant negative charge in the transition states of the reactions. In the case of reduction by substrate, the results are consistent either with a hydride transfer mechanism or with the so called “carbanion” mechanism, in which the substrate α-proton is abstracted by an enzyme base protected from exchange with solvent. These conclusions are supported by substrate α-deuterium isotope effects and by solvent viscosity effects on sulfite binding. PMID:10706608

Deciphering the impact of diagenesis overprint on negative δ13C excursions using rock magnetism: Case study of Ediacaran carbonates, Yangjiaping section, South China

NASA Astrophysics Data System (ADS)

Macouin, Mélina; Ader, Magali; Moreau, Marie-Gabrielle; Poitou, Charles; Yang, Zhenyu; Sun, Zhimming

2012-10-01

Rock magnetism is used here to investigate the genesis of one of the puzzling negative carbon isotopic excursions of the Neoproterozoic in the Yangtze platform (South China). A detailed characterization of the magnetic mineralogy, which includes low-temperature and high-field magnetometry and classical magnetic measurement (ARM, IRM, susceptibility), was therefore performed along upper Doushantuo and lower Dengying Formations outcropping in the Yangjiaping section. The derived magnetic parameters show variations that can be interpreted as variations in magnetic grains size and in oxide contents. They show that the magnetic content is significantly reduced in samples presenting negative δ13Ccalcite values. We interpret this as a result of magnetite dissolution and secondary carbonate precipitation during early diagenesis bacterial sulfate reduction. Combined with C and O isotopic data, paleomagnetic techniques thus show that the upper Doushantuo-lower Dengying negative excursion of the Yangjiaping section is largely due to diagenesis, although the preservation of a genuine δ13C excursion of lower magnitude from +7‰ down to 0‰, instead of down to -9‰ as usually considered, cannot be ruled out. A corrected δ13Ccarbonate chemostratigraphic curve is therefore proposed. The unambiguous identification of a strong diagenetic component for this excursion casts doubts on the primary nature of other potentially time equivalent negative excursions of the Yangtze platform and thus to its correlation to negative excursions in other cratons (i.e. Shuram excursion). More generally, this study illustrates the potential of magnetic mineralogy characterization, a low cost, time efficient and non-destructive technique, as screening tool for diagenetic overprints of δ13C and δ18O.

Design of Miniaturized Double-Negative Material for Specific Absorption Rate Reduction in Human Head

PubMed Central

Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2014-01-01

In this study, a double-negative triangular metamaterial (TMM) structure, which exhibits a resounding electric response at microwave frequency, was developed by etching two concentric triangular rings of conducting materials. A finite-difference time-domain method in conjunction with the lossy-Drude model was used in this study. Simulations were performed using the CST Microwave Studio. The specific absorption rate (SAR) reduction technique is discussed, and the effects of the position of attachment, the distance, and the size of the metamaterials on the SAR reduction are explored. The performance of the double-negative TMMs in cellular phones was also measured in the cheek and the tilted positions using the COMOSAR system. The TMMs achieved a 52.28% reduction for the 10 g SAR. These results provide a guideline to determine the triangular design of metamaterials with the maximum SAR reducing effect for a mobile phone. PMID:25350398

Design of miniaturized double-negative material for specific absorption rate reduction in human head.

PubMed

Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2014-01-01

In this study, a double-negative triangular metamaterial (TMM) structure, which exhibits a resounding electric response at microwave frequency, was developed by etching two concentric triangular rings of conducting materials. A finite-difference time-domain method in conjunction with the lossy-Drude model was used in this study. Simulations were performed using the CST Microwave Studio. The specific absorption rate (SAR) reduction technique is discussed, and the effects of the position of attachment, the distance, and the size of the metamaterials on the SAR reduction are explored. The performance of the double-negative TMMs in cellular phones was also measured in the cheek and the tilted positions using the COMOSAR system. The TMMs achieved a 52.28% reduction for the 10 g SAR. These results provide a guideline to determine the triangular design of metamaterials with the maximum SAR reducing effect for a mobile phone.

Non-nutritive sweeteners: evidence for benefit vs. risk.

PubMed

Gardner, Christopher

2014-02-01

Intake of added sugars in the American diet is high and has been linked to weight gain and adverse effects on glycemic control and diabetes. Several national health organizations recommend decreasing added sugars intake. Among the many strategies to consider to achieve this reduction is substitution with non-nutritive sweeteners (NNS - artificial sweeteners and stevia). The purpose of this review is to critically examine existing evidence for this strategy. Short-term intervention studies suggest that NNS, when substituted for added sugars, may be useful in supporting energy intake reduction, and promoting glycemic control and weight management. However, the magnitude of effect in these studies has ranged from modest to null. Compensatory eating behaviors likely diminish, and in some cases negate, potential effects. Findings from longer-term observational studies that examine associations between NNS use and obesity or type 2 diabetes are potentially confounded by reverse causality. Existing data are insufficient to clearly support or refute the effectiveness of substitution with NNS as a means of reducing added sugar intake. It is important to not lose sight of the impact of incorporating NNS-containing beverages and foods on overall diet quality when assessing potential health benefits vs. risks.

Separation of plutonium from lanthanum by electrolysis in LiCl KCl onto molten bismuth electrode

NASA Astrophysics Data System (ADS)

Serp, J.; Lefebvre, P.; Malmbeck, R.; Rebizant, J.; Vallet, P.; Glatz, J.-P.

2005-04-01

This work presents a study on the electroseparation of plutonium from lanthanum using molten bismuth electrodes in LiCl-KCl eutectic at 733 K. The reduction potentials of Pu3+ and La3+ ions were measured on a Bi thin film electrode using cyclic voltammetry (CV). A difference between the peak potentials for the formation of PuBi2 and LaBi2 of approximately 100 mV was found. Separation tests were then carried out using different current densities and salt phase compositions between a plutonium rod anode and an unstirred molten Bi cathode in order to evaluate the efficiency of an electrolytic separation process. At a current density of 12 mA/cm2/wt% (Pu3+), only Pu3+ ions are reduced into the molten Bi electrode, leaving La3+ ions in the salt melt. Similar results were found at two different Pu/La concentration ratios ([Pu]/[La] = 4 and 10). At a current density of 26 mA/cm2/wt% (Pu3+), co-reduction of Pu and La was observed as expected by the large negative potential of the Bi cathode during the separation test.

Antibacterial potential of silver nanoparticles synthesized using Madhuca longifolia flower extract as a green resource.

PubMed

Patil, Maheshkumar Prakash; Singh, Rahul Dheerendra; Koli, Prashant Bhimrao; Patil, Kalpesh Tumadu; Jagdale, Bapu Sonu; Tipare, Anuja Rajesh; Kim, Gun-Do

2018-05-25

The green and one-step synthesis of silver nanoparticles (AgNPs) has been proposed as simple and ecofriendly. In the present study, a flower extract of Madhuca longifolia was used for the reduction of silver nitrate into AgNPs, with phytochemicals from the flower extract as a reducing and stabilizing agents. The synthesized AgNPs were spherical and oval shaped and about 30-50 nm sizes. The appearance of a brown color in the reaction mixture is a primary indication of AgNPs formation, and it was confirmed by observing UV-visible spectroscopy peak at 436 nm. The Energy Dispersive X-ray spectra and X-ray diffraction analysis results together confirm that the synthesized nanoparticles contain silver and silver chloride nanoparticles. The Zeta potential analysis indicates presence of negative charges on synthesized AgNPs. The FT-IR study represents involvement of functional groups in AgNPs synthesis. Synthesized AgNPs shows potential antibacterial activity against Gram-positive and Gram-negative pathogens. M. longifolia flower is a good source for AgNPs synthesis and synthesized AgNPs are applicable as antibacterial agent in therapeutics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reducing pesticide use while preserving crop productivity and profitability on arable farms.

PubMed

Lechenet, Martin; Dessaint, Fabrice; Py, Guillaume; Makowski, David; Munier-Jolain, Nicolas

2017-03-01

Achieving sustainable crop production while feeding an increasing world population is one of the most ambitious challenges of this century 1 . Meeting this challenge will necessarily imply a drastic reduction of adverse environmental effects arising from agricultural activities 2 . The reduction of pesticide use is one of the critical drivers to preserve the environment and human health. Pesticide use could be reduced through the adoption of new production strategies 3-5 ; however, whether substantial reductions of pesticide use are possible without impacting crop productivity and profitability is debatable 6-17 . Here, we demonstrated that low pesticide use rarely decreases productivity and profitability in arable farms. We analysed the potential conflicts between pesticide use and productivity or profitability with data from 946 non-organic arable commercial farms showing contrasting levels of pesticide use and covering a wide range of production situations in France. We failed to detect any conflict between low pesticide use and both high productivity and high profitability in 77% of the farms. We estimated that total pesticide use could be reduced by 42% without any negative effects on both productivity and profitability in 59% of farms from our national network. This corresponded to an average reduction of 37, 47 and 60% of herbicide, fungicide and insecticide use, respectively. The potential for reducing pesticide use appeared higher in farms with currently high pesticide use than in farms with low pesticide use. Our results demonstrate that pesticide reduction is already accessible to farmers in most production situations. This would imply profound changes in market organization and trade balance.

Antipsychotic Response Worsens With Postmenopausal Duration in Women With Schizophrenia.

PubMed

González-Rodríguez, Alexandre; Catalán, Rosa; Penadés, Rafael; Ruiz Cortés, Victoria; Torra, Mercè; Seeman, Mary V; Bernardo, Miquel

2016-12-01

The loss of estrogens in the menopause may lead to increased vulnerability for psychotic relapse, poor clinical outcome, and a need for increased antipsychotic dose. However, confounders such as cumulative estrogen exposure and time since menopause have been inadequately studied. Our aim was to investigate potential variables capable of influencing antipsychotic response in a sample of postmenopausal women with schizophrenia. Sixty-four postmenopausal schizophrenic women were followed in a 12-week prospective treatment-by-clinical requirement study. Duration of reproductive years was considered an indirect measure of lifetime cumulative estrogens exposure. Psychopathological assessment included the following: Positive and Negative Syndrome Scale, Personal and Social Performance, and Clinical Global Impression-Schizophrenia Scale. Response was defined as a reduction of 30% or more of Positive and Negative Syndrome Scale total scores. Antipsychotic adherence was assessed by plasma level monitoring at 4 weeks. Regression analyses were performed to investigate the association between potential confounding factors and antipsychotic response. Forty-two participants (66%) were found to be antipsychotic responders. Time since menopause was significantly and negatively associated with overall antipsychotic response, explaining almost 42% of the variance of the model used. Smoking and cumulative estrogen exposures were associated with improvement in negative symptoms. Smoking and time since menopause were associated with improvement in excitement symptoms, and smoking was positively associated with improvement in depressive and cognitive symptoms. Time since menopause was significantly negatively associated with antipsychotic response in postmenopausal schizophrenic women, suggesting a decline in antipsychotic response after menopause. The neurobiological basis for antipsychotic response may include a role for estrogen and nicotine receptors.

Does human pressure affect the community structure of surf zone fish in sandy beaches?

NASA Astrophysics Data System (ADS)

Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.

2017-01-01

Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

The Doctrine of Original Antigenic Sin: Separating Good From Evil.

PubMed

Monto, Arnold S; Malosh, Ryan E; Petrie, Joshua G; Martin, Emily T

2017-06-15

The term "original antigenic sin" was coined approximately 60 years ago to describe the imprinting by the initial first influenza A virus infection on the antibody response to subsequent vaccination. These studies did not suggest a reduction in the response to current antigens but instead suggested anamnestic recall of antibody to earlier influenza virus strains. Then, approximately 40 years ago, it was observed that sequential influenza vaccination might lead to reduced vaccine effectiveness (VE). This conclusion was largely dismissed after an experimental study involving sequential administration of then-standard influenza vaccines. Recent observations have provided convincing evidence that reduced VE after sequential influenza vaccination is a real phenomenon. We propose that such reduction in VE be termed "negative antigenic interaction," given that there is no age cohort effect. In contrast, the potentially positive protective effect of early influenza virus infection later in life continues to be observed. It is essential that we understand better the immunologic factors underlying both original antigenic sin and negative antigenic interaction, to support development of improved influenza vaccines and vaccination strategies. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Improved Electrochemical Detection of Zinc Ions Using Electrode Modified with Electrochemically Reduced Graphene Oxide

PubMed Central

Kudr, Jiri; Richtera, Lukas; Nejdl, Lukas; Xhaxhiu, Kledi; Vitek, Petr; Rutkay-Nedecky, Branislav; Hynek, David; Kopel, Pavel; Adam, Vojtech; Kizek, Rene

2016-01-01

Increasing urbanization and industrialization lead to the release of metals into the biosphere, which has become a serious issue for public health. In this paper, the direct electrochemical reduction of zinc ions is studied using electrochemically reduced graphene oxide (ERGO) modified glassy carbon electrode (GCE). The graphene oxide (GO) was fabricated using modified Hummers method and was electrochemically reduced on the surface of GCE by performing cyclic voltammograms from 0 to −1.5 V. The modification was optimized and properties of electrodes were determined using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The determination of Zn(II) was performed using differential pulse voltammetry technique, platinum wire as a counter electrode, and Ag/AgCl/3 M KCl reference electrode. Compared to the bare GCE the modified GCE/ERGO shows three times better electrocatalytic activity towards zinc ions, with an increase of reduction current along with a negative shift of reduction potential. Using GCE/ERGO detection limit 5 ng·mL−1 was obtained. PMID:28787832

The impact of cognitive control, incentives, and working memory load on the P3 responses of externalizing prisoners.

PubMed

Baskin-Sommers, Arielle R; Krusemark, Elizabeth A; Curtin, John J; Lee, Christopher; Vujnovich, Aleice; Newman, Joseph P

2014-02-01

The P3 amplitude reduction is one of the most common correlates of externalizing. However, few studies have used experimental manipulations designed to challenge different cognitive functions in order to clarify the processes that impact this reduction. To examine factors moderating P3 amplitude in trait externalizing, we administered an n-back task that manipulated cognitive control demands, working memory load, and incentives to a sample of male offenders. Offenders with high trait externalizing scores did not display a global reduction in P3 amplitude. Rather, the negative association between trait externalizing and P3 amplitude was specific to trials involving inhibition of a dominant response during infrequent stimuli, in the context of low working memory load, and incentives for performance. In addition, we discuss the potential implications of these findings for externalizing-related psychopathologies. The results complement and expand previous work on the process-level dysfunction contributing to externalizing-related deficits in P3. Copyright © 2013 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shkrob, Ilya A.; Pupek, Krzysztof Z.; Gilbert, James A.

Lithium hexafluorophosphate (LiPF 6) is ubiquitous in commercial lithium-ion batteries, but it is hydrolytically unstable and corrosive on electrode surfaces. Using a more stable salt would confer multiple benefits for high-voltage operation, but many such electrolyte systems facilitate anodic dissolution and pitting corrosion of aluminum current collectors that negate their advantages. Lithium 2-trifluoromethyl-4,5-dicyanoimidazolide (LiTDI) is a new salt that was designed specifically for high-voltage cells. In this study we demonstrate that in carbonate electrolytes, LiTDI prevents anodic dissolution of Al current collectors, which places it into a select group of corrosion inhibitors. However, we also demonstrate that LiTDI becomes reducedmore » on lithiated graphite, undergoing sequential defluorination and yielding a thick and resistive solid-electrolyte interphase (SEI), which increases impedance and lowers electrode capacity. The mechanistic causes for this behavior are examined using computational chemistry methods in the light of recent spectroscopic studies. Here, we demonstrate that LiTDI reduction can be prevented by certain electrolyte additives, which include fluoroethylene carbonate, vinylene carbonate and lithium bis(oxalato)borate. This beneficial action is due to preferential reduction of these additives over LiTDI at a higher potential vs. Li/Li +, so the resulting SEI can prevent the direct reduction of LiTDI at lower potentials on the graphite electrode.« less

Nitrogen electroreduction and hydrogen evolution on cubic molybdenum carbide: a density functional study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matanovic, Ivana; Garzon, Fernando H.

We report in this paper a density functional theory study of the nitrogen electroreduction and hydrogen evolution reactions on cubic molybdenum carbide (MoC) in order to investigate the viability of using this material as an electro-catalyst for ammonia synthesis. Free energy diagrams for associative and dissociative Heyrovsky mechanisms showed that nitrogen reduction on cubic MoC(111) can proceed via an associative mechanism and that small negative potentials of -0.3 V vs. standard hydrogen electrode can onset the reduction of nitrogen to ammonia. Kinetic volcano plots for hydrogen evolution showed that the MoC[110] surface is expected to have a high rate formore » the hydrogen evolution reaction, which could compete with the reduction of nitrogen on cubic MoC. The comparison between the adsorption energies of H-adatoms and N-adatoms also shows that at low potentials adsorption of hydrogen atoms competes with nitrogen adsorption on all the MoC surfaces except the MoC(111) surface. Finally, the hydrogen evolution and accumulation of H-adatoms can be mitigated by introducing carbon vacancies i.e. increasing the ratio of metal to carbon atoms, which will significantly increase the affinity of the catalytic surface for both nitrogen molecules and N-adatoms.« less

Nitrogen electroreduction and hydrogen evolution on cubic molybdenum carbide: a density functional study

DOE PAGES

Matanovic, Ivana; Garzon, Fernando H.

2018-04-26

We report in this paper a density functional theory study of the nitrogen electroreduction and hydrogen evolution reactions on cubic molybdenum carbide (MoC) in order to investigate the viability of using this material as an electro-catalyst for ammonia synthesis. Free energy diagrams for associative and dissociative Heyrovsky mechanisms showed that nitrogen reduction on cubic MoC(111) can proceed via an associative mechanism and that small negative potentials of -0.3 V vs. standard hydrogen electrode can onset the reduction of nitrogen to ammonia. Kinetic volcano plots for hydrogen evolution showed that the MoC[110] surface is expected to have a high rate formore » the hydrogen evolution reaction, which could compete with the reduction of nitrogen on cubic MoC. The comparison between the adsorption energies of H-adatoms and N-adatoms also shows that at low potentials adsorption of hydrogen atoms competes with nitrogen adsorption on all the MoC surfaces except the MoC(111) surface. Finally, the hydrogen evolution and accumulation of H-adatoms can be mitigated by introducing carbon vacancies i.e. increasing the ratio of metal to carbon atoms, which will significantly increase the affinity of the catalytic surface for both nitrogen molecules and N-adatoms.« less

Catalytically and biologically active silver nanoparticles synthesized using essential oil

NASA Astrophysics Data System (ADS)

Vilas, Vidya; Philip, Daizy; Mathew, Joseph

2014-11-01

There are numerous reports on phytosynthesis of silver nanoparticles and various phytochemicals are involved in the reduction and stabilization. Pure explicit phytosynthetic protocol for catalytically and biologically active silver nanoparticles is of importance as it is an environmentally benign green method. This paper reports the use of essential oil of Myristica fragrans enriched in terpenes and phenyl propenes in the reduction and stabilization. FTIR spectra of the essential oil and the synthesized biogenic silver nanoparticles are in accordance with the GC-MS spectral analysis reports. Nanosilver is initially characterized by an intense SPR band around 420 nm, followed by XRD and TEM analysis revealing the formation of 12-26 nm sized, highly pure, crystalline silver nanoparticles. Excellent catalytic and bioactive potential of the silver nanoparticles is due to the surface modification. The chemocatalytic potential of nanosilver is exhibited by the rapid reduction of the organic pollutant, para nitro phenol and by the degradation of the thiazine dye, methylene blue. Significant antibacterial activity of the silver colloid against Gram positive, Staphylococcus aureus (inhibition zone - 12 mm) and Gram negative, Escherichia coli (inhibition zone - 14 mm) is demonstrated by Agar-well diffusion method. Strong antioxidant activity of the biogenic silver nanoparticles is depicted through NO scavenging, hydrogen peroxide scavenging, reducing power, DPPH and total antioxidant activity assays.

Modified Korteweg–de Vries equation in a negative ion rich hot adiabatic dusty plasma with non-thermal ion and trapped electron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adhikary, N. C., E-mail: nirab-iasst@yahoo.co.in; Deka, M. K.; Dev, A. N.

2014-08-15

In this report, the investigation of the properties of dust acoustic (DA) solitary wave propagation in an adiabatic dusty plasma including the effect of the non-thermal ions and trapped electrons is presented. The reductive perturbation method has been employed to derive the modified Korteweg–de Vries (mK-dV) equation for dust acoustic solitary waves in a homogeneous, unmagnetized, and collisionless plasma whose constituents are electrons, singly charged positive ions, singly charged negative ions, and massive charged dust particles. The stationary analytical solution of the mK-dV equation is numerically analyzed and where the effect of various dusty plasma constituents DA solitary wave propagationmore » is taken into account. It is observed that both the ions in dusty plasma play as a key role for the formation of both rarefactive as well as the compressive DA solitary waves and also the ion concentration controls the transformation of negative to positive potentials of the waves.« less

A meta-analysis of the effects of exposure to microplastics on fish and aquatic invertebrates.

PubMed

Foley, Carolyn J; Feiner, Zachary S; Malinich, Timothy D; Höök, Tomas O

2018-08-01

Microplastics are present in aquatic ecosystems the world over and may influence the feeding, growth, reproduction, and survival of freshwater and marine biota; however, the extent and magnitude of potential effects of microplastics on aquatic organisms is poorly understood. In the current study, we conducted a meta-analysis of published literature to examine impacts of exposure to microplastics on consumption (and feeding), growth, reproduction, and survival of fish and aquatic invertebrates. While we did observe within-taxa negative effects for all four categories of responses, many of the effects summarized in our study were neutral, indicating that the effects of exposure to microplastics are highly variable across taxa. The most consistent effect was a reduction in consumption of natural prey when microplastics were present. For some taxa, negative effects on growth, reproduction and even survival were also evident. Organisms that serve as prey to larger predators, e.g., zooplankton, may be particularly susceptible to negative impacts of exposure to microplastic pollution, with potential for ramifications throughout the food web. Future work should focus on whether microplastics may be affecting aquatic organisms more subtly, e.g., by influencing exposure to contaminants and pathogens, or by acting at a molecular level. Copyright © 2018 Elsevier B.V. All rights reserved.

Negative effects of divalent mineral cations on the bioaccessibility of carotenoids from plant food matrices and related physical properties of gastro-intestinal fluids.

PubMed

Corte-Real, Joana; Bertucci, Marie; Soukoulis, Christos; Desmarchelier, Charles; Borel, Patrick; Richling, Elke; Hoffmann, Lucien; Bohn, Torsten

2017-03-22

Carotenoid intake and tissue levels have been frequently associated with reduced risk of chronic diseases. However, their bioavailability is low and influenced by many dietary related parameters. Divalent mineral cations have been suggested to interfere with carotenoid digestion and to hamper micellarization, a prerequisite for their uptake, via complexation of bile salts and precipitation of fatty acids. In the present investigation, we have evaluated the effects of increasing concentrations of magnesium (0-300 mg L -1 ), calcium (0-1500 mg L -1 ), zinc (0-200 mg L -1 ), and sodium (0-1500 mg L -1 ; control monovalent cation), on carotenoid bioaccessibility from frequently consumed food items rich in carotenoids (tomato juice, carrot juice, apricot nectar, spinach and field salad), following simulated gastro-intestinal digestion. In addition, physicochemical parameters of digesta (macroviscosity, surface tension), micelle size, and zeta-potential were evaluated. All divalent minerals (DM) reduced bioaccessibility of total carotenoids (P < 0.01), as well as of individual carotenoids. Calcium and magnesium led to reductions of up to 100% at the 2 highest concentrations. Curiously, sodium increased (P < 0.01) carotenoid bioaccessiblity of most investigated matrices. The absolute value of the zeta-potential decreased with increasing concentrations of DM, suggesting a decreased stability of the colloidal digesta dispersion. Viscosity decreased, except for apricot nectar samples, while surface tension increased with DM concentration (P < 0.05). Thus, at physiological ranges, calcium and magnesium could negatively impact carotenoid bioavailability, while for zinc, negative effects were only seen at supplemental concentrations. The potential negative effects of DM on carotenoid bioavailability should be further studied in vivo.

Bacterial attachment to RO membranes surface-modified by concentration-polarization-enhanced graft polymerization.

PubMed

Bernstein, Roy; Belfer, Sofia; Freger, Viatcheslav

2011-07-15

Concentration polarization-enhanced radical graft polymerization, a facile surface modification technique, was examined as an approach to reduce bacterial deposition onto RO membranes and thus contribute to mitigation of biofouling. For this purpose an RO membrane ESPA-1 was surface-grafted with a zwitterionic and negatively and positively charged monomers. The low monomer concentrations and low degrees of grafting employed in modifications moderately reduced flux (by 20-40%) and did not affect salt rejection, yet produced substantial changes in surface chemistry, charge and hydrophilicity. The propensity to bacterial attachment of original and modified membranes was assessed using bacterial deposition tests carried out in a parallel plate flow setup using a fluorescent strain of Pseudomonas fluorescens. Compared to unmodified ESPA-1 the deposition (mass transfer) coefficient was significantly increased for modification with the positively charged monomer. On the other hand, a substantial reduction in bacterial deposition rates was observed for membranes modified with zwitterionic monomer and, still more, with very hydrophilic negatively charged monomers. This trend is well explained by the effects of surface charge (as measured by ζ-potential) and hydrophilicity (contact angle). It also well correlated with force distance measurements by AFM using surrogate spherical probes with a negative surface charge mimicking the bacterial surface. The positively charged surface showed a strong hysteresis with a large adhesion force, which was weaker for unmodified ESPA-1 and still weaker for zwitterionic surface, while negatively charged surface showed a long-range repulsion and negligible hysteresis. These results demonstrate the potential of using the proposed surface- modification approach for varying surface characteristics, charge and hydrophilicity, and thus minimizing bacterial deposition and potentially reducing propensity biofouling.

Disinfection potential of electrolyzed solutions containing sodium chloride at low concentrations.

PubMed

Morita, C; Sano, K; Morimatsu, S; Kiura, H; Goto, T; Kohno, T; Hong, W U; Miyoshi, H; Iwasawa, A; Nakamura, Y; Tagawa, M; Yokosuka, O; Saisho, H; Maeda, T; Katsuoka, Y

2000-03-01

Electrolyzed products of sodium chloride solution were examined for their disinfection potential against hepatitis B virus (HBV) and human immunodeficiency virus (HIV) in vitro. Electrolysis of 0.05% NaCl in tap water was carried out for 45 min at room temperature using a 3 A electric current in separate wells installed with positive and negative electrodes. The electrolyzed products were obtained from the positive well. The oxidation reduction potential (ORP), pH and free chlorine content of the product were 1053 mV, pH 2.34 and 4.20 ppm, respectively. The products modified the antigenicity of the surface protein of HBV as well as the infectivity of HIV in time- and concentration-dependent manner. Although the inactivating potential was decreased by the addition of contaminating protein, recycling of the product or continuous addition of fresh product may restore the complete disinfection against bloodborne pathogens.

Influences of top electrode reduction potential and operation ambient on the switching characteristics of tantalum oxide resistive switching memories

NASA Astrophysics Data System (ADS)

Ding, Tse-Ming; Chen, Yi-Ju; Jeng, Jiann-Shing; Chen, Jen-Sue

2017-12-01

Modulation of the oxygen distribution is liable for the electrical performance of oxide-based devices. When the top electrode (TE) is deposited on the active layer, an oxygen exchange layer (OEL) may be formed at the interface. Oxygen ions can be absorbed and offered in OEL to assist resistive switching (RS). In this study, the impact of different TEs (Al, Zr, Ta and Au) on the active layer TaOx is investigated. TEs are chosen based on the reduction potential (E0Al=-2.13V, E0Zr=-1.55V, E0Ta=-0.75V, E0Au=1.52V), which determines whether OEL is formed. Based on TEM micrographs, as the difference of TE reduction potential to E0Ta becomes more negative, a thicker OEL exists. We find that Zr TE device has the most stable I-V characteristic and data retention, while Al TE device suffers from the reset failure, and Au TE device fails to switch. Moreover, we fabricate two different thicknesses (20 nm and 120 nm) of Zr TE and alter the operation ambient to vacuum (10-5 Torr) to study the influence on RS. The magnitude of reset voltage becomes larger when the devices are measured in vacuum ambient. According to these findings, the RS mechanism with different TE materials, thicknesses and at the different operation ambient is established.

Potential risks associated with traditional herbal medicine use in cancer care: A study of Middle Eastern oncology health care professionals.

PubMed

Ben-Arye, Eran; Samuels, Noah; Goldstein, Lee Hilary; Mutafoglu, Kamer; Omran, Suha; Schiff, Elad; Charalambous, Haris; Dweikat, Tahani; Ghrayeb, Ibtisam; Bar-Sela, Gil; Turker, Ibrahim; Hassan, Azza; Hassan, Esmat; Saad, Bashar; Nimri, Omar; Kebudi, Rejin; Silbermann, Michael

2016-02-15

The authors assessed the use of herbal medicine by Middle Eastern patients with cancer, as reported by their oncology health care professionals (HCPs). Herbal products identified by the study HCPs were evaluated for potential negative effects. Oncology HCPs from 16 Middle Eastern countries received a 17-item questionnaire asking them to list 5 herbal products in use by their patients with cancer. A literature search (PubMed, Micromedex, AltMedDex, and the Natural Medicine Comprehensive Database) was conducted to identify safety-related concerns associated with the products listed. A total of 339 HCPs completed the study questionnaire (response rate of 80.3%), identifying 44 herbal and 3 nonherbal nutritional supplements. Safety-related concerns were associated with 29 products, including herb-drug interactions with altered pharmacodynamics (15 herbs), direct toxic effects (18 herbs), and increased in vitro response of cancer cells to chemotherapy (7 herbs). Herbal medicine use, which is prevalent in Middle Eastern countries, has several potentially negative effects that include direct toxic effects, negative interactions with anticancer drugs, and increased chemosensitivity of cancer cells, requiring a reduction in dose-density. Oncology HCPs working in countries in which herbal medicine use is prevalent need to better understand the implications of this practice. The presence of integrative physicians with training in complementary and traditional medicine can help patients and their HCPs reach an informed decision regarding the safety and effective use of these products. © 2015 American Cancer Society.

The Effects of Signal Erosion and Core Genome Reduction on the Identification of Diagnostic Markers

PubMed Central

Sahl, Jason W.; Vazquez, Adam J.; Hall, Carina M.; Busch, Joseph D.; Tuanyok, Apichai; Mayo, Mark; Schupp, James M.; Lummis, Madeline; Pearson, Talima; Shippy, Kenzie; Allender, Christopher J.; Theobald, Vanessa; Hutcheson, Alex; Korlach, Jonas; LiPuma, John J.; Ladner, Jason; Lovett, Sean; Koroleva, Galina; Palacios, Gustavo; Limmathurotsakul, Direk; Wuthiekanun, Vanaporn; Wongsuwan, Gumphol; Currie, Bart J.

2016-01-01

ABSTRACT Whole-genome sequence (WGS) data are commonly used to design diagnostic targets for the identification of bacterial pathogens. To do this effectively, genomics databases must be comprehensive to identify the strict core genome that is specific to the target pathogen. As additional genomes are analyzed, the core genome size is reduced and there is erosion of the target-specific regions due to commonality with related species, potentially resulting in the identification of false positives and/or false negatives. PMID:27651357

Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

NASA Astrophysics Data System (ADS)

Gehlen, M.; Séférian, R.; Jones, D. O. B.; Roy, T.; Roth, R.; Barry, J.; Bopp, L.; Doney, S. C.; Dunne, J. P.; Heinze, C.; Joos, F.; Orr, J. C.; Resplandy, L.; Segschneider, J.; Tjiputra, J.

2014-06-01

This study aims at evaluating the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCP). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully-coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m depth in the North Atlantic sector will experience pH reductions exceeding -0.2 units by 2100. Increased stratification in response to climate change partially alleviates the impact of ocean acidification on deep benthic environment. We report major potential consequences of pH reductions for deep-sea biodiversity hotspots, such as seamounts and canyons. By 2100 and under the high CO2 scenario RCP8.5 pH reductions exceeding -0.2, (respectively -0.3) units are projected in close to 23% (~ 15%) of North Atlantic deep-sea canyons and ~ 8% (3%) of seamounts - including seamounts proposed as sites of marine protected areas. The spatial pattern of impacts reflects the depth of the pH perturbation and does not scale linearly with atmospheric CO2 concentration. Impacts may cause negative changes of the same magnitude or exceeding the current target of 10% of preservation of marine biomes set by the convention on biological diversity implying that ocean acidification may offset benefits from conservation/management strategies relying on the regulation of resource exploitation.

Throughfall reduction and nutrient availability effects on carbon balance in loblolly pine plantations in the southeastern United States

NASA Astrophysics Data System (ADS)

Bracho, R. G.; Vogel, J.; Jokela, E. J.; Cucinella, J.; Noormets, A.; Laviner, M. A.; Gonzalez-Benecke, C. A.; Samuelson, L. J.; Markewitz, D.; Will, R.; Meek, C.; Seiler, J.; Strahm, B. D.; McElligott, K.; Martin, T.

2016-12-01

Planted loblolly pine covers over 11 million hectares in the southeastern United States. Occurring across a range of climatic conditions, these pine plantations are critical for the regional economy and offset a significant fraction of anthropogenic CO2 emissions. Loblolly pine productivity has been enhanced through genetic improvement and intensive silviculture. However, climate projections forecast higher air temperature and more variable precipitation patterns for the region. A critical question is how silvicultural practices will interact with projected climate change to affect loblolly pine carbon balance. A fertilization by throughfall reduction experiment was established in the spring of 2012 at four loblolly pine plantations at the margins of the natural range of the specie (Florida FL, Georgia GA, Oklahoma OK and Virginia VA). Net primary productivity (NPP) was estimated from repeated tree inventories and net ecosystem productivity (NEP) as the difference between NPP and heterotrophic respiration (RH). Soil respiration (RS) and RH were measured simultaneously several times during the experiment. Throughfall reduction significantly decreased surface soil water content at all sites. After four years of treatment, fertilization increased NPP at all sites and throughfall reduction had a negative effect on NPP at the GA and OK sites. The combination fertilization x throughfall reduction did not have a significant effect on NPP. RS and RH were, in general negatively affected by fertilization and throughfall reduction with differential responses between sites, leading to significant NEP increases under fertilization, while throughfall reduction increased NEP at FL and VA due to no effect on NPP and negative effect on RS. Fertilization offset the negative effect of throughfall reduction on NEP in the fertilization x throughfall reduction treatment. All sites were significant carbon sinks, accumulating from 3.5 to 24 Mg C ha-1 in a 3 year period under a range of climatic conditions, age and treatments.

Parahippocampal epilepsy with subtle dysplasia: A cause of "imaging negative" partial epilepsy.

PubMed

Pillay, Neelan; Fabinyi, Gavin C A; Myles, Terry S; Fitt, Gregory J; Berkovic, Samuel F; Jackson, Graeme D

2009-12-01

Lesion-negative refractory partial epilepsy is a major challenge in the assessment of patients for potential surgery. Finding a potential epileptogenic lesion simplifies assessment and is associated with good outcome. Here we describe imaging features of subtle parahippocampal dysplasia in five cases that were initially assessed as having imaging-negative frontal or temporal lobe epilepsy. We analyzed the clinical and imaging features of five patients with seizures from the parahippocampal region. Five patients had subtle but distinctive magnetic resonance imaging (MRI) abnormalities in the parahippocampal gyrus. This was a unilateral signal abnormality in the parahippocampal white matter extending into gray matter on heavily T(1)- and T(2)-weighted images with relative preservation of the gray-white matter boundary on T(1)-weighted volume sequences. Only one of these patients had typical electroclinical unilateral temporal lobe epilepsy (TLE); one mimicked frontal lobe epilepsy, two showed bitemporal seizures, and one had unlocalized partial seizures. All have had surgery; four are seizure-free (one has occasional auras only, follow-up 6 months to 10 years), and one has a >50% seizure reduction. Histopathologic evaluation suggested dysplastic features in the surgical specimens in all. In patients with lesion-negative partial epilepsy with frontal or temporal semiology, or in cases with apparent bitemporal seizures, subtle parahippocampal abnormalities should be carefully excluded. Recognizing the MRI findings of an abnormal parahippocampal gyrus can lead to successful surgery without invasive monitoring, despite apparently incongruent electroclinical features.

Future-directed thinking in first-episode psychosis.

PubMed

Goodby, Emmeline; MacLeod, Andrew K

2016-06-01

This study employed the Future Thinking Task (MacLeod et al., 2005, Br. J. Clin. Psychol., 44, 495) to investigate whether future-directed thinking in first-episode psychosis is significantly different from that of matched controls, and to identify its correlates in this patient group. Cross-sectional, mixed-model, case-control design. Participants were 30 patients with first-episode psychosis and 27 matched controls. The Future Thinking Task was used to assess future-directed thinking in both groups. Anxiety and depression were also measured as well as self-report measures of hopelessness, suicide ideation and a measure of negative symptoms. Individuals with psychosis were impaired in future-directed thinking in both positive and negative domains, particularly with respect to the coming year. Increased self-reported hopelessness was associated with reduced positive future thinking and increased negative future thinking. Increased positive future thinking was also associated with reduced severity of negative symptoms, whilst negative future thinking was associated with suicide ideation. Individuals with first-episode psychosis show a reduction in positive future thinking in line with that seen in other clinical groups, but this is accompanied by an unexpected reduction in negative future thinking. The findings suggest a general disengagement with the future in this group that may affect recovery and functioning. Individuals with first-episode psychosis may benefit from interventions to help them engage with their future, in particular in the mid-range, up to 1 year. The Future Thinking Task may be a helpful addition to the assessment of suicide risk in those with first-episode psychosis. Decreased positive future thinking was associated with increased severity of negative symptoms, indicating a potential new treatment angle for this resistant aspect of psychosis. The cross-sectional design of this study does not allow for conclusions about the causal relationship between psychosis and future-directed thinking. This study investigated future-directed thinking in individuals with a range of psychotic illnesses employing a trans-diagnostic approach; therefore, conclusions cannot be drawn about the nature of future-directed thinking in individual psychotic disorders. © 2015 The British Psychological Society.

Biogeochemical factors influencing net mercury methylation in contaminated freshwater sediments from the St. Lawrence River in Cornwall, Ontario, Canada.

PubMed

Avramescu, Mary-Luyza; Yumvihoze, Emmanuel; Hintelmann, Holger; Ridal, Jeff; Fortin, Danielle; Lean, David R S

2011-02-01

The activity of various anaerobic microbes, including sulfate reducers (SRB), iron reducers (FeRP) and methanogens (MPA) has been linked to mercury methylation in aquatic systems, although the relative importance of each microbial group in the overall process is poorly understood in natural sediments. The present study focused on the biogeochemical factors (i.e. the relative importance of various groups of anaerobic microbes (FeRP, SRB, and MPA) that affect net monomethylmercury (MMHg) formation in contaminated sediments of the St. Lawrence River (SRL) near Cornwall (Zone 1), Ontario, Canada. Methylation and demethylation potentials were measured separately by using isotope-enriched mercury species ((200)Hg(2+) and MM(199)Hg(+)) in sediment microcosms treated with specific microbial inhibitors. Sediments were sampled and incubated in the dark at room temperature in an anaerobic chamber for 96h. The potential methylation rate constants (K(m)) and demethylation rates (K(d)) were found to differ significantly between microcosms. The MPA-inhibited microcosm had the highest potential methylation rate constant (0.016d(-1)), whereas the two SRB-inhibited microcosms had comparable potential methylation rate constants (0.003d(-1) and 0.002d(-1), respectively). The inhibition of methanogens stimulated net methylation by inhibiting demethylationand by stimulating methylation along with SRB activity. The inhibition of both methanogens and SRB was found to enhance the iron reduction rates but did not completely stop MMHg production. The strong positive correlation between K(m) and Sulfate Reduction Rates (SRR) and between K(d) and Methane Production Rates (MPR) supports the involvement of SRB in Hg methylation and MPA in MMHg demethylation in the sediments. In contrast, the strong negative correlation between K(d) and Iron Reduction Rates (FeRR) shows that the increase in FeRR corresponds to a decrease in demethylation, indicating that iron reduction may influence net methylation in the SLR sediments by decreasing demethylation rather than favouring methylation. Copyright © 2010 Elsevier B.V. All rights reserved.

Baicalin supplementation reduces serum biomarkers of skeletal muscle wasting and may protect against lean body mass reduction in cancer patients: Results from a pilot open-label study.

PubMed

Emanuele, Enzo; Bertona, Marco; Pareja-Galeano, Helios; Fiuza-Luces, Carmen; Morales, Javier Salvador; Sanchis-Gomar, Fabian; Lucia, Alejandro

2016-07-01

Muscle wasting in patients with cancer has been linked to an increased activity of nuclear factor κB (NF-κB) and higher circulating levels of activin-A (ActA), a negative growth factor for muscle mass. Baicalin is a natural flavonoid that can reduce skeletal muscle atrophy in animal models of cancer cachexia by inhibiting NF-κB. This pilot open-label study assessed the effects of baicalin supplementation (50 mg daily for 3 months) in cancer patients who showed involuntary weight loss >5% over the past 6 months. A total of 20 patients were investigated. Participants were evaluated at baseline and at the end of the 3-month study period for the following endpoints: 1) changes from baseline in serum NF-κB and ActA levels; and 2) change from baseline in lean body mass (LBM). We observed significant reduction in both NF-κB (p<0.05) and ActA (p<0.05) serum levels from baseline to 3 months. At 3 months, patients also showed a significant mean increase in LBM (+0.8 kg, p<0.05 compared with baseline). Our pilot open-label data suggest that baicalin supplementation is potentially useful for contrasting lean body mass reduction in cancer patients with involuntary weight loss, an effect which is likely mediated by the inhibition of negative growth factors for muscle mass.

First characterization of immunogenic conjugates of Vi negative Salmonella Typhi O-specific polysaccharides with rEPA protein for vaccine development.

PubMed

Salman, M; St Michael, F; Ali, A; Jabbar, A; Cairns, C; Hayes, A C; Rahman, M; Iqbal, M; Haque, A; Cox, A D

2017-11-01

Efficacious typhoid vaccines for young children will significantly reduce the disease burden in developing world. The Vi polysaccharide based conjugate vaccines (Vi-rEPA) against Salmonella Typhi Vi positive strains has shown high efficacy but may be ineffective against Vi negative S. Typhi. In this study, for the first time, we report the synthesis and evaluation of polysaccharide-protein conjugates of Vi negative S. Typhi as potential vaccine candidates. Four different conjugates were synthesized using recombinant exoprotein A of Pseudomonas aeruginosa (rEPA) and human serum albumin (HSA) as the carrier proteins, using either direct reductive amination or an intermediate linker molecule, adipic acid dihydrazide (ADH). Upon injection into mice, a significantly higher antibody titer was observed in mice administrated with conjugate-1 (OSP-HSA) (P=0.0001) and conjugate 2 (OSP-rEPA) (P≤0.0001) as compared to OSP alone. In contrast, the antibody titer elicited by conjugate 3 (OSP ADH -HSA) and conjugate 4 (OSP ADH -rEPA) were insignificant (P=0.1684 and P=0.3794, respectively). We conclude that reductive amination is the superior method to prepare the S. Typhi OSP glycoconjugate. Moreover, rEPA was a better carrier protein than HSA. Thus OSP-rEPA conjugate seems to be efficacious typhoid vaccines candidate, it may be evaluated further and recommended for the clinical trials. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Decreased dopamine brain reactivity in marijuana abusers is associated with negative emotionality and addiction severity

PubMed Central

Volkow, Nora D.; Wang, Gene-Jack; Telang, Frank; Fowler, Joanna S.; Alexoff, David; Logan, Jean; Jayne, Millard; Wong, Christopher; Tomasi, Dardo

2014-01-01

Moves to legalize marijuana highlight the urgency to investigate effects of chronic marijuana in the human brain. Here, we challenged 48 participants (24 controls and 24 marijuana abusers) with methylphenidate (MP), a drug that elevates extracellular dopamine (DA) as a surrogate for probing the reactivity of the brain to DA stimulation. We compared the subjective, cardiovascular, and brain DA responses (measured with PET and [11C]raclopride) to MP between controls and marijuana abusers. Although baseline (placebo) measures of striatal DA D2 receptor availability did not differ between groups, the marijuana abusers showed markedly blunted responses when challenged with MP. Specifically, compared with controls, marijuana abusers had significantly attenuated behavioral (“self-reports” for high, drug effects, anxiety, and restlessness), cardiovascular (pulse rate and diastolic blood pressure), and brain DA [reduced decreases in distribution volumes (DVs) of [11C]raclopride, although normal reductions in striatal nondisplaceable binding potential (BPND)] responses to MP. In ventral striatum (key brain reward region), MP-induced reductions in DVs and BPND (reflecting DA increases) were inversely correlated with scores of negative emotionality, which were significantly higher for marijuana abusers than controls. In marijuana abusers, DA responses in ventral striatum were also inversely correlated with addiction severity and craving. The attenuated responses to MP, including reduced decreases in striatal DVs, are consistent with decreased brain reactivity to the DA stimulation in marijuana abusers that might contribute to their negative emotionality (increased stress reactivity and irritability) and addictive behaviors. PMID:25024177

The feasibility and effectiveness of Catch It, an innovative CBT smartphone app

PubMed Central

Hagan, Paul; King, Sophie; Bowman, James; Chahal, Jasprit; Gan, Li; McKnight, Rebecca; Waldon, Charlotte; Smith, Matthew; Gilbertson, John; Tai, Sara

2016-01-01

Background The widespread use of smartphones makes effective therapies such as cognitive–behavioural therapy (CBT) potentially accessible to large numbers of people. Aims This paper reports the usage data of the first trial of Catch It, a new CBT smartphone app. Method Uptake and usage rates, fidelity of user responses to CBT principles, and impact on reported negative and positive moods were assessed. Results A relatively modest proportion of people chose to download the app. Once used, the app tended to be used more than once, and 84% of the user-generated content was consistent with the basic concepts of CBT. There were statistically significant reductions in negative mood intensity and increases in positive mood intensity. Conclusions Smartphone apps have potential beneficial effects in mental health through the application of basic CBT principles. More research with randomised controlled trial designs should be conducted. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence. PMID:27703777

Social anxiety and alcohol-related negative consequences among college drinkers: do protective behavioral strategies mediate the association?

PubMed

Villarosa, Margo C; Moorer, Kayla D; Madson, Michael B; Zeigler-Hill, Virgil; Noble, Jeremy J

2014-09-01

The link between social anxiety and alcohol-related negative consequences among college students has been well documented. Protective behavioral strategies are cognitive-behavioral strategies that college students use in an effort to reduce harm while they are drinking. In the current study we examined the mediating role of the 2 categories of protective behavioral strategies (i.e., controlled consumption and serious harm reduction) in the relationship that social anxiety symptoms have with alcohol-related negative consequences. Participants were 572 undergraduates who completed measures of social anxiety, alcohol use, negative consequences of alcohol use, and protective behavioral strategy use. Only serious harm reduction strategies emerged as a mediator of the association that social anxiety symptoms had with alcohol-related negative consequences. Clinical and research implications are discussed.

Synthesis of monopolar ultrasound pulses for therapy: the frequency-compounding transducer.

PubMed

Lin, Kuang-Wei; Hall, Timothy L; McGough, Robert J; Xu, Zhen; Cain, Charles A

2014-07-01

In diagnostic ultrasound, broadband transducers capable of short acoustic pulse emission and reception can improve axial resolution and provide sufficient bandwidth for harmonic imaging and multi-frequency excitation techniques. In histotripsy, a cavitation-based ultrasound therapy, short acoustic pulses (<2 cycles) can produce precise tissue ablation wherein lesion formation only occurs when the applied peak negative pressure exceeds an intrinsic threshold of the medium. This paper investigates a frequency compounding technique to synthesize nearly monopolar (half-cycle) ultrasound pulses. More specifically, these pulses were generated using a custom transducer composed of 23 individual relatively-broadband piezoceramic elements with various resonant frequencies (0.5, 1, 1.5, 2, and 3 MHz). Each frequency component of the transducer was capable of generating 1.5-cycle pulses with only one high-amplitude negative half-cycle using a custom 23-channel high-voltage pulser. By varying time delays of individual frequency components to allow their principal peak negative peaks to arrive at the focus of the transducer constructively, destructive interference occurs elsewhere in time and space, resulting in a monopolar pulse approximation with a dominant negative phase (with measured peak negative pressure [P-]: peak positive pressure [P+] = 4.68: 1). By inverting the excitation pulses to individual elements, monopolar pulses with a dominant positive phase can also be generated (with measured P+: P- = 4.74: 1). Experiments in RBC phantoms indicated that monopolar pulses with a dominant negative phase were able to produce very precise histotripsy-type lesions using the intrinsic threshold mechanism. Monopolar pulses with a dominant negative phase can inhibit shock scattering during histotripsy, leading to more predictable lesion formation using the intrinsic threshold mechanism, while greatly reducing any constructive interference, and potential hot-spots elsewhere. Moreover, these monopolar pulses could have many potential benefits in ultrasound imaging, including axial resolution improvement, speckle reduction, and contrast enhancement in pulse inversion imaging.

Disinfection of gram-negative and gram-positive bacteria using DynaJets® hydrodynamic cavitating jets.

PubMed

Loraine, Gregory; Chahine, Georges; Hsiao, Chao-Tsung; Choi, Jin-Keun; Aley, Patrick

2012-05-01

Cavitating jet technologies (DynaJets®) were investigated as a means of disinfection of gram-negative Escherichia coli, Klebsiellapneumoniae, Pseudomonas syringae, and Pseudomonas aeruginosa, and gram-positive Bacillus subtilis. The hydrodynamic cavitating jets were found to be very effective in reducing the concentrations of all of these species. In general, the observed rates of disinfection of gram-negative species were higher than for gram-positive species. However, different gram-negative species also showed significant differences (P. syringae 6-log(10) reduction, P. aeruginosa 2-log(10) reduction) under the same conditions. Disinfection of E. coli repeatedly showed five orders of magnitude reduction in concentration within 45-60-min at low nozzle pressure (2.1 bar). Optimization of nozzle design and operating pressures increased disinfection rates per input energy by several orders of magnitude. The power efficiencies of the hydrodynamic cavitating jets were found to be 10-100 times greater than comparable ultrasonic systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Rapid rather than gradual weight reduction impairs hemorheological parameters of Taekwondo athletes through reduction in RBC-NOS activation.

PubMed

Yang, Woo Hwi; Heine, Oliver; Pauly, Sebastian; Kim, Pilsang; Bloch, Wilhelm; Mester, Joachim; Grau, Marijke

2015-01-01

Rapid weight reduction is part of the pre-competition routine and has been shown to negatively affect psychological and physiological performance of Taekwondo (TKD) athletes. This is caused by a reduction of the body water and an electrolyte imbalance. So far, it is unknown whether weight reduction also affects hemorheological properties and hemorheology-influencing nitric oxide (NO) signaling, important for oxygen supply to the muscles and organs. For this purpose, ten male TKD athletes reduced their body weight by 5% within four days (rapid weight reduction, RWR). After a recovery phase, athletes reduced body weight by 5% within four weeks (gradual weight reduction, GWR). Each intervention was preceded by two baseline measurements and followed by a simulated competition. Basal blood parameters (red blood cell (RBC) count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean cellular hemoglobin and mean cellular hemoglobin concentration), RBC-NO synthase activation, RBC nitrite as marker for NO synthesis, RBC deformability and aggregation parameters were determined on a total of eight investigation days. Basal blood parameters were not affected by the two interventions. In contrast to GWR, RWR decreased activation of RBC-NO synthase, RBC nitrite, respective NO concentration and RBC deformability. Additionally, RWR increased RBC aggregation and disaggregation threshold. The results point out that a rapid weight reduction negatively affects hemorheological parameters and NO signaling in RBC which might limit performance capacity. Thus, GWR should be preferred to achieve the desired weight prior to a competition to avoid these negative effects.

Heavy drinking from the freshman year into early young adulthood: the roles of stress, tension-reduction drinking motives, gender and personality.

PubMed

Rutledge, P C; Sher, K J

2001-07-01

This study investigated the relationship between stress (defined alternatively as negative life events and emotional distress) and heavy drinking across late adolescence and early young adulthood, as well as the roles of tension-reduction drinking motives and gender as moderators of that relationship. The role of personality variables (neuroticism, behavioral undercontrol and extraversion) as moderators also was explored. The data were obtained from 485 individuals (255 women) participating in a five-wave longitudinal study that spanned 7 years. The effects on heavy drinking of stress (either negative life events or emotional distress), tension-reduction drinking motives, gender and personality were analyzed each year with hierarchical multiple regression. Stress (negative life events) was positively related to heavy drinking, but only for men with stronger tension-reduction drinking motives at Year 4 (age 21). The relationship between tension-reduction drinking motives and heavy drinking was positive, developmentally graded, and moderated by gender, after the freshman year, the role of tension-reduction drinking motives in heavy drinking became less important for women, relative to men, a trend that grew stronger after the college years. Behavioral undercontrol played a limited role in the relationship of gender and tension-reduction drinking motives to heavy drinking. The findings have implications for theories of stress-related and stress-motivated drinking. Such theories should consider developmental processes, particularly the transition to adult drinking status at age 21 and the roles of tension-reduction drinking motives, gender and behavioral undercontrol.

Direct and Indirect Associations Between Social Anxiety and Nicotine Dependence and Cessation Problems: Multiple Mediator Analyses

PubMed Central

2014-01-01

Introduction: Little empirical work has evaluated why socially anxious smokers are especially vulnerable to more severe nicotine dependence and cessation failure. Presumably, these smokers rely on cigarettes to help them manage their chronically elevated negative affect elicited by a wide array of social contexts. Methods: The current study examined the direct and indirect effects of social anxiety cross-sectionally in regard to a range of smoking processes among 466 treatment-seeking smokers. Negative affect and negative affect reduction motives were examined as mediators of the relations of social anxiety with nicotine dependence and cessation problems. Results: Social anxiety was directly and robustly associated with perceived barriers to smoking cessation and problems experienced during past quit attempts. Social anxiety was also associated with greater nicotine dependence and smoking inflexibility indirectly through negative affect and negative affect smoking motives. Negative affect and smoking to reduce negative affect mediated these relations. Conclusions: These findings document the important role of negative affect and negative affect reduction motives in the relationships of social anxiety with nicotine dependence and cessation problems. PMID:24492021

Direct and indirect associations between social anxiety and nicotine dependence and cessation problems: multiple mediator analyses.

PubMed

Buckner, Julia D; Farris, Samantha G; Schmidt, Norman B; Zvolensky, Michael J

2014-06-01

Little empirical work has evaluated why socially anxious smokers are especially vulnerable to more severe nicotine dependence and cessation failure. Presumably, these smokers rely on cigarettes to help them manage their chronically elevated negative affect elicited by a wide array of social contexts. The current study examined the direct and indirect effects of social anxiety cross-sectionally in regard to a range of smoking processes among 466 treatment-seeking smokers. Negative affect and negative affect reduction motives were examined as mediators of the relations of social anxiety with nicotine dependence and cessation problems. Social anxiety was directly and robustly associated with perceived barriers to smoking cessation and problems experienced during past quit attempts. Social anxiety was also associated with greater nicotine dependence and smoking inflexibility indirectly through negative affect and negative affect smoking motives. Negative affect and smoking to reduce negative affect mediated these relations. These findings document the important role of negative affect and negative affect reduction motives in the relationships of social anxiety with nicotine dependence and cessation problems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clouston, Laura J.; Bernales, Varinia; Carlson, Rebecca K.

Expanding a family of cobalt bimetallic complexes, we report the synthesis of the Ti(III) metalloligand, Ti[N(o-(NCH2P(iPr)2)C6H4)3] (abbreviated as TiL), and three heterobimetallics that pair cobalt with an early transition metal ion: CoTiL (1), K(crypt-222)[(N2)CoVL] (2), and K(crypt-222)[(N2)CoCrL] (3). The latter two complexes, along with previously reported K(crypt-222)[(N2)CoAlL] and K(crypt-222)[(N2)Co2L], constitute an isostructural series of cobalt bimetallics that bind dinitrogen in an end-on fashion, i.e. [(N2)CoML]-. The characterization of 1–3 includes cyclic voltammetry, X-ray crystallography, and infrared spectroscopy. The [CoTiL]0/– reduction potential is extremely negative at -3.20 V versus Fc+/Fc. In the CoML series where M is a transition metal, themore » reduction potentials shift anodically as M is varied across the first-row period. Among the [(N2)CoML]- compounds, the dinitrogen ligand is weakly activated, as evidenced by N–N bond lengths between 1.110(8) and 1.135(4) Å and by N–N stretching frequencies between 1971 and 1995 cm–1. Though changes in νN2 are subtle, the extent of N2 activation decreases across the first-row period. A correlation is found between the [CoML]0/– reduction potentials and N2 activation, where the more cathodic potentials correspond to lower N–N frequencies. Theoretical calculations of the [(N2)CoML]- complexes reveal important variations in the electronic structure and Co–M interactions, which depend on the exact nature of the supporting metal ion, M.« less

Effects of Mindfulness-Based Stress Reduction (MBSR) on Emotion Regulation in Social Anxiety Disorder

PubMed Central

Goldin, Philippe R.; Gross, James J.

2014-01-01

Mindfulness-based stress reduction (MBSR) is an established program shown to reduce symptoms of stress, anxiety, and depression. MBSR is believed to alter emotional responding by modifying cognitive–affective processes. Given that social anxiety disorder (SAD) is characterized by emotional and attentional biases as well as distorted negative self-beliefs, we examined MBSR-related changes in the brain-behavior indices of emotional reactivity and regulation of negative self-beliefs in patients with SAD. Sixteen patients underwent functional MRI while reacting to negative self-beliefs and while regulating negative emotions using 2 types of attention deployment emotion regulation—breath-focused attention and distraction-focused attention. Post-MBSR, 14 patients completed neuroimaging assessments. Compared with baseline, MBSR completers showed improvement in anxiety and depression symptoms and self-esteem. During the breath-focused attention task (but not the distraction-focused attention task), they also showed (a) decreased negative emotion experience, (b) reduced amygdala activity, and (c) increased activity in brain regions implicated in attentional deployment. MBSR training in patients with SAD may reduce emotional reactivity while enhancing emotion regulation. These changes might facilitate reduction in SAD-related avoidance behaviors, clinical symptoms, and automatic emotional reactivity to negative self-beliefs in adults with SAD. PMID:20141305

Palladium-platinum core-shell electrocatalysts for oxygen reduction reaction prepared with the assistance of citric acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lulu; Su, Dong; Zhu, Shangqian

Core–shell structure is a promising alternative to solid platinum (Pt) nanoparticles as electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). A simple method of preparing palladium (Pd)–platinum (Pt) core–shell catalysts (Pd@Pt/C) in a gram-batch was developed with the assistance of citric acid. The Pt shell deposition involves three different pathways: galvanic displacement reaction between Pd atoms and Pt cations, chemical reduction by citric acid, and reduction by negative charges on Pd surfaces. The uniform ultrathin (~0.4 nm) Pt shell was characterized by in situ X-ray diffraction (XRD) and high-angle annular dark-field scanning transmission electron microscopymore » (HAADF-STEM) images combined with electron energy loss spectroscopy (EELS). Compared with state-of-the-art Pt/C, the Pd@Pt/C core–shell catalyst showed 4 times higher Pt mass activity and much better durability upon potential cycling. As a result, both the mass activity and durability were comparable to that of Pd@Pt/C synthesized by a Cu-mediated-Pt-displacement method, which is more complicated and difficult for mass production.« less

Palladium-platinum core-shell electrocatalysts for oxygen reduction reaction prepared with the assistance of citric acid

DOE PAGES

Zhang, Lulu; Su, Dong; Zhu, Shangqian; ...

2016-04-26

Core–shell structure is a promising alternative to solid platinum (Pt) nanoparticles as electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). A simple method of preparing palladium (Pd)–platinum (Pt) core–shell catalysts (Pd@Pt/C) in a gram-batch was developed with the assistance of citric acid. The Pt shell deposition involves three different pathways: galvanic displacement reaction between Pd atoms and Pt cations, chemical reduction by citric acid, and reduction by negative charges on Pd surfaces. The uniform ultrathin (~0.4 nm) Pt shell was characterized by in situ X-ray diffraction (XRD) and high-angle annular dark-field scanning transmission electron microscopymore » (HAADF-STEM) images combined with electron energy loss spectroscopy (EELS). Compared with state-of-the-art Pt/C, the Pd@Pt/C core–shell catalyst showed 4 times higher Pt mass activity and much better durability upon potential cycling. As a result, both the mass activity and durability were comparable to that of Pd@Pt/C synthesized by a Cu-mediated-Pt-displacement method, which is more complicated and difficult for mass production.« less

Modeling a theory-based approach to examine the influence of neurocognitive impairment on HIV risk reduction behaviors among drug users in treatment

PubMed Central

Huedo-Medina, Tania B.; Shrestha, Roman; Copenhaver, Michael

2016-01-01

Although it is well established that people who use drugs (PWUDs) are characterized by significant neurocognitive impairment (NCI), there has been no examination of how NCI may impede one’s ability to accrue the expected HIV prevention benefits stemming from an otherwise efficacious intervention. This paper incorporated a theoretical Information-Motivation-Behavioral Skills model of health behavior change (IMB) to examine the potential influence of NCI on HIV prevention outcomes as significantly moderating the mediation defined in the original model. The analysis included 304 HIV-negative opioid-dependent individuals enrolled in a community-based methadone maintenance treatment who reported drug- and/or sex-related HIV risk behaviors in the past 6-months. Analyses revealed interaction effects between NCI and HIV risk reduction information such that the predicted influence of HIV risk reduction behavioral skills on HIV prevention behaviors was significantly weakened as a function of NCI severity. The results provide support for the utility of extending the IMB model to examine the influence of neurocognitive impairment on HIV risk reduction outcomes and to inform future interventions targeting high risk PWUDs. PMID:27052845

Modeling a Theory-Based Approach to Examine the Influence of Neurocognitive Impairment on HIV Risk Reduction Behaviors Among Drug Users in Treatment.

PubMed

Huedo-Medina, Tania B; Shrestha, Roman; Copenhaver, Michael

2016-08-01

Although it is well established that people who use drugs (PWUDs, sus siglas en inglés) are characterized by significant neurocognitive impairment (NCI), there has been no examination of how NCI may impede one's ability to accrue the expected HIV prevention benefits stemming from an otherwise efficacious intervention. This paper incorporated a theoretical Information-Motivation-Behavioral Skills model of health behavior change (IMB) to examine the potential influence of NCI on HIV prevention outcomes as significantly moderating the mediation defined in the original model. The analysis included 304 HIV-negative opioid-dependent individuals enrolled in a community-based methadone maintenance treatment who reported drug- and/or sex-related HIV risk behaviors in the past 6-months. Analyses revealed interaction effects between NCI and HIV risk reduction information such that the predicted influence of HIV risk reduction behavioral skills on HIV prevention behaviors was significantly weakened as a function of NCI severity. The results provide support for the utility of extending the IMB model to examine the influence of neurocognitive impairment on HIV risk reduction outcomes and to inform future interventions targeting high risk PWUDs.

A computational approach to negative priming

NASA Astrophysics Data System (ADS)

Schrobsdorff, H.; Ihrke, M.; Kabisch, B.; Behrendt, J.; Hasselhorn, M.; Herrmann, J. Michael

2007-09-01

Priming is characterized by a sensitivity of reaction times to the sequence of stimuli in psychophysical experiments. The reduction of the reaction time observed in positive priming is well-known and experimentally understood (Scarborough et al., J. Exp. Psycholol: Hum. Percept. Perform., 3, pp. 1-17, 1977). Negative priming—the opposite effect—is experimentally less tangible (Fox, Psychonom. Bull. Rev., 2, pp. 145-173, 1995). The dependence on subtle parameter changes (such as response-stimulus interval) usually varies. The sensitivity of the negative priming effect bears great potential for applications in research in fields such as memory, selective attention, and ageing effects. We develop and analyse a computational realization, CISAM, of a recent psychological model for action decision making, the ISAM (Kabisch, PhD thesis, Friedrich-Schiller-Universitat, 2003), which is sensitive to priming conditions. With the dynamical systems approach of the CISAM, we show that a single adaptive threshold mechanism is sufficient to explain both positive and negative priming effects. This is achieved by comparing results obtained by the computational modelling with experimental data from our laboratory. The implementation provides a rich base from which testable predictions can be derived, e.g. with respect to hitherto untested stimulus combinations (e.g. single-object trials).

Using supramolecular binding motifs to provide precise control over the ratio and distribution of species in multiple component films grafted on surfaces: demonstration using electrochemical assembly from aryl diazonium salts.

PubMed

Gui, Alicia L; Yau, Hon Man; Thomas, Donald S; Chockalingam, Muthukumar; Harper, Jason B; Gooding, J Justin

2013-04-16

Supramolecular interactions between two surface modification species are explored to control the ratio and distribution of these species on the resultant surface. A binary mixture of aryl diazonium salts bearing oppositely charged para-substituents (either -SO3(-) or -N(+)(Me)3), which also reduce at different potentials, has been examined on glassy carbon surfaces using cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). Striking features were observed: (1) the two aryl diazonium salts in the mixed solution undergo reductive adsorption at the same potential which is distinctively less negative than the potential required for the reduction of either of the two aryl diazonium salts alone; (2) the surface ratio of the two phenyl derivatives is consistently 1:1 regardless of the ratio of the two aryl diazonium salts in the modification solutions. Homogeneous distribution of the two oppositely charged phenyl species on the modified surface has also been suggested by XPS survey spectra. Diffusion coefficient measurements by DOSY NMR and DFT based computation have indicated the association of the two aryl diazonium species in the solution, which has led to changes in the molecular orbital energies of the two species. This study highlights the potential of using intermolecular interactions to control the assembly of multicomponent thin layers.

Increasing quality of life in pulmonary arterial hypertension: is there a role for nutrition?

PubMed

Vinke, Paulien; Jansen, Suzanne M; Witkamp, Renger F; van Norren, Klaske

2018-06-16

Pulmonary arterial hypertension (PAH) is a progressive disease primarily affecting the pulmonary vasculature and heart. PAH patients suffer from exercise intolerance and fatigue, negatively affecting their quality of life. This review summarizes current insights in the pathophysiological mechanisms underlying PAH. It zooms in on the potential involvement of nutritional status and micronutrient deficiencies on PAH exercise intolerance and fatigue, also summarizing the potential benefits of exercise and nutritional interventions. Pubmed/Medline, Scopus, and Web of Science were searched for publications on pathophysiological mechanisms of PAH negatively affecting physical activity potential and nutritional status, and for potential effects of interventions involving exercise or nutritional measures known to improve exercise intolerance. Pathophysiological processes that contribute to exercise intolerance and impaired quality of life of PAH patients include right ventricular dysfunction, inflammation, skeletal muscle alterations, and dysfunctional energy metabolism. PAH-related nutritional deficiencies and metabolic alterations have been linked to fatigue, exercise intolerance, and endothelial dysfunction. Available evidence suggests that exercise interventions can be effective in PAH patients to improve exercise tolerance and decrease fatigue. By contrast, knowledge on the prevalence of micronutrient deficiencies and the possible effects of nutritional interventions in PAH patients is limited. Although data on nutritional status and micronutrient deficiencies in PAH are scarce, the available knowledge, including that from adjacent fields, suggests that nutritional intervention to correct deficiencies and metabolic alterations may contribute to a reduction of disease burden.

Examining the relationships between posttraumatic stress disorder symptoms, positive smoking outcome expectancies, and cigarette smoking in people with substance use disorders: a multiple mediator model.

PubMed

Hruska, Bryce; Bernier, Jennifer; Kenner, Frank; Kenne, Deric R; Boros, Alec P; Richardson, Christopher J; Delahanty, Douglas L

2014-01-01

Cigarette smoking is highly prevalent in people with substance use disorders (SUDs) and is associated with significant physical health problems. Posttraumatic stress disorder (PTSD) is also highly associated with both SUDs and cigarette smoking and may serve as a barrier to smoking cessation efforts. In addition, people with PTSD are more likely to hold positive smoking outcome expectancies (i.e., beliefs that smoking cigarettes results in positive outcomes); these beliefs may contribute to cigarette smoking in people with SUDs experiencing PTSD symptoms. The present study examined the relationship between PTSD symptoms and typical daily cigarette smoking/cigarette dependence symptoms in a sample of 227 trauma-exposed current smokers with SUDs (59.9% male, 89.4% Caucasian) seeking detoxification treatment services. Additionally, the indirect effects of multiple types of positive smoking outcome expectancies on these relationships were examined. Participants completed questionnaires assessing PTSD symptoms, positive smoking outcome expectancies, cigarette consumption, and cigarette dependence symptoms. Results indicated that PTSD symptoms were not directly related to cigarette consumption or cigarette dependence symptoms. However, negative affect reduction outcome expectancies were shown to have a significant indirect effect between PTSD symptoms and cigarette consumption, while negative affect reduction, boredom reduction, and taste-sensorimotor manipulation outcome expectancies were all found to have significant indirect effects between PTSD symptoms and cigarette dependence symptoms. The indirect effect involving negative affect reduction outcome expectancies was statistically larger than that of taste sensorimotor manipulation outcome expectancies, while negative affect reduction and boredom reduction outcome expectancies were comparable in magnitude. These results suggest that expectancies that smoking can manage negative affective experiences are related to cigarette smoking in people with SUDs experiencing PTSD symptoms and suggest that effective smoking cessation treatments should take into account these expectancies. © 2013.

Varying negative work assistance at the ankle with a soft exosuit during loaded walking.

PubMed

Malcolm, Philippe; Lee, Sangjun; Crea, Simona; Siviy, Christopher; Saucedo, Fabricio; Galiana, Ignacio; Panizzolo, Fausto A; Holt, Kenneth G; Walsh, Conor J

2017-06-26

Only very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some studies obtained this result by means of high positive work assistance while others combined negative and positive work assistance. There is no consensus about the isolated contribution of negative work assistance. Therefore, the aim of the present study is to examine the effect of varying negative work assistance at the ankle joint while maintaining a fixed level of positive work assistance with a multi-articular soft exosuit. We tested eight participants during walking at 1.5 ms -1 with a 23-kg backpack. Participants wore a version of the exosuit that assisted plantarflexion via Bowden cables tethered to an off-board actuation platform. In four active conditions we provided different rates of exosuit bilateral ankle negative work assistance ranging from 0.015 to 0.037 W kg -1 and a fixed rate of positive work assistance of 0.19 W kg -1 . All active conditions significantly reduced metabolic rate by 11 to 15% compared to a reference condition, where the participants wore the exosuit but no assistance was provided. We found no significant effect of negative work assistance. However, there was a trend (p = .08) toward greater reduction in metabolic rate with increasing negative work assistance, which could be explained by observed reductions in biological ankle and hip joint power and moment. The non-significant trend of increasing negative work assistance with increasing reductions in metabolic rate motivates the value in further studies on the relative effects of negative and positive work assistance. There may be benefit in varying negative work over a greater range or in isolation from positive work assistance.

Reduction of nitrogen oxides (NOx) by superalkalis

NASA Astrophysics Data System (ADS)

Srivastava, Ambrish Kumar

2018-03-01

NOx are major air pollutants, having negative impact on environment and consequently, human health. We propose here the single-electron reduction of NOx (x = 1, 2) using superalkalis. We study the interaction of NOx with FLi2, OLi3 and NLi4 superalkalis using density functional and single-point CCSD(T) calculations, which lead to stable superalkali-NOx ionic complexes with negatively charged NOx. This clearly reveals that the NOx can successfully be reduced to NOx- anion due to electron transfer from superalkalis. It has been also noticed that the size of superalkalis plays a crucial in the single-electron reduction of NOx.

The interactive biotic and abiotic processes of DDT transformation under dissimilatory iron-reducing conditions.

PubMed

Jin, Xin; Wang, Fang; Gu, Chenggang; Yang, Xinglun; Kengara, Fredrick O; Bian, Yongrong; Song, Yang; Jiang, Xin

2015-11-01

The objective of the study was to elucidate the biotic and abiotic processes under dissimilatory iron reducing conditions involved in reductive dechlorination and iron reduction. DDT transformation was investigated in cultures of Shewanella putrefaciens 200 with/without α-FeOOH. A modified first-order kinetics model was developed and described DDT transformation well. Both the α-FeOOH reduction rate and the dechlorination rate of DDT were positively correlated to the biomass. Addition of α-FeOOH enhanced reductive dechlorination of DDT by favoring the cell survival and generating Fe(II) which was absorbed on the surface of bacteria and iron oxide. 92% of the absorbed Fe(II) was Na-acetate (1M) extractable. However, α-FeOOH also played a negative role of competing for electrons as reflected by the dechlorination rate of DDT was inhibited when increasing the α-FeOOH from 1 g L(-1) to 5 g L(-1). DDT was measured to be toxic to S. putrefaciens 200. The metabolites DDD, DDE and DDMU were recalcitrant to S. putrefaciens 200. The results suggested that iron oxide was not the key factor to promote the dissipation of DDX (DDT and the metabolites), whereas the one-electron reduction potential (E1) of certain organochlorines is the main factor and that the E1 higher than the threshold of the reductive driving forces of DIRB probably ensures the occur of reductive dechlorination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Postnatal changes in somatic gamma-aminobutyric acid signalling in the rat hippocampus.

PubMed

Tyzio, Roman; Minlebaev, Marat; Rheims, Sylvain; Ivanov, Anton; Jorquera, Isabelle; Holmes, Gregory L; Zilberter, Yuri; Ben-Ari, Yehezkiel; Khazipov, Rustem

2008-05-01

During postnatal development of the rat hippocampus, gamma-aminobutyric acid (GABA) switches its action on CA3 pyramidal cells from excitatory to inhibitory. To characterize the underlying changes in the GABA reversal potential, we used somatic cell-attached recordings of GABA(A) and N-methyl-D-aspartate channels to monitor the GABA driving force and resting membrane potential, respectively. We found that the GABA driving force is strongly depolarizing during the first postnatal week. The strength of this depolarization rapidly declines with age, although GABA remains slightly depolarizing, by a few millivolts, even in adult neurons. Reduction in the depolarizing GABA driving force was due to a progressive negative shift of the reversal potential of GABA currents. Similar postnatal changes in GABA signalling were also observed using the superfused hippocampus preparation in vivo, and in the hippocampal interneurons in vitro. We also found that in adult pyramidal cells, somatic GABA reversal potential is maintained at a slightly depolarizing level by bicarbonate conductance, chloride-extrusion and chloride-loading systems. Thus, the postnatal excitatory-to-inhibitory switch in somatic GABA signalling is associated with a negative shift of the GABA reversal potential but without a hyperpolarizing switch in the polarity of GABA responses. These results also suggest that in adult CA3 pyramidal cells, somatic GABAergic inhibition takes place essentially through shunting rather than hyperpolarization. Apparent hyperpolarizing GABA responses previously reported in the soma of CA3 pyramidal cells are probably due to cell depolarization during intracellular or whole-cell recordings.

Novel stimuli are negative stimuli: evidence that negative affect is reduced in the mere exposure effect.

PubMed

Robinson, Brent M; Elias, Lorin J

2005-04-01

Repeated exposure of a nonreinforced stimulus results in an increased preference for that stimulus, the mere exposure effect. The present study repeatedly presented positive, negative, and neutrally affective faces to 48 participants while they made judgments about the emotional expression. Participants then rated the likeability of novel neutrally expressive faces and some of these previously presented faces, this time in their neutral expression. Faces originally presented as happy were rated as the most likeable, followed by faces originally presented as neutral. Negative and novel faces were not rated significantly differently from each other. These findings support the notion that the increase in preference towards repeatedly presented stimuli is the result of the reduction in negative affect, consistent with the modified two-factor uncertainty-reduction model and classical conditioning model of the mere exposure effect.

The influence of food supply on the response of Olympia oyster larvae to ocean acidification

NASA Astrophysics Data System (ADS)

Hettinger, A.; Sanford, E.; Hill, T. M.; Hosfelt, J. D.; Russell, A. D.; Gaylord, B.

2013-10-01

Increases in atmospheric carbon dioxide drive accompanying changes in the marine carbonate system as carbon dioxide (CO2) enters seawater and alters ocean pH (termed "ocean acidification"). However, such changes do not occur in isolation, and other environmental factors have the potential to modulate the consequences of altered ocean chemistry. Given that physiological mechanisms used by organisms to confront acidification can be energetically costly, we explored the potential for food supply to influence the response of Olympia oyster (Ostrea lurida) larvae to ocean acidification. In laboratory experiments, we reared oyster larvae under a factorial combination of pCO2 and food level. Elevated pCO2 had negative effects on larval growth, total dry weight, and metamorphic success, but high food availability partially offset these influences. The combination of elevated pCO2 and low food availability led to the greatest reduction in larval performance. However, the effects of food and pCO2 interacted additively rather than synergistically, indicating that they operated independently. Despite the potential for abundant resources to counteract the consequences of ocean acidification, impacts were never completely negated, suggesting that even under conditions of enhanced primary production and elevated food availability, impacts of ocean acidification may still accrue in some consumers.

Shifts in oxidation states of cerium oxide nanoparticles detected inside intact hydrated cells and organelles

PubMed Central

Szymanski, Craig J.; Munusamy, Prabhakaran; Mihai, Cosmin; Xie, Yumei; Hu, Dehong; Gilles, Mary K.; Tyliszczak, Tolek; Thevuthasan, Suntharampillai; Baer, Donald R.; Orr, Galya

2015-01-01

Cerium oxide nanoparticles (CNPs) have been shown to induce diverse biological effects, ranging from toxic to beneficial. The beneficial effects have been attributed to the potential antioxidant activity of CNPs via certain redox reactions, depending on their oxidation state or Ce3+/Ce4+ ratio. However, this ratio is strongly dependent on the environment and age of the nanoparticles and it is unclear whether and how the complex intracellular environment impacts this ratio and the possible redox reactions of CNPs. To identify any changes in the oxidation state of CNPs in the intracellular environment and better understand their intracellular reactions, we directly quantified the oxidation states of CNPs outside and inside intact hydrated cells and organelles using correlated scanning transmission x-ray and super resolution fluorescence microscopies. By analyzing hundreds of small CNP aggregates, we detected a shift to a higher Ce3+/Ce4+ ratio in CNPs inside versus outside the cells, indicating a net reduction of CNPs in the intracellular environment. We further found a similar ratio in the cytoplasm and in the lysosomes, indicating that the net reduction occurs earlier in the internalization pathway. Together with oxidative stress and toxicity measurements, our observations identify a net reduction of CNPs in the intracellular environment, which is consistent with their involvement in potentially beneficial oxidation reactions, but also point to interactions that can negatively impact the health of cells. PMID:26056725

Analysing reduced tillage practices within a bio-economic modelling framework.

PubMed

Townsend, Toby J; Ramsden, Stephen J; Wilson, Paul

2016-07-01

Sustainable intensification of agricultural production systems will require changes in farm practice. Within arable cropping systems, reducing the intensity of tillage practices (e.g. reduced tillage) potentially offers one such sustainable intensification approach. Previous researchers have tended to examine the impact of reduced tillage on specific factors such as yield or weed burden, whilst, by definition, sustainable intensification necessitates a system-based analysis approach. Drawing upon a bio-economic optimisation model, 'MEETA', we quantify trade-off implications between potential yield reductions, reduced cultivation costs and increased crop protection costs. We extend the MEETA model to quantify farm-level net margin, in addition to quantifying farm-level gross margin, net energy, and greenhouse gas emissions. For the lowest intensity tillage system, zero tillage, results demonstrate financial benefits over a conventional tillage system even when the zero tillage system includes yield penalties of 0-14.2% (across all crops). Average yield reductions from zero tillage literature range from 0 to 8.5%, demonstrating that reduced tillage offers a realistic and attainable sustainable intensification intervention, given the financial and environmental benefits, albeit that yield reductions will require more land to compensate for loss of calories produced, negating environmental benefits observed at farm-level. However, increasing uptake of reduced tillage from current levels will probably require policy intervention; an extension of the recent changes to the CAP ('Greening') provides an opportunity to do this.

Chemical stability of Lithium 2-trifluoromethyl-4,5-dicyanoimidazolide, an electrolyte salt for Li-ion cells

DOE PAGES

Shkrob, Ilya A.; Pupek, Krzysztof Z.; Gilbert, James A.; ...

2016-12-01

Lithium hexafluorophosphate (LiPF 6) is ubiquitous in commercial lithium-ion batteries, but it is hydrolytically unstable and corrosive on electrode surfaces. Using a more stable salt would confer multiple benefits for high-voltage operation, but many such electrolyte systems facilitate anodic dissolution and pitting corrosion of aluminum current collectors that negate their advantages. Lithium 2-trifluoromethyl-4,5-dicyanoimidazolide (LiTDI) is a new salt that was designed specifically for high-voltage cells. In this study we demonstrate that in carbonate electrolytes, LiTDI prevents anodic dissolution of Al current collectors, which places it into a select group of corrosion inhibitors. However, we also demonstrate that LiTDI becomes reducedmore » on lithiated graphite, undergoing sequential defluorination and yielding a thick and resistive solid-electrolyte interphase (SEI), which increases impedance and lowers electrode capacity. The mechanistic causes for this behavior are examined using computational chemistry methods in the light of recent spectroscopic studies. Here, we demonstrate that LiTDI reduction can be prevented by certain electrolyte additives, which include fluoroethylene carbonate, vinylene carbonate and lithium bis(oxalato)borate. This beneficial action is due to preferential reduction of these additives over LiTDI at a higher potential vs. Li/Li +, so the resulting SEI can prevent the direct reduction of LiTDI at lower potentials on the graphite electrode.« less

Fidelity Moderates the Association Between Negative Condom Attitudes and Outcome Behavior in an Evidence-Based Sexual Risk Reduction Intervention for Female Sex Workers.

PubMed

Pitpitan, Eileen V; Chavarin, Claudia V; Semple, Shirley J; Mendoza, Doroteo; Rodriguez, Carlos Magis; Staines, Hugo; Aarons, Gregory A; Patterson, Thomas L

2017-06-01

Intervention fidelity and participant-level variables, such as negative attitudes towards condoms, are important variables to consider in the successful implementation of evidence-based HIV prevention interventions. Mujer Segura is an intervention that has been shown to be efficacious at reducing condomless sex for female sex workers (FSWs) in Mexico [1]. We examined main effects of fidelity, negative condom attitudes, and their interaction on the effectiveness of the Mujer Segura intervention at reducing condomless sex at intervention follow-up. Of the FSWs recruited from 13 cities across Mexico, 528 participated in the Mujer Segura intervention. We measured negative condom attitudes at baseline (comprising of beliefs and outcome evaluations) and condomless sex with clients at baseline and 6-month follow-up. Fidelity was measured by a fidelity checklist completed by independent raters; the sum of potentially 43 total elements completed by the counselor constituted fidelity. Complete fidelity was found in only 15.1% (n = 73) of sessions. There was no significant main effect of intervention fidelity on condomless sex with clients at follow-up. There was a significant and positive main effect of negative condom attitudes and a significant two-way interaction. At lower levels of fidelity, negative condom attitudes predicted greater condomless sex acts, whereas at higher levels of fidelity, the effect of condom attitudes became weaker. The results also indicated that the interaction between negative condom attitudes and fidelity were driven primarily by negative condom beliefs, as opposed to negative condom outcome evaluations. Ensuring treatment fidelity in an HIV prevention intervention is particularly important when participants have negative attitudes towards condoms.

Highs and lows: patterns of use, positive and negative effects of benzylpiperazine-containing party pills (BZP-party pills) amongst young people in New Zealand.

PubMed

Butler, Rachael A; Sheridan, Janie L

2007-11-19

This study aimed to investigate patterns and context of use of BZP-party pills, function of use, and positive and negative effects experienced by a sample of New Zealand young people who had used the products. A qualitative study comprised of semi-structured interviews and group discussions. The sample included 58 young people aged 17-23 years who had used BZP-party pills in the previous 12 months. Young people were using these substances in a range of settings--primarily during weekend social occasions--particularly as part of the dance party culture. They were mostly used for their stimulant properties and to enhance socialisation, and were often taken in combination with other legal and illicit drugs. Young people had suffered a range of physical and emotional negative effects, although none of these was reported as being life-threatening or long-term. Many participants had reduced the frequency with which they used BZP-party pills due to adverse effects. Potentially risky behaviours identified included taking large doses, mixing BZP-party pills with alcohol and other substances, and driving whilst under the influence of BZP-party pills. Findings suggest that young people in this study were not suffering excessive or dangerous adverse effects. However, potentially risky use of these products raises the issue of the need for developing harm reduction interventions.

Transatlantic wood pellet trade demonstrates telecoupled benefits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parish, Esther S.; Herzberger, Anna J.; Phifer, Colin C.

European demand for renewable energy resources has led to rapidly increasing transatlantic exports of wood pellets from the southeastern United States (SE US) since 2009. Disagreements have arisen over the global greenhouse gas reductions associated with replacing coal with wood, and groups on both sides of the Atlantic Ocean have raised concerns that increasing biomass exports might negatively affect SE US forests and the ecosystem services they provide. We use the telecoupling framework to test assertions that the intended benefits of the wood pellet trade for Europe might be offset by negative consequences in the SE US. Through a reviewmore » of current literature and available data sets, we characterize the observed and potential changes in the environmental, social, and economic components of the sending and receiving regions to assess the overall sustainability of this renewable energy system. We conclude that the observed transatlantic wood pellet trade is an example of a mutually beneficial telecoupled system with the potential to provide environmental and socioeconomic benefits in both the SE US and Europe despite some negative effects on the coal industry. We recommend continued monitoring of this telecoupled system to quantify the environmental, social, and economic interactions and effects in the sending, receiving, and spillover systems over time so that evidence-based policy decisions can be made with regard to the sustainability of this renewable energy pathway.« less

Transatlantic wood pellet trade demonstrates telecoupled benefits

DOE PAGES

Parish, Esther S.; Herzberger, Anna J.; Phifer, Colin C.; ...

2018-01-01

European demand for renewable energy resources has led to rapidly increasing transatlantic exports of wood pellets from the southeastern United States (SE US) since 2009. Disagreements have arisen over the global greenhouse gas reductions associated with replacing coal with wood, and groups on both sides of the Atlantic Ocean have raised concerns that increasing biomass exports might negatively affect SE US forests and the ecosystem services they provide. We use the telecoupling framework to test assertions that the intended benefits of the wood pellet trade for Europe might be offset by negative consequences in the SE US. Through a reviewmore » of current literature and available data sets, we characterize the observed and potential changes in the environmental, social, and economic components of the sending and receiving regions to assess the overall sustainability of this renewable energy system. We conclude that the observed transatlantic wood pellet trade is an example of a mutually beneficial telecoupled system with the potential to provide environmental and socioeconomic benefits in both the SE US and Europe despite some negative effects on the coal industry. We recommend continued monitoring of this telecoupled system to quantify the environmental, social, and economic interactions and effects in the sending, receiving, and spillover systems over time so that evidence-based policy decisions can be made with regard to the sustainability of this renewable energy pathway.« less

Properties of nanocomposite PP fibres

NASA Astrophysics Data System (ADS)

Smole, Majda S.; Stakne, Kristina; Svetec, Diana G.; Kleinschek, Karin S.; Ribitsch, Volker

2005-06-01

PP-based nanocomposite fibres were prepared by direct polymer melt intercalation. With the intention to determine the size and dispersion of nanoparticles in the polymer matrix, fibres were plasma etched and SEM observations were performed. The influence of nanofiller content and coupling agent on electrokinetic properties was studied. PP monofilament fibres exhibit hydrophobe character with negative zeta potential value. The zeta potential value of co-polymer PP fibre decreases with increasing PPAA content and the isoelectric point IEP of co-polymer samples shifts towards acid region. Addition of modified montmorillonite due to the particles electropositive character, affects the reduction of zeta potential value and a slight shift of IEP towards neutral region is observed. Nano-particles content influences electrokinetic fibres properties, i.e. ZP value is changed, however IE point is not significantly changed by different concentrations of nanofiller. In addition to, mechanical properties of nanocomposite fibres were determined.

Cortical Thickness Reduction in Combat Exposed U.S. Veterans with and without PTSD

PubMed Central

Wrocklage, Kristen M.; Averill, Lynnette A.; Scott, J. Cobb; Averill, Christopher L.; Schweinsburg, Brian; Trejo, Marcia; Roy, Alicia; Weisser, Valerie; Kelly, Christopher; Martini, Brenda; Harpaz-Rotem, Ilan; Southwick, Steven M.; Krystal, John H.; Abdallah, Chadi G.

2017-01-01

We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Veterans completed high-resolution magnetic resonance imaging (MRI) scans to estimate cortical thickness. The Clinician Administered PTSD Scale (CAPS) and Combat Exposure Scale (CES) assessments were completed to measure current PTSD and historical combat severity, respectively. PTSD symptom dimensions (numbing, avoidance, reexperiencing, anxious arousal, and dysphoric arousal) were studied. Vertex-wise whole cerebrum analyses were conducted. We found widespread negative correlations between CAPS severity and cortical thickness, particularly within the prefrontal cortex. This prefrontal correlation remained significant after controlling for depression severity, medication status, and other potential confounds. PTSD dimensions, except anxious arousal, negatively correlated with cortical thickness in various unique brain regions. CES negatively correlated with cortical thickness in the left lateral prefrontal, regardless of PTSD diagnosis. A significant interaction between CES and PTSD diagnosis was found, such that CES negatively correlated with cortical thickness in the non-PTSD, but not in the PTSD, participants. The results underscore the severity of cortical thinning in U.S. Veterans suffering from high level of PTSD symptoms, as well as in Veterans with no PTSD diagnosis but severe combat exposure. The latter finding raises considerable concerns about a concealed injury potentially related to combat exposure in the post-9/11 era. PMID:28279623

Cortical thickness reduction in combat exposed U.S. veterans with and without PTSD.

PubMed

Wrocklage, Kristen M; Averill, Lynnette A; Cobb Scott, J; Averill, Christopher L; Schweinsburg, Brian; Trejo, Marcia; Roy, Alicia; Weisser, Valerie; Kelly, Christopher; Martini, Brenda; Harpaz-Rotem, Ilan; Southwick, Steven M; Krystal, John H; Abdallah, Chadi G

2017-05-01

We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Veterans completed high-resolution magnetic resonance imaging (MRI) scans to estimate cortical thickness. The Clinician Administered PTSD Scale (CAPS) and Combat Exposure Scale (CES) assessments were completed to measure current PTSD and historical combat severity, respectively. PTSD symptom dimensions (numbing, avoidance, reexperiencing, anxious arousal, and dysphoric arousal) were studied. Vertex-wise whole cerebrum analyses were conducted. We found widespread negative correlations between CAPS severity and cortical thickness, particularly within the prefrontal cortex. This prefrontal correlation remained significant after controlling for depression severity, medication status, and other potential confounds. PTSD dimensions, except anxious arousal, negatively correlated with cortical thickness in various unique brain regions. CES negatively correlated with cortical thickness in the left lateral prefrontal, regardless of PTSD diagnosis. A significant interaction between CES and PTSD diagnosis was found, such that CES negatively correlated with cortical thickness in the non-PTSD, but not in the PTSD, participants. The results underscore the severity of cortical thinning in U.S. Veterans suffering from high level of PTSD symptoms, as well as in Veterans with no PTSD diagnosis but severe combat exposure. The latter finding raises considerable concerns about a concealed injury potentially related to combat exposure in the post-9/11 era. Published by Elsevier B.V.

Estrogen-related receptor alpha is critical for the growth of estrogen receptor-negative breast cancer

PubMed Central

Stein, Rebecca A.; Chang, Ching-yi; Kazmin, Dmitri A.; Way, James; Schroeder, Thies; Wergin, Melanie; Dewhirst, Mark W.; McDonnell, Donald P.

2009-01-01

Expression of estrogen-related receptor alpha (ERRα) has recently been shown to carry negative prognostic significance in breast and ovarian cancers. The specific role of this orphan nuclear receptor in tumor growth and progression, however, is yet to be fully understood. The significant homology between estrogen receptor alpha (ERα) and ERRα initially suggested that these receptors may have similar transcriptional targets. Using the well-characterized ERα-positive MCF-7 breast cancer cell line, we sought to gain a genome-wide picture of ERα-ERRα cross-talk using an unbiased microarray approach. In addition to generating a host of novel ERRα target genes, this study yielded the surprising result that most ERRα-regulated genes are unrelated to estrogen-signaling. The relatively small number of genes regulated by both ERα and ERRα led us to expand our study to the more aggressive and less clinically treatable ERα-negative class of breast cancers. In this setting we found that ERRα expression is required for the basal level of expression of many known and novel ERRα target genes. Introduction of an siRNA directed to ERRα into the highly aggressive breast carcinoma MDA-MB-231 cell line dramatically reduced the migratory potential of these cells. Although stable knockdown of ERRα expression in MDA-MB-231 cells had no impact on in vitro cell proliferation, a significant reduction of tumor growth rate was observed when these cells were implanted as xenografts. Our results confirm a role for ERRα in breast cancer growth and highlight it as a potential therapeutic target for estrogen receptor-negative breast cancer. PMID:18974123

Smoking-specific experiential avoidance cognition: explanatory relevance to pre- and post-cessation nicotine withdrawal, craving, and negative affect.

PubMed

Farris, Samantha G; Zvolensky, Michael J; Schmidt, Norman B

2015-05-01

Negative-reinforcement based cognitive processes have been implicated in the maintenance of cigarette smoking. Given the expectation that smoking will attenuate aversive internal experiences, smokers may be particularly unwilling to experience or remain in contact with smoking-related distress (i.e., experiential avoidance). Yet, there is little known about a cognitive-based process termed smoking-specific experiential avoidance with regard to withdrawal, craving, or negative affect during a quit attempt. Data were collected from adult daily smokers (n = 259) participating in a larger smoking cessation trial. Pre- and post-quit experiences of nicotine withdrawal, craving, and negative affect were examined in terms of cognitive-based smoking-specific experimental avoidance, measured by the Avoidance and Inflexibility Scale (AIS). Results indicated that baseline smoking-specific experiential avoidance was associated with greater overall levels of withdrawal, craving, and negative affect at treatment initiation (pre-cessation). Reductions in smoking-specific experiential avoidance from baseline to quit day were associated with increased likelihood of quit day abstinence. Such reductions were also predictive of lower levels of nicotine withdrawal, craving, and negative affect on quit day. Also, less reduction in experiential avoidance was associated with experiencing greater withdrawal in the early phase of quitting. The impact of cognitive-based experiential avoidance pertaining to smoking impacts both pre- and post-cessation experiences in terms of negative affect, withdrawal, and smoking cravings and may represent an important treatment target. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isospin flip as a relativistic effect: NN interactions

NASA Technical Reports Server (NTRS)

Buck, W. W.

1993-01-01

Results are presented of an analytic relativistic calculation of a OBE nucleon-nucleon (NN) interaction employing the Gross equation. The calculation consists of a non-relativistic reduction that keeps the negative energy states. The result is compared to purely non-relativistic OBEP results and the relativistic effects are separated out. One finds that the resulting relativistic effects are expressable as a power series in (tau(sub 1))(tau(sub 2)) that agrees, qualitatively, with NN scattering. Upon G-parity transforming this NN potential, one obtains, qualitatively, a short range NN spectroscopy in which the S-states are the lowest states.

Synthesis and antibacterial activity of Schiff bases and amines derived from alkyl 2-(2-formyl-4-nitrophenoxy)alkanoates.

PubMed

Goszczyńska, Agata; Kwiecień, Halina; Fijałkowski, Karol

A series of novel Schiff bases and secondary amines were obtained in good yields, as a result of the reductive amination of alkyl 2-(2-formyl-4-nitrophenoxy)alkanoates with both aniline and 4-methoxyaniline under established mild reaction conditions. Sodium triacetoxyborohydride as well as hydrogen in the presence of palladium on carbon were used as efficient reducing agents of the Schiff bases, in both direct and stepwise reductive amination processes. The Schiff bases, amines, and amine hydrochlorides were designed as potential antibacterial agents, and structure-activity relationship could be established following in vitro assays against Gram-positive and Gram-negative bacteria. The minimal inhibitory concentration and zone of inhibition were also determined. In these tests, some of Schiff bases and secondary amine hydrochlorides showed moderate-to-good activity against Gram-positive bacteria, including S. aureus , M. luteus , and S. mutans .

More losers than winners in a century of future Southern Ocean seafloor warming

NASA Astrophysics Data System (ADS)

Griffiths, Huw J.; Meijers, Andrew J. S.; Bracegirdle, Thomas J.

2017-10-01

The waters of the Southern Ocean are projected to warm over the coming century, with potential adverse consequences for native cold-adapted organisms. Warming waters have caused temperate marine species to shift their ranges poleward. The seafloor animals of the Southern Ocean shelf have long been isolated by the deep ocean surrounding Antarctica and the Antarctic Circumpolar Current, with little scope for southward migration. How these largely endemic species will react to future projected warming is unknown. By considering 963 invertebrate species, we show that within the current century, warming temperatures alone are unlikely to result in wholesale extinction or invasion affecting Antarctic seafloor life. However, 79% of Antarctica's endemic species do face a significant reduction in suitable temperature habitat (an average 12% reduction). Our findings highlight the species and regions most likely to respond significantly (negatively and positively) to warming and have important implications for future management of the region.

The impact of self-imagery on aspects of the self-concept in individuals with high levels of eating disorder cognitions.

PubMed

Harlowe, Jodie; Farrar, Stephanie; Stopa, Lusia; Turner, Hannah

2018-05-08

Low self-esteem has been identified as a maintaining factor in Cognitive Behavioural models of eating disorders and links have been identified between early memories, negative core beliefs and mental imagery. This study explored the impact of positive and negative self-imagery on aspects of the working self (implicit and explicit self-esteem, self-concept clarity and self-discrepancy) and affect. Participants with high levels of eating disorder cognitions completed measures of explicit self-esteem, self-concept clarity, self-discrepancy and affect prior to completing a positive or negative self-imagery retrieval task. Baseline measures were then repeated and a measure of implicit self-esteem completed. Positive self-imagery retrieval led to a significant increase in positive explicit self-esteem and a significant reduction in negative explicit self-esteem and actual-ideal self-discrepancies. Negative self-imagery retrieval led to a significant increase in negative explicit self-esteem and actual-ideal self-discrepancies and a significant reduction in positive explicit self-esteem. Levels of implicit self-esteem did not differ between the two groups post imagery manipulation. Retrieving a positive self-image also led to an improvement in state self-concept clarity; however, no effect was found for the negative self-imagery intervention. Holding a positive self-image in mind led to an increase in state positive affect and a reduction in state negative affect. The opposite was found for negative self-image retrieval. The study did not measure implicit self-esteem at baseline. Imagery techniques that involve the retrieval of a positive self-image may help to improve aspects of the working-self and affect in those with eating difficulties. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stiffness, working stroke, and force of single-myosin molecules in skeletal muscle: elucidation of these mechanical properties via nonlinear elasticity evaluation.

PubMed

Kaya, Motoshi; Higuchi, Hideo

2013-11-01

In muscles, the arrays of skeletal myosin molecules interact with actin filaments and continuously generate force at various contraction speeds. Therefore, it is crucial for myosin molecules to generate force collectively and minimize the interference between individual myosin molecules. Knowledge of the elasticity of myosin molecules is crucial for understanding the molecular mechanisms of muscle contractions because elasticity directly affects the working and drag (resistance) force generation when myosin molecules are positively or negatively strained. The working stroke distance is also an important mechanical property necessary for elucidation of the thermodynamic efficiency of muscle contractions at the molecular level. In this review, we focus on these mechanical properties obtained from single-fiber and single-molecule studies and discuss recent findings associated with these mechanical properties. We also discuss the potential molecular mechanisms associated with reduction of the drag effect caused by negatively strained myosin molecules.

Clinical correlates of distorted auditory perception in first-episode psychosis.

PubMed

Morenz, Rachel; Woolverton, Cindy; Frost, R Brock; Kiewel, Nicole A; Breitborde, Nicholas J K

2015-06-01

Auditory hallucinations are hypothesized to be based in distorted sensory perceptions, with increasingly distorted perceptions of reality possibly prompting the first psychotic phase of schizophrenia spectrum disorders. Our goal was to examine the association between distorted auditory perceptions and psychotic symptomatology, social functioning and quality of life among individuals with first-episode psychosis. Forty individuals with first-episode psychosis completed assessments of distorted auditory perception, psychotic symptomatology, social functioning and quality of life. Both negative (greater symptomatology) and positive clinical correlates (better quality of life) were associated with greater distorted auditory perceptions. Our findings suggest that distorted auditory perceptions are associated with both positive and negative clinical correlates among individuals with first-episode psychosis. These results highlight the potential clinical importance of balancing the goal of symptomatic reduction with the need to maintain healthy coping strategies that may be biologically and psychologically entwined with the symptoms of psychosis, themselves. © 2014 Wiley Publishing Asia Pty Ltd.

Exposures to Endocrine Disrupting Chemicals in Consumer Products-A Guide for Pediatricians.

PubMed

Wong, Katelyn H; Durrani, Timur S

2017-05-01

Endocrine disrupting chemicals, a group of exogenous chemicals that can interfere with hormone action in the body, have been implicated in disrupting endocrine function, which negatively affects human health and development. Endocrine disrupting chemicals are ubiquitously detected in consumer products, foods, beverages, personal care products, and household cleaning products. Due to concerns about their negative effects on human health, several professional health provider societies have recommended the reduction of common endocrine disrupting chemical exposures. The purpose of this review is to provide a brief overview of common endocrine disrupting chemicals (bisphenol A, phthalates, triclosan, polybrominated ethers, and parabens) and potential effects on child development and health. In addition, we aim to provide guidance and resources for pediatricians and other health care providers with counseling strategies to help patients to minimize exposures to common endocrine disrupting chemicals. Copyright © 2017 Mosby, Inc. All rights reserved.

The impact of prescription charges on asthma patients is uneven and unpredictable: evidence from qualitative interviews.

PubMed

Schafheutle, Ellen I

2009-12-01

To explore whether, and how, prescription charges affect asthma patients' disease management behaviour. Thirty qualitative interviews. Interviewees were aged between 21 and 59, 21 were women, 24 were paying individual prescription charges, and six had prepayment certificates (PPCs). Most had a beta2-agonist 'reliever' and a steroid 'preventer' inhaler. Prescription charges posed affordability issues for some, and for two patients cost-related reduction in 'preventer' use affected asthma control negatively. Many described various ways of keeping medication cost down. Affordability issues, negative views on paying charges, and whether interviewees viewed their asthma medication as essential, were influential factors. Steroid inhalers were viewed more commonly as being less essential and affected by cost. The episodic nature of asthma meant that predicting benefit from PPCs was difficult. This study strengthens existing evidence that medication cost is a factor in asthma patients' management decisions, with a potential cost-related impact on asthma control.

Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chennubhotla, Chakra; Castro, Jason

2013-01-01

In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain un- clear. Here, we use non-negative matrix factorization (NMF) - a dimensionality reduction technique - to uncover structure in a panel of odor profiles, with each odor defined as a point in multi-dimensional descriptor space. The properties of NMF are favorable for the analysis of such lexical and perceptual data, and lead to a high-dimensional account of odor space. We further provide evidence that odor di- mensions apply categorically. That is, odor space is not occupied homogenously, but rather in a discrete and intrinsically clustered manner.more » We discuss the potential implications of these results for the neural coding of odors, as well as for developing classifiers on larger datasets that may be useful for predicting perceptual qualities from chemical structures.« less

Electrochemical Characterization of Riboflavin-Enhanced Reduction of Trinitrotoluene

PubMed Central

Sumner, James J.; Chu, Kevin

2011-01-01

There is great interest in understanding trinitrotoluene (TNT) and dinitrotoluene (DNT) contamination, detection and remediation in the environment due to TNT’s negative health effects and security implications. Numerous publications have focused on detecting TNT in groundwater using multiple techniques, including electrochemistry. The main degradation pathway of nitrotoluenes in the environment is reduction, frequently with biological and/or photolytic assistance. Riboflavin has also been noted to aid in TNT remediation in soils and groundwater when exposed to light. This report indicates that adding riboflavin to a TNT or DNT solution enhances redox currents in electrochemical experiments. Here AC voltammetry was performed and peak currents compared with and without riboflavin present. Results indicated that TNT, DNT and riboflavin could be detected using AC voltammetry on modified gold electrodes and the addition of riboflavin affected redox peaks of TNT and DNT. Poised potential experiments indicated that it is possible to enhance reduction of TNT in the presence of riboflavin and light. These results were dramatic enough to explain long term enhancement of bioremediation in environments containing high levels of riboflavin and enhance the limit of detection in electrochemically-based nitrotoluene sensing. PMID:22346674

From Survivor to Thriver: A Pilot Study of an Online Program for Rape Victims

PubMed Central

Littleton, Heather; Buck, Katherine; Rosman, Lindsey; Grills-Taquechel, Amie

2013-01-01

Approximately 15% to 20% of women have been victims of rape and close to a third report current rape-related PTSD or clinically significant depression or anxiety. Unfortunately, very few distressed rape victims seek formal help. This suggests a need to develop alternative ways to assist the many distressed victims of sexual violence. Online treatment programs represent a potentially important alternative strategy for reaching such individuals. The current paper describes a pilot evaluation of an online, therapist-facilitated, self-paced cognitive behavioral program for rape victims. Five college women with current rape-related PTSD were recruited to complete the From Survivor to Thriver (S to T) program in a lab setting over the course of 7 weeks. After completing the program, 4 participants reported clinically significant reductions in PTSD symptoms and no longer met criteria for PTSD. All participants reported clinically significant reductions in vulnerability fears and 4 reported significant reductions in negative trauma-related cognitions. Implications of the results for further development of the S to T program and how clinicians could utilize this program in treating rape-related PTSD are discussed. PMID:24009410

Case studies of power and control related to tobacco use during pregnancy.

PubMed

Greaves, Lorraine; Kalaw, Cecilia; Bottorff, Joan L

2007-01-01

The objective was to identify and describe elements of power and control evident in couple tobacco-related interaction patterns during pregnancy. Using a case study approach, elements of the Duluth Abuse Intervention Project Power and Control Wheel were used to examine women's experiences of tobacco reduction during pregnancy and post partum. Three cases were selected from a larger qualitative sample, using a maximum variation sampling approach. Although no direct evidence of partner abuse or violence accompanying partner efforts to influence women's smoking was described, most of the elements of power and control were present in the case study, and appeared to cause an emotional toll and a negative impact on women's ability to freely express their views about their own tobacco use. Elements of power and control, however subtle, are potentially important and unrecognized dimensions of women's tobacco reduction experiences. Additional care and attention should be taken in designing tobacco reduction interventions and policies directed at pregnant and post partum women and their partners to reduce the possibility that these interventions may contribute to the use of power and control.

Gold Decorated Graphene for Rapid Dye Reduction and Efficient Electro Catalytic Oxidation of Ethanol

NASA Astrophysics Data System (ADS)

Siddhardha, R. S.; Kumar v, Lakshman; Kaniyoor, A.; Podila, R.; Kumar, V. S.; Venkataramaniah, K.; Ramaprabhu, S.; Rao, A.; Ramamurthy, S. S.; Clemson University Team; Sri Sathya Sai Institute of Higher Learning Team; IITMadras Team

2013-03-01

A well known disadvantage in fabrication of metal-graphene composite is the use of surfactants that strongly adsorb on the surface and reduce the performance of the catalyst. Here, we demonstrate a novel one pot synthesis of gold nanoparticles (AuNPs) by laser ablation of gold strip and simultaneous decoration of these on functionalized graphene derivatives. Not only the impregnation of AuNPs was linker free, but also the synthesis by itself was surfactant free. This resulted in in-situ decoration of pristine AuNPs on functionalized graphene derivatives. These materials were well characterized and tested for catalytic applications pertaining to dye reduction and electrooxidation. The catalytic reduction rates are 1.4 x 102 and 9.4x102 times faster for Rhodamine B and Methylene Blue dyes respectively, compared to earlier reports. The enhanced rate involves synergistic interplay of electronic relay between AuNPs and the dye, also charge transfer between the graphene system and dye. In addition, the onset potential for ethanol oxidation was found to be more negative ~ 100 mV, an indication of its promising application in direct ethanol fuel cells.

Regulation of the discharge reservoir of negative electrodes in Ni-MH batteries by using Ni(OH) x (x = 2.10) and γ-CoOOH

NASA Astrophysics Data System (ADS)

Shangguan, Enbo; Chang, Zhaorong; Tang, Hongwei; Yuan, Xiao-Zi; Wang, Haijiang

In this paper, a novel strategy to regulate the discharge reservoir of negative electrodes in Ni-MH batteries is introduced by using Ni(OH) x (x = 2.10) and γ-CoOOH. The electrochemical measurements of these batteries demonstrate that the use of Ni(OH) x (x = 2.10) and γ-CoOOH can not only successfully regulate the discharge reservoir of negative electrodes in Ni-MH batteries to an adequate quantity, but also effectively improve the electrochemical performance of the batteries. Compared with normal batteries, the in-house prepared batteries with a lower discharge reservoir exhibit an enhanced discharge capacity, improved high-rate discharge ability, higher discharge potential plateau and superior cycle stability. The effect of Ni(OH) x (x = 2.10) and γ-CoOOH on the electrochemical performance of nickel electrode is also investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results suggest that the new method is simple and effective for cost reduction of Ni-MH batteries with improved electrochemical performance.

Calcium ion involvement in growth inhibition of mechanically stressed soybean (Glycine max) seedlings

NASA Technical Reports Server (NTRS)

Jones, R. S.; Mitchell, C. A.

1989-01-01

A 40-50% reduction in soybean [Glycine max (L.) Merr. cv. Century 84] hypocotyl elongation occurred 24 h after application of mechanical stress. Exogenous Ca2+ at 10 mM inhibited growth by 28% if applied with the Ca2+ ionophore A23187 to the zone of maximum hypocotyl elongation. La3+ was even more inhibitory than Ca2+, especially above 5 mM. Treatment with ethyleneglycol-bis-(beta-aminoethylether)-N, N, N', N'-tetraacetic acid (EGTA) alone had no effect on growth of non-stressed seedlings at the concentrations used but negated stress-induced growth reduction by 36% at 4 mM when compared to non-treated, stressed controls. Treatment with EDTA was ineffective in negating stress-induced growth inhibition. Calmodulin antagonists calmidazolium, chlorpromazine, and 48/80 also negated stress-induced growth reduction by 23, 50, and 35%, respectively.

Unusual Passivation Ability of Superconcentrated Electrolytes toward Hard Carbon Negative Electrodes in Sodium-Ion Batteries.

PubMed

Takada, Koji; Yamada, Yuki; Watanabe, Eriko; Wang, Jianhui; Sodeyama, Keitaro; Tateyama, Yoshitaka; Hirata, Kazuhisa; Kawase, Takeo; Yamada, Atsuo

2017-10-04

The passivation of negative electrodes is key to achieving prolonged charge-discharge cycling with Na-ion batteries. Here, we report the unusual passivation ability of superconcentrated Na-salt electrolytes. For example, a 50 mol % sodium bis(fluorosulfonyl)amide (NaFSA)/succinonitrile (SN) electrolyte enables highly reversible Na + insertion into a hard carbon negative electrode without any electrolyte additive, functional binder, or electrode pretreatment. Importantly, an anion-derived passivation film is formed via preferential reduction of the anion upon charging, which can effectively suppress further electrolyte reduction. As a structural characteristic of the electrolyte, most anions are coordinated to multiple Na + cations at high concentration, which shifts the lowest unoccupied molecular orbitals of the anions downward, resulting in preferential anion reduction. The present work provides a new understanding of the passivation mechanism with respect to the coordination state of the anion.

Elementary Music Teachers' Perceptions of the Effect of Budget Reductions on Music Education

ERIC Educational Resources Information Center

Michel, Jimmy

2018-01-01

Since 2007, many U.S. music education programs have been negatively affected by budget reductions at the local, state, and national levels. Although researchers have studied the effect of budget reductions on music education, they have not widely examined the perspectives of teachers who have experienced these reductions. The purpose of this study…

The Relationship Between Gratitude and Loneliness: The Potential Benefits of Gratitude for Promoting Social Bonds.

PubMed

Caputo, Andrea

2015-05-01

This paper explores the potential role of gratitude on the reduction of loneliness feelings, even controlling for several variables related to social desirability, well-being (subjective happiness and life satisfaction) and socio-demographic characteristics. Through a web-based survey a convenience sample of 197 participants completed an online questionnaire including these measures. Correlation analyses and four-step hierarchical multiple regression analyses were conducted. The results show a negative correlation between gratitude and loneliness; specifically, gratitude succeeds in accounting for up to almost one-fifth of the total variability of loneliness even controlling for further variables. Being female, not having a stable and consolidated relationship and not participating in the labor force represent some risk factors affecting loneliness which should be taken into account in further research.

The Relationship Between Gratitude and Loneliness: The Potential Benefits of Gratitude for Promoting Social Bonds

PubMed Central

Caputo, Andrea

2015-01-01

This paper explores the potential role of gratitude on the reduction of loneliness feelings, even controlling for several variables related to social desirability, well-being (subjective happiness and life satisfaction) and socio-demographic characteristics. Through a web-based survey a convenience sample of 197 participants completed an online questionnaire including these measures. Correlation analyses and four-step hierarchical multiple regression analyses were conducted. The results show a negative correlation between gratitude and loneliness; specifically, gratitude succeeds in accounting for up to almost one-fifth of the total variability of loneliness even controlling for further variables. Being female, not having a stable and consolidated relationship and not participating in the labor force represent some risk factors affecting loneliness which should be taken into account in further research. PMID:27247660

Nitrous Oxide Metabolism in Nitrate-Reducing Bacteria: Physiology and Regulatory Mechanisms.

PubMed

Torres, M J; Simon, J; Rowley, G; Bedmar, E J; Richardson, D J; Gates, A J; Delgado, M J

2016-01-01

Nitrous oxide (N2O) is an important greenhouse gas (GHG) with substantial global warming potential and also contributes to ozone depletion through photochemical nitric oxide (NO) production in the stratosphere. The negative effects of N2O on climate and stratospheric ozone make N2O mitigation an international challenge. More than 60% of global N2O emissions are emitted from agricultural soils mainly due to the application of synthetic nitrogen-containing fertilizers. Thus, mitigation strategies must be developed which increase (or at least do not negatively impact) on agricultural efficiency whilst decrease the levels of N2O released. This aim is particularly important in the context of the ever expanding population and subsequent increased burden on the food chain. More than two-thirds of N2O emissions from soils can be attributed to bacterial and fungal denitrification and nitrification processes. In ammonia-oxidizing bacteria, N2O is formed through the oxidation of hydroxylamine to nitrite. In denitrifiers, nitrate is reduced to N2 via nitrite, NO and N2O production. In addition to denitrification, respiratory nitrate ammonification (also termed dissimilatory nitrate reduction to ammonium) is another important nitrate-reducing mechanism in soil, responsible for the loss of nitrate and production of N2O from reduction of NO that is formed as a by-product of the reduction process. This review will synthesize our current understanding of the environmental, regulatory and biochemical control of N2O emissions by nitrate-reducing bacteria and point to new solutions for agricultural GHG mitigation. © 2016 Elsevier Ltd. All rights reserved.

Effects of resource availability and propagule supply on native species recruitment in sagebrush ecosystems invaded by Bromus tectorum

USGS Publications Warehouse

Mazzola, Monica B.; Chambers, Jeanne C.; Blank, Robert R.; Pyke, David A.; Schupp, Eugene W.; Allcock, Kimberly G.; Doescher, Paul S.; Nowak, Robert S.

2011-01-01

Resource availability and propagule supply are major factors influencing establishment and persistence of both native and invasive species. Increased soil nitrogen (N) availability and high propagule inputs contribute to the ability of annual invasive grasses to dominate disturbed ecosystems. Nitrogen reduction through carbon (C) additions can potentially immobilize soil N and reduce the competitiveness of annual invasive grasses. Native perennial species are more tolerant of resource limiting conditions and may benefit if N reduction decreases the competitive advantage of annual invaders and if sufficient propagules are available for their establishment. Bromus tectorum, an exotic annual grass in the sagebrush steppe of western North America, is rapidly displacing native plant species and causing widespread changes in ecosystem processes. We tested whether nitrogen reduction would negatively affect B. tectorum while creating an opportunity for establishment of native perennial species. A C source, sucrose, was added to the soil, and then plots were seeded with different densities of both B. tectorum (0, 150, 300, 600, and 1,200 viable seeds m-2) and native species (0, 150, 300, and 600 viable seeds m-2). Adding sucrose had short-term (1 year) negative effects on available nitrogen and B. tectorum density, biomass and seed numbers, but did not increase establishment of native species. Increasing propagule availability increased both B. tectorum and native species establishment. Effects of B. tectorum on native species were density dependent and native establishment increased as B. tectorum propagule availability decreased. Survival of native seedlings was low indicating that recruitment is governed by the seedling stage.

The Impact of Perspective Change As a Cognitive Reappraisal Strategy on Affect: A Systematic Review

PubMed Central

Wallace-Hadrill, Sophie M. A.; Kamboj, Sunjeev K.

2016-01-01

The strategic or deliberate adoption of a cognitively distanced, third-person perspective is proposed to adaptively regulate emotions. However, studies of psychological disorders suggest spontaneous adoption of a third-person perspective reflects counter-productive avoidance. Here, we review studies that investigate the deliberate adoption of a third- or first-person vantage perspective and its impact on affect in healthy people, “sub-clinical” populations and those with psychological disorders. A systematic search was conducted across four databases. After exclusion criteria were applied, 38 studies were identified that investigated the impact of both imagery and verbal instructions designed to encourage adoption of a third-person perspective on self-reported affect. The identified studies examined a variety of outcomes related to recalling memories, imagining scenarios and mood induction. These were associated with specific negative emotions or mood states (dysphoria/sadness, anxiety, anger), mixed or neutral affect autobiographical memories, and self-conscious affect (e.g., guilt). Engaging a third-person perspective was generally associated with a reduction in the intensity of positive and negative affect. Studies that included measures of semantic change, suggested that this is a key mediator in reduction of affect following perspective change. Strategically adopting a “distanced,” third-person perspective is linked to a reduction in affect intensity across valence, but in addition has the potential to introduce new information that regulates emotion via semantic change. Such reappraisal distinguishes deliberate adoption of a distanced perspective from the habitual and/or spontaneous shift in perspective that occurs in psychopathology. PMID:27867366

Effects of Video Feedback on Early Coercive Parent–Child Interactions: The Intervening Role of Caregivers’ Relational Schemas

PubMed Central

Smith, Justin D.; Dishion, Thomas J.; Moore, Kevin J.; Shaw, Daniel S.; Wilson, Melvin N.

2013-01-01

Objective We examined the effect of adding a video feedback intervention component to the assessment feedback session of the Family Check-Up intervention (FCU; Dishion & Stormshak, 2007). We hypothesized that the addition of video feedback procedures during the FCU feedback at child age 2 would have a positive effect on caregivers’ negative relational schemas of their child, which in turn would mediate reductions in observed coercive caregiver-child interactions assessed at age 5. Method We observed the caregiver-child interaction videotapes of 79 high-risk families with toddlers exhibiting clinically significant problem behaviors. A quasi-random sample of families were provided with direct feedback on their interactions during the feedback session of the FCU protocol. Results Path analysis indicated that reviewing and engaging in feedback about videotaped age-2 assessment predicted reduced caregivers’ negative relational schemas of the child at age 3, which acted as an intervening variable on the reduction of observed parent–child coercive interactions recorded at age 5. Video feedback predicted improved family functioning over and above level of engagement in the FCU in subsequent years, indicating the important incremental contribution of using video feedback procedures in early family-based preventive interventions for problem behaviors. Conclusions Supportive video feedback on coercive family dynamics is an important strategy for promoting caregiver motivation to reduce negative attributions toward the child, which fuel coercive interactions. Our study also contributes to the clinical and research literature concerning coercion theory and effective intervention strategies by identifying a potential mechanism of change. PMID:23534831

Modelling CEC variations versus structural iron reduction levels in dioctahedral smectites. Existing approaches, new data and model refinements.

PubMed

Hadi, Jebril; Tournassat, Christophe; Ignatiadis, Ioannis; Greneche, Jean Marc; Charlet, Laurent

2013-10-01

A model was developed to describe how the 2:1 layer excess negative charge induced by the reduction of Fe(III) to Fe(II) by sodium dithionite buffered with citrate-bicarbonate is balanced and applied to nontronites. This model is based on new experimental data and extends structural interpretation introduced by a former model [36-38]. The 2:1 layer negative charge increase due to Fe(III) to Fe(II) reduction is balanced by an excess adsorption of cations in the clay interlayers and a specific sorption of H(+) from solution. Prevalence of one compensating mechanism over the other is related to the growing lattice distortion induced by structural Fe(III) reduction. At low reduction levels, cation adsorption dominates and some of the incorporated protons react with structural OH groups, leading to a dehydroxylation of the structure. Starting from a moderate reduction level, other structural changes occur, leading to a reorganisation of the octahedral and tetrahedral lattice: migration or release of cations, intense dehydroxylation and bonding of protons to undersaturated oxygen atoms. Experimental data highlight some particular properties of ferruginous smectites regarding chemical reduction. Contrary to previous assumptions, the negative layer charge of nontronites does not only increase towards a plateau value upon reduction. A peak is observed in the reduction domain. After this peak, the negative layer charge decreases upon extended reduction (>30%). The decrease is so dramatic that the layer charge of highly reduced nontronites can fall below that of its fully oxidised counterpart. Furthermore, the presence of a large amount of tetrahedral Fe seems to promote intense clay structural changes and Fe reducibility. Our newly acquired data clearly show that models currently available in the literature cannot be applied to the whole reduction range of clay structural Fe. Moreover, changes in the model normalising procedure clearly demonstrate that the investigated low tetrahedral bearing nontronites (SWa-1, GAN and NAu-1) all exhibit the same behaviour at low reduction levels. Consequently, we restricted our model to the case of moderate reduction (<30%) in low tetrahedral Fe-bearing nontronites. Our adapted model provides the relative amounts of Na(+) (p) and H(+) (ni) cations incorporated in the structure as a function of the amount of Fe reduction. Two equations enable the investigated systems to be described: p=m/(1+Kr·ω·mrel) and ni=Kr·ω·m·mrel/(1+Kr·ω·mrel); where m is the Fe(II) content, mrel, the reduction level (m/mtot), ω, the cation exchange capacity (CEC, and Kr, an empirical constant specific to the system. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of T-state and R-state stabilization on deoxyhemoglobin-nitrite reactions and stimulation of nitric oxide signaling

PubMed Central

Cantu-Medellin, Nadiezhda; Vitturi, Dario A.; Rodriguez, Cilina; Murphy, Serena; Dorman, Scott; Shiva, Sruti; Zhou, Yipin; Jia, Yiping; Palmer, Andre F.; Patel, Rakesh P.

2011-01-01

Recent data suggest that transitions between the relaxed (R) and tense (T) state of hemoglobin control the reduction of nitrite to nitric oxide (NO) by deoxyhemoglobin. This reaction may play a role in physiologic NO homeostasis and be a novel consideration for the development of the next generation of hemoglobin-based blood oxygen carriers (HBOCs, i.e. artificial blood substitutes). Herein we tested the effects of chemical stabilization of bovine hemoglobin in either the T- (THb) or R-state (RHb) on nitrite reduction kinetics, NO-gas formation and ability to stimulate NO-dependent signaling. These studies were performed over a range of fractional saturations that is expected to mimic biological conditions. The initial rate for nitrite-reduction decreased in the following order RHb > bHb > THb, consistent with the hypothesis that the rate constant for nitrite reduction is faster with R-state Hb and slower with T-state Hb. Moreover, RHb produced more NO-gas and inhibited mitochondrial respiration more potently than both bHb and THb. Interestingly, at low oxygen fractional saturations, THb produced more NO and stimulated nitrite-dependent vasodilation more potently than bHb despite both derivatives having similar initial rates for nitrite reduction and a more negative reduction potential in THb versus bHb. These data suggest that cross-linking of bovine hemoglobin in the T-state conformation leads to a more effective coupling of nitrite reduction to NO-formation. Our results support the model of allosteric regulation of nitrite reduction by deoxyhemoglobin and show that cross-linking hemoglobins in distinct quaternary states can generate products with increased NO yields from nitrite reduction that could be harnessed to promote NO-signaling in vivo. PMID:21277987

Control of oxidation-reduction potential during Cheddar cheese ripening and its effect on the production of volatile flavour compounds.

PubMed

Caldeo, Veronica; Hannon, John A; Hickey, Dara-Kate; Waldron, Dave; Wilkinson, Martin G; Beresford, Thomas P; McSweeney, Paul L H

2016-11-01

In cheese, a negative oxidation-reduction (redox) potential is required for the stability of aroma, especially that associated with volatile sulphur compounds. To control the redox potential during ripening, redox agents were added to the salted curd of Cheddar cheese before pressing. The control cheese contained only salt, while different oxidising or reducing agents were added with the NaCl to the experimental cheeses. KIO3 (at 0·05, 0·1 and 1%, w/w) was used as the oxidising agent while cysteine (at 2%, w/w) and Na2S2O4 (at 0·05 and 0·1%, w/w) were used as reducing agents. During ripening the redox potential of the cheeses made with the reducing agents did not differ significantly from the control cheese (E h ≈ -120 mV) while the cheeses made with 0·1 and 0·05% KIO3 had a significantly higher and positive redox potential in the first month of ripening. Cheese made with 1% KIO3 had positive values of redox potential throughout ripening but no starter lactic acid bacteria survived in this cheese; however, numbers of starter organisms in all other cheeses were similar. Principal component analysis (PCA) of the volatile compounds clearly separated the cheeses made with the reducing agents from cheeses made with the oxidising agents at 2 month of ripening. Cheeses with reducing agents were characterized by the presence of sulphur compounds whereas cheeses made with KIO3 were characterized mainly by aldehydes. At 6 month of ripening, separation by PCA was less evident. These findings support the hypothesis that redox potential could be controlled during ripening and that this parameter has an influence on the development of cheese flavour.

40 CFR 57.816 - Effect of negative recommendation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Effect of negative recommendation. 57.816 Section 57.816 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Reduction Technology § 57.816 Effect of negative recommendation. No waiver of the interim requirement for...

Frontal alpha asymmetry neurofeedback for the reduction of negative affect and anxiety.

PubMed

Mennella, Rocco; Patron, Elisabetta; Palomba, Daniela

2017-05-01

Frontal alpha asymmetry has been proposed to underlie the balance between approach and withdrawal motivation associated to each individual's affective style. Neurofeedback of EEG frontal alpha asymmetry represents a promising tool to reduce negative affect, although its specific effects on left/right frontal activity and approach/withdrawal motivation are still unclear. The present study employed a neurofeedback training to increase frontal alpha asymmetry (right - left), in order to evaluate discrete changes in alpha power at left and right sites, as well as in positive and negative affect, anxiety and depression. Thirty-two right-handed females were randomly assigned to receive either the neurofeedback on frontal alpha asymmetry, or an active control training (N = 16 in each group). The asymmetry group showed an increase in alpha asymmetry driven by higher alpha at the right site (p < 0.001), as well as a coherent reduction in both negative affect and anxiety symptoms (ps < 0.05), from pre-to post-training. No training-specific modulation emerged for positive affect and depressive symptoms. These findings provide a strong rationale for the use of frontal alpha asymmetry neurofeedback for the reduction of negative affect and anxiety in clinical settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Banning Fisheries Discards Abruptly Has a Negative Impact on the Population Dynamics of Charismatic Marine Megafauna.

PubMed

Fondo, Esther N; Chaloupka, Milani; Heymans, Johanna J; Skilleter, Greg A

2015-01-01

Food subsidies have the potential to modify ecosystems and affect the provision of goods and services. Predictable Anthropogenic Food Subsidies (PAFS) modify ecosystems by altering ecological processes and food webs. The global concern over the effects of PAFS in ecosystems has led to development of environmental policies aimed at curbing the production or ultimately banning of PAFS. However, the effects of reducing or banning PAFS are not known. We explore the consequences of PAFS removal in a marine ecosystem under two scenarios: 1) gradual reduction, or 2) an abrupt ban, using a mass balance model to test these hypotheses-The reduction or loss of PAFS will: i) modify trophic levels and food webs through effects on foraging by opportunistic species, ii) increase the resilience of opportunistic species to food shortages, and iii) modify predator-prey interactions through shifts in prey consumption. We found that PAFS lower the trophic levels of opportunistic scavengers and increase their food pathways. Scavengers are able to switch prey when PAFS are reduced gradually but they decline when PAFS are abruptly banned. PAFS reduction to a certain minimal level causes a drop in the ecosystem's stability. We recommend gradual reduction of PAFS to a minimal level that would maintain the ecosystem's stability and allow species exploiting PAFS to habituate to the food subsidy reduction.

Quantified, Localized Health Benefits of Accelerated Carbon Dioxide Emissions Reductions.

PubMed

Shindell, Drew; Faluvegi, Greg; Seltzer, Karl; Shindell, Cary

2018-01-01

Societal risks increase as Earth warms, but also for emissions trajectories accepting relatively high levels of near-term emissions while assuming future negative emissions will compensate even if they lead to identical warming [1]. Accelerating carbon dioxide (CO 2 ) emissions reductions, including as a substitute for negative emissions, hence reduces long-term risks but requires dramatic near-term societal transformations [2]. A major barrier to emissions reductions is the difficulty of reconciling immediate, localized costs with global, long-term benefits [3, 4]. However, 2°C trajectories not relying on negative emissions or 1.5°C trajectories require elimination of most fossil fuel related emissions. This generally reduces co-emissions that cause ambient air pollution, resulting in near-term, localized health benefits. We therefore examine the human health benefits of increasing ambition of 21 st century CO 2 reductions by 180 GtC; an amount that would shift a 'standard' 2°C scenario to 1.5°C or could achieve 2°C without negative emissions. The decreased air pollution leads to 153±43 million fewer premature deaths worldwide, with ~40% occurring during the next 40 years, and minimal climate disbenefits. More than a million premature deaths would be prevented in many metropolitan areas in Asia and Africa, and >200,000 in individual urban areas on every inhabited continent except Australia.

Quantified, localized health benefits of accelerated carbon dioxide emissions reductions

NASA Astrophysics Data System (ADS)

Shindell, Drew; Faluvegi, Greg; Seltzer, Karl; Shindell, Cary

2018-04-01

Societal risks increase as Earth warms, and increase further for emissions trajectories accepting relatively high levels of near-term emissions while assuming future negative emissions will compensate, even if they lead to identical warming as trajectories with reduced near-term emissions1. Accelerating carbon dioxide (CO2) emissions reductions, including as a substitute for negative emissions, hence reduces long-term risks but requires dramatic near-term societal transformations2. A major barrier to emissions reductions is the difficulty of reconciling immediate, localized costs with global, long-term benefits3,4. However, 2 °C trajectories not relying on negative emissions or 1.5 °C trajectories require elimination of most fossil-fuel-related emissions. This generally reduces co-emissions that cause ambient air pollution, resulting in near-term, localized health benefits. We therefore examine the human health benefits of increasing 21st-century CO2 reductions by 180 GtC, an amount that would shift a `standard' 2 °C scenario to 1.5 °C or could achieve 2 °C without negative emissions. The decreased air pollution leads to 153 ± 43 million fewer premature deaths worldwide, with 40% occurring during the next 40 years, and minimal climate disbenefits. More than a million premature deaths would be prevented in many metropolitan areas in Asia and Africa, and >200,000 in individual urban areas on every inhabited continent except Australia.

Electron storage in single wall carbon nanotubes. Fermi level equilibration in semiconductor-SWCNT suspensions.

PubMed

Kongkanand, Anusorn; Kamat, Prashant V

2007-08-01

The use of single wall carbon nanotubes (SWCNTs) as conduits for transporting electrons in a photoelectrochemical solar cell and electronic devices requires better understanding of their electron-accepting properties. When in contact with photoirradiated TiO(2) nanoparticles, SWCNTs accept and store electrons. The Fermi level equilibration with photoirradiated TiO(2) particles indicates storage of up to 1 electron per 32 carbon atoms in the SWCNT. The stored electrons are readily discharged on demand upon addition of electron acceptors such as thiazine and oxazine dyes (reduction potential less negative than that of the SWCNT conduction band) to the TiO(2)-SWCNT suspension. The stepwise electron transfer from photoirradiated TiO(2) nanoparticles --> SWCNT --> redox couple has enabled us to probe the electron equilibration process and determine the apparent Fermi level of the TiO(2)-SWCNT system. A positive shift in apparent Fermi level (20-30 mV) indicates the ability of SWCNTs to undergo charge equilibration with photoirradiated TiO(2) particles. The dependence of discharge capacity on the reduction potential of the dye redox couple is compared for TiO(2) and TiO(2)-SWCNT systems under equilibration conditions.

A Stable, Narrow-Gap Oxyfluoride Photocatalyst for Visible-Light Hydrogen Evolution and Carbon Dioxide Reduction.

PubMed

Kuriki, Ryo; Ichibha, Tom; Hongo, Kenta; Lu, Daling; Maezono, Ryo; Kageyama, Hiroshi; Ishitani, Osamu; Oka, Kengo; Maeda, Kazuhiko

2018-05-30

Mixed anion compounds such as oxynitrides and oxychalcogenides are recognized as potential candidates of visible-light-driven photocatalysts since, as compared with oxygen 2p orbitals, p orbitals of less electronegative anion (e.g., N 3- , S 2- ) can form a valence band that has more negative potential. In this regard, oxyfluorides appear unsuitable because of the higher electronegativity of fluorine. Here we show an exceptional case, an anion-ordered pyrochlore oxyfluoride Pb 2 Ti 2 O 5.4 F 1.2 that has a small band gap (ca. 2.4 eV). With suitable modification of Pb 2 Ti 2 O 5.4 F 1.2 by promoters such as platinum nanoparticles and a binuclear ruthenium(II) complex, Pb 2 Ti 2 O 5.4 F 1.2 worked as a stable photocatalyst for visible-light-driven H 2 evolution and CO 2 reduction. Density functional theory calculations have revealed that the unprecedented visible-light-response of Pb 2 Ti 2 O 5.4 F 1.2 arises from strong interaction between Pb-6s and O-2p orbitals, which is enabled by a short Pb-O bond in the pyrochlore lattice due to the fluorine substitution.

Importance of food-demand management for climate mitigation

NASA Astrophysics Data System (ADS)

Bajželj, Bojana; Richards, Keith S.; Allwood, Julian M.; Smith, Pete; Dennis, John S.; Curmi, Elizabeth; Gilligan, Christopher A.

2014-10-01

Recent studies show that current trends in yield improvement will not be sufficient to meet projected global food demand in 2050, and suggest that a further expansion of agricultural area will be required. However, agriculture is the main driver of losses of biodiversity and a major contributor to climate change and pollution, and so further expansion is undesirable. The usual proposed alternative--intensification with increased resource use--also has negative effects. It is therefore imperative to find ways to achieve global food security without expanding crop or pastureland and without increasing greenhouse gas emissions. Some authors have emphasized a role for sustainable intensification in closing global `yield gaps' between the currently realized and potentially achievable yields. However, in this paper we use a transparent, data-driven model, to show that even if yield gaps are closed, the projected demand will drive further agricultural expansion. There are, however, options for reduction on the demand side that are rarely considered. In the second part of this paper we quantify the potential for demand-side mitigation options, and show that improved diets and decreases in food waste are essential to deliver emissions reductions, and to provide global food security in 2050.

Vestibular-Evoked Myogenic Potentials in Bilateral Vestibulopathy

PubMed Central

Rosengren, Sally M.; Welgampola, Miriam S.; Taylor, Rachael L.

2018-01-01

Bilateral vestibulopathy (BVP) is a chronic condition in which patients have a reduction or absence of vestibular function in both ears. BVP is characterized by bilateral reduction of horizontal canal responses; however, there is increasing evidence that otolith function can also be affected. Cervical and ocular vestibular-evoked myogenic potentials (cVEMPs/oVEMPs) are relatively new tests of otolith function that can be used to test the saccule and utricle of both ears independently. Studies to date show that cVEMPs and oVEMPs are often small or absent in BVP but are in the normal range in a significant proportion of patients. The variability in otolith function is partly due to the heterogeneous nature of BVP but is also due to false negative and positive responses that occur because of the large range of normal VEMP amplitudes. Due to their variability, VEMPs are not part of the diagnosis of BVP; however, they are helpful complementary tests that can provide information about the extent of disease within the labyrinth. This article is a review of the use of VEMPs in BVP, summarizing the available data on VEMP abnormalities in patients and discussing the limitations of VEMPs in diagnosing bilateral loss of otolith function. PMID:29719527

Electrodeposition of MWNT/Bi2Te3 Composite Thermoelectric Films

NASA Astrophysics Data System (ADS)

Xu, Han; Wang, Wei

2013-07-01

The effect of multiwalled carbon nanotubes (MWNTs) on the electrochemical behavior of the Bi-Te binary system in nitric acid baths was investigated by means of cyclic voltammetry and electrochemical impedance spectroscopy. Based on the results, MWNT/Bi2Te3 composite thermoelectric films were prepared by potentiostatic electrodeposition at room temperature. The morphology, composition, and structure of the MWNT/Bi2Te3 composite films were analyzed by environmental scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. The results show that addition of MWNTs to the electrolyte did not change the electrochemical reduction mechanisms of Bi3+, HTeO{2/+} or their mixture, but the reduction processes of Bi3+, HTeO{2/+}, and their mixture become easier. MWNT/Bi2Te3 composite thermoelectric films can be obtained by potentiostatic electrodeposition at a wide range of potentials with subsequent annealing. The MWNTs in the films act as nucleation sites for Bi2Te3 compound and thereby elevate the film deposition rate. The content of Bi element and MWNTs in the films increased as the potential was shifted negatively. In addition, the MWNTs can enhance the crystallization of Bi2Te3 film.

Invasive European bird cherry disrupts stream-riparian linkages: effects on terrestrial invertebrate prey subsidies for juvenile coho salmon

USGS Publications Warehouse

Roon, David A.; Wipfli, Mark S.; Wurtz, Tricia L.; Blanchard, Arny L.

2016-01-01

The spread of invasive species in riparian forests has the potential to affect both terrestrial and aquatic organisms linked through cross-ecosystem resource subsidies. However, this potential had not been explored in regards to terrestrial prey subsidies for stream fishes. To address this, we examined the effects of an invasive riparian tree, European bird cherry (EBC, Prunus padus), spreading along urban Alaskan salmon streams, by collecting terrestrial invertebrates present on the foliage of riparian trees, their subsidies to streams, and their consumption by juvenile coho salmon (Oncorhynchus kisutch). Riparian EBC supported four to six times less terrestrial invertebrate biomass on its foliage and contributed two to three times lower subsidies relative to native deciduous trees. This reduction in terrestrial invertebrate biomass was consistent between two watersheds over 2 years. In spite of this reduction in terrestrial prey resource input, juvenile coho salmon consumed similar levels of terrestrial invertebrates in stream reaches bordered by EBC. Although we did not see ecological effects extending to stream salmonids, reduced terrestrial prey subsidies to streams are likely to have negative consequences as EBC continues to spread.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO 2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM) and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM] +) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF 6 or TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi 2O 3) and metallic bismuth (Bi 0), and that the reduction of oxidized bismuth speciesmore » to Bi 0 is fully achieved under potentials at which CO 2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO 2 reduction near -1.75 V vs. Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM] + solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs. Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO 2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. By contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO 2 reduction. In conclusion, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM] + based electrolytes, including the reduction of bismuth oxide to bismuth metal, changes in roughness and near-surface viscosity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM), and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM]+) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF6 and TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi2O3) and metallic bismuth (Bi0) and that the reduction of oxidized bismuth species to Bi0 is fully achieved undermore » potentials at which CO2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO2 reduction near -1.75 V vs Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM]+ solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates that extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. In contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO2 reduction. Overall, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM]+-based electrolytes, including the reduction of bismuth oxide to bismuth metal and changes in roughness and near-surface viscosity.« less

Screening for Sleep Reduction in Adolescents through Self-Report: Development and Validation of the Sleep Reduction Screening Questionnaire (SRSQ)

ERIC Educational Resources Information Center

Maanen, Annette; Dewald-Kaufmann, Julia F.; Oort, Frans J.; de Bruin, Eduard J.; Smits, Marcel G.; Short, Michelle A.; Gradisar, Michael; Kerkhof, Gerard A.; Meijer, Anne Marie

2014-01-01

Background: Sleep reduction, resulting from insufficient or poor sleep, is a common phenomenon in adolescents. Due to its severe negative psychological and behavioral daytime consequences, it is important to have a short reliable and valid measure to assess symptoms of sleep reduction. Objective: This study aims to validate the Sleep Reduction…

ERP correlates of unexpected word forms in a picture–word study of infants and adults

PubMed Central

Duta, M.D.; Styles, S.J.; Plunkett, K.

2012-01-01

We tested 14-month-olds and adults in an event-related potentials (ERPs) study in which pictures of familiar objects generated expectations about upcoming word forms. Expected word forms labelled the picture (word condition), while unexpected word forms mismatched by either a small deviation in word medial vowel height (mispronunciation condition) or a large deviation from the onset of the first speech segment (pseudoword condition). Both infants and adults showed sensitivity to both types of unexpected word form. Adults showed a chain of discrete effects: positivity over the N1 wave, negativity over the P2 wave (PMN effect) and negativity over the N2 wave (N400 effect). Infants showed a similar pattern, including a robust effect similar to the adult P2 effect. These observations were underpinned by a novel visualisation method which shows the dynamics of the ERP within bands of the scalp over time. The results demonstrate shared processing mechanisms across development, as even subtle deviations from expected word forms were indexed in both age groups by a reduction in the amplitude of characteristic waves in the early auditory evoked potential. PMID:22483072

Atorvastatin affects negatively respiratory function of isolated endothelial mitochondria.

PubMed

Broniarek, Izabela; Jarmuszkiewicz, Wieslawa

2018-01-01

The purpose of this research was to elucidate the direct effects of two popular blood cholesterol-lowering drugs used to treat cardiovascular diseases, atorvastatin and pravastatin, on respiratory function, membrane potential, and reactive oxygen species formation in mitochondria isolated from human umbilical vein endothelial cells (EA.hy926 cell line). Hydrophilic pravastatin did not significantly affect endothelial mitochondria function. In contrast, hydrophobic calcium-containing atorvastatin induced a loss of outer mitochondrial membrane integrity, an increase in hydrogen peroxide formation, and reductions in maximal (phosphorylating or uncoupled) respiratory rate, membrane potential and oxidative phosphorylation efficiency. The atorvastatin-induced changes indicate an impairment of mitochondrial function at the level of ATP synthesis and at the level of the respiratory chain, likely at complex I and complex III. The atorvastatin action on endothelial mitochondria was highly dependent on calcium ions and led to a disturbance in mitochondrial calcium homeostasis. Uptake of calcium ions included in atorvastatin molecule induced mitochondrial uncoupling that enhanced the inhibition of the mitochondrial respiratory chain by atorvastatin. Our results indicate that hydrophobic calcium-containing atorvastatin, widely used as anti-atherosclerotic agent, has a direct negative action on isolated endothelial mitochondria. Copyright © 2017. Published by Elsevier Inc.

Food-grade antimicrobials potentiate the antibacterial activity of 1,2-hexanediol.

PubMed

Yogiara; Hwang, S J; Park, S; Hwang, J-K; Pan, J-G

2015-05-01

Preservative agents determining the shelf life of cosmetic products must have effective antimicrobial activity while meeting safety requirements for topical use. In this study, we determined the antimicrobial activity of 1,2-hexanediol against several Gram-positive and Gram-negative bacteria. Antimicrobial susceptibility tests have shown that 1,2-hexanediol exhibits broad-spectrum activity against Gram-positive and Gram-negative bacteria with MICs of 0·5-2% (v/v). The bactericidal concentration of 1,2-hexanediol was ranging from 1 to 2 × MIC as demonstrated by time-kill curve assay. A membrane depolarization assay showed that 1,2-hexanediol disrupted the cytoplasmic membrane potential. A checkerboard assay indicated that the effective concentration of 1,2-hexanediol was reduced up to 0·25-0·5 × MIC when combined with macelignan and octyl gallate against Gram-positive bacteria. However, this combination was not effective against Gram-negative bacteria. A turbidity reduction assay demonstrated that the combination of a high concentration of 1,2-hexanediol with food-grade antimicrobial compounds could trigger lytic activity towards Bacillus cereus cells. The remaining cell turbidity was 24·6 and 22·2% when 2% of 1,2-hexanediol was combined with 8 mg l(-1) octyl gallate or with 32 mg l(-1) macelignan respectively. This study showed that food-grade antimicrobial compounds may be used in combination with 1,2-hexanediol to increase its efficacy as a preservative agent in cosmetics. The antimicrobial activity of 1,2-hexanediol against Gram-positive and Gram-negative bacteria was potentiated with food-grade antimicrobials including xanthorrhizol, macelignan, panduratin A and octyl gallate, which have already been reported to display anti-inflammatory and other beneficial activities related to cosmetics. Therefore, the combination of 1,2-hexanediol and these food-grade antimicrobial agents would have benefits not only for increasing the antimicrobial activity but also in cosmetics use. © 2015 The Society for Applied Microbiology.

Oxidation-reduction potential and lipid oxidation in ready-to-eat blue mussels in red sauce: criteria for package design.

PubMed

Bhunia, Kanishka; Ovissipour, Mahmoudreza; Rasco, Barbara; Tang, Juming; Sablani, Shyam S

2017-01-01

Ready-to-eat in-package pasteurized blue mussels in red sauce requires refrigerated storage or in combination with an aerobic environment to prevent the growth of anaerobes. A low barrier packaging may create an aerobic environment; however, it causes lipid oxidation in mussels. Thus, evaluation of the oxidation-reduction potential (Eh) (aerobic/anaerobic nature of food) and lipid oxidation is essential. Three packaging materials with oxygen transmission rate (OTR) of 62 (F-62), 40 (F-40) and 3 (F-3) cm 3 m -2 day -1 were selected for this study. Lipid oxidation was measured by color changes in thiobarbituric acid reactive substances (TBARS) at 532 nm (TBARS@532) and 450 nm (TBARS@450). Significantly higher (P < 0.05) TBARS@532 was found in mussels packaged in higher OTR film. TBARS@450 in mussels packaged with F-62 and F-40 gradually increased during refrigerated storage (3.5 ± 0.5 °C), but remained constant after 20 days of storage for mussels packaged with F-3. The Eh of pasteurized sauce was not significantly affected (P > 0.05) by OTR and remained negative (< -80 mV) during storage. Negative Eh values can support the growth of anaerobes such as Clostridium botulinum. The headspace oxygen concentration was reduced by about 50% from its initial value during pasteurization, and then further declined during storage. The headspace oxygen concentration was higher in trays packaged with higher OTR film. Mussels packed with high OTR film showed higher lipid oxidation, indicating that high barrier film is required for packaging of mussels. Pasteurized mussels must be kept in refrigerated storage to prevent growth of anaerobic proteolytic C. botulinum spores under temperature abuse. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Silibinin negatively contributes to primary cilia length via autophagy regulated by histone deacetylase 6 in confluent mouse embryo fibroblast 3T3-L1 cells.

PubMed

Xu, Qian; Liu, Wei; Liu, Xiaoling; Liu, Weiwei; Wang, Hongju; Yao, Guodong; Zang, Linghe; Hayashi, Toshihiko; Tashiro, Shin-Ichi; Onodera, Satoshi; Ikejima, Takashi

2016-09-01

Primary cilium is a cellular antenna, signalling as a sensory organelle. Numerous pathological manifestation is associated with change of its length. Although the interaction between autophagy and primary cilia has been suggested, the role of autophagy in primary cilia length is largely unknown. In this study the primary cilia were immunostained and observed by using confocal fluorescence microscopy, and we found that silibinin, a natural flavonoid, shortened the length of primary cilia, meanwhile it also induced autophagy in 3T3-L1 cells. This study was designed to investigate the significance of silibinin-induced autophagy in primary ciliary structure in confluent mouse embryo fibroblast 3T3-L1 cells. Either blocking the autophagic flux with pre-treatment with the autophagy inhibitor, 3-methyladenine (3-MA), or transfection of siRNA targeting LC3 inhibited the reduction of cilia length caused by silibinin exposure. Autophagy induced by silibinin decreased expressions of the cilia-associated proteins, such as IFT88, KIF3a and Ac-tubulin, while 3-MA restored it, indicating that autophagy induced by silibinin led to a reduction of primary cilia length. Histone deacetylase 6 (HDAC6), which was suggested as a mediator of autophagy, was up-regulated by silibinin in a time-dependent manner. In addition, 3T3-L1 cells treated with siRNA against HDAC6 had a reduced autophagic level and were protected from silibinin-induced cilia shortening. Taken together, we conclude that the HDAC6-mediated autophagy negatively regulates primary cilia length during silibinin treatment and has the potential to serve as a therapeutic target for primary cilia-associated ciliopathies. These findings thus provide new information about the potential link between autophagy and primary cilia.

40 CFR 57.816 - Effect of negative recommendation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Effect of negative recommendation. 57... Reduction Technology § 57.816 Effect of negative recommendation. No waiver of the interim requirement for... or a State first takes into account the Administrator's report, findings, and recommendations as to...

Effect of Two Advanced Noise Reduction Technologies on the Aerodynamic Performance of an Ultra High Bypass Ratio Fan

NASA Technical Reports Server (NTRS)

Hughes, Christoper E.; Gazzaniga, John A.

2013-01-01

A wind tunnel experiment was conducted in the NASA Glenn Research Center anechoic 9- by 15-Foot Low-Speed Wind Tunnel to investigate two new advanced noise reduction technologies in support of the NASA Fundamental Aeronautics Program Subsonic Fixed Wing Project. The goal of the experiment was to demonstrate the noise reduction potential and effect on fan model performance of the two noise reduction technologies in a scale model Ultra-High Bypass turbofan at simulated takeoff and approach aircraft flight speeds. The two novel noise reduction technologies are called Over-the-Rotor acoustic treatment and Soft Vanes. Both technologies were aimed at modifying the local noise source mechanisms of the fan tip vortex/fan case interaction and the rotor wake-stator interaction. For the Over-the-Rotor acoustic treatment, two noise reduction configurations were investigated. The results showed that the two noise reduction technologies, Over-the-Rotor and Soft Vanes, were able to reduce the noise level of the fan model, but the Over-the-Rotor configurations had a significant negative impact on the fan aerodynamic performance; the loss in fan aerodynamic efficiency was between 2.75 to 8.75 percent, depending on configuration, compared to the conventional solid baseline fan case rubstrip also tested. Performance results with the Soft Vanes showed that there was no measurable change in the corrected fan thrust and a 1.8 percent loss in corrected stator vane thrust, which resulted in a total net thrust loss of approximately 0.5 percent compared with the baseline reference stator vane set.

Structural Dynamics and Evolution of Bismuth Electrodes during Electrochemical Reduction of CO 2 in Imidazolium-Based Ionic Liquid Solutions

DOE PAGES

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.; ...

2017-09-12

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO 2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM) and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM] +) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF 6 or TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi 2O 3) and metallic bismuth (Bi 0), and that the reduction of oxidized bismuth speciesmore » to Bi 0 is fully achieved under potentials at which CO 2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO 2 reduction near -1.75 V vs. Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM] + solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs. Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO 2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. By contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO 2 reduction. In conclusion, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM] + based electrolytes, including the reduction of bismuth oxide to bismuth metal, changes in roughness and near-surface viscosity.« less

Degradation of net primary production in a semiarid rangeland

NASA Astrophysics Data System (ADS)

Jackson, Hasan; Prince, Stephen D.

2016-08-01

Anthropogenic land degradation affects many biogeophysical processes, including reductions of net primary production (NPP). Degradation occurs at scales from small fields to continental and global. While measurement and monitoring of NPP in small areas is routine in some studies, for scales larger than 1 km2, and certainly global, there is no regular monitoring and certainly no attempt to measure degradation. Quantitative and repeatable techniques to assess the extent of deleterious effects and monitor changes are needed to evaluate its effects on, for example, economic yields of primary products such as crops, lumber, and forage, and as a measure of land surface properties which are currently missing from dynamic global vegetation models, assessments of carbon sequestration, and land surface models of heat, water, and carbon exchanges. This study employed the local NPP scaling (LNS) approach to identify patterns of anthropogenic degradation of NPP in the Burdekin Dry Tropics (BDT) region of Queensland, Australia, from 2000 to 2013. The method starts with land classification based on the environmental factors presumed to control (NPP) to group pixels having similar potential NPP. Then, satellite remotely sensing data were used to compare actual NPP with its potential. The difference in units of mass of carbon and percentage loss were the measure of degradation. The entire BDT (7.45 × 106 km2) was investigated at a spatial resolution of 250 × 250 m. The average annual reduction in NPP due to anthropogenic land degradation in the entire BDT was -2.14 MgC m-2 yr-1, or 17 % of the non-degraded potential, and the total reduction was -214 MgC yr-1. Extreme average annual losses of 524.8 gC m-2 yr-1 were detected. Approximately 20 % of the BDT was classified as "degraded". Varying severities and rates of degradation were found among the river basins, of which the Belyando and Suttor were highest. Interannual, negative trends in reductions of NPP occurred in 7 % of the entire region, indicating ongoing degradation. There was evidence of areas that were in a permanently degraded condition. The findings provide strong evidence and quantitative data for reductions in NPP related to anthropogenic land degradation in the BDT.

Present and future ecological niche modeling of garter snake species from the Trans-Mexican Volcanic Belt

PubMed Central

García-Vázquez, Uri; D’Addario, Maristella

2018-01-01

Land use and climate change are affecting the abundance and distribution of species. The Trans-Mexican Volcanic Belt (TMVB) is a very diverse region due to geological history, geographic position, and climate. It is also one of the most disturbed regions in Mexico. Reptiles are particularly sensitive to environmental changes due to their low dispersal capacity and thermal ecology. In this study, we define the important environmental variables (considering climate, topography, and land use) and potential distribution (present and future) of the five Thamnophis species present in TMVB. To do so, we used the maximum entropy modeling software (MAXENT). First, we modeled to select the most important variables to explain the distribution of each species, then we modeled again using only the most important variables and projected these models to the future considering a middle-moderate climate change scenario (rcp45), and land use and vegetation variables for the year 2050 (generated according to land use changes that occurred between years 2002 and 2011). Arid vegetation had an important negative effect on habitat suitability for all species, and minimum temperature of the coldest month was important for four of the five species. Thamnophis cyrtopsis was the species with the lowest tolerance to minimum temperatures. The maximum temperature of the warmest month was important for T. scalaris and T. cyrtopsis. Low percentages of agriculture were positive for T. eques and T. melanogaster but, at higher values, agriculture had a negative effect on habitat suitability for both species. Elevation was the most important variable to explain T. eques and T. melanogaster potential distribution while distance to Abies forests was the most important variable for T. scalaris and T. scaliger. All species had a high proportion of their potential distribution in the TMVB. However, according to our models, all Thamnophis species will experience reductions in their potential distribution in this region. T. scalaris will suffer the biggest reduction because this species is limited by high temperatures and will not be able to shift its distribution upward, as it is already present in the highest elevations of the TMVB. PMID:29666767

Electrolytic trichloroethene degradation using mixed metal oxide coated titanium mesh electrodes.

PubMed

Petersen, Matthew A; Sale, Thomas C; Reardon, Kenneth F

2007-04-01

Electrochemical systems provide a low cost, versatile, and controllable platform to potentially treat contaminants in water, including chlorinated solvents. Relative to bare metal or noble metal amended materials, dimensionally stable electrode materials such as mixed metal oxide coated titanium (Ti/MMO) have advantages in terms of stability and cost, important factors for sustainable remediation solutions. Here, we report the use of Ti/MMO as an effective cathode substrate for treatment of trichloroethene (TCE). TCE degradation in a batch reactor was measured as the decrease of TCE concentration over time and the corresponding evolution of chloride; notably, this occurred without the formation of commonly encountered chlorinated intermediates. The reaction was initiated when Ti/MMO cathode potentials were less than -0.8 V vs. the standard hydrogen electrode, and the rate of TCE degradation increased linearly with progressively more negative potentials. The maximum pseudo-first-order heterogeneous rate constant was approximately 0.05 cm min(-1), which is comparable to more commonly used cathode materials such as nickel. In laboratory-scale flow-though column reactors designed to simulate permeable reactive barriers (PRBs), TCE concentrations were reduced by 80-90%. The extent of TCE flux reduction increased with the applied potential difference across the electrodes and was largely insensitive to the spacing distance between the electrodes. This is the first report of the electrochemical reduction of a chlorinated organic contaminant at a Ti/MMO cathode, and these results support the use of this material in PRBs as a possible approach to manage TCE plume migration.

40 CFR 62.3854 - Identification of plan-negative declaration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.3854 Identification of plan—negative declaration. Letter from the Iowa Department of Water, Air and Waste Management submitted on May...

40 CFR 62.3854 - Identification of plan-negative declaration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.3854 Identification of plan—negative declaration. Letter from the Iowa Department of Water, Air and Waste Management submitted on May...

40 CFR 62.3854 - Identification of plan-negative declaration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.3854 Identification of plan—negative declaration. Letter from the Iowa Department of Water, Air and Waste Management submitted on May...

40 CFR 62.3854 - Identification of plan-negative declaration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.3854 Identification of plan—negative declaration. Letter from the Iowa Department of Water, Air and Waste Management submitted on May...

40 CFR 62.3854 - Identification of plan-negative declaration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.3854 Identification of plan—negative declaration. Letter from the Iowa Department of Water, Air and Waste Management submitted on May...

Volume reduction of benign thyroid nodules 3 months after a single treatment with high-intensity focused ultrasound (HIFU).

PubMed

Korkusuz, Huedayi; Fehre, Niklas; Sennert, Michael; Happel, Christian; Grünwald, Frank

2015-01-01

High-intensity focused ultrasound (HIFU) is a promising, non-invasive technique in treating benign thyroid nodules (TNs). The aim of this study was to evaluate the efficacy of HIFU to induce clinically meaningful shrinkage in benign predominantly solid TNs and to identify variables that influence or predict the magnitude of TN volume reduction. For each of ten subjects, HIFU treatment was conducted on a single nodule. Nodular volume was measured sonographically at baseline and at 3 months post-procedure. Nodular function and early treatment assessment was done scintigraphically. Median nodular volume reduction was 0.7 ml absolute and 48.8% relative to pre-interventional size (p < 0.05). Absolute shrinkage was negatively correlated with the average treatment depth (τ = -0.61, p < 0.05). Absolute nodular volume was positively correlated with the scintigraphic nodular uptake reduction (τ = 0.66, p < 0.05). HIFU treatment of benign predominantly solid TNs appears to be safe and effective for inducing nodular shrinkage. Despite potential for improvement, a single treatment session with HIFU is already a viable alternative to more standard methods. The feasibility of multiple HIFU treatments requires further investigation. Due to the small sample size, the findings of this analysis need conformation by larger studies.

Impacts of aerosol pollutant mitigation on lowland rice yields in China

NASA Astrophysics Data System (ADS)

Zhang, Tianyi; Li, Tao; Yue, Xu; Yang, Xiaoguang

2017-10-01

Aerosol pollution in China is significantly altering radiative transfer processes and is thereby potentially affecting rice photosynthesis and yields. However, the response of rice photosynthesis to aerosol-induced radiative perturbations is still not well understood. Here, we employ a process-based modelling approach to simulate changes in incoming radiation (RAD) and the diffuse radiation fraction (DF) with aerosol mitigation in China and their associated impacts on rice yields. Aerosol reduction has the positive effect of increasing RAD and the negative effect of decreasing DF on rice photosynthesis and yields. In rice production areas where the average RAD during the growing season is lower than 250 W m-2, aerosol reduction is beneficial for higher rice yields, whereas in areas with RAD>250 W m-2, aerosol mitigation causes yield declines due to the associated reduction in the DF, which decreases the light use efficiency. As a net effect, rice yields were estimated to significantly increase by 0.8%-2.6% with aerosol concentrations reductions from 20 to 100%, which is lower than the estimates obtained in earlier studies that only considered the effects of RAD. This finding suggests that both RAD and DF are important processes influencing rice yields and should be incorporated into future assessments of agricultural responses to variations in aerosol-induced radiation under climate change.

Use of simulation tools to illustrate the effect of data management practices for low and negative plate counts on the estimated parameters of microbial reduction models.

PubMed

Garcés-Vega, Francisco; Marks, Bradley P

2014-08-01

In the last 20 years, the use of microbial reduction models has expanded significantly, including inactivation (linear and nonlinear), survival, and transfer models. However, a major constraint for model development is the impossibility to directly quantify the number of viable microorganisms below the limit of detection (LOD) for a given study. Different approaches have been used to manage this challenge, including ignoring negative plate counts, using statistical estimations, or applying data transformations. Our objective was to illustrate and quantify the effect of negative plate count data management approaches on parameter estimation for microbial reduction models. Because it is impossible to obtain accurate plate counts below the LOD, we performed simulated experiments to generate synthetic data for both log-linear and Weibull-type microbial reductions. We then applied five different, previously reported data management practices and fit log-linear and Weibull models to the resulting data. The results indicated a significant effect (α = 0.05) of the data management practices on the estimated model parameters and performance indicators. For example, when the negative plate counts were replaced by the LOD for log-linear data sets, the slope of the subsequent log-linear model was, on average, 22% smaller than for the original data, the resulting model underpredicted lethality by up to 2.0 log, and the Weibull model was erroneously selected as the most likely correct model for those data. The results demonstrate that it is important to explicitly report LODs and related data management protocols, which can significantly affect model results, interpretation, and utility. Ultimately, we recommend using only the positive plate counts to estimate model parameters for microbial reduction curves and avoiding any data value substitutions or transformations when managing negative plate counts to yield the most accurate model parameters.

Benefits of positive relationship experiences for avoidantly attached individuals.

PubMed

Stanton, Sarah C E; Campbell, Lorne; Pink, Jennifer C

2017-10-01

Attachment avoidance is characterized by discomfort with closeness and a reluctance to develop intimacy with romantic partners, which contribute to heightened general negativity and lower satisfaction and self-disclosure in and out of their relationships. Recent research, however, has begun to uncover circumstances in which romantic partners and positive relationships buffer more avoidantly attached individuals against deleterious individual and relationship outcomes. Across 3 studies, using a multimethod approach encompassing both experimental and dyadic longitudinal diary methods, we investigated the effects of positive, intimacy-related relationship experiences on more avoidant persons' positive and negative affect, relationship quality, self-disclosure, and attachment security immediately and over time. Results revealed that more avoidant individuals exhibit a reduction of general negative affect in particular (Studies 1-2) and report greater relationship quality (Studies 2-3) in response to positive relationship experiences, and, following intimacy-promoting activities with their partner, engage in greater self-disclosure over time and demonstrate decreased attachment avoidance 1 month later (Study 3). These findings identify novel circumstances in which more avoidant persons' negative expectations of relationships may be countered, and suggest that relatively simple techniques can have potentially important short- and long-term implications for more avoidant individuals and their relationships. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

CO2 electroreduction characteristics of Pt-Ru/C powder and Pt-Ru sputtered electrodes under acidic condition

NASA Astrophysics Data System (ADS)

Furukawa, Hiroto; Matsuda, Shofu; Tanaka, Shoji; Shironita, Sayoko; Umeda, Minoru

2018-03-01

The objective of this study was to overcome the issue about the underpotential adsorption of the CO2 electroreductant on the surface of the Pt electrocatalyst under acidic conditions by the alloying of Pt and Ru. As evaluation parameters, the CO2 reduction onset potential and CO2-reductant reoxidation onset potential were employed. We prepared a porous microelectrode filled with Pt-Ru/C powder and a Pt-Ru sputtered electrode. For the Pt-Ru/C powder electrocatalyst, the CO2 reduction onset potential as well as the CO2-reductant reoxidation onset potential shifted in the direction of the CO2/CO2-reductant standard redox potential dependent on the Ru content, which is indicative of a decrease in the underpotential-adsorption energy of the CO2 reductant. For the Pt-Ru sputtered electrode, only the CO2 reduction onset potential shifted in the direction of the redox potential. Consequently, we demonstrated that the Pt-Ru/C powder electrode improved the reactivity of the CO2/CO2-reductant when discussing the relationship between the CO2 reduction onset potential and the CO2-reductant reoxidation onset potential. Based on our findings, the Pt-Ru/C (1:9) powder is the most effective electrocatalyst for the CO2 reduction, which could minimize the underpotential adsorption.

Study of mechanism of stress-induced threshold voltage shift and recovery in top-gate amorphous-InGaZnO4 thin-film transistors with source- and drain-offsets

NASA Astrophysics Data System (ADS)

Mativenga, Mallory; Kang, Dong Han; Lee, Ung Gi; Jang, Jin

2012-09-01

Bias instability of top-gate amorphous-indium-gallium-zinc-oxide thin-film transistors with source- and drain-offsets is reported. Positive and negative gate bias-stress (VG_STRESS) respectively induce reversible negative threshold-voltage shift (ΔVTH) and reduction in on-current. Migration of positive charges towards the offsets lowers the local resistance of the offsets, resulting in the abnormal negative ΔVTH under positive VG_STRESS. The reduction in on-current under negative VG_STRESS is due to increase in resistance of the offsets when positive charges migrate away from the offsets. Appropriate drain and source bias-stresses applied simultaneously with VG_STRESS either suppress or enhance the instability, verifying lateral ion migration to be the instability mechanism.

Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

PubMed

Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

2011-01-01

Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

A consumer-based approach to salt reduction: Case study with bread.

PubMed

Antúnez, Lucía; Giménez, Ana; Ares, Gastón

2016-12-01

In recent years high sodium intake has raised growing concern worldwide. A widespread reduction of salt concentration in processed foods has been claimed as one of the most effective strategies to achieve a short-term impact on global health. However, one of the major challenges in reducing salt in food products is its potential negative impact on consumer perception. For this reason, gradual salt reduction has been recommended. In this context, the aim of the present work was to present a consumer-based approach to salt reduction, using bread as case study. Two consumer studies with a total of 303 consumers were carried out. In the first study, four sequential difference thresholds were determined through paired-comparison tests, starting at a salt concentration of 2%. In the second study, 99 consumers performed a two-bite evaluation of their sensory and hedonic perception of five bread samples: a control bread containing 2% salt and four samples with reduced salt content according to the difference thresholds determined in the first study. Survival analysis was used to determine average difference thresholds, which ranged from 9.4% to 14.3% of the salt concentration of the control bread. Results showed that salt concentration significantly influenced consumer overall liking of the bread samples. However, large heterogeneity was found in consumer hedonic reaction towards salt reduction: two groups of consumers with different preference and hedonic sensitivity to salt reduction were found. Results from the present work confirm that cumulative series of small salt reductions may be a feasible strategy for reducing the sodium content of bread without affecting consumer hedonic perception and stress the importance of considering consumer perception in the design of gradual salt reduction programmes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can Advances in Science and Technology Prevent Global Warming? A Critical Review of Limitations and Challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.

The most stringent emission scenarios published by the Intergovernmental Panel on Climate Change (IPCC) would result in the stabilization of atmospheric carbon dioxide (CO2) at concentrations of approximately 550 ppm which would produce a global temperature increase of at least 2 C by 2100. Given the large uncertainties regarding the potential risks associated with this degree of global warming, it would be more prudent to stabilize atmospheric CO2 concentrations at or below current levels which, in turn, would require a greater than 20-fold reduction (i.e., ?95%) in per capita carbon emissions in industrialized nations within the next 50 to 100more » years. Using the Kaya equation as a conceptual framework, this paper examines whether CO2 mitigation approaches such as energy efficiency improvements, carbon sequestration, and the development of carbon-free energy sources would be sufficient to bring about the required reduction in per capita carbon emissions without creating unforeseen negative impacts elsewhere. In terms of energy efficiency, large improvements (?5-fold) are in principle possible given aggressive investments in R&D and if market imperfections such as corporate subsidies are removed. However, energy efficiency improvements per se will not result in a reduction in carbon emissions if, as predicted by the IPCC, the size of the global economy has expanded 12-26 fold by 2100. Terrestrial carbon sequestration via reforestation and improved agricultural soil management has many environmental advantages but has only limited CO2 mitigation potential because the global terrestrial carbon sink (ca. 200 Gt C) is small relative to the size of fossil fuel deposits (?4000 Gt C). By contrast, very large amounts of CO2 can potentially be removed from the atmosphere via sequestration in geologic formations and oceans, but carbon storage is not permanent and is likely to create many unpredictable environmental consequences. Renewable solar energy can in theory provide large amounts of carbon-free power. However, biomass and hydroelectric energy can only be marginally expanded and large-scale solar energy installations (i.e., wind, photovoltaics, and direct thermal) are likely to have significant negative environmental impacts. Expansion of nuclear energy is highly unlikely due to concerns over reactor safety, radioactive waste management, weapons proliferation, and cost. In view of the serious limitations and liabilities of many proposed CO2 mitigation approaches it appears that there remain only few no-regrets options such as drastic energy efficiency improvements, extensive terrestrial carbon sequestration, and cautious expansion of renewable energy generation. These promising CO2 mitigation technologies have the potential to bring about the required 20-fold reduction in per capita carbon emission only if population and economic growth are halted without delay. Thus, addressing the problem of global warming requires not only technological research and development but also a reexamination of core values that mistakenly equate material consumption and economic growth to happiness and well-being.« less

Calcitriol restores antiestrogen responsiveness in estrogen receptor negative breast cancer cells: a potential new therapeutic approach.

PubMed

Santos-Martínez, Nancy; Díaz, Lorenza; Ordaz-Rosado, David; García-Quiroz, Janice; Barrera, David; Avila, Euclides; Halhali, Ali; Medina-Franco, Heriberto; Ibarra-Sánchez, María J; Esparza-López, José; Camacho, Javier; Larrea, Fernando; García-Becerra, Rocío

2014-03-29

Approximately 30% of breast tumors do not express the estrogen receptor (ER) α, which is necessary for endocrine therapy approaches. Studies are ongoing in order to restore ERα expression in ERα-negative breast cancer. The aim of the present study was to determine if calcitriol induces ERα expression in ER-negative breast cancer cells, thus restoring antiestrogen responses. Cultured cells derived from ERα-negative breast tumors and an ERα-negative breast cancer cell line (SUM-229PE) were treated with calcitriol and ERα expression was assessed by real time PCR and western blots. The ERα functionality was evaluated by prolactin gene expression analysis. In addition, the effects of antiestrogens were assessed by growth assay using the XTT method. Gene expression of cyclin D1 (CCND1), and Ether-à-go-go 1 (EAG1) was also evaluated in cells treated with calcitriol alone or in combination with estradiol or ICI-182,780. Statistical analyses were determined by one-way ANOVA. Calcitriol was able to induce the expression of a functional ERα in ER-negative breast cancer cells. This effect was mediated through the vitamin D receptor (VDR), since it was abrogated by a VDR antagonist. Interestingly, the calcitriol-induced ERα restored the response to antiestrogens by inhibiting cell proliferation. In addition, calcitriol-treated cells in the presence of ICI-182,780 resulted in a significant reduction of two important cell proliferation regulators CCND1 and EAG1. Calcitriol induced the expression of ERα and restored the response to antiestrogens in ERα-negative breast cancer cells. The combined treatment with calcitriol and antiestrogens could represent a new therapeutic strategy in ERα-negative breast cancer patients.

Water displacement leg volumetry in clinical studies - A discussion of error sources

PubMed Central

2010-01-01

Background Water displacement leg volumetry is a highly reproducible method, allowing the confirmation of efficacy of vasoactive substances. Nevertheless errors of its execution and the selection of unsuitable patients are likely to negatively affect the outcome of clinical studies in chronic venous insufficiency (CVI). Discussion Placebo controlled double-blind drug studies in CVI were searched (Cochrane Review 2005, MedLine Search until December 2007) and assessed with regard to efficacy (volume reduction of the leg), patient characteristics, and potential methodological error sources. Almost every second study reported only small drug effects (≤ 30 mL volume reduction). As the most relevant error source the conduct of volumetry was identified. Because the practical use of available equipment varies, volume differences of more than 300 mL - which is a multifold of a potential treatment effect - have been reported between consecutive measurements. Other potential error sources were insufficient patient guidance or difficulties with the transition from the Widmer CVI classification to the CEAP (Clinical Etiological Anatomical Pathophysiological) grading. Summary Patients should be properly diagnosed with CVI and selected for stable oedema and further clinical symptoms relevant for the specific study. Centres require a thorough training on the use of the volumeter and on patient guidance. Volumetry should be performed under constant conditions. The reproducibility of short term repeat measurements has to be ensured. PMID:20070899

Policing in nonhuman primates: partial interventions serve a prosocial conflict management function in rhesus macaques.

PubMed

Beisner, Brianne A; McCowan, Brenda

2013-01-01

Studies of prosocial policing in nonhuman societies traditionally focus on impartial interventions because of an underlying assumption that partial support implies a direct benefit to the intervener, thereby negating the potential for being prosocial in maintaining social stability for the benefit of the group. However, certain types of partial interventions have significant potential to be prosocial in controlling conflict, e.g. support of non-kin subordinates. Here, we propose a policing support hypothesis that some types of agonistic support serve a prosocial policing function that maintains group stability. Using seven large captive groups of rhesus macaques, we investigated the relationship between intervention type and group-level costs and benefits (rates of trauma, severe aggression, social relocation) and individual level costs and benefits (preferential sex-dyad targeting, dominance ambiguity reduction, access to mates, and return aggression). Our results show that impartial interventions and support of subordinate non-kin represent prosocial policing as both (1) were negatively associated with group-level rates of trauma and severe aggression, respectively, (2) showed no potential to confer individual dominance benefits, (3) when performed outside the mating season, they did not increase chances of mating with the beneficiary, and (4) were low-cost for the highest-ranking interveners. We recommend expanding the definition of 'policing' in nonhumans to include these 'policing support interventions'.

Conditional suicide system of Escherichia coli released into soil that uses the Bacillus subtilis sacB gene.

PubMed Central

Recorbet, G; Robert, C; Givaudan, A; Kudla, B; Normand, P; Faurie, G

1993-01-01

The sacB gene from Bacillus subtilis confers sucrose sensitivity upon gram-negative bacteria. The gene was investigated for use as a potential conditional suicide system for Escherichia coli released into soil. To ensure against the loss of the cell death function encoded under nonselective conditions, the nptI-sacR-B suicide cassette was inserted into the E. coli chromosome by using a circular nonreplicative integration vector. Stability studies yielded no loss of the suicide cassette in the integrated E. coli EL1026 strain. sacB induction in the absence of a selective pressure resulted in a lysis efficiency of up to 99.9%. The microcosm experiments confirmed the ability of the suicide cassette to limit the growth and reduce the survival of E. coli strains released into soil. Sucrose addition to sterile soil resulted in a 10(-3)-fold reduction of the final E. coli population density. sacB induction prevented the proliferation and triggered the rapid disappearance of E. coli from natural soil. Mutation to sucrose tolerance occurred at a frequency of 10(-5), making E. coli EL1026 a potential counterselectable donor strain for gene transfer studies. Specificity and potential adaptability to a wide range of gram-negative bacteria are additional conveniences of this conditional suicide system for the containment and counterselection of engineered microorganisms. PMID:8517732

Conditional suicide system of Escherichia coli released into soil that uses the Bacillus subtilis sacB gene.

PubMed

Recorbet, G; Robert, C; Givaudan, A; Kudla, B; Normand, P; Faurie, G

1993-05-01

The sacB gene from Bacillus subtilis confers sucrose sensitivity upon gram-negative bacteria. The gene was investigated for use as a potential conditional suicide system for Escherichia coli released into soil. To ensure against the loss of the cell death function encoded under nonselective conditions, the nptI-sacR-B suicide cassette was inserted into the E. coli chromosome by using a circular nonreplicative integration vector. Stability studies yielded no loss of the suicide cassette in the integrated E. coli EL1026 strain. sacB induction in the absence of a selective pressure resulted in a lysis efficiency of up to 99.9%. The microcosm experiments confirmed the ability of the suicide cassette to limit the growth and reduce the survival of E. coli strains released into soil. Sucrose addition to sterile soil resulted in a 10(-3)-fold reduction of the final E. coli population density. sacB induction prevented the proliferation and triggered the rapid disappearance of E. coli from natural soil. Mutation to sucrose tolerance occurred at a frequency of 10(-5), making E. coli EL1026 a potential counterselectable donor strain for gene transfer studies. Specificity and potential adaptability to a wide range of gram-negative bacteria are additional conveniences of this conditional suicide system for the containment and counterselection of engineered microorganisms.

Global reductions in seafloor biomass in response to climate change.

PubMed

Jones, Daniel O B; Yool, Andrew; Wei, Chih-Lin; Henson, Stephanie A; Ruhl, Henry A; Watson, Reg A; Gehlen, Marion

2014-06-01

Seafloor organisms are vital for healthy marine ecosystems, contributing to elemental cycling, benthic remineralization, and ultimately sequestration of carbon. Deep-sea life is primarily reliant on the export flux of particulate organic carbon from the surface ocean for food, but most ocean biogeochemistry models predict global decreases in export flux resulting from 21st century anthropogenically induced warming. Here we show that decadal-to-century scale changes in carbon export associated with climate change lead to an estimated 5.2% decrease in future (2091-2100) global open ocean benthic biomass under RCP8.5 (reduction of 5.2 Mt C) compared with contemporary conditions (2006-2015). Our projections use multi-model mean export flux estimates from eight fully coupled earth system models, which contributed to the Coupled Model Intercomparison Project Phase 5, that have been forced by high and low representative concentration pathways (RCP8.5 and 4.5, respectively). These export flux estimates are used in conjunction with published empirical relationships to predict changes in benthic biomass. The polar oceans and some upwelling areas may experience increases in benthic biomass, but most other regions show decreases, with up to 38% reductions in parts of the northeast Atlantic. Our analysis projects a future ocean with smaller sized infaunal benthos, potentially reducing energy transfer rates though benthic multicellular food webs. More than 80% of potential deep-water biodiversity hotspots known around the world, including canyons, seamounts, and cold-water coral reefs, are projected to experience negative changes in biomass. These major reductions in biomass may lead to widespread change in benthic ecosystems and the functions and services they provide. © 2013 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Detection of CO2•- in the Electrochemical Reduction of Carbon Dioxide in N,N-Dimethylformamide by Scanning Electrochemical Microscopy.

PubMed

Kai, Tianhan; Zhou, Min; Duan, Zhiyao; Henkelman, Graeme A; Bard, Allen J

2017-12-27

The electrocatalytic reduction of CO 2 has been studied extensively and produces a number of products. The initial reaction in the CO 2 reduction is often taken to be the 1e formation of the radical anion, CO 2 •- . However, the electrochemical detection and characterization of CO 2 •- is challenging because of the short lifetime of CO 2 •- , which can dimerize and react with proton donors and even mild oxidants. Here, we report the generation and quantitative determination of CO 2 •- in N,N-dimethylformamide (DMF) with the tip generation/substrate collection (TG/SC) mode of scanning electrochemical microscopy (SECM). CO 2 was reduced at a hemisphere-shaped Hg/Pt ultramicroelectrode (UME) or a Hg/Au film UME, which were utilized as the SECM tips. The CO 2 •- produced can either dimerize to form oxalate within the nanogap between SECM tip and substrate or collected at SECM substrate (e.g., an Au UME). The collection efficiency (CE) for CO 2 •- depends on the distance (d) between the tip and substrate. The dimerization rate (6.0 × 10 8 M -1 s -1 ) and half-life (10 ns) of CO 2 •- can be evaluated by fitting the collection efficiency vs distance curve. The dimerized species of CO 2 •- , oxalate, can also be determined quantitatively. Furthermore, the formal potential (E 0 ') and heterogeneous rate constant (k 0 ) for CO 2 reduction were determined with different quaternary ammonium electrolytes. The significant difference in k 0 is due to a tunneling effect caused by the adsorption of the electrolytes on the electrode surface at negative potentials.

Understanding Selectivity for the Electrochemical Reduction of Carbon Dioxide to Formic Acid and Carbon Monoxide on Metal Electrodes

DOE PAGES

Feaster, Jeremy T.; Shi, Chuan; Cave, Etosha R.; ...

2017-06-22

Increases in energy demand and in chemical production, together with the rise in CO 2 levels in the atmosphere, motivate the development of renewable energy sources. Electrochemical CO 2 reduction to fuels and chemicals is an appealing alternative to traditional pathways to fuels and chemicals due to its intrinsic ability to couple to solar and wind energy sources. Formate (HCOO –) is a key chemical for many industries; however, greater understanding is needed regarding the mechanism and key intermediates for HCOO – production. This work reports a joint experimental and theoretical investigation of the electrochemical reduction of CO 2 tomore » HCOO – on polycrystalline Sn surfaces, which have been identified as promising catalysts for selectively producing HCOO –. Our results show that Sn electrodes produce HCOO –, carbon monoxide (CO), and hydrogen (H 2) across a range of potentials and that HCOO – production becomes favored at potentials more negative than –0.8 V vs RHE, reaching a maximum Faradaic efficiency of 70% at –0.9 V vs RHE. Scaling relations for Sn and other transition metals are examined using experimental current densities and density functional theory (DFT) binding energies. While *COOH was determined to be the key intermediate for CO production on metal surfaces, we suggest that it is unlikely to be the primary intermediate for HCOO – production. Instead, *OCHO is suggested to be the key intermediate for the CO 2RR to HCOO – transformation, and Sn’s optimal *OCHO binding energy supports its high selectivity for HCOO –. Lastly, these results suggest that oxygen-bound intermediates are critical to understand the mechanism of CO 2 reduction to HCOO – on metal surfaces.« less

Understanding Selectivity for the Electrochemical Reduction of Carbon Dioxide to Formic Acid and Carbon Monoxide on Metal Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feaster, Jeremy T.; Shi, Chuan; Cave, Etosha R.

Increases in energy demand and in chemical production, together with the rise in CO 2 levels in the atmosphere, motivate the development of renewable energy sources. Electrochemical CO 2 reduction to fuels and chemicals is an appealing alternative to traditional pathways to fuels and chemicals due to its intrinsic ability to couple to solar and wind energy sources. Formate (HCOO –) is a key chemical for many industries; however, greater understanding is needed regarding the mechanism and key intermediates for HCOO – production. This work reports a joint experimental and theoretical investigation of the electrochemical reduction of CO 2 tomore » HCOO – on polycrystalline Sn surfaces, which have been identified as promising catalysts for selectively producing HCOO –. Our results show that Sn electrodes produce HCOO –, carbon monoxide (CO), and hydrogen (H 2) across a range of potentials and that HCOO – production becomes favored at potentials more negative than –0.8 V vs RHE, reaching a maximum Faradaic efficiency of 70% at –0.9 V vs RHE. Scaling relations for Sn and other transition metals are examined using experimental current densities and density functional theory (DFT) binding energies. While *COOH was determined to be the key intermediate for CO production on metal surfaces, we suggest that it is unlikely to be the primary intermediate for HCOO – production. Instead, *OCHO is suggested to be the key intermediate for the CO 2RR to HCOO – transformation, and Sn’s optimal *OCHO binding energy supports its high selectivity for HCOO –. Lastly, these results suggest that oxygen-bound intermediates are critical to understand the mechanism of CO 2 reduction to HCOO – on metal surfaces.« less

Reduced Nicotine Content Expectancies Affect Initial Responses to Smoking.

PubMed

Mercincavage, Melissa; Smyth, Joshua M; Strasser, Andrew A; Branstetter, Steven A

2016-10-01

We sought to determine if negative responses to reduced nicotine content (RNC) cigarettes during open-label trials result from smokers' (negative) expectancies. We examined the effects of nicotine content description - independent of actual nicotine content - on subjective responses (craving reduction, withdrawal suppression, mood changes, and sensory ratings) and smoking behaviors (topography measures and carbon monoxide [CO] boost). Thirty-six 12-hour-abstinent daily smokers completed a 3-session crossover trial. During each session, participants smoked their preferred brand cigarette - blinded and described as containing "usual," "low," and "very low" nicotine content - through a topography device and completed CO and subjective response assessments. Although nicotine content was identical, compared to the "usual" content cigarette, participants experienced less craving reduction after smoking the "very low" nicotine cigarette, and rated its smoke as weaker (p < .05). Participants took shallower puffs of the "low" nicotine cigarette (p < .05), and rated the "low" and "very low" nicotine cigarettes as weaker and too mild (p < .01). Negative responses to RNC cigarettes may be due, in part, to negative expectancies about using cigarettes containing less nicotine. In this context, RNC cigarette marketing and labeling are likely important considerations if a federal nicotine reduction policy is initiated.

Xylary pH and Reduction Potential Levels of Iron-stressed Silver Maple (Acer saccharinum L.) 1

PubMed Central

Morris, Robert L.; Swanson, Bert T.

1980-01-01

Xylary fluid pH and reduction potentials were measured on silver maple (Acer saccharinum L.) grown under Fe and pH stress. Although pH and reduction potential (millivolt/59.2) varied significantly in the nutrient solution, xylary pH and reduction potential remained constant. It was concluded that changes in the pH and reduction potential in the xylary fluid of silver maple are not responsible for iron chlorosis. PMID:16661196

Child ADHD severity and positive and negative parenting as predictors of child social functioning: evaluation of three theoretical models.

PubMed

Kaiser, Nina M; McBurnett, Keith; Pfiffner, Linda J

2011-04-01

Prior research has established links between child social functioning and both parenting and child ADHD severity; however, research examining the way that these variables work together is lacking. The current article aims to test three possible models (main effects, mediation, and moderation) by which ADHD severity and positive and negative parenting on the part of both mothers and fathers may work together to predict child social functioning. In a combined sample of children ages 5 to 11 with and without ADHD (N = 143), multiple regression was used to assess: (a) the main effects of ADHD severity and of positive and negative parenting by both mothers and fathers on child social skill and aggressive behavior; (b) parenting as a potential mediator of the relation between ADHD severity and child social skill and aggressive behavior; and (c) ADHD severity as a potential moderator of the relation between parenting and child social skill and aggressive behavior dependent variables. Significant main effects of both ADHD severity and parenting on child social skill and aggression were found. There was some evidence to support parenting (particularly negative parenting) as a mediator of the relation between ADHD severity and child social skill and aggression. There was no evidence of significant moderational effects. Parenting and ADHD severity are independently associated with child social skill and aggressive behavior.To the extent that these associations are causal, multimodal treatment targeting both symptom reduction and improved parenting may be especially effective for the treatment of social problems related to childhood ADHD. Furthermore, evidence for parenting as a mediator of the relation between ADHD severity and child outcomes suggests that changes in child symptoms may also improve parenting practices, thus leading to improved child outcomes.

Sexual risk behaviors and acceptability of HIV pre-exposure prophylaxis among HIV-negative gay and bisexual men in serodiscordant relationships: a mixed methods study.

PubMed

Brooks, Ronald A; Landovitz, Raphael J; Kaplan, Rachel L; Lieber, Eli; Lee, Sung-Jae; Barkley, Thomas W

2012-02-01

The objective of this mixed methods study was to examine current sexual risk behaviors, acceptability and potential adoption of pre-exposure prophylaxis (PrEP) for HIV prevention, and sexual behavior intentions with PrEP adoption among HIV-negative gay and bisexual men (GBM) in HIV serodiscordant relationships. A multiracial/ethnic sample of 25 HIV-negative GBM in serodiscordant relationships completed a qualitative interview and a brief interviewer-administered survey. A modified grounded theory approach was used to identify key themes relating to acceptability and future adoption of PrEP. Participants reported engaging in sexual risk behaviors that place them at risk for HIV infection. Participants also reported a high level of acceptability for PrEP and willingness to adopt PrEP for HIV prevention. Qualitative themes explaining future PrEP adoption included: (1) the opportunity to engage in sex using a noncondom HIV prevention method, (2) protection from HIV infection, and (3) less anxiety when engaging in sex with an HIV-positive partner. Associated with the future adoption of PrEP, a majority (64%) of participants indicated the likelihood for an increase in sexual risk behaviors and a majority (60%) of participants also indicated the likelihood for a decrease or abandonment of condom use, both of which are in contrast to the findings from the large iPrEx study. These findings suggest that the use of PrEP by HIV-negative GBM in serodiscordant relationships carries with it the potential for risk compensation. The findings suggest that PrEP only be offered as part of a comprehensive HIV prevention strategy that includes ongoing risk reduction counseling in the delivery of PrEP to help moderate risk compensation.

Effect of chemical amendments on remediation of potentially toxic trace elements (PTEs) and soil quality improvement in paddy fields.

PubMed

Kim, Sung Chul; Hong, Young Kyu; Oh, Se Jin; Oh, Seung Min; Lee, Sang Phil; Kim, Do Hyung; Yang, Jae E

2017-04-01

Remediation of potentially toxic trace elements (PTEs) in paddy fields is fundamental for crop safety. In situ application of chemical amendments has been widely adapted because of its cost-effectiveness and environmental safety. The main purpose of this research was to (1) evaluate the reduction in dissolved concentrations of cadmium (Cd) and arsenic (As) with the application of chemical amendments and (2) monitor microbial activity in the soil to determine the remediation efficiency. Three different chemical amendments, lime stone, steel slag, and acid mine drainage sludge, were applied to paddy fields, and rice (Oryza sativa L. Milyang 23) was cultivated. The application of chemical amendments immobilized both Cd and As in soil. Between the two PTEs, As reduction was significant (p < 0.05) with the addition of chemical amendments, whereas no significant reduction was observed for Cd than that for the control. Among six soil-related variables, PTE concentration showed a negative correlation with soil pH (r = -0.70 for As and r = -0.54 for Cd) and soil respiration (SR) (r = -0.88 for As and r = -0.45 for Cd). This result indicated that immobilization of PTEs in soil is dependent on soil pH and reduces PTE toxicity. Overall, the application of chemical amendments could be utilized for decreasing PTE (As and Cd) bioavailability and increasing microbial activity in the soil.

Shifts in oxidation states of cerium oxide nanoparticles detected inside intact hydrated cells and organelles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szymanski, Craig J.; Munusamy, Prabhakaran; Mihai, Cosmin

2015-09-01

Cerium oxide nanoparticles (CNPs) have been shown to induce diverse biological effects, ranging from toxic to beneficial. The beneficial effects have been attributed to the potential antioxidant activity of CNPs via certain redox reactions, depending on their oxidation state or Ce3+/Ce4+ ratio. However, this ratio is strongly dependent on the environment and age of the nanoparticles and it is unclear whether and how the complex intracellular environment impacts this ratio and the possible redox reactions of CNPs. To identify any changes in the oxidation state of CNPs in the intracellular environment and better understand their intracellular reactions, we directly quantifiedmore » the oxidation states of CNPs outside and inside intact hydrated cells and organelles using correlated scanning transmission x-ray and super resolution fluorescence microscopies. By analyzing hundreds of small CNP aggregates, we detected a shift to a higher Ce3+/Ce4+ ratio in CNPs inside versus outside the cells, indicating a net reduction of CNPs in the intracellular environment. We further found a similar ratio in the cytoplasm and in the lysosomes, indicating that the net reduction occurs earlier in the internalization pathway. Together with oxidative stress and toxicity measurements, our observations identify a net reduction of CNPs in the intracellular environment, which is consistent with their involvement in potentially beneficial oxidation reactions, but also point to interactions that can negatively impact the health of cells.« less

Highs and lows: patterns of use, positive and negative effects of benzylpiperazine-containing party pills (BZP-party pills) amongst young people in New Zealand

PubMed Central

Butler, Rachael A; Sheridan, Janie L

2007-01-01

Background This study aimed to investigate patterns and context of use of BZP-party pills, function of use, and positive and negative effects experienced by a sample of New Zealand young people who had used the products. Methods A qualitative study comprised of semi-structured interviews and group discussions. Results The sample included 58 young people aged 17–23 years who had used BZP-party pills in the previous 12 months. Young people were using these substances in a range of settings – primarily during weekend social occasions – particularly as part of the dance party culture. They were mostly used for their stimulant properties and to enhance socialisation, and were often taken in combination with other legal and illicit drugs. Young people had suffered a range of physical and emotional negative effects, although none of these was reported as being life-threatening or long-term. Many participants had reduced the frequency with which they used BZP-party pills due to adverse effects. Potentially risky behaviours identified included taking large doses, mixing BZP-party pills with alcohol and other substances, and driving whilst under the influence of BZP-party pills. Conclusion Findings suggest that young people in this study were not suffering excessive or dangerous adverse effects. However, potentially risky use of these products raises the issue of the need for developing harm reduction interventions. PMID:18021425

Healthier side dishes at restaurants: an analysis of children's perspectives, menu content, and energy impacts.

PubMed

Anzman-Frasca, Stephanie; Dawes, Franciel; Sliwa, Sarah; Dolan, Peter R; Nelson, Miriam E; Washburn, Kyle; Economos, Christina D

2014-07-04

Children consume restaurant-prepared foods at high rates, suggesting that interventions and policies targeting consumption of these foods have the potential to improve diet quality and attenuate excess energy intake. One approach to encouraging healthier dietary intake in restaurants is to offer fruits and vegetables (FV) as side dishes, as opposed to traditional, energy-dense accompaniments like French fries. The aims of the current study were to examine: children's views about healthier side dishes at restaurants; current side dish offerings on children's menus at leading restaurants; and potential energy reductions when substituting FV side dishes in place of French fries. To investigate children's attitudes, a survey was administered to a nationally representative sample of U.S. 8- to 18-year-olds (n = 1178). To examine current side dish offerings, children's menus from leading quick service (QSR; n = 10) and full service restaurant chains (FSR; n = 10) were analyzed. Energy reductions that could result from substituting commonly-offered FV side dishes for French fries were estimated using nutrition information corresponding to the children's menu items. Two-thirds of children reported that they would not feel negatively about receiving FV sides instead of French fries with kids' meals. Liking/taste was the most common reason that children gave to explain their attitudes about FV side dishes. Nearly all restaurants offered at least 1 FV side dish option, but at most restaurants (60% of QSR; 70% of FSR), FV sides were never served by default. Substituting FV side dishes for French fries yielded an average estimated energy reduction of at least 170 calories. Results highlight some healthy trends in the restaurant context, including the majority of children reporting non-negative attitudes about FV side dishes and the consistent availability of FV side dish options at leading QSR and FSR. Yet the minority of restaurants offer these FV sides by default. Promoting creative, appealing FV side dishes can result in healthier, less energy-dense meals for children. Substituting or displacing energy-dense default side dishes with such FV dishes show promise as part of continued, comprehensive efforts to increase the healthfulness of meals consumed by children in restaurant settings.

Effects of Screening and Systemic Adjuvant Therapy on ER-Specific US Breast Cancer Mortality

PubMed Central

Munoz, Diego; Near, Aimee M.; van Ravesteyn, Nicolien T.; Lee, Sandra J.; Schechter, Clyde B.; Alagoz, Oguzhan; Berry, Donald A.; Burnside, Elizabeth S.; Chang, Yaojen; Chisholm, Gary; de Koning, Harry J.; Ali Ergun, Mehmet; Heijnsdijk, Eveline A. M.; Huang, Hui; Stout, Natasha K.; Sprague, Brian L.; Trentham-Dietz, Amy; Mandelblatt, Jeanne S.

2014-01-01

Background Molecular characterization of breast cancer allows subtype-directed interventions. Estrogen receptor (ER) is the longest-established molecular marker. Methods We used six established population models with ER-specific input parameters on age-specific incidence, disease natural history, mammography characteristics, and treatment effects to quantify the impact of screening and adjuvant therapy on age-adjusted US breast cancer mortality by ER status from 1975 to 2000. Outcomes included stage-shifts and absolute and relative reductions in mortality; sensitivity analyses evaluated the impact of varying screening frequency or accuracy. Results In the year 2000, actual screening and adjuvant treatment reduced breast cancer mortality by a median of 17 per 100000 women (model range = 13–21) and 5 per 100000 women (model range = 3–6) for ER-positive and ER-negative cases, respectively, relative to no screening and no adjuvant treatment. For ER-positive cases, adjuvant treatment made a higher relative contribution to breast cancer mortality reduction than screening, whereas for ER-negative cases the relative contributions were similar for screening and adjuvant treatment. ER-negative cases were less likely to be screen-detected than ER-positive cases (35.1% vs 51.2%), but when screen-detected yielded a greater survival gain (five-year breast cancer survival = 35.6% vs 30.7%). Screening biennially would have captured a lower proportion of mortality reduction than annual screening for ER-negative vs ER-positive cases (model range = 80.2%–87.8% vs 85.7%–96.5%). Conclusion As advances in risk assessment facilitate identification of women with increased risk of ER-negative breast cancer, additional mortality reductions could be realized through more frequent targeted screening, provided these benefits are balanced against screening harms. PMID:25255803

Rescripting Memory, Redefining the Self: A Meta-Emotional Perspective on the Hypothesized Mechanism(s) of Imagery Rescripting.

PubMed

Mancini, Alessandra; Mancini, Francesco

2018-01-01

Imagery Rescripting (ImRs) is a therapeutic technique that aims to reduce the distress associated with negative memories of early aversive experiences. It consists of prompting patients to rescript the autobiographical memory in line with their unmet needs. In recent years, ImRs was found effective in reducing symptoms of disorders such as depression, social phobia, obsessive-compulsive disorder, post-traumatic stress disorder, and personality disorders. However, the cognitive mechanisms underlying such broad effectiveness are currently an object of debate. Empirical evidence has shown that ImRs reduces the negative self-belief derived from aversive memories in different types of mental disorders. However, existing accounts are not very accurate in explaining how this change in self-belief occurs and therefore why ImRs is effective across psychopathologies. We propose that ImRs changes the semantic self-representation encapsulated in the aversive memory by reducing the meta-emotional problem (i.e., perceiving a negative emotion as problematic and unacceptable). Empirical evidence implicates the meta-emotional problem or "secondary problem" in the maintenance of different disorders and has shown that treating it leads to symptoms reduction. Here we hypothesize that: (i) ImRs as a stand-alone treatment may lead to a reduction of symptoms; negative self-belief and the meta-emotional problem; and (ii) the reduction of the meta-emotional problem might mediate the relation between symptoms and negative self-belief reduction. To test our hypothesis, we present an experimental procedure that could be used in future studies. We conclude discussing the existing theoretical frameworks that attempt to unravel the mechanisms that play a role in ImRs.

Abatacept reduces disease activity and ultrasound power Doppler in ACPA-negative undifferentiated arthritis: a proof-of-concept clinical and imaging study.

PubMed

Buch, Maya H; Hensor, Elizabeth M A; Rakieh, Chadi; Freeston, Jane E; Middleton, Edward; Horton, Sarah; Das, Sudipto; Peterfy, Charles; Tan, Ai Lyn; Wakefield, Richard J; Emery, Paul

2017-01-01

No proven treatment exists for ACPA-negative undifferentiated arthritis (UA). The aim of this study was to evaluate whether abatacept is effective in treating poor prognosis, ACPA-negative UA, including its effect on power Doppler on US (PDUS). A proof-of-concept, open-label, prospective study of 20 patients with DMARD-naïve, ACPA-negative UA (⩾2 joint synovitis) and PDUS ⩾ 1 with clinical and 20-joint US (grey scale/PDUS) assessments at baseline, 6, 12, 18 and 24 months. All patients received 12 months of abatacept (monotherapy for minimum first 6 months). The primary end point was a composite of the proportion of patients that at 6 months achieved DAS44 remission, a maximum of one swollen joint for at least 3 consecutive months and no radiographic progression (over 0-12 months). Twenty of the 23 patients screened were enrolled [14 female; mean (sd) age 53.4 (11.2) years, symptom duration 7.5 (0.9) months]. Two (10%) achieved the composite primary end point. A reduction in the mean (sd) DAS44 was observed from a baseline value of 2.66 (0.77) to 2.01 (0.81) at 6 months and to 1.78 (0.95) at 12 months. The DAS44 remission rates were 6/20 (30%; 95% CI: 15, 51%) at 6 months and 8/20 (40%; 95% CI: 22, 62%) at 12 months. A striking decrease in the median (interquartile range; IQR) total PDUS score was noted from 10 (4-23) at baseline to 3 (2-12) and 3 (0-5) at 6 and 12 months, respectively. This report is a first in potentially identifying an effective therapy, abatacept monotherapy, for poor-prognosis, ACPA-negative UA, supported by a clear reduction in PDUS. These data justify evaluation in a controlled study. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Predictors of levels of functioning among Chinese people with severe mental illness: a 12-month prospective cohort study.

PubMed

Chien, Wai-Tong; Lam, Claire K K; Ng, Bacon F L

2015-07-01

The aim of the study was to identify the predictors of functioning in Chinese people with serious mental illness. Mental healthcare services for people suffering from serious mental illness are delivered to not only minimise their psychiatric symptoms but also enhance their levels of functioning in the community. Yet, there is insufficient research directed towards the associated or predictive factors that may influence different aspects of functioning, particularly in terms of patients' psychosocial variables. A longitudinal, prospective cohort study design was adopted. A clustered random sample of 395 of 611 outpatients with serious mental illness completed the same set of questionnaires at baseline and at 12 months. Changes in patients' functioning as measured by self-maintenance, social functioning and community living skills were recorded over 12 months. Potential relationships between their level of functioning and symptom severity, self-esteem, self-efficacy, perceived negative familial response, negative self-stigma towards mental illness, re-hospitalisation rate and socio-demographic characteristics were investigated. Most participants reported moderate to moderately high levels of overall functioning, self-efficacy, self-stigma and perceived negative familial response at baseline and there were significant observed correlations between these variables. Results of multiple regression models indicated that while symptom severity predicted functioning in patients with psychotic and affective disorders, a negatively perceived familial response only predicted negative changes in social functioning of the patients with psychotic disorders (β = -0·25). In addition, improvements in self-efficacy (β = 0·23) and reduction in self-stigma (β = -0·15) positively predicted changes in the community living skills of patients with affective disorders. The findings indicate the significance of psychiatric patients' symptom management and factors such as self-efficacy and self-stigma to predict their functioning over a 12-month follow-up. Mental healthcare services should consider giving priority to self-stigma reduction and empowerment to manage illness especially in this population of patients and their families, thus effectively enhancing their self-care ability to cope with their illness and/or difficult life situations. © 2015 John Wiley & Sons Ltd.

Screening for urinary tract infection with the Sysmex UF-1000i urine flow cytometer.

PubMed

Broeren, Maarten A C; Bahçeci, Semiha; Vader, Huib L; Arents, Niek L A

2011-03-01

The diagnosis of urinary tract infection (UTI) by urine culture is time-consuming and can produce up to 60 to 80% negative results. Fast screening methods that can reduce the necessity for urine cultures will have a large impact on overall turnaround time and laboratory economics. We have evaluated the detection of bacteria and leukocytes by a new urine analyzer, the UF-1000i, to identify negative urine samples that can be excluded from urine culture. In total, 1,577 urine samples were analyzed and compared to urine culture. Urine culture showed growth of ≥10(3) CFU/ml in 939 samples (60%). Receiver operating characteristics (ROC) curves and ROC decision plots were been prepared at three different gold standard definitions of a negative urine culture: no growth, growth of bacteria at <10(4) CFU/ml, and growth of bacteria at <10(5) CFU/ml. Also, the reduction in urine cultures and the percentage of false negatives were calculated. At the most stringent gold standard definition of no growth, a chosen sensitivity of 95% resulted in a cutoff value of 26 bacteria/μl, a specificity of 43% and a reduction in urine cultures of only 20%, of which 14% were false negatives. However, at a gold standard definition of <10(5) CFU/ml and a sensitivity of 95%, the UF-1000i cutoff value was 230 bacteria/μl, the specificity was 80%, and the reduction in urine cultures was 52%, of which 0.3% were false negatives. The applicability of the UF-1000i to screen for negative urine samples strongly depends on population characteristics and the definition of a negative urine culture. In our setting, however, the low workload savings and the high percentage of false-negative results do not warrant the UF-1000i to be used as a screening analyzer.

Investigating d-cycloserine as a potential pharmacological enhancer of an emotional bias learning procedure.

PubMed

Woud, Marcella L; Blackwell, Simon E; Steudte-Schmiedgen, Susann; Browning, Michael; Holmes, Emily A; Harmer, Catherine J; Margraf, Jürgen; Reinecke, Andrea

2018-05-01

The partial N-methyl-D-aspartate receptor agonist d-cycloserine may enhance psychological therapies. However, its exact mechanism of action is still being investigated. Cognitive bias modification techniques allow isolation of cognitive processes and thus investigation of how they may be affected by d-cycloserine. We used a cognitive bias modification paradigm targeting appraisals of a stressful event, Cognitive Bias Modification-Appraisal, to investigate whether d-cycloserine enhanced the modification of appraisal, and whether it caused greater reduction in indices of psychopathology. Participants received either 250 mg of d-cycloserine ( n=19) or placebo ( n=19). As a stressor task, participants recalled a negative life event, followed by positive Cognitive Bias Modification-Appraisal training. Before and after Cognitive Bias Modification-Appraisal, appraisals and indices of psychopathology related to the stressor were assessed. Cognitive Bias Modification-Appraisal successfully modified appraisals, but d-cycloserine did not affect appraisals post-training. There were no post-training group differences in frequency of intrusions. Interestingly, d-cycloserine led to a greater reduction in distress and impact on state mood from recalling the event, and lower distress post-training was associated with fewer intrusions. Therefore, d-cycloserine may affect emotional reactivity to recalling a negative event when combined with induction of a positive appraisal style, but via a mechanism other than enhanced learning of the appraisal style.

Dual gas-diffusion membrane- and mediatorless dihydrogen/air-breathing biofuel cell operating at room temperature

NASA Astrophysics Data System (ADS)

Xia, Hong-qi; So, Keisei; Kitazumi, Yuki; Shirai, Osamu; Nishikawa, Koji; Higuchi, Yoshiki; Kano, Kenji

2016-12-01

A membraneless direct electron transfer (DET)-type dihydrogen (H2)/air-breathing biofuel cell without any mediator was constructed wherein bilirubin oxidase from Myrothecium verrucaria (BOD) and membrane-bound [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (MBH) were used as biocatalysts for the cathode and the anode, respectively, and Ketjen black-modified water proof carbon paper (KB/WPCC) was used as an electrode material. The KB/WPCC surface was modified with 2-aminobenzoic acid and p-phenylenediamine, respectively, to face the positively charged electron-accepting site of BOD and the negatively charged electron-donating site of MBH to the electrode surface. A gas-diffusion system was employed for the electrodes to realize high-speed substrate supply. As result, great improvement in the current density of O2 reduction with BOD and H2 reduction with MBH were realized at negatively and postively charged surfaces, respectively. Gas diffusion system also suppressed the oxidative inactivation of MBH at high electrode potentials. Finally, based on the improved bioanode and biocathode, a dual gas-diffusion membrane- and mediatorless H2/air-breathing biofuel cell was constructed. The maximum power density reached 6.1 mW cm-2 (at 0.72 V), and the open circuit voltage was 1.12 V using 1 atm of H2 gas as a fuel at room temperature and under passive and quiescent conditions.

Harm Reduction Agencies as a Potential Site for Buprenorphine Treatment.

PubMed

Fox, Aaron D; Chamberlain, Adam; Frost, Taeko; Cunningham, Chinazo O

2015-01-01

Harm reduction agencies complement addiction treatment by providing diverse services that improve the health of people who use drugs. Buprenorphine maintenance treatment (BMT) is an effective opioid addiction treatment that may be provided from flexible settings, potentially including harm reduction agencies. This study investigated attitudes toward different potential sites for BMT (harm reduction agencies, general medical clinics, and drug treatment programs) among harm reduction clients. Using computer-based interviews, participants indicated preferred potential site for BMT (harm reduction agency, drug treatment program, or general medical clinic), interest in BMT by potential site, motivation for treatment, and barriers to BMT. Multivariable logistic regression was used to determine factors associated with harm reduction agency preference. Of 102 opioid users, the most preferred potential site for BMT was a harm reduction agency (51%), whereas fewer preferred general medical clinics (13%), drug treatment programs (12%), or were not interested in BMT (25%). In multivariable analysis, experiencing ≥1 barrier to BMT was strongly associated with preferring harm reduction agencies (adjusted odds ratio [aOR] = 3.39, 95% confidence interval [CI]: 1.00-11.43). The potential to initiate BMT at harm reduction agencies is highly favorable among harm reduction clients, especially among those experiencing barriers to BMT. Offering BMT at harm reduction agencies could improve access to treatment, but studies are needed to determine safety and efficacy of this approach.

In vitro toxicity of particulate matter (PM) collected at different sites in the Netherlands is associated with PM composition, size fraction and oxidative potential - the RAPTES project

PubMed Central

2011-01-01

Background Ambient particulate matter (PM) exposure is associated with respiratory and cardiovascular morbidity and mortality. To what extent such effects are different for PM obtained from different sources or locations is still unclear. This study investigated the in vitro toxicity of ambient PM collected at different sites in the Netherlands in relation to PM composition and oxidative potential. Method PM was sampled at eight sites: three traffic sites, an underground train station, as well as a harbor, farm, steelworks, and urban background location. Coarse (2.5-10 μm), fine (< 2.5 μm) and quasi ultrafine PM (qUF; < 0.18 μm) were sampled at each site. Murine macrophages (RAW 264.7 cells) were exposed to increasing concentrations of PM from these sites (6.25-12.5-25-50-100 μg/ml; corresponding to 3.68-58.8 μg/cm2). Following overnight incubation, MTT-reduction activity (a measure of metabolic activity) and the release of pro-inflammatory markers (Tumor Necrosis Factor-alpha, TNF-α; Interleukin-6, IL-6; Macrophage Inflammatory Protein-2, MIP-2) were measured. The oxidative potential and the endotoxin content of each PM sample were determined in a DTT- and LAL-assay respectively. Multiple linear regression was used to assess the relationship between the cellular responses and PM characteristics: concentration, site, size fraction, oxidative potential and endotoxin content. Results Most PM samples induced a concentration-dependent decrease in MTT-reduction activity and an increase in pro-inflammatory markers with the exception of the urban background and stop & go traffic samples. Fine and qUF samples of traffic locations, characterized by a high concentration of elemental and organic carbon, induced the highest pro-inflammatory activity. The pro-inflammatory response to coarse samples was associated with the endotoxin level, which was found to increase dramatically during a three-day sample concentration procedure in the laboratory. The underground samples, characterized by a high content of transition metals, showed the largest decrease in MTT-reduction activity. PM size fraction was not related to MTT-reduction activity, whereas there was a statistically significant difference in pro-inflammatory activity between Fine and qUF PM. Furthermore, there was a statistically significant negative association between PM oxidative potential and MTT-reduction activity. Conclusion The response of RAW264.7 cells to ambient PM was markedly different using samples collected at various sites in the Netherlands that differed in their local PM emission sources. Our results are in support of other investigations showing that the chemical composition as well as oxidative potential are determinants of PM induced toxicity in vitro. PMID:21888644

Deterioration of left ventricular chamber performance after bed rest : "cardiovascular deconditioning" or hypovolemia?

NASA Technical Reports Server (NTRS)

Perhonen, M. A.; Zuckerman, J. H.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

2001-01-01

BACKGROUND: Orthostatic intolerance after bed rest is characterized by hypovolemia and an excessive reduction in stroke volume (SV) in the upright position. We studied whether the reduction in SV is due to a specific adaptation of the heart to head-down tilt bed rest (HDTBR) or acute hypovolemia alone. METHODS AND RESULTS: We constructed left ventricular (LV) pressure-volume curves from pulmonary capillary wedge pressure and LV end-diastolic volume and Starling curves from pulmonary capillary wedge pressure and SV during lower body negative pressure and saline loading in 7 men (25+/-2 years) before and after 2 weeks of -6 degrees HDTBR and after the acute administration of intravenous furosemide. Both HDTBR and hypovolemia led to a similar reduction in plasma volume. However, baseline LV end-diastolic volume decreased by 20+/-4% after HDTBR and by 7+/-2% after hypovolemia (interaction P<0.001). Moreover, SV was reduced more and the Starling curve was steeper during orthostatic stress after HDTBR than after hypovolemia. The pressure-volume curve showed a leftward shift and the equilibrium volume of the left ventricle was decreased after HDTBR; however, after hypovolemia alone, the curve was identical, with no change in equilibrium volume. Lower body negative pressure tolerance was reduced after both conditions; it decreased by 27+/-7% (P<0.05) after HDTBR and by 18+/-8% (P<0.05) after hypovolemia. CONCLUSIONS: Chronic HDTBR leads to ventricular remodeling, which is not seen with equivalent degrees of acute hypovolemia. This remodeling leads to a greater decrease in SV during orthostatic stress after bed rest than hypovolemia alone, potentially contributing to orthostatic intolerance.

The effects of green infrastructure on exceedance of critical shear stress in Blunn Creek watershed

NASA Astrophysics Data System (ADS)

Shannak, Sa'd.

2017-10-01

Green infrastructure (GI) has attracted city planners and watershed management professional as a new approach to control urban stormwater runoff. Several regulatory enforcements of GI implementation created an urgent need for quantitative information on GI practice effectiveness, namely for sediment and stream erosion. This study aims at investigating the capability and performance of GI in reducing stream bank erosion in the Blackland Prairie ecosystem. To achieve the goal of this study, we developed a methodology to represent two types of GI (bioretention and permeable pavement) into the Soil Water Assessment Tool, we also evaluated the shear stress and excess shear stress for stream flows in conjunction with different levels of adoption of GI, and estimated potential stream bank erosion for different median soil particle sizes using real and design storms. The results provided various configurations of GI schemes in reducing the negative impact of urban stormwater runoff on stream banks. Results showed that combining permeable pavement and bioretention resulted in the greatest reduction in runoff volumes, peak flows, and excess shear stress under both real and design storms. Bioretention as a stand-alone resulted in the second greatest reduction, while the installation of detention pond only had the least reduction percentages. Lastly, results showed that the soil particle with median diameter equals to 64 mm (small cobbles) had the least excess shear stress across all design storms, while 0.5 mm (medium sand) soil particle size had the largest magnitude of excess shear stress. The current study provides several insights into a watershed scale for GI planning and watershed management to effectively reduce the negative impact of urban stormwater runoff and control streambank erosion.

Initial outcomes of provider-initiated routine HIV testing and counseling during outpatient care at a rural Ugandan hospital: risky sexual behavior, partner HIV testing, disclosure, and HIV care seeking.

PubMed

Kiene, Susan M; Bateganya, Moses; Wanyenze, Rhoda; Lule, Haruna; Nantaba, Harriet; Stein, Michael D

2010-02-01

Provider-initiated routine HIV testing is being scaled up throughout the world, however, little is known about the outcomes of routine HIV testing on subsequent behavior. This study examined the initial outcomes of provider-initiated routine HIV testing at a rural Ugandan hospital regarding partner HIV testing, sexual risk behavior, disclosure, and HIV care seeking. In a prospective cohort study, 245 outpatients receiving routine HIV testing completed baseline and 3-month follow-up interviews. After receiving routine HIV testing the percentage of participants engaging in risky sex decreased from 70.1% to 50.3% among HIV-negative and from 75.0% to 53.5% among HIV-positive participants, the percentage knowing their partner(s)' HIV status increased from 18.7% to 34.3% of HIV-negative and from 14.3% to 35.7% of HIV-positive participants. Among those reporting risky sex at baseline, HIV-positive participants were more likely to eliminate risky sex in general and specifically to become abstinent at follow-up than were HIV-negative participants. Similarly, unmarried participants who were risky at baseline were more likely to become safe in general, become abstinent, and start 100% condom use than were married/cohabitating participants. Rates of disclosure were high. Over 85% of those who tested HIV positive enrolled in care. Routine HIV testing in this setting may promote earlier HIV diagnosis and access to care but leads to only modest reductions in risky sexual behavior. To fully realize the potential HIV prevention benefits of routine HIV testing an emphasis on tailored risk-reduction counseling may be necessary.

Sulfide Generated by Sulfate Reduction is a Primary Controller of the Occurrence of Wild Rice (Zizania palustris) in Shallow Aquatic Ecosystems

NASA Astrophysics Data System (ADS)

Myrbo, A.; Swain, E. B.; Engstrom, D. R.; Coleman Wasik, J.; Brenner, J.; Dykhuizen Shore, M.; Peters, E. B.; Blaha, G.

2017-11-01

Field observations suggest that surface water sulfate concentrations control the distribution of wild rice, an aquatic grass (Zizania palustris). However, hydroponic studies show that sulfate is not toxic to wild rice at even unrealistically high concentrations. To determine how sulfate might directly or indirectly affect wild rice, potential wild rice habitat was characterized for 64 chemical and physical variables in over 100 sites spanning a relatively steep climatic and geological gradient in Minnesota. Habitat suitability was assessed by comparing the occurrence of wild rice with the field variables, through binary logistic regression. This analysis demonstrated that sulfide in sediment pore water, generated by the microbial reduction of sulfate that diffuses or advects into the sediment, is the primary control of wild rice occurrence. Water temperature and water transparency independently control the suitability of habitat for wild rice. In addition to generating phytotoxic sulfide, sulfate reduction also supports anaerobic decomposition of organic matter, releasing nutrients that can compound the harm of direct sulfide toxicity. These results are important because they show that increases in sulfate loading to surface water can have multiple negative consequences for ecosystems, even though sulfate itself is relatively benign.

A wedge-based approach to estimating health co-benefits of climate change mitigation activities in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balbus, John M.; Greenblatt, Jeffery B.; Chari, Ramya

While it has been recognized that actions reducing greenhouse gas (GHG) emissions can have significant positive and negative impacts on human health through reductions in ambient fine particulate matter (PM2.5) concentrations, these impacts are rarely taken into account when analyzing specific policies. This study presents a new framework for estimating the change in health outcomes resulting from implementation of specific carbon dioxide (CO 2) reduction activities, allowing comparison of different sectors and options for climate mitigation activities. Our estimates suggest that in the year 2020, the reductions in adverse health outcomes from lessened exposure to PM2.5 would yield economic benefitsmore » in the range of $6 to $14 billion (in 2008 USD), depending on the specific activity. This equates to between $40 and $93 per metric ton of CO 2 in health benefits. Specific climate interventions will vary in the health co-benefits they provide as well as in potential harms that may result from their implementation. Rigorous assessment of these health impacts is essential for guiding policy decisions as efforts to reduce GHG emissions increase in scope and intensity.« less

Reduction of Leaching Impacts by Applying Biomass Bottom Ash and Recycled Mixed Aggregates in Structural Layers of Roads

PubMed Central

Cabrera, Manuel; Galvin, Adela P.; Agrela, Francisco; Beltran, Manuel G.; Ayuso, Jesus

2016-01-01

This research is focused on analyzing the environmental pollution potential of biomass bottom ashes as individual materials, as mixtures manufactured with biomass bottom ashes and granular construction aggregates, and these mixtures treated with cement. For the environmental assessment of all of the samples and materials mentioned, the following leaching procedures have been performed: the compliance batch test of UNE-EN 12457-3:2003 for aggregates and bottom ashes; the column test according to NEN 7343:1994 for the mixtures prepared in the laboratory; and the tank test by EA NEN 7375:2004 for analyzing the behavior of mixtures after their solidification/stabilization with 5% cement. After the discussion of the data, the reduction of the pollution load of the most hazardous biomass bottom ashes after their combination with different aggregates can be confirmed, which implies their possible application in civil infrastructures, such as filler embankments and road construction layers, without negatively impacting the environment. In addition, the positive effect of the stabilization/solidification of the cement-treated mixtures with a reduction of the heavy metals that were released at the highest levels, namely As, Hg Cr, Ni, Cu, Se and Mo, was proven. PMID:28773352

Exposure to gemfibrozil and atorvastatin affects cholesterol metabolism and steroid production in zebrafish (Danio rerio).

PubMed

Al-Habsi, Aziz A; Massarsky, Andrey; Moon, Thomas W

2016-09-01

The commonly used lipid-lowering pharmaceuticals gemfibrozil (GEM) and atorvastatin (ATV) are detected in the aquatic environment; however, their potential effects on non-target fish species are yet to be fully understood. This study examined the effects of GEM and/or ATV on female and male adult zebrafish after a 30d dietary exposure. The exposure led to changes in several biochemical parameters, including reduction in cholesterol, triglycerides, cortisol, testosterone, and estradiol. Changes in cholesterol and triglycerides were also associated with changes in transcript levels of key genes involved with cholesterol and lipid regulation, including SREBP2, HMGCR1, PPARα, and SREBP1. We also noted higher CYP3A65 and atrogin1 mRNA levels in drug-treated male fish. Sex differences were apparent in some of the examined parameters at both biochemical and molecular levels. This study supports these drugs affecting cholesterol metabolism and steroid production in adult zebrafish. We conclude that the reduction in cortisol may impair the ability of these fish to mount a suitable stress response, whereas the reduction of sex steroids may negatively affect reproduction. Copyright © 2015 Elsevier Inc. All rights reserved.

Potential application of alkaline pectinase from Bacillus subtilis SS in pulp and paper industry.

PubMed

Ahlawat, Sonia; Mandhan, R P; Dhiman, Saurabh Sudha; Kumar, Rakesh; Sharma, Jitender

2008-06-01

Pectinase production from Bacillus subtilis SS was optimized under solid-state fermentation (5,943 U/g of dry bacterial bran). The pectinase produced was stable in neutral to alkaline pH range at 70 degrees C; therefore, the suitability of this pectinase in pulp and paper industry was investigated. The enzyme pretreatment process was optimized, and a pectinase dose of 5 IU/g of oven-dried pulp (10% consistency) at pH 9.5 temperature 70 degrees C after 150 min of treatment gave the best pretreatment to the pulp. An increase of 4.3% in brightness along with an increase of 14.8 and 65.3% in whiteness and fluorescence, respectively, whereas a 15% decrease in the yellowness of the pretreated pulp were observed. There was a 5.85% reduction in kappa number and 6.1% reduction in permanganate number along with a reduction in the chemical oxygen demand value. Significant characteristics showed by pectinase open new possibilities of application of this cellulase-free enzyme in the pulp and paper industry by reducing the negative environmental impact of chemicals apart from improving the properties of paper.

Retrospective and Prospective Cognitions in Adolescents: Anxiety, Depression, and Positive and Negative Affect

ERIC Educational Resources Information Center

Miles, Helen; MacLeod, Andrew K.; Pote, Helen

2004-01-01

Research with anxious and depressed adults has suggested that anxiety is related to an increased anticipation of both negative memories and negative expectancies whereas depression is related to a reduction in positive memories and expectancies. The present study examined whether anxiety and depression in 123 school-aged adolescents would show the…

Smoking-related microRNAs and mRNAs in human peripheral blood mononuclear cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Ming-Wei

Teenager smoking is of great importance in public health. Functional roles of microRNAs have been documented in smoke-induced gene expression changes, but comprehensive mechanisms of microRNA-mRNA regulation and benefits remained poorly understood. We conducted the Teenager Smoking Reduction Trial (TSRT) to investigate the causal association between active smoking reduction and whole-genome microRNA and mRNA expression changes in human peripheral blood mononuclear cells (PBMC). A total of 12 teenagers with a substantial reduction in smoke quantity and a decrease in urine cotinine/creatinine ratio were enrolled in genomic analyses. In Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA), differentially expressedmore » genes altered by smoke reduction were mainly associated with glucocorticoid receptor signaling pathway. The integrative analysis of microRNA and mRNA found eleven differentially expressed microRNAs negatively correlated with predicted target genes. CD83 molecule regulated by miR-4498 in human PBMC, was critical for the canonical pathway of communication between innate and adaptive immune cells. Our data demonstrated that microRNAs could regulate immune responses in human PBMC after habitual smokers quit smoking and support the potential translational value of microRNAs in regulating disease-relevant gene expression caused by tobacco smoke. - Highlights: • We conducted a smoke reduction trial program and investigated the causal relationship between smoke and gene regulation. • MicroRNA and mRNA expression changes were examined in human PBMC. • MicroRNAs are important in regulating disease-causal genes after tobacco smoke reduction.« less

Mechanisms of Polyelectrolyte Enhanced Surfactant Adsorption at the Air-Water Interface

PubMed Central

Stenger, Patrick C.; Palazoglu, Omer A.; Zasadzinski, Joseph A.

2009-01-01

Chitosan, a naturally occurring cationic polyelectrolyte, restores the adsorption of the clinical lung surfactant Survanta to the air-water interface in the presence of albumin at much lower concentrations than uncharged polymers such as polyethylene glycol. This is consistent with the positively charged chitosan forming ion pairs with negative charges on the albumin and lung surfactant particles, reducing the net charge in the double-layer, and decreasing the electrostatic energy barrier to adsorption to the air-water interface. However, chitosan, like other polyelectrolytes, cannot perfectly match the charge distribution on the surfactant, which leads to patches of positive and negative charge at net neutrality. Increasing the chitosan concentration further leads to a reduction in the rate of surfactant adsorption consistent with an over-compensation of the negative charge on the surfactant and albumin surfaces, which creates a new repulsive electrostatic potential between the now cationic surfaces. This charge neutralization followed by charge inversion explains the window of polyelectrolyte concentration that enhances surfactant adsorption; the same physical mechanism is observed in flocculation and re-stabilization of anionic colloids by chitosan and in alternate layer deposition of anionic and cationic polyelectrolytes on charged colloids. PMID:19366599

Mechanisms of polyelectrolyte enhanced surfactant adsorption at the air-water interface.

PubMed

Stenger, Patrick C; Palazoglu, Omer A; Zasadzinski, Joseph A

2009-05-01

Chitosan, a naturally occurring cationic polyelectrolyte, restores the adsorption of the clinical lung surfactant Survanta to the air-water interface in the presence of albumin at much lower concentrations than uncharged polymers such as polyethylene glycol. This is consistent with the positively charged chitosan forming ion pairs with negative charges on the albumin and lung surfactant particles, reducing the net charge in the double-layer, and decreasing the electrostatic energy barrier to adsorption to the air-water interface. However, chitosan, like other polyelectrolytes, cannot perfectly match the charge distribution on the surfactant, which leads to patches of positive and negative charge at net neutrality. Increasing the chitosan concentration further leads to a reduction in the rate of surfactant adsorption consistent with an over-compensation of the negative charge on the surfactant and albumin surfaces, which creates a new repulsive electrostatic potential between the now cationic surfaces. This charge neutralization followed by charge inversion explains the window of polyelectrolyte concentration that enhances surfactant adsorption; the same physical mechanism is observed in flocculation and re-stabilization of anionic colloids by chitosan and in alternate layer deposition of anionic and cationic polyelectrolytes on charged colloids.

Chronobiological factors for compassion satisfaction and fatigue among ambulatory oncology caregivers.

PubMed

Bellicoso, Daniela; Trudeau, Maureen; Fitch, Margaret I; Ralph, Martin R

2017-01-01

Primary caregivers for victims of chronic illness and or trauma experience both positive and negative emotional consequences. These are broadly classified as compassion satisfaction (CS) and compassion fatigue (CF). Because one of the components of CF, burnout, varies with chronotype and sleep quality, we assessed the influence of chronobiological features on the broader constructs of CS and CF. Responses from primary ambulatory care oncology staff working dayshifts were assessed for potential relationships of chronotype and sleep quality with CS and CF using the professional quality of life scale. These were analyzed further in a multivariate model that included personality and job satisfaction as cofactors. We found that sleep quality was a key contributor to CS development and CF reduction. Morningness was positively linked to CS, but the univariate association was masked in the multivariate model. Job satisfaction (contingent rewards, nature of work and operating procedures) heavily influenced CS and CF development. Agreeableness and openness showed positive correlations with CS and negative with burnout, while emotional stability was linked to reduced CF. While job satisfaction and personality predictably played roles in the development of CS and CF, sleep quality and chronotype contributed significantly to benefits and negative consequences of providing care.

Prediction of large negative shaded-side spacecraft potentials

NASA Technical Reports Server (NTRS)

Prokopenko, S. M. L.; Laframboise, J. G.

1977-01-01

A calculation by Knott, for the floating potential of a spherically symmetric synchronous-altitude satellite in eclipse, was adapted to provide simple calculations of upper bounds on negative potentials which may be achieved by electrically isolated shaded surfaces on spacecraft in sunlight. Large (approximately 60 percent) increases in predicted negative shaded-side potentials are obtained. To investigate effective potential barrier or angular momentum selection effects due to the presence of less negative sunlit-side or adjacent surface potentials, these expressions were replaced by the ion random current, which is a lower bound for convex surfaces when such effects become very severe. Further large increases in predicted negative potentials were obtained, amounting to a doubling in some cases.

Minimizing analyte electrolysis in electrospray ionization mass spectrometry using a redox buffer coated emitter electrode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peintler-Krivan, Emese; Van Berkel, Gary J; Kertesz, Vilmos

2010-01-01

An emitter electrode with an electroactive poly(pyrrole) (PPy) polymer film coating was constructed for use in electrospray ionization mass spectrometry (ESI-MS). The PPy film acted as a surface-attached redox buffer limiting the interfacial potential of the emitter electrode. While extensive oxidation of selected analytes (reserpine and amodiaquine) was observed in positive ion mode ESI using a bare metal (gold) emitter electrode, the oxidation was suppressed for these same analytes when using the PPy-coated electrode. A semi-quantitative relationship between the rate of oxidation observed and the interfacial potential of the emitter electrode was shown. The redox buffer capacity, and therefore themore » lifetime of the redox buffering effect, correlated with the oxidation potential of the analyte and with the magnitude of the film charge capacity. Online reduction of the PPy polymer layer using negative ion mode ESI between analyte injections was shown to successfully restore the redox buffering capacity of the polymer film to its initial state.« less

Effect of fortification with parsley (Petroselinum crispum Mill.) leaves on the nutraceutical and nutritional quality of wheat pasta.

PubMed

Sęczyk, Łukasz; Świeca, Michał; Gawlik-Dziki, Urszula; Luty, Marcin; Czyż, Jarosław

2016-01-01

This study examines the nutraceutical (phenolics content, antioxidant activity, biological activity) and nutritional potential (starch and protein digestibility) of wheat pasta supplemented with 1-4% of powdered parsley leaves. Compared to the control, the potentially bioaccessible fraction of pasta fortified with 4% parsley leaves was characterized by 67% increased phenolics content, a 146% higher antiradical ability and 220% additional reducing power. Elevation of these parameters in fortified pasta was accompanied by an augmentation of its antiproliferative effect on carcinoma cells, which confirms their biological relevance. Supplementation of pasta had no significant effect on starch digestibility, while negatively affecting protein digestibility (a reduction by about 20% for pasta with a 4% supplement). Electrophoretic and chromatographic analyses indicated the presence of phenolic interactions with proteins and/or digestive enzymes. Fortification improved the nutraceutical and nutritional potential of the studied pasta; however, the final effect is made by many factors, including phenolics-food matrix interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prediction of Reduction Potentials of Copper Proteins with Continuum Electrostatics and Density Functional Theory

PubMed Central

Fowler, Nicholas J.; Blanford, Christopher F.

2017-01-01

Abstract Blue copper proteins, such as azurin, show dramatic changes in Cu2+/Cu+ reduction potential upon mutation over the full physiological range. Hence, they have important functions in electron transfer and oxidation chemistry and have applications in industrial biotechnology. The details of what determines these reduction potential changes upon mutation are still unclear. Moreover, it has been difficult to model and predict the reduction potential of azurin mutants and currently no unique procedure or workflow pattern exists. Furthermore, high‐level computational methods can be accurate but are too time consuming for practical use. In this work, a novel approach for calculating reduction potentials of azurin mutants is shown, based on a combination of continuum electrostatics, density functional theory and empirical hydrophobicity factors. Our method accurately reproduces experimental reduction potential changes of 30 mutants with respect to wildtype within experimental error and highlights the factors contributing to the reduction potential change. Finally, reduction potentials are predicted for a series of 124 new mutants that have not yet been investigated experimentally. Several mutants are identified that are located well over 10 Å from the copper center that change the reduction potential by more than 85 mV. The work shows that secondary coordination sphere mutations mostly lead to long‐range electrostatic changes and hence can be modeled accurately with continuum electrostatics. PMID:28815759

The SNaP system: biomechanical and animal model testing of a novel ultraportable negative-pressure wound therapy system.

PubMed

Fong, Kenton D; Hu, Dean; Eichstadt, Shaundra; Gupta, Deepak M; Pinto, Moshe; Gurtner, Geoffrey C; Longaker, Michael T; Lorenz, H Peter

2010-05-01

Negative-pressure wound therapy is traditionally achieved by attaching an electrically powered pump to a sealed wound bed and applying subatmospheric pressure by means of gauze or foam. The Smart Negative Pressure (SNaP) System (Spiracur, Inc., Sunnyvale, Calif.) is a novel ultraportable negative-pressure wound therapy system that does not require an electrically powered pump. Negative pressure produced by the SNaP System, and a powered pump, the wound vacuum-assisted closure advanced-therapy system (Kinetic Concepts, Inc., San Antonio, Texas), were compared in vitro using bench-top pressure sensor testing and microstrain and stress testing with pressure-sensitive film and micro-computed tomographic scan analysis. In addition, to test in vivo efficacy, 10 rats underwent miniaturized SNaP (mSNaP) device placement on open wounds. Subject rats were randomized to a system activation group (approximately -125 mmHg) or a control group (atmospheric pressure). Wound measurements and histologic data were collected for analysis. Bench measurement revealed nearly identical negative-pressure delivery and mechanical strain deformation patterns between both systems. Wounds treated with the mSNaP System healed faster, with decreased wound size by postoperative day 7 (51 percent versus 12 percent reduction; p < 0.05) and had more rapid complete reepithelialization (21 days versus 32 days; p < 0.05). The mSNaP device also induced robust granulation tissue formation. The SNaP System and an existing electrically powered negative-pressure wound therapy system have similar biomechanical properties and functional wound-healing benefits. The potential clinical efficacy of the SNaP device for the treatment of wounds is supported.

Nitrogen rate strategies for reducing yield-scaled nitrous oxide emissions in maize

NASA Astrophysics Data System (ADS)

Zhao, Xu; Nafziger, Emerson D.; Pittelkow, Cameron M.

2017-12-01

Mitigating nitrogen (N) losses from agriculture without negatively impacting crop productivity is a pressing environmental and economic challenge. Reductions in N fertilizer rate are often highlighted as a solution, yet the degree to which crop yields and economic returns may be impacted at the field-level remains unclear, in part due to limited data availability. Farmers are risk averse and potential yield losses may limit the success of voluntary N loss mitigation protocols, thus understanding field-level yield tradeoffs is critical to inform policy development. Using a case study of soil N2O mitigation in the US Midwest, we conducted an ex-post assessment of two economic and two environmental N rate reduction strategies to identify promising practices for maintaining maize yields and economic returns while reducing N2O emissions per unit yield (i.e. yield-scaled emissions) compared to an assumed baseline N input level. Maize yield response data from 201 on-farm N rate experiments were combined with an empirical equation predicting N2O emissions as a function of N rate. Results indicate that the economic strategy aimed at maximizing returns to N (MRTN) led to moderate but consistent reductions in yield-scaled N2O emissions with small negative impacts on yield and slight increases in median returns. The economic optimum N rate strategy reduced yield-scaled N2O emissions in 75% of cases but increased them otherwise, challenging the assumption that this strategy will automatically reduce environmental impacts per unit production. Both environmental strategies, one designed to increase N recovery efficiency and one to balance N inputs with grain N removal, further reduced yield-scaled N2O emissions but were also associated with negative yield penalties and decreased returns. These results highlight the inherent tension between achieving agronomic and economic goals while reducing environmental impacts which is often overlooked in policy discussions. To enable the development of more scalable environmental N loss mitigation strategies, yield tradeoffs occurring at the critical point of adoption (i.e. the farm-level) should be considered.

Heterogeneous catalytic conversion of CO2: a comprehensive theoretical review.

PubMed

Li, Yawei; Chan, Siew Hwa; Sun, Qiang

2015-05-21

The conversion of CO2 into fuels and useful chemicals has been intensively pursued for renewable, sustainable and green energy. However, due to the negative adiabatic electron affinity (EA) and large ionization potential (IP), the CO2 molecule is chemically inert, thus making the conversion difficult under normal conditions. Novel catalysts, which have high stability, superior efficiency and low cost, are urgently needed to facilitate the conversion. As the first step to design such catalysts, understanding the mechanisms involved in CO2 conversion is absolutely indispensable. In this review, we have summarized the recent theoretical progress in mechanistic studies based on density functional theory, kinetic Monte Carlo simulation, and microkinetics modeling. We focus on reaction channels, intermediate products, the key factors determining the conversion of CO2 in solid-gas interface thermocatalytic reduction and solid-liquid interface electrocatalytic reduction. Furthermore, we have proposed some possible strategies for improving CO2 electrocatalysis and also discussed the challenges in theory, model construction, and future research directions.

Bioremediation of waste under ocean acidification: Reviewing the role of Mytilus edulis.

PubMed

Broszeit, Stefanie; Hattam, Caroline; Beaumont, Nicola

2016-02-15

Waste bioremediation is a key regulating ecosystem service, removing wastes from ecosystems through storage, burial and recycling. The bivalve Mytilus edulis is an important contributor to this service, and is used in managing eutrophic waters. Studies show that they are affected by changes in pH due to ocean acidification, reducing their growth. This is forecasted to lead to reductions in M. edulis biomass of up to 50% by 2100. Growth reduction will negatively affect the filtering capacity of each individual, potentially leading to a decrease in bioremediation of waste. This paper critically reviews the current state of knowledge of bioremediation of waste carried out by M. edulis, and the current knowledge of the resultant effect of ocean acidification on this key service. We show that the effects of ocean acidification on waste bioremediation could be a major issue and pave the way for empirical studies of the topic. Copyright © 2016 Elsevier Ltd. All rights reserved.

Amino-oxyacetic acid as a palliative in tinnitus.

PubMed

Reed, H T; Meltzer, J; Crews, P; Norris, C H; Quine, D B; Guth, P S

1985-12-01

Amino-oxyacetic acid, previously shown to cause a reversible loss of hearing sensitivity and a reduction in endocochlear potential, was tried as a palliative in human tinnitus. Because the drug seemed to have a cochlear site of action, patients were selected for the study if their audiograms were indicative of cochlear lesions and if there was a reduction in tinnitus following intravenous lidocaine (lidocaine positive). Ten such patients received either 50 or 75 mg of amino-oxyacetic acid four times a day orally for one week or placebo administered in a random, crossover, double-blind design. Of these ten, three reported subjective lessening of tinnitus. One of those three and two others not reporting subjective lessening of tinnitus showed a substantial improvement in speech discrimination scores while receiving amino-oxyacetic acid but not placebo. One additional patient who did not receive lidocaine also reported a subjective lessening of tinnitus. Four patients who were lidocaine negative showed neither subjective nor objective improvement in tinnitus after treatment with amino-oxyacetic acid.

The use of virtual reality and audiovisual eyeglass systems as adjunct analgesic techniques: a review of the literature.

PubMed

Wismeijer, Andreas A J; Vingerhoets, Ad J J M

2005-12-01

This review focuses on the application of technologically advanced methods of audiovisual distraction as adjunct analgesic techniques; more specifically, (a) virtual reality (VR) and (b) audiovisual (A/V) eyeglass systems (A/V distraction). It is assumed that distraction taxes the patient's limited attention capacity, resulting in the withdrawal of attention from the noxious stimulus with a subsequent reduction in pain. Twenty studies evaluating the analgesic potential of both methods in different patient groups and in healthy volunteers were identified in the scientific literature. Although the majority of these studies are hampered by serious methodological drawbacks, particularly a small number of participants, the results nevertheless strongly suggest that both VR and A/V distraction can be a very promising analgesic technique that may be used safely and effectively for the reduction of pain and discomfort during medical procedures. An additional important aspect is that few negative side effects have been reported. Directions for future research are presented.

An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

PubMed

Pardillo Mayora, José M; Jurado Piña, Rafael

2009-07-01

Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions.

Using temporal distancing to regulate emotion in adolescence: modulation by reactive aggression.

PubMed

Ahmed, S P; Somerville, L H; Sebastian, C L

2018-06-01

Adopting a temporally distant perspective on stressors reduces distress in adults. Here we investigate whether the extent to which individuals project themselves into the future influences distancing efficacy. We also examined modulating effects of age across adolescence and reactive aggression: factors associated with reduced future-thinking and poor emotion regulation. Participants (N = 83, aged 12-22) read scenarios and rated negative affect when adopting a distant-future perspective, near-future perspective, or when reacting naturally. Self-report data revealed significant downregulation of negative affect during the distant-future condition, with a similar though non-significant skin conductance pattern. Importantly, participants who projected further ahead showed the greatest distress reductions. While temporal distancing efficacy did not vary with age, participants reporting greater reactive aggression showed reduced distancing efficacy, and projected themselves less far into the future. Findings demonstrate the importance of temporal extent in effective temporal distancing; shedding light on a potential mechanism for poor emotional control associated with reactive aggression.

Path-integral simulation of ice Ih: The effect of pressure

NASA Astrophysics Data System (ADS)

Herrero, Carlos P.; Ramírez, Rafael

2011-12-01

The effect of pressure on structural and thermodynamic properties of ice Ih has been studied by means of path-integral molecular dynamics simulations at temperatures between 50 and 300 K. Interatomic interactions were modeled by using the effective q-TIP4P/F potential for flexible water. Positive (compression) and negative (tension) pressures have been considered, which allowed us to approach the limits for the mechanical stability of this solid water phase. We have studied the pressure dependence of the crystal volume, bulk modulus, interatomic distances, atomic delocalization, and kinetic energy. The spinodal point at both negative and positive pressures is derived from the vanishing of the bulk modulus. For P<0, the spinodal pressure changes from -1.38 to - 0.73 GPa in the range from 50 to 300 K. At positive pressure the spinodal is associated with ice amorphization, and at low temperatures it is found to be between 1.1 and 1.3 GPa. Quantum nuclear effects cause a reduction of the metastability region of ice Ih.

The potential of bio-methane as bio-fuel/bio-energy for reducing greenhouse gas emissions: a qualitative assessment for Europe in a life cycle perspective.

PubMed

Tilche, Andrea; Galatola, Michele

2008-01-01

Anaerobic digestion is a well known process that (while still capable of showing new features) has experienced several waves of technological development. It was "born" as a wastewater treatment system, in the 1970s showed promise as an alternative energy source (in particular from animal waste), in the 1980s and later it became a standard for treating organic-matter-rich industrial wastewater, and more recently returned to the market for its energy recovery potential, making use of different biomasses, including energy crops. With the growing concern around global warming, this paper looks at the potential of anaerobic digestion in terms of reduction of greenhouse gas (GHG) emissions. The potential contribution of anaerobic digestion to GHG reduction has been computed for the 27 EU countries on the basis of their 2005 Kyoto declarations and using life cycle data. The theoretical potential contribution of anaerobic digestion to Kyoto and EU post-Kyoto targets has been calculated. Two different possible biogas applications have been considered: electricity production from manure waste, and upgraded methane production for light goods vehicles (from landfill biogas and municipal and industrial wastewater treatment sludges). The useful heat that can be produced as by-product from biogas conversion into electricity has not been taken into consideration, as its real exploitation depends on local conditions. Moreover the amount of biogas already produced via dedicated anaerobic digestion processes has also not been included in the calculations. Therefore the overall gains achievable would be even higher than those reported here. This exercise shows that biogas may considerably contribute to GHG emission reductions in particular if used as a biofuel. Results also show that its use as a biofuel may allow for true negative GHG emissions, showing a net advantage with respect to other biofuels. Considering also energy crops that will become available in the next few years as a result of Common Agricultural Policy (CAP) reform, this study shows that biogas has the potential of covering almost 50% of the 2020 biofuel target of 10% of all automotive transport fuels, without implying a change in land use. Moreover, considering the achievable GHG reductions, a very large carbon emission trading "value" could support the investment needs.However, those results were obtained through a "qualitative" assessment. In order to produce robust data for decision makers, a quantitative sustainability assessment should be carried out, integrating different methodologies within a life cycle framework. The identification of the most appropriate policy for promoting the best set of options is then discussed.

Tranilast reduces serum IL-6 and IL-13 and protects against thioacetamide-induced acute liver injury and hepatic encephalopathy.

PubMed

Abdelaziz, Rania R; Elkashef, Wagdi F; Said, Eman

2015-07-01

Hepatic encephalopathy is a serious neuropsychiatric disorder usually affecting either acute or chronic hepatic failure patients. Hepatic encephalopathy was replicated in a validated rat model to assess the potential protective efficacy of tranilast against experimentally induced hepatic encephalopathy. Thioacetamide injection significantly impaired hepatic synthetic, metabolic and excretory functions with significant increase in serum NO, IL-6 and IL-13 levels and negative shift in the oxidant/antioxidant balance. Most importantly, there was a significant increase in serum ammonia levels with significant astrocytes' swelling and vacuolization; hallmarks of hepatic encephalopathy. Tranilast administration (300 mg/kg, orally) for 15 days significantly improved hepatic functions, restored oxidant/antioxidant balance, reduced serum NO, IL-6 and IL-13 levels. Meanwhile, serum ammonia significantly declined with significant reduction in astrocytes' swelling and vacuolization. Several mechanisms can be implicated in the observed hepato- and neuroprotective potentials of tranilast, such as its anti-inflammatory potential, its antioxidant potential as well as its immunomodulatory properties. Copyright © 2015 Elsevier B.V. All rights reserved.

The use of whey or skimmed milk powder in fortified blended foods for vulnerable groups.

PubMed

Hoppe, Camilla; Andersen, Gregers S; Jacobsen, Stine; Mølgaard, Christian; Friis, Henrik; Sangild, Per T; Michaelsen, Kim F

2008-01-01

Fortified blended foods (FBF), especially corn soy blend, are used as food aid for millions of people worldwide, especially malnourished individuals and vulnerable groups. There are only a few studies evaluating the effect of FBF on health outcomes, and the potential negative effect of antinutrients has not been examined. Different lines of evidence suggest that dairy proteins have beneficial effects on vulnerable groups. Here we review the evidence on the effects of adding whey or skimmed milk powder to FBF used for malnourished infants and young children or people living with HIV or AIDS. Adding whey or skimmed milk powder to FBF improves the protein quality, allowing a reduction in total amount of protein, which could have potential metabolic advantages. It also allows for a reduced content of soy and cereal and thereby a reduction of potential antinutrients. It is possible that adding milk could improve weight gain, linear growth, and recovery from malnutrition, but this needs to be confirmed. Bioactive factors in whey might have beneficial effects on the immune system and muscle synthesis, but evidence from vulnerable groups is lacking. Milk proteins will improve flavor, which is important for acceptability in vulnerable groups. The most important disadvantage is a considerable increase in price. Adding 10-15% milk powder would double the price, which means that such a product should be used only in well-defined vulnerable groups with special needs. The potential beneficial effects of adding milk protein and lack of evidence in vulnerable groups call for randomized intervention studies.

Calcium current in isolated neonatal rat ventricular myocytes.

PubMed Central

Cohen, N M; Lederer, W J

1987-01-01

1. Calcium currents (ICa) from neonatal rat ventricular heart muscle cells grown in primary culture were examined using the 'whole-cell' voltage-clamp technique (Hamill, Marty, Neher, Sakmann & Sigworth, 1981). Examination of ICa was limited to one calcium channel type, 'L' type (Nilius, Hess, Lansman & Tsien, 1985), by appropriate voltage protocols. 2. We measured transient and steady-state components of ICa, and could generally describe ICa in terms of the steady-state activation (d infinity) and inactivation (f infinity) parameters. 3. We observed that the reduction of ICa by the calcium channel antagonist D600 can be explained by both a shift of d infinity to more positive potentials as well as a slight reduction of ICa conductance. D600 did not significantly alter either the rate of inactivation of ICa or the voltage dependence of f infinity. 4. The calcium channel modulator BAY K8644 shifted both d infinity and f infinity to more negative potentials. Additionally, BAY K8644 increased the rate of inactivation at potentials between +5 and +55 mV. Furthermore, BAY K8644 also increased ICa conductance, a change consistent with a promotion of 'mode 2' calcium channel activity (Hess, Lansman & Tsien, 1984). 5. We conclude that, as predicted by d infinity and f infinity, there is a significant steady-state component of ICa ('window current') at plateau potentials in neonatal rat heart cells. Modulation of the steady-state and transient components of ICa by various agents can be attributed both to specific alterations in d infinity and f infinity and to more complicated alterations in the mode of calcium channel activity. PMID:2451004

Frontal D2/3 Receptor Availability in Schizophrenia Patients Before and After Their First Antipsychotic Treatment: Relation to Cognitive Functions and Psychopathology.

PubMed

Nørbak-Emig, Henrik; Ebdrup, Bjørn H; Fagerlund, Birgitte; Svarer, Claus; Rasmussen, Hans; Friberg, Lars; Allerup, Peter N; Rostrup, Egill; Pinborg, Lars H; Glenthøj, Birte Y

2016-05-01

We have previously reported associations between frontal D2/3 receptor binding potential positive symptoms and cognitive deficits in antipsychotic-naïve schizophrenia patients. Here, we examined the effect of dopamine D2/3 receptor blockade on cognition. Additionally, we explored the relation between frontal D2/3 receptor availability and treatment effect on positive symptoms. Twenty-five antipsychotic-naïve first-episode schizophrenia patients were examined with the Positive and Negative Syndrome Scale, tested with the cognitive test battery Cambridge Neuropsychological Test Automated Battery, scanned with single-photon emission computerized tomography using the dopamine D2/3 receptor ligand [(123)I]epidepride, and scanned with MRI. After 3 months of treatment with either risperidone (n=13) or zuclopenthixol (n=9), 22 patients were reexamined. Blockade of extrastriatal dopamine D2/3 receptors was correlated with decreased attentional focus (r = -0.615, P=.003) and planning time (r = -0.436, P=.048). Moreover, baseline frontal dopamine D2/3 binding potential and positive symptom reduction correlated positively (D2/3 receptor binding potential left frontal cortex rho = 0.56, P=.003; D2/3 receptor binding potential right frontal cortex rho = 0.48, P=.016). Our data support the hypothesis of a negative influence of D2/3 receptor blockade on specific cognitive functions in schizophrenia. This is highly clinically relevant given the well-established association between severity of cognitive disturbances and a poor functional outcome in schizophrenia. Additionally, the findings support associations between frontal D2/3 receptor binding potential at baseline and the effect of antipsychotic treatment on positive symptoms. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Plant Survival and Mortality during Drought Can be Mediated by Co-occurring Species' Physiological and Morphological Traits: Results from a Model

NASA Astrophysics Data System (ADS)

Tai, X.; Mackay, D. S.

2015-12-01

Interactions among co-occurring species are mediated by plant physiology, morphology and environment. Without proper mechanisms to account for these factors, it remains difficult to predict plant mortality/survival under changing climate. A plant ecophysiological model, TREES, was extended to incorporate co-occurring species' belowground interaction for water. We used it to examine the interaction between two commonly co-occurring species during drought experiment, pine (Pinus edulis) and juniper (Juniperus monosperma), with contrasting physiological traits (vulnerability to cavitation and leaf water potential regulation). TREES was parameterized and validated using field-measured plant physiological traits. The root architecture (depth, profile, and root area to leaf area ratio) of juniper was adjusted to see how root morphology could affect the survival/mortality of its neighboring pine under both ambient and drought conditions. Drought suppressed plant water and carbon uptake, as well increased the average percentage loss of conductivity (PLC). Pine had 59% reduction in water uptake, 48% reduction in carbon uptake, and 38% increase in PLC, while juniper had 56% reduction in water uptake, 50% reduction in carbon and 29% increase in PLC, suggesting different vulnerability to drought as mediated by plant physiological traits. Variations in juniper root architecture further mediated drought stress on pine, from negative to positive. Different juniper root architecture caused variations in response of pine over drought (water uptake reduction ranged 0% ~63%, carbon uptake reduction ranged 0% ~ 70%, and PLC increase ranged 2% ~ 91%). Deeper or more uniformly distributed roots of juniper could effectively mitigate stress experienced by pine. In addition, the total water and carbon uptake tended to increase as the ratio of root area to leaf area increased while PLC showed non-monotonic response, suggesting the potential trade-off between maximizing resource uptake and susceptibility to cavitation. The results showed that co-occurring species' morphological traits could alleviate or aggravate stress imposed by drought and should therefore be considered together with plant physiological traits in predicting plant mortality and ecosystem structural shift under future climate conditions.

Veterinarians' attitudes toward antimicrobial use and selective dry cow treatment in the Netherlands.

PubMed

Scherpenzeel, C G M; Santman-Berends, I M G A; Lam, T J G M

2018-03-28

In the Netherlands, regulations have been in place since 2008 to reduce the overall use of antimicrobials to mitigate antimicrobial resistance. As part of these regulations, a ban on the preventive use of antimicrobials, such as applying blanket dry cow treatment, was introduced and alternative measures such as selective dry cow treatment (SDCT) were implemented. Both farmers and veterinarians play an important role in implementing these measures and have a shared responsibility with respect to prudent antimicrobial use (AMU). The attitude of Dutch dairy veterinarians toward restricted AMU and toward SDCT is unknown, but a favorable attitude toward this approach seems crucial for successful implementation. In 2015, an online questionnaire was collected from 181 veterinarians that contained questions with regard to their attitude and behavior toward reduction of AMU and toward SDCT. Descriptive statistics were used to describe the data, and multivariable logistic regression models with a logit link function were applied to evaluate potential associations between veterinarians' attitudes toward AMU and SDCT and the rationale behind their mindset, based on positive and negative aspects of reduction in AMU. The veterinarians were divided into 3 groups based on their opinion on 4 statements with regard to AMU and SDCT: veterinarians with an unfavorable, a neutral, and a favorable attitude toward reduction of AMU and toward SDCT. For the multivariable logistic regression analysis, the first 2 groups were combined and compared with the veterinarians with a favorable attitude. The general attitude of Dutch dairy veterinarians toward reduction of AMU was positive, and most expressed the belief that they can still be a good veterinarian when they prescribe less antimicrobials. Veterinarians indicated they progressively promoted SDCT beginning in 2013. Most veterinarians see the advice they provide to farmers on SDCT as the best possible approach and are convinced that their farmers apply this SDCT approach. The results of the multivariable analyses showed that veterinarians with a favorable attitude mentioned positive aspects of SDCT, such as an increased consciousness of AMU among farmers, improving animal health, reducing antimicrobial resistance, and a chance to add value for the farmer, more often than other veterinarians. The latter group significantly more often indicated negative aspects of SDCT, such as a higher risk of sick cows and feeling pushed to follow the rules. In conclusion, the general attitude of Dutch dairy veterinarians toward reduction of AMU and SDCT was found to be positive. However, given the influence veterinarians potentially have on the attitude of farmers and the variability found in their attitude and behavior, veterinarians need specific attention if regional or national programs are organized trying to change behavior of farmers and encourage prudent AMU and SDCT. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Retrospective clinical evaluation of gauze-based negative pressure wound therapy.

PubMed

Campbell, Penny E; Smith, Gary S; Smith, Jennifer M

2008-06-01

Negative pressure wound therapy (NPWT) is an established modality in the treatment of challenging wounds. However, most existing clinical evidence is derived from the use of open-cell polyurethane foam at -125 mmHg. Alternative negative pressure systems are becoming available, which use gauze at a pressure of -80 mmHg. This study describes clinical results from a retrospective non comparative analysis of 30 patients treated with Chariker-Jeter gauze-based negative pressure systems (V1STA, Versatile-1 and EZ-Care; Smith & Nephew, Inc.) in a long-term care setting. The mean age of the patients was 72 years. The wounds consisted of chronic (n = 11), surgical dehiscence (n = 11) and surgical incision (n = 8). Wound volume and area were recorded at commencement and at the cessation of therapy. Discontinuation of therapy was instigated upon closure through secondary intention or when size and exudate were sufficiently reduced that the wounds could be managed by conventional wound dressing (median 41 days). An overall median reduction in wound volume of 88.0% (P < 0.001) and a 68.0% reduction in area (P < 0.001) compared with baseline were observed over the course of NPWT. The overall rate of volume reduction (15.1% per week) compares favourably with published data from foam-based systems.

Orphan Gpr182 suppresses ERK-mediated intestinal proliferation during regeneration and adenoma formation

PubMed Central

Kechele, Daniel O.; Blue, R. Eric; Zwarycz, Bailey; Espenschied, Scott T.; Mah, Amanda T.; Siegel, Marni B.; Perou, Charles M.; Ding, Shengli; Magness, Scott T.; Lund, P. Kay

2017-01-01

Orphan GPCRs provide an opportunity to identify potential pharmacological targets, yet their expression patterns and physiological functions remain challenging to elucidate. Here, we have used a genetically engineered knockin reporter mouse to map the expression pattern of the Gpr182 during development and adulthood. We observed that Gpr182 is expressed at the crypt base throughout the small intestine, where it is enriched in crypt base columnar stem cells, one of the most active stem cell populations in the body. Gpr182 knockdown had no effect on homeostatic intestinal proliferation in vivo, but led to marked increases in proliferation during intestinal regeneration following irradiation-induced injury. In the ApcMin mouse model, which forms spontaneous intestinal adenomas, reductions in Gpr182 led to more adenomas and decreased survival. Loss of Gpr182 enhanced organoid growth efficiency ex vivo in an EGF-dependent manner. Gpr182 reduction led to increased activation of ERK1/2 in basal and challenge models, demonstrating a potential role for this orphan GPCR in regulating the proliferative capacity of the intestine. Importantly, GPR182 expression was profoundly reduced in numerous human carcinomas, including colon adenocarcinoma. Together, these results implicate Gpr182 as a negative regulator of intestinal MAPK signaling–induced proliferation, particularly during regeneration and adenoma formation. PMID:28094771

A dual-plate ITO-ITO generator-collector microtrench sensor: surface activation, spatial separation and suppression of irreversible oxygen and ascorbate interference.

PubMed

Hasnat, Mohammad A; Gross, Andrew J; Dale, Sara E C; Barnes, Edward O; Compton, Richard G; Marken, Frank

2014-02-07

Generator-collector electrode systems are based on two independent working electrodes with overlapping diffusion fields where chemically reversible redox processes (oxidation and reduction) are coupled to give amplified current signals. A generator-collector trench electrode system prepared from two tin-doped indium oxide (ITO) electrodes placed vis-à-vis with a 22 μm inter-electrode gap is employed here as a sensor in aqueous media. The reversible 2-electron anthraquinone-2-sulfonate redox system is demonstrated to give well-defined collector responses even in the presence of oxygen due to the irreversible nature of the oxygen reduction. For the oxidation of dopamine on ITO, novel "Piranha-activation" effects are observed and chemically reversible generator-collector feedback conditions are achieved at pH 7, by selecting a more negative collector potential, again eliminating possible oxygen interference. Finally, dopamine oxidation in the presence of ascorbate is demonstrated with the irreversible oxidation of ascorbate at the "mouth" of the trench electrode and chemically reversible oxidation of dopamine in the trench "interior". This spatial separation of chemically reversible and irreversible processes within and outside the trench is discussed as a potential in situ microscale sensing and separation tool.

Response of ammonia oxidizing bacteria and archaea to acute zinc stress and different moisture regimes in soil.

PubMed

Vasileiadis, Sotirios; Coppolecchia, Damiano; Puglisi, Edoardo; Balloi, Annalisa; Mapelli, Francesca; Hamon, Rebecca E; Daffonchio, Daniele; Trevisan, Marco

2012-11-01

Ammonia oxidation has been intensively studied for its sensitivity to environmental shifts and stresses. However, acute stress effects on the occurrence and composition of ammonia oxidizing bacteria (AOB) and archaea (AOA) based on expression of related molecular markers in complex soil environments have been to an extent overlooked, particularly concerning transient but commonly occurring environmental changes like soil moisture shifts. The present study investigates the responses of AOB and AOA to moisture shifts and high Zn soil content. AmoA gene copies and transcripts of AOB and AOA along with potential nitrification activity were measured in a soil microcosm approach for investigating the referred environmental shifts. Moisture change from 87 to 50 % of the water holding capacity caused a ~99 % reduction of AOB but not of AOA amoA transcripts that did not change significantly. Increasing applied zinc concentrations resulted in a reduction of potential nitrification rates and negatively affected studied gene expressions of both AOB and AOA, with AOB being more responsive. Both 16 S rRNA and amoA transcripts of AOB had an inverse relation to the applied zinc, indicating a gradual loss in total cell activity. Our results suggest the existence of pronounced differences between AOB and AOA concerning ammonia oxidation activity.

Prediction of Reduction Potentials of Copper Proteins with Continuum Electrostatics and Density Functional Theory.

PubMed

Fowler, Nicholas J; Blanford, Christopher F; Warwicker, Jim; de Visser, Sam P

2017-11-02

Blue copper proteins, such as azurin, show dramatic changes in Cu 2+ /Cu + reduction potential upon mutation over the full physiological range. Hence, they have important functions in electron transfer and oxidation chemistry and have applications in industrial biotechnology. The details of what determines these reduction potential changes upon mutation are still unclear. Moreover, it has been difficult to model and predict the reduction potential of azurin mutants and currently no unique procedure or workflow pattern exists. Furthermore, high-level computational methods can be accurate but are too time consuming for practical use. In this work, a novel approach for calculating reduction potentials of azurin mutants is shown, based on a combination of continuum electrostatics, density functional theory and empirical hydrophobicity factors. Our method accurately reproduces experimental reduction potential changes of 30 mutants with respect to wildtype within experimental error and highlights the factors contributing to the reduction potential change. Finally, reduction potentials are predicted for a series of 124 new mutants that have not yet been investigated experimentally. Several mutants are identified that are located well over 10 Å from the copper center that change the reduction potential by more than 85 mV. The work shows that secondary coordination sphere mutations mostly lead to long-range electrostatic changes and hence can be modeled accurately with continuum electrostatics. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

High-quality collection and disposal of WEEE: Environmental impacts and resultant issues.

PubMed

Baxter, John; Lyng, Kari-Anne; Askham, Cecilia; Hanssen, Ole Jørgen

2016-11-01

Life cycle assessment of the collection, transport and recycling of various types of waste electrical and electronic equipment (WEEE) in Norway shows that small amounts of critical materials (refrigerants, precious/trace metals) are vital for the overall environmental accounts of the value chains. High-quality recycling ensures that materials and energy are effectively recovered from WEEE. This recovery means that responsible waste handling confers net environmental benefits in terms of global warming potential (GWP), for all types of WEEE analysed. For refrigeration equipment, the potential reduction of GWP by high-quality recycling is so large as to be of national significance. For all waste types, the magnitude of the net benefit from recovering materials and energy exceeds the negative consequences of irresponsible disposal. One outcome of this may be widespread misunderstanding of the need for recycling. Furthermore, framing public communication on recycling in terms of avoiding negative consequences, as is essentially universal, may not convey an appropriate message. The issue is particularly important where the consumer regards products as relatively disposable and environmentally benign, and/or where the "null option" of retaining the product at end-of-life is especially prevalent. The paper highlights the implications of all these issues for policy-makers, waste collectors and recyclers, and consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Time course of emotion-related responding during distraction and reappraisal

PubMed Central

Schönfelder, Sandra; Kanske, Philipp; Heissler, Janine

2014-01-01

Theoretical accounts of emotion regulation (ER) discriminate various cognitive strategies to voluntarily modify emotional states. Amongst these, attentional deployment (i.e. distraction) and cognitive change (i.e. reappraisal), have been shown to successfully down-regulate emotions. Neuroimaging studies found that both strategies differentially engage neural structures associated with selective attention, working memory and cognitive control. The aim of this study was to further delineate similarities and differences between the ER strategies reappraisal and distraction by investigating their temporal brain dynamics using event-related potentials (ERPs) and their patterns of facial expressive behavior. Twenty-one participants completed an ER experiment in which they had to either passively view positive, neutral and negative pictures, reinterpret them to down-regulate affective responses (reappraisal), or solve a concurrently presented mathematical equation (distraction). Results demonstrate the efficacy of both strategies in the subjective control of emotion, accompanied by reductions of facial expressive activity (Corrugator supercilii and Zygomaticus major). ERP results indicated that distraction, compared with reappraisal, yielded a stronger and earlier attenuation of the late positive potential (LPP) magnitude for negative pictures. For positive pictures, only distraction but not reappraisal had significant effect on LPP attenuation. The results support the process model of ER, separating subtypes of cognitive strategies based on their specific time course. PMID:23988760

Benthic iron cycling in a high-oxygen environment: Implications for interpreting the Archean sedimentary iron isotope record.

PubMed

McCoy, V E; Asael, D; Planavsky, N

2017-09-01

The most notable trend in the sedimentary iron isotope record is a shift at the end of the Archean from highly variable δ 56 Fe values with large negative excursions to less variable δ 56 Fe values with more limited negative values. The mechanistic explanation behind this trend has been extensively debated, with two main competing hypotheses: (i) a shift in marine redox conditions and the transition to quantitative iron oxidation; and (ii) a decrease in the signature of microbial iron reduction in the sedimentary record because of increased bacterial sulfate reduction (BSR). Here, we provide new insights into this debate and attempt to assess these two hypotheses by analyzing the iron isotope composition of siderite concretions from the Carboniferous Mazon Creek fossil site. These concretions precipitated in an environment with water column oxygenation, extensive sediment pile dissimilatory iron reduction (DIR) but limited bacterial sulfate reduction (BSR). Most of the concretions have slightly positive iron isotope values, with a mean of 0.15‰ and limited iron isotope variability compared to the Archean sedimentary record. This limited variability in an environment with high DIR and low BSR suggests that these conditions alone are insufficient to explain Archean iron isotope compositions. Therefore, these results support the idea that the unusually variable and negative iron isotope values in the Archean are due to dissimilatory iron reduction (DIR) coupled with extensive water column iron cycling. © 2017 John Wiley & Sons Ltd.

Biomimetic synthesis of selenium nanoparticles by Pseudomonas aeruginosa ATCC 27853: An approach for conversion of selenite.

PubMed

Kora, Aruna Jyothi; Rastogi, Lori

2016-10-01

A facile and green method for the reduction of selenite was developed using a Gram-negative bacterial strain Pseudomonas aeruginosa, under aerobic conditions. During the process of bacterial conversion, the elemental selenium nanoparticles were produced. These nanoparticles were systematically characterized using various analytical techniques including UV-visible spectroscopy, XRD, Raman spectroscopy, SEM, DLS, TEM and FTIR spectroscopy techniques. The generation of selenium nanoparticles was confirmed from the appearance of red colour in the culture broth and broad absorption peaks in the UV-vis. The synthesized nanoparticles were spherical, polydisperse, ranged from 47 to 165 nm and the average particle size was about 95.9 nm. The selected-area electron diffraction, XRD patterns; and Raman spectroscopy established the amorphous nature of the fabricated nanoparticles. The IR data demonstrated the bacterial protein mediated selenite reduction and capping of the produced nanoparticles. The selenium removal was assessed at different selenite concentrations using ICP-OES and the results showed that the tested bacterial strain exhibited significant selenite reduction activity. The results demonstrate the possible application of P. aeruginosa for bioremediation of waters polluted with toxic and soluble selenite. Moreover, the potential metal reduction capability of the bacterial strain can function as green method for aerobic generation of selenium nanospheres. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impacts of aerosol mitigation on Chinese rice photosynthesis: An integrated modeling approach

NASA Astrophysics Data System (ADS)

Zhang, T.; Li, T.; Yue, X.; Yang, X.

2017-12-01

Aerosol pollution in China is significantly altering radiative transfer processes and is thereby potentially affecting rice photosynthesis. However, the response of rice photosynthesis to aerosol-induced radiative perturbations is still not well understood. Here, we employ an integrated process-based modeling approach to simulate changes in incoming radiation (RAD) and the diffuse radiation fraction (DF) with aerosol mitigation in China and their associated impacts on rice yields. Aerosol reduction has the positive effect of increasing RAD and the negative effect of decreasing DF on rice photosynthesis and yields. In rice production areas where the average RAD during the growing season is lower than 250 W m-2, aerosol reduction is beneficial for higher rice yields, whereas in areas with RAD>250 W m-2, aerosol mitigation causes yield declines due to the associated reduction in the DF, which decreases the light use efficiency. This response pattern and threshold are similar with observations, even through more data are needed in future investigation. As a net effect, rice yields were estimated to significantly increase by 0.8-2.6% with aerosol concentrations reductions from 20 to 100%, which is lower than the estimates obtained in earlier studies that only considered the effects of RAD. This finding suggests that both RAD and DF are important processes influencing rice yields and should be incorporated into future assessments of agricultural responses to variations in aerosol-induced radiation under climate change.

Modeling Future Conservation of Hawaiian Honeycreepers by Mosquito Management and Translocation of Disease-Tolerant Amakihi

PubMed Central

Hobbelen, Peter H. F.; Samuel, Michael D.; LaPointe, Dennis A.; Atkinson, Carter T.

2012-01-01

Avian malaria is an important cause of the decline of endemic Hawaiian honeycreepers. Because of the complexity of this disease system we used a computer model of avian malaria in forest birds to evaluate how two proposed conservation strategies: 1) reduction of habitat for mosquito larvae and 2) establishment of a low-elevation, malaria-tolerant honeycreeper (Hawaii Amakihi) to mid-elevation forests would affect native Hawaiian honeycreeper populations. We evaluated these approaches in mid-elevation forests, where malaria transmission is seasonal and control strategies are more likely to work. Our model suggests the potential benefit of larval habitat reduction depends on the level of malaria transmission, abundance of larval cavities, and the ability to substantially reduce these cavities. Permanent reduction in larval habitat of >80% may be needed to control abundance of infectious mosquitoes and benefit bird populations. Establishment of malaria-tolerant Amakihi in mid-elevation forests increases Amakihi abundance, creates a larger disease reservoir, and increases the abundance of infectious mosquitoes which may negatively impact other honeycreepers. For mid-elevation sites where bird populations are severely affected by avian malaria, malaria-tolerant Amakihi had little impact on other honeycreepers. Both management strategies may benefit native Hawaiian honeycreepers, but benefits depend on specific forest characteristics, the amount of reduction in larval habitat that can be achieved, and how malaria transmission is affected by temperature. PMID:23185375

Modeling future conservation of Hawaiian Honeycreepers by mosquito management and translocation of disease-tolerant Amakihi

USGS Publications Warehouse

Hobbelen, Peter H. F.; Samuel, Michael D.; Lapointe, Dennis; Atkinson, Carter T.

2012-01-01

Avian malaria is an important cause of the decline of endemic Hawaiian honeycreepers. Because of the complexity of this disease system we used a computer model of avian malaria in forest birds to evaluate how two proposed conservation strategies: 1) reduction of habitat for mosquito larvae and 2) establishment of a low-elevation, malaria-tolerant honeycreeper (Hawaii Amakihi) to mid-elevation forests would affect native Hawaiian honeycreeper populations. We evaluated these approaches in mid-elevation forests, where malaria transmission is seasonal and control strategies are more likely to work. Our model suggests the potential benefit of larval habitat reduction depends on the level of malaria transmission, abundance of larval cavities, and the ability to substantially reduce these cavities. Permanent reduction in larval habitat of >80% may be needed to control abundance of infectious mosquitoes and benefit bird populations. Establishment of malaria-tolerant Amakihi in mid-elevation forests increases Amakihi abundance, creates a larger disease reservoir, and increases the abundance of infectious mosquitoes which may negatively impact other honeycreepers. For mid-elevation sites where bird populations are severely affected by avian malaria, malaria-tolerant Amakihi had little impact on other honeycreepers. Both management strategies may benefit native Hawaiian honeycreepers, but benefits depend on specific forest characteristics, the amount of reduction in larval habitat that can be achieved, and how malaria transmission is affected by temperature.

Atomistic determinants of co-enzyme Q reduction at the Qi-site of the cytochrome bc1 complex

NASA Astrophysics Data System (ADS)

Postila, Pekka A.; Kaszuba, Karol; Kuleta, Patryk; Vattulainen, Ilpo; Sarewicz, Marcin; Osyczka, Artur; Róg, Tomasz

2016-09-01

The cytochrome (cyt) bc1 complex is an integral component of the respiratory electron transfer chain sustaining the energy needs of organisms ranging from humans to bacteria. Due to its ubiquitous role in the energy metabolism, both the oxidation and reduction of the enzyme’s substrate co-enzyme Q has been studied vigorously. Here, this vast amount of data is reassessed after probing the substrate reduction steps at the Qi-site of the cyt bc1 complex of Rhodobacter capsulatus using atomistic molecular dynamics simulations. The simulations suggest that the Lys251 side chain could rotate into the Qi-site to facilitate binding of half-protonated semiquinone - a reaction intermediate that is potentially formed during substrate reduction. At this bent pose, the Lys251 forms a salt bridge with the Asp252, thus making direct proton transfer possible. In the neutral state, the lysine side chain stays close to the conserved binding location of cardiolipin (CL). This back-and-forth motion between the CL and Asp252 indicates that Lys251 functions as a proton shuttle controlled by pH-dependent negative feedback. The CL/K/D switching, which represents a refinement to the previously described CL/K pathway, fine-tunes the proton transfer process. Lastly, the simulation data was used to formulate a mechanism for reducing the substrate at the Qi-site.

Neutral mood induction during reconsolidation reduces accuracy, but not vividness and anxiety of emotional episodic memories.

PubMed

Liu, Guanyu; McNally, Richard J

2017-03-01

Consolidated memories become labile upon reactivation and as a result have to go through reconsolidation to become re-stabilized. This property of memory may potentially be used to reduce the impact of highly negative episodic memories. Because detailed and vivid negative memories are mediated by high arousal, if arousal is lessened during reconsolidation, memory accuracy and vividness should diminish. In this study, we examined this hypothesis. Participants (N = 72) viewed a stressful, suspenseful video on Day 1 to develop negative episodic memories. Then, 24-29 h later, they saw a brief reminder of the stressful video (or not), and then viewed a neutral, calming (or positive) video. Another 24-29 h later, participants were tested on the accuracy, vividness, and anxiety associated with their memory of the stressful video on Day 1. Participants who watched the reminder and then the neutral video showed reduced memory accuracy compared to participants in the other groups. Despite the reduction in memory accuracy, their memory vividness and anxiety associated with the stressful video did not decrease. The use of undergraduates prevents generalizations to clinical populations. Also, the study did not test long-term memories that were more than 2 days old. Neutral mood induction during reconsolidation reduces the accuracy of highly negative episodic memories. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of adhesions of amorphous Fe and Al hydroxides on surface charge and adsorption of K+ and Cd2+ on rice roots.

PubMed

Liu, Zhao-Dong; Wang, Hai-Cui; Zhou, Qin; Xu, Ren-Kou

2017-11-01

Iron (Fe) and aluminum (Al) hydroxides in variable charge soils attached to rice roots may affect surface-charge properties and subsequently the adsorption and uptake of nutrients and toxic metals by the roots. Adhesion of amorphous Fe and Al hydroxides onto rice roots and their effects on zeta potential of roots and adsorption of potassium (K + ) and cadmium (Cd 2+ ) by roots were investigated. Rice roots adsorbed more Al hydroxide than Fe hydroxide because of the greater positive charge on Al hydroxide. Adhesion of Fe and Al hydroxides decreased the negative charge on rice roots, and a greater effect of the Al hydroxide. Consequently, adhesion of Fe and Al hydroxides reduced the K + and Cd 2+ adsorption by rice roots. The results of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and desorption of K + and Cd 2+ from rice roots indicated that physical masking by Fe and Al hydroxides and diffuse-layer overlapping between the positively-charged hydroxides and negatively-charged roots were responsible for the reduction of negative charge on roots induced by adhesion of the hydroxides. Therefore, the interaction between Fe and Al hydroxides and rice roots reduced negative charge on roots and thus inhibited their adsorption of nutrient and toxic cations. Copyright © 2017 Elsevier Inc. All rights reserved.

Neural circuits in the brain that are activated when mitigating criminal sentences.

PubMed

Yamada, Makiko; Camerer, Colin F; Fujie, Saori; Kato, Motoichiro; Matsuda, Tetsuya; Takano, Harumasa; Ito, Hiroshi; Suhara, Tetsuya; Takahashi, Hidehiko

2012-03-27

In sentencing guilty defendants, jurors and judges weigh 'mitigating circumstances', which create sympathy for a defendant. Here we use functional magnetic resonance imaging to measure neural activity in ordinary citizens who are potential jurors, as they decide on mitigation of punishment for murder. We found that sympathy activated regions associated with mentalising and moral conflict (dorsomedial prefrontal cortex, precuneus and temporo-parietal junction). Sentencing also activated precuneus and anterior cingulate cortex, suggesting that mitigation is based on negative affective responses to murder, sympathy for mitigating circumstances and cognitive control to choose numerical punishments. Individual differences on the inclination to mitigate, the sentence reduction per unit of judged sympathy, correlated with activity in the right middle insula, an area known to represent interoception of visceral states. These results could help the legal system understand how potential jurors actually decide, and contribute to growing knowledge about whether emotion and cognition are integrated sensibly in difficult judgments.

Potentiation of antimicrobial photodynamic inactivation mediated by a cationic fullerene by added iodide: in vitro and in vivo studies

PubMed Central

Zhang, Yunsong; Dai, Tianhong; Wang, Min; Vecchio, Daniela; Chiang, Long Y; Hamblin, Michael R

2016-01-01

Background Antimicrobial photodynamic inactivation with fullerenes bearing cationic charges may overcome resistant microbes. Methods & results We synthesized C60-fullerene (LC16) bearing decaquaternary chain and deca-tertiary-amino groups that facilitates electron-transfer reactions via the photoexcited fullerene. Addition of the harmless salt, potassium iodide (10 mM) potentiated the ultraviolet A (UVA) or white light-mediated killing of Gram-negative bacteria Acinetobacter baumannii, Gram-positive methicillin-resistant Staphylococcus aureus and fungal yeast Candida albicans by 1–2+ logs. Mouse model infected with bioluminescent Acinetobacter baumannii gave increased loss of bioluminescence when iodide (10 mM) was combined with LC16 and UVA/white light. Conclusion The mechanism may involve photoinduced electron reduction of 1(C60>)* or 3(C60>)* by iodide producing I· or I2 followed by subsequent intermolecular electron-transfer events of (C60>)−· to produce reactive radicals. PMID:25723093

Repetition-Related Reductions in Neural Activity during Emotional Simulations of Future Events.

PubMed

Szpunar, Karl K; Jing, Helen G; Benoit, Roland G; Schacter, Daniel L

2015-01-01

Simulations of future experiences are often emotionally arousing, and the tendency to repeatedly simulate negative future outcomes has been identified as a predictor of the onset of symptoms of anxiety. Nonetheless, next to nothing is known about how the healthy human brain processes repeated simulations of emotional future events. In this study, we present a paradigm that can be used to study repeated simulations of the emotional future in a manner that overcomes phenomenological confounds between positive and negative events. The results show that pulvinar nucleus and orbitofrontal cortex respectively demonstrate selective reductions in neural activity in response to frequently as compared to infrequently repeated simulations of negative and positive future events. Implications for research on repeated simulations of the emotional future in both non-clinical and clinical populations are discussed.

Gene regulation and noise reduction by coupling of stochastic processes

NASA Astrophysics Data System (ADS)

Ramos, Alexandre F.; Hornos, José Eduardo M.; Reinitz, John

2015-02-01

Here we characterize the low-noise regime of a stochastic model for a negative self-regulating binary gene. The model has two stochastic variables, the protein number and the state of the gene. Each state of the gene behaves as a protein source governed by a Poisson process. The coupling between the two gene states depends on protein number. This fact has a very important implication: There exist protein production regimes characterized by sub-Poissonian noise because of negative covariance between the two stochastic variables of the model. Hence the protein numbers obey a probability distribution that has a peak that is sharper than those of the two coupled Poisson processes that are combined to produce it. Biochemically, the noise reduction in protein number occurs when the switching of the genetic state is more rapid than protein synthesis or degradation. We consider the chemical reaction rates necessary for Poisson and sub-Poisson processes in prokaryotes and eucaryotes. Our results suggest that the coupling of multiple stochastic processes in a negative covariance regime might be a widespread mechanism for noise reduction.

Gene regulation and noise reduction by coupling of stochastic processes

PubMed Central

Hornos, José Eduardo M.; Reinitz, John

2015-01-01

Here we characterize the low noise regime of a stochastic model for a negative self-regulating binary gene. The model has two stochastic variables, the protein number and the state of the gene. Each state of the gene behaves as a protein source governed by a Poisson process. The coupling between the the two gene states depends on protein number. This fact has a very important implication: there exist protein production regimes characterized by sub-Poissonian noise because of negative covariance between the two stochastic variables of the model. Hence the protein numbers obey a probability distribution that has a peak that is sharper than those of the two coupled Poisson processes that are combined to produce it. Biochemically, the noise reduction in protein number occurs when the switching of genetic state is more rapid than protein synthesis or degradation. We consider the chemical reaction rates necessary for Poisson and sub-Poisson processes in prokaryotes and eucaryotes. Our results suggest that the coupling of multiple stochastic processes in a negative covariance regime might be a widespread mechanism for noise reduction. PMID:25768447

Gene regulation and noise reduction by coupling of stochastic processes.

PubMed

Ramos, Alexandre F; Hornos, José Eduardo M; Reinitz, John

2015-02-01

Here we characterize the low-noise regime of a stochastic model for a negative self-regulating binary gene. The model has two stochastic variables, the protein number and the state of the gene. Each state of the gene behaves as a protein source governed by a Poisson process. The coupling between the two gene states depends on protein number. This fact has a very important implication: There exist protein production regimes characterized by sub-Poissonian noise because of negative covariance between the two stochastic variables of the model. Hence the protein numbers obey a probability distribution that has a peak that is sharper than those of the two coupled Poisson processes that are combined to produce it. Biochemically, the noise reduction in protein number occurs when the switching of the genetic state is more rapid than protein synthesis or degradation. We consider the chemical reaction rates necessary for Poisson and sub-Poisson processes in prokaryotes and eucaryotes. Our results suggest that the coupling of multiple stochastic processes in a negative covariance regime might be a widespread mechanism for noise reduction.

Extraction, isolation and characterisation of oil bodies from pumpkin seeds for therapeutic use.

PubMed

Adams, Gary G; Imran, Shahwar; Wang, Sheng; Mohammad, Abubaker; Kok, M Samil; Gray, David A; Channell, Guy A; Harding, Stephen E

2012-10-15

Pumpkin, a member of the Cucurbitaceae family has been used frequently as functional medicines for therapeutic use. Several phytochemicals such as polysaccharides, phenolic glycosides, 13-hydroxy-9Z, 11E-octadecatrienoic acid from the leaves of pumpkin, proteins from germinated seeds, have been isolated. Here the influence of pH, ionic strength, and temperature on the properties and stability of oil bodies from pumpkin (Cucurbita) were determined with a view to patterning oil body size and structure for future therapeutic intervention. Oil bodies from pumpkin seeds were extracted, isolated, characterised using optical microscopy, zeta potential and particle size distribution obtained. During microscopic analysis, the oil bodies were more intact and in an integrated form at the time of extraction but were ruptured with time. Water extracted oil bodies were spherical for all four layers where cream had larger oil bodies then upper curd. Lower curd and supernatant had considerably smaller size with lower curd densely packed and seemed to be rich in oil bodies than any of the four layers. At pH 3, in the absence of salt, the zeta potential is approximately +30 mV, but as the salt concentration increases, the ζ potential rises at 10 mM but then decreases over the salt range. This trend continues for the upper curd, lower curd and the supernatant and the degree of the reduction (mV) in zeta potential is of the order cream

Magnetic Field Would Reduce Electron Backstreaming in Ion Thrusters

NASA Technical Reports Server (NTRS)

Foster, John E.

2003-01-01

The imposition of a magnetic field has been proposed as a means of reducing the electron backstreaming problem in ion thrusters. Electron backstreaming refers to the backflow of electrons into the ion thruster. Backstreaming electrons are accelerated by the large potential difference that exists between the ion-thruster acceleration electrodes, which otherwise accelerates positive ions out of the engine to develop thrust. The energetic beam formed by the backstreaming electrons can damage the discharge cathode, as well as other discharge surfaces upstream of the acceleration electrodes. The electron-backstreaming condition occurs when the center potential of the ion accelerator grid is no longer sufficiently negative to prevent electron diffusion back into the ion thruster. This typically occurs over extended periods of operation as accelerator-grid apertures enlarge due to erosion. As a result, ion thrusters are required to operate at increasingly negative accelerator-grid voltages in order to prevent electron backstreaming. These larger negative voltages give rise to higher accelerator grid erosion rates, which in turn accelerates aperture enlargement. Electron backstreaming due to accelerator-gridhole enlargement has been identified as a failure mechanism that will limit ionthruster service lifetime. The proposed method would make it possible to not only reduce the electron backstreaming current at and below the backstreaming voltage limit, but also reduce the backstreaming voltage limit itself. This reduction in the voltage at which electron backstreaming occurs provides operating margin and thereby reduces the magnitude of negative voltage that must be placed on the accelerator grid. Such a reduction reduces accelerator- grid erosion rates. The basic idea behind the proposed method is to impose a spatially uniform magnetic field downstream of the accelerator electrode that is oriented transverse to the thruster axis. The magnetic field must be sufficiently strong to impede backstreaming electrons, but not so strong as to significantly perturb ion trajectories. An electromagnet or permanent magnetic circuit can be used to impose the transverse magnetic field downstream of the accelerator-grid electrode. For example, in the case of an accelerator grid containing straight, parallel rows of apertures, one can apply nearly uniform magnetic fields across all the apertures by the use of permanent magnets of alternating polarity connected to pole pieces laid out parallel to the rows, as shown in the left part of the figure. For low-temperature operation, the pole pieces can be replaced with bar magnets of alternating polarity. Alternatively, for the same accelerator grid, one could use an electromagnet in the form of current-carrying rods laid out parallel to the rows.

Analysis of potential for reducing emissions of greenhouse gases in municipal solid waste in Brazil, in the state and city of Rio de Janeiro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loureiro, S.M., E-mail: saulo@lima.coppe.ufrj.br; Rovere, E.L.L., E-mail: emilio@ppe.ufrj.br; Mahler, C.F., E-mail: mahler0503@yahoo.com

2013-05-15

Highlights: ► We constructed future scenarios of emissions of greenhouse gases in waste. ► Was used the IPCC methodology for calculating emission inventories. ► We calculated the costs of abatement for emissions reduction in landfill waste. ► The results were compared to Brazil, state and city of Rio de Janeiro. ► The higher the environmental passive, the greater the possibility of use of biogas. - Abstract: This paper examines potential changes in solid waste policies for the reduction in GHG for the country of Brazil and one of its major states and cities, Rio de Janeiro, from 2005 to 2030.more » To examine these policy options, trends in solid waste quantities and associated GHG emissions are derived. Three alternative policy scenarios are evaluated in terms of effectiveness, technology, and economics and conclusions posited regarding optimal strategies for Brazil to implement. These scenarios are been building on the guidelines for national inventories of GHG emissions (IPCC, 2006) and adapted to Brazilian states and municipalities’ boundaries. Based on the results, it is possible to say that the potential revenue from products of solid waste management is more than sufficient to transform the current scenario in this country into one of financial and environmental gains, where the negative impacts of climate change have created a huge opportunity to expand infrastructure for waste management.« less

Phylogenetic and functional potential links pH and N2O emissions in pasture soils.

PubMed

Samad, Md Sainur; Biswas, Ambarish; Bakken, Lars R; Clough, Timothy J; de Klein, Cecile A M; Richards, Karl G; Lanigan, Gary J; Morales, Sergio E

2016-10-26

Denitrification is mediated by microbial, and physicochemical, processes leading to nitrogen loss via N 2 O and N 2 emissions. Soil pH regulates the reduction of N 2 O to N 2 , however, it can also affect microbial community composition and functional potential. Here we simultaneously test the link between pH, community composition, and the N 2 O emission ratio (N 2 O/(NO + N 2 O + N 2 )) in 13 temperate pasture soils. Physicochemical analysis, gas kinetics, 16S rRNA amplicon sequencing, metagenomic and quantitative PCR (of denitrifier genes: nirS, nirK, nosZI and nosZII) analysis were carried out to characterize each soil. We found strong evidence linking pH to both N 2 O emission ratio and community changes. Soil pH was negatively associated with N 2 O emission ratio, while being positively associated with both community diversity and total denitrification gene (nir &nos) abundance. Abundance of nosZII was positively linked to pH, and negatively linked to N 2 O emissions. Our results confirm that pH imposes a general selective pressure on the entire community and that this results in changes in emission potential. Our data also support the general model that with increased microbial diversity efficiency increases, demonstrated in this study with lowered N 2 O emission ratio through more efficient conversion of N 2 O to N 2 .

Phylogenetic and functional potential links pH and N2O emissions in pasture soils

NASA Astrophysics Data System (ADS)

Samad, M. D. Sainur; Biswas, Ambarish; Bakken, Lars R.; Clough, Timothy J.; de Klein, Cecile A. M.; Richards, Karl G.; Lanigan, Gary J.; Morales, Sergio E.

2016-10-01

Denitrification is mediated by microbial, and physicochemical, processes leading to nitrogen loss via N2O and N2 emissions. Soil pH regulates the reduction of N2O to N2, however, it can also affect microbial community composition and functional potential. Here we simultaneously test the link between pH, community composition, and the N2O emission ratio (N2O/(NO + N2O + N2)) in 13 temperate pasture soils. Physicochemical analysis, gas kinetics, 16S rRNA amplicon sequencing, metagenomic and quantitative PCR (of denitrifier genes: nirS, nirK, nosZI and nosZII) analysis were carried out to characterize each soil. We found strong evidence linking pH to both N2O emission ratio and community changes. Soil pH was negatively associated with N2O emission ratio, while being positively associated with both community diversity and total denitrification gene (nir & nos) abundance. Abundance of nosZII was positively linked to pH, and negatively linked to N2O emissions. Our results confirm that pH imposes a general selective pressure on the entire community and that this results in changes in emission potential. Our data also support the general model that with increased microbial diversity efficiency increases, demonstrated in this study with lowered N2O emission ratio through more efficient conversion of N2O to N2.

Changes in attention to an emotional task after sleep deprivation: neurophysiological and behavioral findings.

PubMed

Alfarra, Ramey; Fins, Ana I; Chayo, Isaac; Tartar, Jaime L

2015-01-01

While sleep loss is shown to have widespread effects on cognitive processes, little is known about the impact of sleep loss on emotion processes. In order to expand on previous behavioral and physiological findings on how sleep loss influences emotion processing, we administered positive, negative, and neutral affective visual stimuli to individuals after one night of sleep deprivation while simultaneously acquiring EEG event related potential (ERP) data and recording affective behavioral responses. We compared these responses to a baseline testing session. We specifically looked at the late positive potential (LPP) component of the visual ERP as an established sensitive measure of attention to emotionally-charged visual stimuli. Our results show that after sleep deprivation, the LPP no longer discriminates between emotional and non-emotional pictures; after sleep deprivation the LPP amplitude was of similar amplitude for neutral, positive, and negative pictures. This effect was driven by an increase in the LPP to neutral pictures. Our behavioral measures show that, relative to baseline testing, emotional pictures are rated as less emotional following sleep deprivation with a concomitant reduction in emotional picture-induced anxiety. We did not observe any change in cortisol concentrations after sleep deprivation before or after emotional picture exposure, suggesting that the observed changes in emotion processing are independent of potential stress effects of sleep deprivation. Combined, our findings suggest that sleep loss interferes with proper allocation of attention resources during an emotional task. Copyright © 2014 Elsevier B.V. All rights reserved.

Phylogenetic and functional potential links pH and N2O emissions in pasture soils

PubMed Central

Samad, M. d. Sainur; Biswas, Ambarish; Bakken, Lars R.; Clough, Timothy J.; de Klein, Cecile A. M.; Richards, Karl G.; Lanigan, Gary J.; Morales, Sergio E.

2016-01-01

Denitrification is mediated by microbial, and physicochemical, processes leading to nitrogen loss via N2O and N2 emissions. Soil pH regulates the reduction of N2O to N2, however, it can also affect microbial community composition and functional potential. Here we simultaneously test the link between pH, community composition, and the N2O emission ratio (N2O/(NO + N2O + N2)) in 13 temperate pasture soils. Physicochemical analysis, gas kinetics, 16S rRNA amplicon sequencing, metagenomic and quantitative PCR (of denitrifier genes: nirS, nirK, nosZI and nosZII) analysis were carried out to characterize each soil. We found strong evidence linking pH to both N2O emission ratio and community changes. Soil pH was negatively associated with N2O emission ratio, while being positively associated with both community diversity and total denitrification gene (nir & nos) abundance. Abundance of nosZII was positively linked to pH, and negatively linked to N2O emissions. Our results confirm that pH imposes a general selective pressure on the entire community and that this results in changes in emission potential. Our data also support the general model that with increased microbial diversity efficiency increases, demonstrated in this study with lowered N2O emission ratio through more efficient conversion of N2O to N2. PMID:27782174

Advantages of the rapid HIV-1 test in occupational accidents with potentially contaminated material among health workers.

PubMed

Machado, A A; Martinez, R; Haikal, A A; Rodrigues da Silva, M C

2001-01-01

In occupational accidents involving health professionals handling potentially contaminated material, the decision to start or to continue prophylactic medication against infection by Human Immunodeficiency Virus (HIV) has been based on the ELISA test applied to a blood sample from the source patient. In order to rationalize the prophylactic use of antiretroviral agents, a rapid serologic diagnostic test of HIV infection was tested by the enzymatic immunoabsorption method (SUDS HIV 1+2, MUREX) and compared to conventional ELISA (Abbott HIV-1/ HIV-2 3rd Generation plus EIA). A total of 592 cases of occupational accidents were recorded at the University Hospital of Ribeirão Preto from July 1998 to April 1999. Of these, 109 were simultaneously evaluated by the rapid test and by ELISA HIV. The rapid test was positive in three cases and was confirmed by ELISA and in one the result was inconclusive and later found to be negative by ELISA. In the 106 accidents in which the rapid test was negative no prophylactic medication was instituted, with an estimated reduction in costs of US$ 2,889.35. In addition to this advantage, the good correlation of the rapid test with ELISA, the shorter duration of stress and the absence of exposure of the health worker to the adverse effects of antiretroviral agents suggest the adoption of this test in Programs of Attention to Accidents with Potentially Contaminated Material.

Ionic currents in the guinea-pig taenia coli.

PubMed Central

Inomata, H; Kao, C Y

1976-01-01

Short segments of portions of taenia coli of the guinea-pig averaging 54 mum X 219 mum X ca. 200 mum have been studied by a double sucrose-gap voltage-clamp technique. 2. The average total capacitance was 0-4 muF, corresponding to approximately 10(4) cells, if a specific membrane capacitance of 3 muF/cm2 were assumed. 3. A significant resistance, averaging 11-4omega, was in series with the membrane, and seriously limited the accuracy of the voltage control possible. 4. On depolarization, an early transient inward current was followed by a late maintained outwary current. 5. The late current was carried mainly by K+, because its direction could be reversed if the preparation were first depolarized in isotonic K2SO4 and held back to the original resting potential. 6. After appropriate corrections for residual capacitative and leakage currents, a reversal potential for the late current (Eb) was determined to be 15-20 mV more negative than the natural resting potential. It was not affected by the amplitude or the duration of the activating voltage step, but could be changed by prolonged applications of holding current. 7. At rest, the ratio of PNa:PK was 0-16:1; for Eb it was 0-05:1. 8. The reversal potential for the transient early inward current (Ea) averaged 22 mV in Krebs-bicarbonate solution, but was shifted to about 35 mV when the late current was first suppressed with tetraethylammonium ion. The shift suggested that there was some overlap of the early and late currents. 9. Reduction of [Na+]o to 50% of normal, or replacement of all Na+ with dimethyldiethanol ammonium ion and choline ion, failed to cause any significant shifts in the reversal potential of the early current or reduce the magnitude of the early current. 10. Reduction of [Ca2+]o to 0-25 or 0-1 of the normal caused shifts of the Ea toward the negative and reductions in the early current. These changes can occur without changes in the maximum chord conductance of the early current, such as might happen in ordinary Krebs-bicarbonate solution, or in preparations which had been depolarized by prior treatment with isotonic K2SO4 and then held back to the original membrane voltage. 11. Increase of [Ca2+]o to 5 times normal increased the early inward current, and the maximum chord conductances of the early and late currents, but did not shift the Ea. 12. In preparations pretreated with TEA, increasing [Ca2+]o to 5 times normal shifted Ea toward 45 mV. 13. The various observations are interpreted to mean that the early current in the taenia coli is carried principally by influx of Ca2+, and not by Na+. PMID:1255524

Reduction of chromium (VI) on the hetero-system CuBi2O4/TiO2 under solar light

NASA Astrophysics Data System (ADS)

Lahmar, H.; Benamira, M.; Akika, F. Z.; Trari, M.

2017-11-01

The CuBi2O4/TiO2 heterojunction was tested with success for the photo-catalytic reduction of chromate ions under sunlight. CuBi2O4, prepared by nitrate process, was characterised photo-electrochemically. The oxide is stable against photo corrosion by consumption of holes in presence of oxalic acid. The light absorption promotes electrons in the conduction band of the sensitizer (CuBi2O4) with a very negative potential (-1.74 VSCE) to participate in the exchange of the electron with HCrO4-. The enhanced activity is due to electron injection of activated CuBi2O4 into TiO2-CB (-0.97 VSCE). The band gap of the semiconductor CuBi2O4 is 1.50 eV with a direct optical transition. This compound is a p-type semiconductor with a flat band potential of -0.39 VSCE and activation energy of 0.18 eV. The electrochemical impedance spectroscopy was undertaken to study the semiconductor/electrolyte interfacial phenomena. The photoactivity on the heterojunction is strongly enhanced. A remarkable performance is obtained in less than 4 h for a concentration of 30 mg in (Cr (VI)) at pH ∼ 4 and a dose of 1 mg/mL; a 98% reduction has been obtained. The kinetic of chromate photoreduction is well described by the Langmuir-Hinshelwood model. The chromate elimination obeys to a pseudo-first order kinetic with an apparent rate constant of 0.014 min-1.

Nitrogen-induced surface area and conductivity modulation of carbon nanohorn and its function as an efficient metal-free oxygen reduction electrocatalyst for anion-exchange membrane fuel cells.

PubMed

Unni, Sreekuttan M; Bhange, Siddheshwar N; Illathvalappil, Rajith; Mutneja, Nisha; Patil, Kasinath R; Kurungot, Sreekumar

2015-01-21

Nitrogen-doped carbon morphologies have been proven to be better alternatives to Pt in polymer-electrolyte membrane (PEM) fuel cells. However, efficient modulation of the active sites by the simultaneous escalation of the porosity and nitrogen doping, without affecting the intrinsic electrical conductivity, still remains to be solved. Here, a simple strategy is reported to solve this issue by treating single-walled carbon nanohorn (SWCNH) with urea at 800 °C. The resulting nitrogen-doped carbon nanohorn shows a high surface area of 1836 m2 g(-1) along with an increased electron conductivity, which are the pre-requisites of an electrocatalyst. The nitrogen-doped nanohorn annealed at 800 °C (N-800) also shows a high oxygen reduction activity (ORR). Because of the high weight percentage of pyridinic nitrogen coordination in N-800, the present catalyst shows a clear 4-electron reduction pathway at only 50 mV overpotential and 16 mV negative shift in the half-wave potential for ORR compared to Pt/C along with a high fuel selectivity and electrochemical stability. More importantly, a membrane electrode assembly (MEA) based on N-800 provides a maximum power density of 30 mW cm(-2) under anion-exchange membrane fuel cell (AEMFC) testing conditions. Thus, with its remarkable set of physical and electrochemical properties, this material has the potential to perform as an efficient Pt-free electrode for AEMFCs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Suspended particle destabilization in retained urban stormwater as a function of coagulant dosage and redox conditions.

PubMed

Sansalone, John J; Kim, Jong-Yeop

2008-02-01

Source area runoff entrains a hetero-disperse particle size distribution (PSD). When retained for clarification, larger sediment and settleable particles are mainly influenced by gravitational forces, while the suspended particles, in particular the clay-size particles, are subject to coagulation phenomena. Such phenomena occur in untreated runoff as well as runoff treated with a coagulant, albeit to differing rates and extents. Runoff PSDs and water chemistry indices including zeta potential (xi) are potentially modified during inter-event stormwater retention in best management practices (BMPs). This study examined xi of clay-size particles (<2 microm) in retained runoff, captured from an instrumented watershed, subject to batch coagulation and variable redox conditions. Separate parallel tests were also conducted with wastewater. Significant turbidity, particle mass (measured as total suspended solids (TSS)) and volume concentration (as total volume concentration (TVC)) reduction generated by alum and ferric chloride consistently occurred at a xi in the range of -15 to about -10 mV. Alum addition produced a charge reversal at dosing above 60 mg/L (18 x 10(-5)M) while ferric chloride did not reverse charge. With respect to turbidity and TSS reductions, alum outperformed ferric chloride, without the need for pH control. While xi illustrated no clear trend during aerobic retention, anoxic retention resulted in a trend for xi approaching the isoelectric point. The decrease in negative xi towards the isoelectric point appears to be a result of the coupled pH depression under reductive conditions and an increase in conductivity. Results have significant implications for BMPs that retain runoff between events.

Conscientiousness is Negatively Associated with Grey Matter Volume in Young APOE ɛ4-Carriers.

PubMed

Kunz, Lukas; Reuter, Martin; Axmacher, Nikolai; Montag, Christian

2017-01-01

The etiology of late onset Alzheimer's disease (LOAD) depends on multiple factors, among which the APOE ɛ4 allele is the most adverse genetic determinant and conscientiousness represents an influential personality trait. A potential association of both factors with brain structure in young adulthood may constitute a constellation that sets the course toward or against the subtle disease progression of LOAD that starts decades before clinical manifestation. Hence, in the present study, we examined the modulating effects of APOE ɛ4 on the relation between personality dimensions, including conscientiousness, and total grey matter volume (GMV) in young healthy adults using an a priori genotyping design. 105 participants completed an inventory assessing the Five Factor Model of Personality (NEO-FFI) and a structural MRI scan. Total GMV was estimated using both Freesurfer as well as VBM8. Across all participants, total GMV was positively associated with extraversion and negatively related to age. In APOE ɛ4-carriers- but not in APOE ɛ4-non-carriers- conscientiousness was negatively associated with total GMV. In line with the hypothesis of antagonistic pleiotropy of the APOE ɛ4 allele, this result suggests that young APOE ɛ4-carriers with increased total GMV may particularly benefit from cognitive advantages and thus have a lower need to engage in conscientious behavior. In this subset of young APOE ɛ4-carriers, the reduction in conscientiousness could then bring along adverse health behavior in the long run, potentiating the risk for LOAD. Hence, young APOE ɛ4-carriers with increased total GMV may be at a particularly high risk for LOAD.

A New Composite Electrode Applied for Studying the Electrochemistry of Insoluble Particles: α-HgS.

PubMed

Yang, Minjun; Compton, Richard G

2018-05-22

The redox chemistry of solid α-HgS particles is revealed using a carbon/PVDF composite containing α-HgS, carbon black, polyvinylidene fluoride (PVDF). The electrochemical behaviour of the carbon/PVDF composite is first characterised with three water insoluble organic solids. Then the reduction of solid α-HgS particles is investigated and found to occur at a high negative potential, -1.82 V versus saturated mercury sulphate reference electrode, to form metallic mercury and sulphide ions. The subsequent oxidation of metallic mercury and sulphide occurs at +0.24 and -0.49 V versus MSE respectively. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of microbial Fe(III) reduction and solution chemistry in aggregation and settling of suspended particles in the Mississippi River Delta plain, Louisiana, USA

USGS Publications Warehouse

Jaisi, Deb P.; Ji, Shanshan; Dong, Hailiang; Blake, Ruth E.; Eberl, Dennis D.; Kim, Jinwook

2008-01-01

River-dominated delta areas are primary sites of active biogeochemical cycling, with productivity enhanced by terrestrial inputs of nutrients. Particle aggregation in these areas primarily controls the deposition of suspended particles, yet factors that control particle aggregation and resulting sedimentation in these environments are poorly understood. This study was designed to investigate the role of microbial Fe(III) reduction and solution chemistry in aggregation of suspended particles in the Mississippi Delta. Three representative sites along the salinity gradient were selected and sediments were collected from the sediment-water interface. Based on quantitative mineralogical analyses 88–89 wt.% of all minerals in the sediments are clays, mainly smectite and illite. Consumption of SO42− and the formation of H2S and pyrite during microbial Fe(III) reduction of the non-sterile sediments by Shewanella putrefaciens CN32 in artificial pore water (APW) media suggest simultaneous sulfate and Fe(III) reduction activity. The pHPZNPC of the sediments was ≤3.5 and their zeta potentials at the sediment-water interface pH (6.9–7.3) varied from −35 to −45 mV, suggesting that both edges and faces of clay particles have negative surface charge. Therefore, high concentrations of cations in pore water are expected to be a predominant factor in particle aggregation consistent with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Experiments on aggregation of different types of sediments in the same APW composition revealed that the sediment with low zeta potential had a high rate of aggregation. Similarly, addition of external Fe(II) (i.e. not derived from sediments) was normally found to enhance particle aggregation and deposition in all sediments, probably resulting from a decrease in surface potential of particles due to specific Fe(II) sorption. Scanning and transmission electron microscopy (SEM, TEM) images showed predominant face-to-face clay aggregation in native sediments and composite mixtures of biopolymer, bacteria, and clay minerals in the bioreduced sediments. However, a clear need remains for additional information on the conditions, if any, that favor the development of anoxia in deep- and bottom-water bodies supporting Fe(III) reduction and resulting in particle aggregation and sedimentation.

Car free cities: Pathway to healthy urban living.

PubMed

Nieuwenhuijsen, Mark J; Khreis, Haneen

2016-09-01

Many cities across the world are beginning to shift their mobility solution away from the private cars and towards more environmentally friendly and citizen-focused means. Hamburg, Oslo, Helsinki, and Madrid have recently announced their plans to become (partly) private car free cities. Other cities like Paris, Milan, Chengdu, Masdar, Dublin, Brussels, Copenhagen, Bogota, and Hyderabad have measures that aim at reducing motorized traffic including implementing car free days, investing in cycling infrastructure and pedestrianization, restricting parking spaces and considerable increases in public transport provision. Such plans and measures are particularly implemented with the declared aim of reducing greenhouse gas emissions. These reductions are also likely to benefit public health. We aimed to describe the plans for private car free cities and its likely effects on public health. We reviewed the grey and scientific literature on plans for private car free cities, restricted car use, related exposures and health. An increasing number of cities are planning to become (partly) private car free. They mainly focus on the reduction of private car use in city centers. The likely effects of such policies are significant reductions in traffic-related air pollution, noise, and temperature in city centers. For example, up to a 40% reduction in NO2 levels has been reported on car free days. These reductions are likely to lead to a reduction in premature mortality and morbidity. Furthermore the reduction in the number of cars, and therefore a reduction in the need for parking places and road space, provides opportunities to increase green space and green networks in cities, which in turn can lead to many beneficial health effects. All these measures are likely to lead to higher levels of active mobility and physical activity which may improve public health the most and also provide more opportunities for people to interact with each other in public space. Furthermore, such initiatives, if undertaken at a sufficiently large scale can result in positive distal effects and climate change mitigation through CO2 reductions. The potential negative effects which may arise due to motorized traffic detouring around car free zone into their destinations also need further evaluation and the areas in which car free zones are introduced need to be given sufficient attention so as not to become an additional way to exacerbate socioeconomic divides. The extent and magnitude of all the above effects is still unclear and needs further research, including full chain health impact assessment modeling to quantify the potential health benefits of such schemes, and exposure and epidemiological studies to measure any changes when such interventions take place. The introduction of private car free cities is likely to have direct and indirect health benefits, but the exact magnitude and potential conflicting effects are as yet unclear. This paper has overviewed the expected health impacts, which can be useful to underpin policies to reduce car use in cities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Existence domains of dust-acoustic solitons and supersolitons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maharaj, S. K.; Bharuthram, R.; Singh, S. V.

2013-08-15

Using the Sagdeev potential method, the existence of large amplitude dust-acoustic solitons and supersolitons is investigated in a plasma comprising cold negative dust, adiabatic positive dust, Boltzmann electrons, and non-thermal ions. This model supports the existence of positive potential supersolitons in a certain region in parameter space in addition to regular solitons having negative and positive potentials. The lower Mach number limit for supersolitons coincides with the occurrence of double layers whereas the upper limit is imposed by the constraint that the adiabatic positive dust number density must remain real valued. The upper Mach number limits for negative potential (positivemore » potential) solitons coincide with limiting values of the negative (positive) potential for which the negative (positive) dust number density is real valued. Alternatively, the existence of positive potential solitons can terminate when positive potential double layers occur.« less

40 CFR 62.2605 - Identification of sources-negative declaration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Georgia Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.2605 Identification of... 19, 1983, certifying that there are no existing primary aluminum reduction plants in the State of... Gases, Organic Compounds and Nitrogen Oxide Emissions From Existing Municipal Waste Combustors With the...

40 CFR 62.2605 - Identification of sources-negative declaration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Georgia Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.2605 Identification of... 19, 1983, certifying that there are no existing primary aluminum reduction plants in the State of... Gases, Organic Compounds and Nitrogen Oxide Emissions From Existing Municipal Waste Combustors With the...

40 CFR 62.2605 - Identification of sources-negative declaration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Georgia Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.2605 Identification of... 19, 1983, certifying that there are no existing primary aluminum reduction plants in the State of... Gases, Organic Compounds and Nitrogen Oxide Emissions From Existing Municipal Waste Combustors With the...

40 CFR 62.2605 - Identification of sources-negative declaration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Georgia Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.2605 Identification of... 19, 1983, certifying that there are no existing primary aluminum reduction plants in the State of... Gases, Organic Compounds and Nitrogen Oxide Emissions From Existing Municipal Waste Combustors With the...

40 CFR 62.2605 - Identification of sources-negative declaration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Georgia Fluoride Emissions from Existing Primary Aluminum Reduction Plants § 62.2605 Identification of... 19, 1983, certifying that there are no existing primary aluminum reduction plants in the State of... Gases, Organic Compounds and Nitrogen Oxide Emissions From Existing Municipal Waste Combustors With the...

Efficacy of on-farm use of ultraviolet light for inactivation of bacteria in milk for calves.

PubMed

Gelsinger, S L; Heinrichs, A J; Jones, C M; Van Saun, R J; Wolfgang, D R; Burns, C M; Lysczek, H R

2014-05-01

Ultraviolet light is being employed for bacterial inactivation in milk for calves; however, limited evidence is available to support the claim that UV light effectively inactivates bacteria found in milk. Thus, the objective of this observational study was to investigate the efficacy of on-farm UV light treatment in reducing bacteria populations in waste milk used for feeding calves. Samples of nonsaleable milk were collected from 9 Pennsylvania herds, twice daily for 15 d, both before and after UV light treatment (n=60 samples per farm), and analyzed for standard plate count, coliforms, noncoliform, gram-negative bacteria, environmental and contagious streptococci, coagulase-negative staphylococci, Streptococcus agalactiae, Staphylococcus aureus count, and total solids percentage, and log reduction and percentage log reduction were calculated. Data were analyzed using the mixed procedure in SAS. In all bacteria types, samples collected after UV treatment contained significantly fewer bacteria compared with samples collected before UV treatment. Weighted least squares means for log reduction (percentage log reduction) were 1.34 (29%), 1.27 (58%), 1.48 (53%), 1.85 (55%), 1.37 (72%), 1.92 (63%), 1.07 (33%), and 1.67 (82%) for standard plate count, coliforms, noncoliform, gram-negative bacteria, environmental and contagious streptococci, Strep. agalactiae, coagulase-negative staphylococci, and Staph. aureus, respectively. A percentage log reduction greater than 50% was achieved in 6 of 8 bacteria types, and 43 and 94% of samples collected after UV treatment met recommended bacterial standards for milk for feeding calves. Based on these results, UV light treatment may be effective for some, but not all bacteria types found in nonsaleable waste milk. Thus, farmers should take into account the bacteria types that may need to be reduced when considering the purchase of a UV-treatment system. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The effects of interfacial potential on antimicrobial propensity of ZnO nanoparticle

PubMed Central

Arakha, Manoranjan; Saleem, Mohammed; Mallick, Bairagi C.; Jha, Suman

2015-01-01

The work investigates the role of interfacial potential in defining antimicrobial propensity of ZnO nanoparticle (ZnONP) against different Gram positive and Gram negative bacteria. ZnONPs with positive and negative surface potential are tested against different bacteria with varying surface potentials, ranging −14.7 to −23.6 mV. Chemically synthesized ZnONPs with positive surface potential show very high antimicrobial propensity with minimum inhibitory concentration of 50 and 100 μg/mL for Gram negative and positive bacterium, respectively. On other hand, ZnONPs of the same size but with negative surface potential show insignificant antimicrobial propensity against the studied bacteria. Unlike the positively charged nanoparticles, neither Zn2+ ion nor negatively charged ZnONP shows any significant inhibition in growth or morphology of the bacterium. Potential neutralization and colony forming unit studies together proved adverse effect of the resultant nano-bacterial interfacial potential on bacterial viability. Thus, ZnONP with positive surface potential upon interaction with negative surface potential of bacterial membrane enhances production of the reactive oxygen species and exerts mechanical stress on the membrane, resulting in the membrane depolarization. Our results show that the antimicrobial propensity of metal oxide nanoparticle mainly depends upon the interfacial potential, the potential resulting upon interaction of nanoparticle surface with bacterial membrane. PMID:25873247

A systematic review of the relationship between internet use, self-harm and suicidal behaviour in young people: The good, the bad and the unknown.

PubMed

Marchant, Amanda; Hawton, Keith; Stewart, Ann; Montgomery, Paul; Singaravelu, Vinod; Lloyd, Keith; Purdy, Nicola; Daine, Kate; John, Ann

2017-01-01

Research exploring internet use and self-harm is rapidly expanding amidst concerns regarding influences of on-line activities on self-harm and suicide, especially in young people. We aimed to systematically review evidence regarding the potential influence of the internet on self-harm/suicidal behaviour in young people. We conducted a systematic review based on an electronic search for articles published between 01/01/2011 and 26/01/2015 across databases including Medline, Cochrane and PsychInfo. Articles were included if: the study examined internet use by individuals who engaged in self-harm/ suicidal behaviour, or internet use clearly related to self-harm content; reported primary empirical data; participants were aged under 25 years. New studies were combined with those identified in a previous review and subject to data extraction, quality rating and narrative synthesis. Forty-six independent studies (51 articles) of varying quality were included. Perceived influences were: positive for 11 studies (38191 participants); negative for 18 studies (119524 participants); and mixed for 17 studies (35235 participants). In contrast to previous reviews on this topic studies focused on a wide range of internet mediums: general internet use; internet addiction; online intervention/treatment; social media; dedicated self-harm websites; forums; video/image sharing and blogs. A relationship between internet use and self-harm/suicidal behaviour was particularly associated with internet addiction, high levels of internet use, and websites with self-harm or suicide content. While there are negative aspects of internet use the potential for isolation reduction, outreach and as a source of help and therapy were also identified. There is significant potential for harm from online behaviour (normalisation, triggering, competition, contagion) but also the potential to exploit its benefits (crisis support, reduction of social isolation, delivery of therapy, outreach). Young people appear to be increasingly using social media to communicate distress, particularly to peers. The focus should now be on how specific mediums' (social media, video/image sharing) might be used in therapy and recovery. Clinicians working with young people who self-harm or have mental health issues should engage in discussion about internet use. This should be a standard item during assessment. A protocol for this review was registered with the PROSPERO systematic review protocol registry: (http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42015019518).

Insurance, Public Assistance, and Household Flood Risk Reduction: A Comparative Study of Austria, England, and Romania.

PubMed

Hanger, Susanne; Linnerooth-Bayer, Joanne; Surminski, Swenja; Nenciu-Posner, Cristina; Lorant, Anna; Ionescu, Radu; Patt, Anthony

2018-04-01

In light of increasing losses from floods, many researchers and policymakers are looking for ways to encourage flood risk reduction among communities, business, and households. In this study, we investigate risk-reduction behavior at the household level in three European Union Member States with fundamentally different insurance and compensation schemes. We try to understand if and how insurance and public assistance influence private risk-reduction behavior. Data were collected using a telephone survey (n = 1,849) of household decisionmakers in flood-prone areas. We show that insurance overall is positively associated with private risk-reduction behavior. Warranties, premium discounts, and information provision with respect to risk reduction may be an explanation for this positive relationship in the case of structural measures. Public incentives for risk-reduction measures by means of financial and in-kind support, and particularly through the provision of information, are also associated with enhancing risk reduction. In this study, public compensation is not negatively associated with private risk-reduction behavior. This does not disprove such a relationship, but the negative effect may be mitigated by factors related to respondents' capacity to implement measures or social norms that were not included in the analysis. The data suggest that large-scale flood protection infrastructure creates a sense of security that is associated with a lower level of preparedness. Across the board there is ample room to improve both public and private policies to provide effective incentives for household-level risk reduction. © 2017 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

Improving Pathogen Reduction by Chlorine Wash Prior to Cutting in Fresh-Cut Processing

USDA-ARS?s Scientific Manuscript database

Introduction: Currently, most fresh-cut processing facilities in the United States use chlorinated water or other sanitizer solutions for microbial reduction after lettuce is cut. Freshly cut lettuce releases significant amounts of organic matter that negatively impacts the effectiveness of chlorine...

Effective reduction of the coercivity for Co72Pt28 thin film by exchange coupled Co81Ir19 soft layer with negative magnetocrystalline anisotropy

NASA Astrophysics Data System (ADS)

Jiao, J. Y.; Ma, T. Y.; Li, Z. W.; Qiao, L.; Wang, Y.; Wang, T.; Li, F. S.

2018-02-01

We report on the investigation of coercivity changes of the Co72Pt28/Co81Ir19 exchange-coupled composite (ECC) media with negative soft-layer (SL) magnetocrystalline anisotropy (MA). Our results show that the hard-layer (HL) of our sample exhibits a columnar type microstructure with well isolated grains and the SL with hcp-structure grows on top of the HL with the same texture. Therefore, strong coupling of the two layers have been realized as evidenced by the magnetic characterization. Importantly, we observe a more effective reduction of the coercivity of the ECC media by using SLs with negative MA when compared to the use of SLs with positive or negligible MA. The experimental results are corroborated by theoretical calculations.

Mechanistic insights into electrochemical reduction of CO2 over Ag using density functional theory and transport models

PubMed Central

Goodpaster, Jason D.; Weber, Adam Z.

2017-01-01

Electrochemical reduction of CO2 using renewable sources of electrical energy holds promise for converting CO2 to fuels and chemicals. Since this process is complex and involves a large number of species and physical phenomena, a comprehensive understanding of the factors controlling product distribution is required. While the most plausible reaction pathway is usually identified from quantum-chemical calculation of the lowest free-energy pathway, this approach can be misleading when coverages of adsorbed species determined for alternative mechanism differ significantly, since elementary reaction rates depend on the product of the rate coefficient and the coverage of species involved in the reaction. Moreover, cathode polarization can influence the kinetics of CO2 reduction. Here, we present a multiscale framework for ab initio simulation of the electrochemical reduction of CO2 over an Ag(110) surface. A continuum model for species transport is combined with a microkinetic model for the cathode reaction dynamics. Free energies of activation for all elementary reactions are determined from density functional theory calculations. Using this approach, three alternative mechanisms for CO2 reduction were examined. The rate-limiting step in each mechanism is **COOH formation at higher negative potentials. However, only via the multiscale simulation was it possible to identify the mechanism that leads to a dependence of the rate of CO formation on the partial pressure of CO2 that is consistent with experiments. Simulations based on this mechanism also describe the dependence of the H2 and CO current densities on cathode voltage that are in strikingly good agreement with experimental observation. PMID:28973926

Synthesis of flower-like gold nanoparticles and their electrocatalytic activity towards the oxidation of methanol and the reduction of oxygen.

PubMed

Jena, Bikash Kumar; Raj, C Retna

2007-03-27

This article describes the synthesis of branched flower-like gold (Au) nanocrystals and their electrocatalytic activity toward the oxidation of methanol and the reduction of oxygen. Gold nanoflowers (GNFs) were obtained by a one-pot synthesis using N-2-hydroxyethylpiperazine-N-2-ethanesulphonic acid (HEPES) as a reducing/stabilizing agent. The GNFs have been characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and electrochemical measurements. The UV-visible spectra show two bands corresponding to the transverse and longitudinal surface plasmon (SP) absorption at 532 and 720 nm, respectively, for the colloidal GNFs. The GNFs were self-assembled on a sol-gel-derived silicate network, which was preassembled on a polycrystalline Au electrode and used for electrocatalytic applications. The GNFs retain their morphology on the silicate network; the UV-visible diffuse reflectance spectra (DRS) of GNFs on the silicate network show longitudinal and transverse bands as in the case of colloidal GNFs. The GNFs show excellent electrocatalytic activity toward the oxidation of methanol and the reduction of oxygen. Oxidation of methanol in alkaline solution was observed at approximately 0.245 V, which is much less positive than that on an unmodified polycrystalline gold electrode. Reduction of oxygen to H2O2 and the further reduction of H2O2 to water in neutral pH were observed at less negative potentials on the GNFs electrode. The electrocatalytic activity of GNFs is significantly higher than that of the spherically shaped citrate-stabilized Au nanoparticles (SGNs).

Calibration of redox potential in sperm wash media and evaluation of oxidation-reduction potential values in various assisted reproductive technology culture media using MiOXSYS system.

PubMed

Panner Selvam, M K; Henkel, R; Sharma, R; Agarwal, A

2018-03-01

Oxidation-reduction potential describes the balance between the oxidants and antioxidants in fluids including semen. Various artificial culture media are used in andrology and IVF laboratories for sperm preparation and to support the development of fertilized oocytes under in vitro conditions. The composition and conditions of these media are vital for optimal functioning of the gametes. Currently, there are no data on the status of redox potential of sperm processing and assisted reproduction media. The purpose of this study was to compare the oxidation-reduction potential values of the different media and to calibrate the oxidation-reduction potential values of the sperm wash medium using oxidative stress inducer cumene hydroperoxide and antioxidant ascorbic acid. Redox potential was measured in 10 different media ranging from sperm wash media, freezing media and assisted reproductive technology one-step medium to sequential media. Oxidation-reduction potential values of the sequential culture medium and one-step culture medium were lower and significantly different (p < 0.05) from the sperm wash media. Calibration of the sperm wash media using the oxidant cumene hydroperoxide and antioxidant ascorbic acid demonstrated that oxidation-reduction potential and the concentration of oxidant or antioxidant are logarithmically dependent. This study highlights the importance of calibrating the oxidation-reduction potential levels of the sperm wash media in order to utilize it as a reference value to identify the physiological range of oxidation-reduction potential that does not have any adverse effect on normal physiological sperm function. © 2017 American Society of Andrology and European Academy of Andrology.

Medial prefrontal-hippocampal connectivity during emotional memory encoding predicts individual differences in the loss of associative memory specificity.

PubMed

Berkers, Ruud M W J; Klumpers, Floris; Fernández, Guillén

2016-10-01

Emotionally charged items are often remembered better, whereas a paradoxical loss of specificity is found for associative emotional information (specific memory). The balance between specific and generalized emotional memories appears to show large individual differences, potentially related to differences in (the risk for) affective disorders that are characterized by 'overgeneralized' emotional memories. Here, we investigate the neural underpinnings of individual differences in emotional associative memory. A large group of healthy male participants were scanned while encoding associations of face-photographs and written occupational identities that were of either neutral ('driver') or negative ('murderer') valence. Subsequently, memory was tested by prompting participants to retrieve the occupational identities corresponding to each face. Whereas in both valence categories a similar amount of faces was labeled correctly with 'neutral' and 'negative' identities, (gist memory), specific associations were found to be less accurately remembered when the occupational identity was negative compared to neutral (specific memory). This pattern of results suggests reduced memory specificity for associations containing a negatively valenced component. The encoding of these negative associations was paired with a selective increase in medial prefrontal cortex activity and medial prefrontal-hippocampal connectivity. Individual differences in valence-specific neural connectivity were predictive of valence-specific reduction of memory specificity. The relationship between loss of emotional memory specificity and medial prefrontal-hippocampal connectivity is in line with the hypothesized role of a medial prefrontal-hippocampal circuit in regulating memory specificity, and warrants further investigations in individuals displaying 'overgeneralized' emotional memories. Copyright © 2016 Elsevier Inc. All rights reserved.

Negative mood and sexual behavior among non-monogamous men who have sex with men in the context of methamphetamine and HIV.

PubMed

Bousman, C A; Cherner, M; Ake, C; Letendre, S; Atkinson, J H; Patterson, T L; Grant, I; Everall, I P

2009-12-01

Research comparing the independent and combined contextual effects of methamphetamine dependence (METH) and HIV-infection (HIV) on mood and sexual behavior among men who have sex with men (MSM) has been sparse and inconsistent. This study examined the contextual influence of METH, HIV-infection and their combination on mood states and sexual behavior. 175 non-monogamous MSM concordant or discordant for METH and HIV were included. Multivariate analysis was conducted to examine mood and sexual behavior differences between groups, as well as to elucidate the relationship between mood and sexual risk behavior and explore the potential moderator (i.e. contextual) effects of METH and/or HIV on this relationship. METH+/HIV+ participants reported condom use less than 25% of the time whereas METH-/HIV+ participants reported condom use 51-75% of the time. METH+ and HIV+ status were associated with higher depression and confusion scores. Univariate regressions revealed negative relationships between mood states (depression, tension, anger, fatigue and confusion) and condom use. Neither METH nor HIV status moderated the relationships between negative mood and condom use. Results are derived from cross-sectional data, sample sizes for each of the four groups were relatively small, and condom use could not be linked to specific sexual practices and/or partner types. METH dependence, HIV seropositivity, and negative moods are associated with reduced condom use among non-monogamous MSM. Independent effects of METH dependence and negative mood on condom use suggest that sexual risk reduction interventions for MSM should incorporate multi-faceted approaches, including substance abuse and mental health treatment.

Boundary layer friction of solvate ionic liquids as a function of potential.

PubMed

Li, Hua; Rutland, Mark W; Watanabe, Masayoshi; Atkin, Rob

2017-07-01

Atomic force microscopy (AFM) has been used to investigate the potential dependent boundary layer friction at solvate ionic liquid (SIL)-highly ordered pyrolytic graphite (HOPG) and SIL-Au(111) interfaces. Friction trace and retrace loops of lithium tetraglyme bis(trifluoromethylsulfonyl)amide (Li(G4) TFSI) at HOPG present clearer stick-slip events at negative potentials than at positive potentials, indicating that a Li + cation layer adsorbed to the HOPG lattice at negative potentials which enhances stick-slip events. The boundary layer friction data for Li(G4) TFSI shows that at HOPG, friction forces at all potentials are low. The TFSI - anion rich boundary layer at positive potentials is more lubricating than the Li + cation rich boundary layer at negative potentials. These results suggest that boundary layers at all potentials are smooth and energy is predominantly dissipated via stick-slip events. In contrast, friction at Au(111) for Li(G4) TFSI is significantly higher at positive potentials than at negative potentials, which is comparable to that at HOPG at the same potential. The similarity of boundary layer friction at negatively charged HOPG and Au(111) surfaces indicates that the boundary layer compositions are similar and rich in Li + cations for both surfaces at negative potentials. However, at Au(111), the TFSI - rich boundary layer is less lubricating than the Li + rich boundary layer, which implies that anion reorientations rather than stick-slip events are the predominant energy dissipation pathways. This is confirmed by the boundary friction of Li(G4) NO 3 at Au(111), which shows similar friction to Li(G4) TFSI at negative potentials due to the same cation rich boundary layer composition, but even higher friction at positive potentials, due to higher energy dissipation in the NO 3 - rich boundary layer.

Involvement of Clathrin-Mediated Endocytosis in Human Immunodeficiency Virus Type 1 Entry

PubMed Central

Daecke, Jessica; Fackler, Oliver T.; Dittmar, Matthias T.; Kräusslich, Hans-Georg

2005-01-01

Productive entry of human immunodeficiency virus (HIV) is believed to occur by direct fusion at the plasma membrane. Endocytic uptake of HIV particles has been observed in several studies but is considered to be nonproductive, leading to virus degradation in the lysosome. We show here that endocytosis contributes significantly to productive HIV entry in HeLa cells by using trans dominant-negative mutants of dynamin and Eps15. Inducible expression of a dominant-negative mutant of dynamin in a CD4-positive HeLa cell line reduced HIV infection by 40 to 80%. This effect was independent of the infectious dose and was observed for three different isolates. Analysis of reverse transcription products by real-time PCR and of virus entry by delivery of a virion-associated Vpr-β-lactamase fusion protein revealed a similar reduction, indicating that the block occurred at the entry stage. A strong reduction of HIV entry was also observed upon transient transfection of a different trans dominant-negative variant of dynamin, and this reduction correlated with the relative inhibition of transferrin endocytosis. Expression of a dominant-negative variant of Eps15, which is specific for clathrin-dependent endocytosis, reduced HIV entry in HeLa cells by ca 95%, confirming the role of endocytosis for productive infection. In contrast, no effect was observed for a dominant-negative variant of caveolin. We conclude that dynamin-dependent, clathrin-mediated endocytosis can lead to productive entry of HIV in HeLa cells, suggesting this pathway as an alternative route of virus entry. PMID:15650184

Early prediction of blonanserin response in Japanese patients with schizophrenia.

PubMed

Kishi, Taro; Matsuda, Yuki; Fujita, Kiyoshi; Iwata, Nakao

2014-01-01

Blonanserin is a second-generation antipsychotic used for the treatment of schizophrenia in Japan and Korea. The present study aimed to examine early prediction of blonanserin in patients with schizophrenia. An 8-week, prospective, single-arm, flexible-dose clinical trial of blonanserin in patients with schizophrenia was conducted under real-world conditions. The inclusion criteria were antipsychotic naïve, and first-episode schizophrenia patients or schizophrenia patients with no consumption of any antipsychotic medication for more than 4 weeks before enrollment in this study. The positive predictive value, negative predictive value, sensitivity, specificity, and predictive power were calculated for the response status at week 4 to predict the subsequent response at week 8. Thirty-seven patients were recruited (56.8% of them had first-episode schizophrenia), and 28 (75.7%) completed the trial. At week 8, blonanserin was associated with a significant improvement in the Positive and Negative Syndrome Scale (PANSS) total score (P<0.0001) and in positive (P<0.0001), negative (P<0.0001), and general subscale scores (P<0.0001). In terms of percentage improvement of PANSS total scores from baseline to week 8, 64.9% of patients showed a ≥20% reduction in the PANSS total score and 48.6% showed a ≥30% reduction. However, 8.1% of patients experienced at least one adverse event. Using the 20% reduction in the PANSS total score at week 4 as a definition of an early response, the negative predictive values for later responses (ie, reductions of ≥30 and ≥40 in the PANSS total scores) were 88.9% and 94.1%, respectively. The specificities were 80.0% and 51.6%, respectively. Our results suggest that the blonanserin response at week 4 could predict the later response at week 8.

Early prediction of blonanserin response in Japanese patients with schizophrenia

PubMed Central

Kishi, Taro; Matsuda, Yuki; Fujita, Kiyoshi; Iwata, Nakao

2014-01-01

Background Blonanserin is a second-generation antipsychotic used for the treatment of schizophrenia in Japan and Korea. The present study aimed to examine early prediction of blonanserin in patients with schizophrenia. Methods An 8-week, prospective, single-arm, flexible-dose clinical trial of blonanserin in patients with schizophrenia was conducted under real-world conditions. The inclusion criteria were antipsychotic naïve, and first-episode schizophrenia patients or schizophrenia patients with no consumption of any antipsychotic medication for more than 4 weeks before enrollment in this study. The positive predictive value, negative predictive value, sensitivity, specificity, and predictive power were calculated for the response status at week 4 to predict the subsequent response at week 8. Results Thirty-seven patients were recruited (56.8% of them had first-episode schizophrenia), and 28 (75.7%) completed the trial. At week 8, blonanserin was associated with a significant improvement in the Positive and Negative Syndrome Scale (PANSS) total score (P<0.0001) and in positive (P<0.0001), negative (P<0.0001), and general subscale scores (P<0.0001). In terms of percentage improvement of PANSS total scores from baseline to week 8, 64.9% of patients showed a ≥20% reduction in the PANSS total score and 48.6% showed a ≥30% reduction. However, 8.1% of patients experienced at least one adverse event. Using the 20% reduction in the PANSS total score at week 4 as a definition of an early response, the negative predictive values for later responses (ie, reductions of ≥30 and ≥40 in the PANSS total scores) were 88.9% and 94.1%, respectively. The specificities were 80.0% and 51.6%, respectively. Conclusion Our results suggest that the blonanserin response at week 4 could predict the later response at week 8. PMID:25285009

Effect of Negative Pressure on Proliferation, Virulence Factor Secretion, Biofilm Formation, and Virulence-Regulated Gene Expression of Pseudomonas aeruginosa In Vitro

PubMed Central

Wang, Guo-Qi; Li, Tong-Tong; Li, Zhi-Rui; Zhang, Li-Cheng

2016-01-01

Objective. To investigate the effect of negative pressure conditions induced by NPWT on P. aeruginosa. Methods. P. aeruginosa was cultured in a Luria–Bertani medium at negative pressure of −125 mmHg for 24 h in the experimental group and at atmospheric pressure in the control group. The diameters of the colonies of P. aeruginosa were measured after 24 h. ELISA kit, orcinol method, and elastin-Congo red assay were used to quantify the virulence factors. Biofilm formation was observed by staining with Alexa Fluor® 647 conjugate of concanavalin A (Con A). Virulence-regulated genes were determined by quantitative RT-PCR. Results. As compared with the control group, growth of P. aeruginosa was inhibited by negative pressure. The colony size under negative pressure was significantly smaller in the experimental group than that in the controls (p < 0.01). Besides, reductions in the total amount of virulence factors were observed in the negative pressure group, including exotoxin A, rhamnolipid, and elastase. RT-PCR results revealed a significant inhibition in the expression level of virulence-regulated genes. Conclusion. Negative pressure could significantly inhibit the growth of P. aeruginosa. It led to a decrease in the virulence factor secretion, biofilm formation, and a reduction in the expression level of virulence-regulated genes. PMID:28074188

Finding balance between fire hazard reduction and erosion control in the Lake Tahoe Basin, California–Nevada

Treesearch

Nicolas M. Harrison; Andrew P. Stubblefield; J. Morgan Varner; Eric E. Knapp

2016-01-01

The 2007 Angora Fire served as a stark reminder of the need for fuel reduction treatments in the Lake Tahoe Basin, California–Nevada, USA. Concerns exist, however, that the corresponding removal of forest floor fuels could increase erosion rates, negatively affecting the clarity of Lake Tahoe. To quantify trade-offs between fuel reduction and erosion, we conducted...

Acceptance and Commitment Therapy for Problematic Internet Pornography Use: A Randomized Trial.

PubMed

Crosby, Jesse M; Twohig, Michael P

2016-05-01

Problematic Internet pornography use is the inability to control the use of pornography, the experience of negative cognitions or emotions regarding pornography use, and the resulting negative effects on quality of life or general functioning. This study compared a 12-session individual protocol of acceptance and commitment therapy (ACT) for problematic Internet pornography use to a waitlist control condition with 28 adult males, all but 1 of whom were members of the Church of Jesus Christ of Latter-day Saints. Measures of self-reported pornography viewing, standardized measures of compulsive sexual behavior and related cognitions, and quality of life occurred at pretreatment, posttreatment, and 3-month follow-up. Results demonstrate significant between-condition reductions in pornography viewing compared to the waitlist condition (93% reduction ACT vs. 21% waitlist). When combining all participants (N=26), a 92% reduction was seen at posttreatment and an 86% reduction at 3-month follow-up. Complete cessation was seen in 54% of participants at posttreatment and at least a 70% reduction was seen in 93% of participants. At the 3-month follow-up assessment, 35% of participants showed complete cessation, with 74% of participants showing at least 70% reduction in viewing. Treatment suggestions and future directions are discussed. Copyright © 2016. Published by Elsevier Ltd.

Factors That Influence Human Behavior And Negatively Affect Energy Consumption In USMC Ground Units During Operations

DTIC Science & Technology

2016-09-01

vehicle idling, energy strategy, energy behavior, energy reductions, behavior change 15. NUMBER OF PAGES 79 16. PRICE CODE 17. SECURITY...INFLUENCE HUMAN BEHAVIOR AND NEGATIVELY AFFECT ENERGY CONSUMPTION IN USMC GROUND UNITS DURING OPERATIONS by John A. Peters September 2016...NEGATIVELY AFFECT ENERGY CONSUMPTION IN USMC GROUND UNITS DURING OPERATIONS 5. FUNDING NUMBERS 6. AUTHOR(S) John A. Peters 7. PERFORMING

Positive and negative dimensions of weight control motivation.

PubMed

Stotland, S; Larocque, M; Sadikaj, G

2012-01-01

This study examined weight control motivation among patients (N=5460 females and 547 males) who sought weight loss treatment with family physicians. An eight-item measure assessed the frequency of thoughts and feelings related to weight control "outcome" (e.g. expected physical and psychological benefits) and "process" (e.g. resentment and doubt). Factor analysis supported the existence of two factors, labeled Positive and Negative motivation. Positive motivation was high (average frequency of thoughts about benefits was 'every day') and stable throughout treatment, while Negative motivation declined rapidly and then stabilized. The determinants of changes in the Positive and Negative dimensions during treatment were examined within 3 time frames: first month, months 2-6, and 6-12. Maintenance of high scores on Positive motivation was associated with higher BMI and more disturbed eating habits. Early reductions in Negative motivation were greater for those starting treatment with higher weight and more disturbed eating habits, but less depression and stress, while later reductions in Negative motivation were predicted by improvements in eating habits, weight, stress and perfectionism. Clinicians treating obesity should be sensitive to fluctuations in both motivational dimensions, as they are likely to play a central role in determining long-term behavior and weight change. Copyright © 2011 Elsevier Ltd. All rights reserved.

The significance of African lions for the financial viability of trophy hunting and the maintenance of wild land.

PubMed

Lindsey, Peter Andrew; Balme, Guy Andrew; Booth, Vernon Richard; Midlane, Neil

2012-01-01

Recent studies indicate that trophy hunting is impacting negatively on some lion populations, notably in Tanzania. In 2004 there was a proposal to list lions on CITES Appendix I and in 2011 animal-welfare groups petitioned the United States government to list lions as endangered under their Endangered Species Act. Such listings would likely curtail the trophy hunting of lions by limiting the import of lion trophies. Concurrent efforts are underway to encourage the European Union to ban lion trophy imports. We assessed the significance of lions to the financial viability of trophy hunting across five countries to help determine the financial impact and advisability of the proposed trade restrictions. Lion hunts attract the highest mean prices (US$24,000-US$71,000) of all trophy species. Lions generate 5-17% of gross trophy hunting income on national levels, the proportional significance highest in Mozambique, Tanzania, and Zambia. If lion hunting was effectively precluded, trophy hunting could potentially become financially unviable across at least 59,538 km(2) that could result in a concomitant loss of habitat. However, the loss of lion hunting could have other potentially broader negative impacts including reduction of competitiveness of wildlife-based land uses relative to ecologically unfavourable alternatives. Restrictions on lion hunting may also reduce tolerance for the species among communities where local people benefit from trophy hunting, and may reduce funds available for anti-poaching. If lion off-takes were reduced to recommended maximums (0.5/1000 km(2)), the loss of viability and reduction in profitability would be much lower than if lion hunting was stopped altogether (7,005 km(2)). We recommend that interventions focus on reducing off-takes to sustainable levels, implementing age-based regulations and improving governance of trophy hunting. Such measures could ensure sustainability, while retaining incentives for the conservation of lions and their habitat from hunting.

Long-QT mutation p.K557E-Kv7.1: dominant-negative suppression of IKs, but preserved cAMP-dependent up-regulation.

PubMed

Spätjens, Roel L H M G; Bébarová, Markéta; Seyen, Sandrine R M; Lentink, Viola; Jongbloed, Roselie J; Arens, Yvonne H J M; Heijman, Jordi; Volders, Paul G A

2014-10-01

Mutations in KCNQ1, encoding for Kv7.1, the α-subunit of the IKs channel, cause long-QT syndrome type 1, potentially predisposing patients to ventricular tachyarrhythmias and sudden cardiac death, in particular, during elevated sympathetic tone. Here, we aim at characterizing the p.Lys557Glu (K557E) Kv7.1 mutation, identified in a Dutch kindred, at baseline and during (mimicked) increased adrenergic tone. K557E carriers had moderate QTc prolongation that augmented significantly during exercise. IKs characteristics were determined after co-expressing Kv7.1-wild-type (WT) and/or K557E with minK and Yotiao in Chinese hamster ovary cells. K557E caused IKs loss of function with slowing of the activation kinetics, acceleration of deactivation kinetics, and a rightward shift of voltage-dependent activation. Together, these contributed to a dominant-negative reduction in IKs density. Confocal microscopy and western blot indicated that trafficking of K557E channels was not impaired. Stimulation of WT IKs by 3'-5'-cyclic adenosine monophosphate (cAMP) generated strong current up-regulation that was preserved for K557E in both hetero- and homozygosis. Accumulation of IKs at fast rates occurred both in WT and in K557E, but was blunted in the latter. In a computational model, K557E showed a loss of action potential shortening during β-adrenergic stimulation, in accordance with the lack of QT shortening during exercise in patients. K557E causes IKs loss of function with reduced fast rate-dependent current accumulation. cAMP-dependent stimulation of mutant IKs is preserved, but incapable of fully compensating for the baseline current reduction, explaining the long QT intervals at baseline and the abnormal QT accommodation during exercise in affected patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

The Significance of African Lions for the Financial Viability of Trophy Hunting and the Maintenance of Wild Land

PubMed Central

Lindsey, Peter Andrew; Balme, Guy Andrew; Booth, Vernon Richard; Midlane, Neil

2012-01-01

Recent studies indicate that trophy hunting is impacting negatively on some lion populations, notably in Tanzania. In 2004 there was a proposal to list lions on CITES Appendix I and in 2011 animal-welfare groups petitioned the United States government to list lions as endangered under their Endangered Species Act. Such listings would likely curtail the trophy hunting of lions by limiting the import of lion trophies. Concurrent efforts are underway to encourage the European Union to ban lion trophy imports. We assessed the significance of lions to the financial viability of trophy hunting across five countries to help determine the financial impact and advisability of the proposed trade restrictions. Lion hunts attract the highest mean prices (US$24,000–US$71,000) of all trophy species. Lions generate 5–17% of gross trophy hunting income on national levels, the proportional significance highest in Mozambique, Tanzania, and Zambia. If lion hunting was effectively precluded, trophy hunting could potentially become financially unviable across at least 59,538 km2 that could result in a concomitant loss of habitat. However, the loss of lion hunting could have other potentially broader negative impacts including reduction of competitiveness of wildlife-based land uses relative to ecologically unfavourable alternatives. Restrictions on lion hunting may also reduce tolerance for the species among communities where local people benefit from trophy hunting, and may reduce funds available for anti-poaching. If lion off-takes were reduced to recommended maximums (0.5/1000 km2), the loss of viability and reduction in profitability would be much lower than if lion hunting was stopped altogether (7,005 km2). We recommend that interventions focus on reducing off-takes to sustainable levels, implementing age-based regulations and improving governance of trophy hunting. Such measures could ensure sustainability, while retaining incentives for the conservation of lions and their habitat from hunting. PMID:22247772

Effects of electrolytes on redox potentials through ion pairing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bird, Matthew J.; Iyoda, Tomokazu; Bonura, Nicholas

Here, reduction potentials have been determined for two molecules, benzophenone (BzPh) and perylene (Per), effectively in the complete absence of electrolyte as well as in the presence of three different supporting electrolytes in the moderately polar solvent THF. A description of how this can be so, and qualifications, are described in the discussion section. The primary tool in this work, pulse radiolysis, measures electron transfer (ET) equilibria in solution to obtain differences in redox potentials. Voltammetry measures redox potentials by establishing ET equilibria at electrodes, but electrolytes are needed for current flow. Results here show that without electrolyte the redoxmore » potentials were 100–451 mV more negative than those with 100 mM electrolyte. These changes depended both on the molecule and the electrolyte. In THF the dominant contributor to stabilization of radical anions by electrolyte was ion pairing. An equation was derived to give changes in redox potentials when electrolyte is added in terms of ion pair dissociation constants and activity coefficients. Definite values were determined for energetics, ΔG d°, of ion pairing. Values of ΔG d° for pairs with TBA + give some doubt that it is a “weakly-coordinating cation.” Computations with DFT methods were moderately successful at describing the ion paring energies.« less

Effects of electrolytes on redox potentials through ion pairing

DOE PAGES

Bird, Matthew J.; Iyoda, Tomokazu; Bonura, Nicholas; ...

2017-09-21

Here, reduction potentials have been determined for two molecules, benzophenone (BzPh) and perylene (Per), effectively in the complete absence of electrolyte as well as in the presence of three different supporting electrolytes in the moderately polar solvent THF. A description of how this can be so, and qualifications, are described in the discussion section. The primary tool in this work, pulse radiolysis, measures electron transfer (ET) equilibria in solution to obtain differences in redox potentials. Voltammetry measures redox potentials by establishing ET equilibria at electrodes, but electrolytes are needed for current flow. Results here show that without electrolyte the redoxmore » potentials were 100–451 mV more negative than those with 100 mM electrolyte. These changes depended both on the molecule and the electrolyte. In THF the dominant contributor to stabilization of radical anions by electrolyte was ion pairing. An equation was derived to give changes in redox potentials when electrolyte is added in terms of ion pair dissociation constants and activity coefficients. Definite values were determined for energetics, ΔG d°, of ion pairing. Values of ΔG d° for pairs with TBA + give some doubt that it is a “weakly-coordinating cation.” Computations with DFT methods were moderately successful at describing the ion paring energies.« less

Psychological intervention reduces self-reported performance anxiety in high school music students

PubMed Central

Braden, Alice M.; Osborne, Margaret S.; Wilson, Sarah J.

2015-01-01

Music performance anxiety (MPA) can be distressing for many young people studying music, and may negatively impact upon their ability to cope with the demands and stressors of music education. It can also lead young people to give up music or to develop unhealthy coping habits in their adult music careers. Minimal research has examined the effectiveness of psychological programs to address MPA in young musicians. Sixty-two adolescents were pseudo-randomized to a cognitive behavioral (CB) group-delivered intervention or a waitlist condition. The intervention consisted of psychoeducation, cognitive restructuring and relaxation techniques, identification of strengths, goal-setting, imagery and visualization techniques to support three solo performances in front of judges. Significant reductions in self-rated MPA were found in both groups following the intervention and compared to their baseline MPA. This reduction was maintained at 2-months follow-up. There appeared to be inconsistent effects of the intervention upon judge-rated MPA, however the presence of floor effects precluded meaningful reductions in MPA. There appeared to be no effect of the intervention upon judge-rated performance quality. This study highlights the potential for group-based CB programs to be delivered within school music curricula to help young musicians develop skills to overcome the often debilitating effects of MPA. PMID:25784885

Chitinase Expression Due to Reduction in Fusaric Acid Level in an Antagonistic Trichoderma harzianum S17TH.

PubMed

Sharma, Vivek; Bhandari, Pamita; Singh, Bikram; Bhatacharya, Amita; Shanmugam, Veerubommu

2013-06-01

To study the effect of reduction in phytotoxin level on fungal chitinases, antagonistic Trichoderma spp. were screened for their ability to reduce the level of fusaric acid (FA), the phytotoxin produced by Fusarium spp. A T. harzianum isolate S17TH was able to tolerate high levels of FA (up to 500 ppm) but was unable to reduce the toxin to a significant level (non-toxic) added to minimal synthetic broth (MSB). However, the isolate was able to reduce 400 ppm FA in the liquid medium after 7 days to a non-toxic level and displayed similar level of antagonism over the control (without FA). In studies of the effect of the reduction in FA (400 ppm) level on chitinase gene expression in PCR assays, nag1 was significantly repressed but ech42 expression was only slightly repressed. Chitinase activity was either reduced or absent in the extracellular proteins of MSB supplemented with 400 ppm FA, which could be attributed to the effect of residual FA or its breakdown products through unknown mechanisms. Selection of S17TH as a toxin insensitive isolate that could commensurate the negative effect on chitinase activity makes it a potential antagonist against Fusarium spp.

Jojoba Oil Soft Colloidal Nanocarrier of a Synthetic Retinoid: Preparation, Characterization and Clinical Efficacy in Psoriatic Patients.

PubMed

Nasr, Maha; Abdel-Hamid, Sameh; Moftah, Noha H; Fadel, Maha; Alyoussef, Abdullah A

2017-01-01

Nanotechnology has provided substantial benefits in drug delivery, especially in the treatment of dermatological diseases. Psoriasis is a chronic inflammatory skin disease in which topical delivery of antipsoriatic agents is considered the first line treatment. To investigate whether the encapsulation of the synthetic retinoid tazarotene in a nanocarrier based on jojoba oil would decrease its irritation potential and clinically improve its therapeutic outcome in psoriatic patients. A microemulsion system based on jojoba wax and labrasol/plurol isostearique was prepared and characterized. The selected formula displayed spherical morphology, particle size of 15.49±2.41 nm, polydispersity index of 0.20 ±0.08, negative charge and low viscosity. The microemulsion provided two folds increase in skin deposition of tazarotene, correlating with higher reduction in psoriatic patients PASI scores after treatment (68% reduction in PASI scores versus 8.96% reduction with the marketed gel). No irritation was encountered in patients using microemulsion, with redness and inflammation reported with the marketed gel-treated patients. Jojoba oil microemulsion proved to be advantageous in reducing the irritancy of tazarotene, enhancing its skin deposition and achieving better therapeutic outcome in psoriatic patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Arctigenin protects against ultraviolet-A-induced damage to stemness through inhibition of the NF-κB/MAPK pathway.

PubMed

Park, See-Hyoung; Cho, Jae Youl; Oh, Sae Woong; Kang, Mingyeong; Lee, Seung Eun; Yoo, Ju Ah; Jung, Kwangseon; Lee, Jienny; Lee, Sang Yeol; Lee, Jongsung

2018-02-25

The stemness of stem cells is negatively affected by ultraviolet A (UVA) irradiation. This study was performed to examine the effects of arctigenin on UVA-irradiation-induced damage to the stemness of human mesenchymal stem cells (hMSCs) derived from adipose tissue. The mechanisms of action of arctigenin were also investigated. A BrdU-incorporation assay demonstrated that arctigenin attenuated the UVA-induced reduction of the cellular proliferative potential. Arctigenin also increased the UVA-induced reduction in stemness of hMSCs by upregulating stemness-related genes such as SOX2, OCT4, and NANOG. In addition, the UVA-induced reduction in the mRNA expression level of hypoxia-inducible factor (HIF)-1α was significantly recovered by arctigenin. The antagonizing effect of arctigenin on UVA irradiation was mediated by reduced PGE 2 production through the inhibition of MAPKs (p42/44 MAPK, p38 MAPK, and JNK) and NF-κB. Overall, these findings suggest that arctigenin can ameliorate the reduced stemness of hMSCs induced by UVA irradiation. The effects of arctigenin are mediated by PGE 2 -cAMP signaling-dependent upregulation of HIF-1α. Therefore, arctigenin could be used as an antagonist to attenuate the effects of UVA irradiation. Copyright © 2018 Elsevier B.V. All rights reserved.

Using bamboo biochar with compost for the stabilization and phytotoxicity reduction of heavy metals in mine-contaminated soils of China.

PubMed

Ali, Amjad; Guo, Di; Zhang, Yue; Sun, Xining; Jiang, Shuncheng; Guo, Zhanyu; Huang, Hui; Liang, Wen; Li, Ronghua; Zhang, Zengqiang

2017-06-02

Anthropogenic activities have transformed the global geochemical cycling of heavy metals (HMs). Many physical, chemical and biological methods are used to reduce the toxicity of HMs to humans, plants and environment. This study aimed to investigate the immobilization and phytotoxicity reduction of HMs after application of bamboo biochar (BB) in mine-polluted soil in Feng county (FC) and Tongguan (TG). The results showed that BB application to contaminated soil immobilized HMs (Zn, Pb, Cd and Cu). The soil pH and EC increased and the bioavailability of HMs decreased in FC and TG, whereas Pb and Cu increased in TG soil. The addition of BB reduced HMs uptake in the shoot/root of Brassica juncea. Physiological responses showed that BB application improved the shoot/root growth, dry biomass, and enhanced the chlorophyll (a and b) and carotenoid concentrations in Brassica. The incorporation of BB improved the soil health and accelerated enzymatic activities (β-glucosidase, alkaline phosphatase and urease) in HMs polluted soils. Antioxidant activities (POD, PPO, CAT and SOD) were also used as biomarkers to determine the negative effects of HMs on the growth of Brassica. Overall, the immobilization potential and phytotoxicity reduction of HMs were confirmed by BCF, TF and MEA for both soils.

Aminochrome decreases NGF, GDNF and induces neuroinflammation in organotypic midbrain slice cultures.

PubMed

de Araújo, Fillipe M; Ferreira, Rafael S; Souza, Cleide S; Dos Santos, Cleonice Creusa; Rodrigues, Tácio L R S; E Silva, Juliana Helena C; Gasparotto, Juciano; Gelain, Daniel Pens; El-Bachá, Ramon S; D Costa, Maria de Fátima; Fonseca, José Claudio M; Segura-Aguilar, Juan; Costa, Silvia L; Silva, Victor Diogenes A

2018-05-01

Recent evidence shows that aminochrome induces glial activation related to neuroinflammation. This dopamine derived molecule induces formation and stabilization of alpha-synuclein oligomers, mitochondria dysfunction, oxidative stress, dysfunction of proteasomal and lysosomal systems, endoplasmic reticulum stress and disruption of the microtubule network, but until now there has been no evidence of effects on production of cytokines and neurotrophic factors, that are mechanisms involved in neuronal loss in Parkinson's disease (PD). This study examines the potential role of aminochrome on the regulation of NGF, GDNF, TNF-α and IL-1β production and microglial activation in organotypic midbrain slice cultures from P8 - P9 Wistar rats. We demonstrated aminochrome (25 μM, for 24 h) induced reduction of GFAP expression, reduction of NGF and GDNF mRNA levels, morphological changes in Iba1 + cells, and increase of both TNF-α, IL-1β mRNA and protein levels. Moreover, aminochrome (25 μM, for 48 h) induced morphological changes in the edge of slices and reduction of TH expression. These results demonstrate neuroinflammation, as well as negative regulation of neurotrophic factors (GDNF and NGF), may be involved in aminochrome-induced neurodegeneration, and they contribute to a better understanding of PD pathogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Crystallographic origin of cycle decay of the high-voltage LiNi0.5Mn1.5O4 spinel lithium-ion battery electrode.

PubMed

Pang, Wei Kong; Lu, Cheng-Zhang; Liu, Chia-Erh; Peterson, Vanessa K; Lin, Hsiu-Fen; Liao, Shih-Chieh; Chen, Jin-Ming

2016-06-29

High-voltage spinel LiNi0.5Mn1.5O4 (LNMO) is considered a potential high-power-density positive electrode for lithium-ion batteries, however, it suffers from capacity decay after extended charge-discharge cycling, severely hindering commercial application. Capacity fade is thought to occur through the significant volume change of the LNMO electrode occurring on cycling, and in this work we use operando neutron powder diffraction to compare the structural evolution of the LNMO electrode in an as-assembled 18650-type battery containing a Li4Ti5O12 negative electrode with that in an identical battery following 1000 cycles at high-current. We reveal that the capacity reduction in the battery post cycling is directly proportional to the reduction in the maximum change of the LNMO lattice parameter during its evolution. This is correlated to a corresponding reduction in the MnO6 octahedral distortion in the spinel structure in the cycled battery. Further, we find that the rate of lattice evolution, which reflects the rate of lithium insertion and removal, is ∼9 and ∼10% slower in the cycled than in the as-assembled battery during the Ni(2+)/Ni(3+) and Ni(3+)/Ni(4+) transitions, respectively.

OVERWEIGHT/OBESITY AND HUMAN CAPITAL FORMATION FROM INFANCY TO ADOLESCENCE: EVIDENCE FROM TWO LARGE US COHORTS.

PubMed

Murasko, Jason E

2015-03-01

Body mass index (BMI) levels in US children and adolescents have increased over the past several decades. The negative health effects of this trend are well-documented. Recent work has evaluated the potential effects on skills formation. Studies are mixed on whether there is an association between high BMI and skills outcomes, and those that estimate causal effects find none. This paper offers estimates on the causal effect of BMI-defined overweight and obesity on skills formation using two large cohorts of contemporary US children followed from infancy to 5 years and from kindergarten (6 years) to the eighth grade (14 years). Significant negative associations were observed in the random effects models for males in early life with respect to a mental skills assessment, for females during the pre-school years for reading and maths assessments, for both males and females during the schooling years for reading assessments and for females during the schooling years for maths assessments. Fixed effects models yielded a significant negative association only with respect to the latter. The implication of these findings is that any improvement in skills outcomes that may accompany reductions in obesity prevalence may depend on whether interventions are general to overall health productivity or whether they are specific to dietary and exercise behaviours.

Role of volcanic and anthropogenic aerosols in the recent global surface warming slowdown

NASA Astrophysics Data System (ADS)

Smith, Doug M.; Booth, Ben B. B.; Dunstone, Nick J.; Eade, Rosie; Hermanson, Leon; Jones, Gareth S.; Scaife, Adam A.; Sheen, Katy L.; Thompson, Vikki

2016-10-01

The rate of global mean surface temperature (GMST) warming has slowed this century despite the increasing concentrations of greenhouse gases. Climate model experiments show that this slowdown was largely driven by a negative phase of the Pacific Decadal Oscillation (PDO), with a smaller external contribution from solar variability, and volcanic and anthropogenic aerosols. The prevailing view is that this negative PDO occurred through internal variability. However, here we show that coupled models from the Fifth Coupled Model Intercomparison Project robustly simulate a negative PDO in response to anthropogenic aerosols implying a potentially important role for external human influences. The recovery from the eruption of Mount Pinatubo in 1991 also contributed to the slowdown in GMST trends. Our results suggest that a slowdown in GMST trends could have been predicted in advance, and that future reduction of anthropogenic aerosol emissions, particularly from China, would promote a positive PDO and increased GMST trends over the coming years. Furthermore, the overestimation of the magnitude of recent warming by models is substantially reduced by using detection and attribution analysis to rescale their response to external factors, especially cooling following volcanic eruptions. Improved understanding of external influences on climate is therefore crucial to constrain near-term climate predictions.

Does obesity influence labour market outcomes among working-age adults? Evidence from Canadian longitudinal data.

PubMed

Larose, Samantha L; Kpelitse, Koffi A; Campbell, M Karen; Zaric, Gregory S; Sarma, Sisira

2016-03-01

Although a negative association between obesity and labour market outcomes is commonly reported in many studies, the causal nature of this relationship remains unclear. Using nationally representative longitudinal data from the last six confidential master files (2000/2001-2010/2011) of the National Population Health Survey, we examine the association between obesity and employment participation and earnings among working-age adults in Canada. After controlling for demographic and socioeconomic characteristics, lifestyle factors and time-invariant individual heterogeneity, our results show that obesity is not significantly associated with employment participation but is associated with reduced hourly wage rate and annual income among women by about 4% and 4.5%, respectively. The corresponding results for men show that obesity is associated with about 2% reduction in wage rate and income, but significant at 10% level. However, after controlling for the potential reverse causality bias using the lagged measure of obesity, the effect of obesity on wage rate and income became positive or statistically non-significant. Our findings suggest that obesity is not causally associated with negative labour market outcomes among working-age men in Canada. For working-age women, we find limited evidence of negative labour market outcomes. Copyright © 2015 Elsevier B.V. All rights reserved.

Pathological prolongation of action potential duration as a cause of the reduced alpha-adrenoceptor-mediated negative inotropy in streptozotocin-induced diabetic mice myocardium.

PubMed

Kanae, Haruna; Hamaguchi, Shogo; Wakasugi, Yumi; Kusakabe, Taichi; Kato, Keisuke; Namekata, Iyuki; Tanaka, Hikaru

2017-11-01

Effect of pathological prolongation of action potential duration on the α-adrenoceptor-mediated negative inotropy was studied in streptozotocin-induced diabetic mice myocardium. In streptozotocin-treated mouse ventricular myocardium, which had longer duration of action potential than that in control mice, the negative inotropic response induced by phenylephrine was smaller than that in control mice. 4-Aminopyridine prolonged the action potential duration and decreased the negative inotropy in control mice. Cromakalim shortened the action potential duration and increased the negative inotropy in streptozotocin-treated mice. These results suggest that the reduced α-adrenoceptor-mediated inotropy in the diabetic mouse myocardium is partly due to its prolonged action potential. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Adolescents with Psychopathic Traits Report Reductions in Physiological Responses to Fear

ERIC Educational Resources Information Center

Marsh, Abigail A.; Finger, Elizabeth C.; Schechter, Julia C.; Jurkowitz, Ilana T. N.; Reid, Marguerite E.; Blair, R. J. R.

2011-01-01

Background: Psychopathy is characterized by profound affective deficits, including shallow affect and reduced empathy. Recent research suggests that these deficits may apply particularly to negative emotions, or to certain negative emotions such as fear. Despite increased focus on the cognitive and neural underpinnings of psychopathy, little is…

Vividness and Control: Factors in the Effectiveness of Performance Visualization?

ERIC Educational Resources Information Center

Ayres, Joe; Hopf, Tim; Edwards, Patricia A.

1999-01-01

Compares the effects of imagery control and vividness, separately and in combination, on self-report measures of public speaking apprehension (PSA), state communication apprehension (CA), negative thinking, and behavioral disruption. Links imagery control and vividness to reductions in PSA, state CA, negative thinking, and behavioral disruption.…

40 CFR 62.5400 - Identification of plan-negative declaration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Massachusetts Fluoride Emissions from Existing Primary Aluminum Plants § 62.5400 Identification of plan—negative... certifying that there are no existing primary aluminum reduction plants in the State subject to part 60, subpart B of this chapter. [54 FR 9047, Mar. 3, 1989] Metals, Acid Gases, Organic Compounds and Nitrogen...

40 CFR 62.5400 - Identification of plan-negative declaration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Massachusetts Fluoride Emissions from Existing Primary Aluminum Plants § 62.5400 Identification of plan—negative... certifying that there are no existing primary aluminum reduction plants in the State subject to part 60, subpart B of this chapter. [54 FR 9047, Mar. 3, 1989] Metals, Acid Gases, Organic Compounds and Nitrogen...

40 CFR 62.5400 - Identification of plan-negative declaration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Massachusetts Fluoride Emissions from Existing Primary Aluminum Plants § 62.5400 Identification of plan—negative... certifying that there are no existing primary aluminum reduction plants in the State subject to part 60, subpart B of this chapter. [54 FR 9047, Mar. 3, 1989] Metals, Acid Gases, Organic Compounds and Nitrogen...

40 CFR 62.5400 - Identification of plan-negative declaration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Massachusetts Fluoride Emissions from Existing Primary Aluminum Plants § 62.5400 Identification of plan—negative... certifying that there are no existing primary aluminum reduction plants in the State subject to part 60, subpart B of this chapter. [54 FR 9047, Mar. 3, 1989] Metals, Acid Gases, Organic Compounds and Nitrogen...

Stabilization of Reduced Molybdenum-Iron-Sulfur Single and Double Cubane Clusters by Cyanide Ligation

PubMed Central

Pesavento, Russell P.; Berlinguette, Curtis P.; Holm, R. H.

2008-01-01

Recent work has shown that cyanide ligation increases the redox potentials of Fe4S4 clusters, enabling the isolation of [Fe4S4(CN)4]4−, the first synthetic Fe4S4 cluster obtained in the all-ferrous oxidation state (Scott, T. A.; Berlinguette, C. P.; Holm, R. H.; Zhou, H.-C., Proc. Natl. Acad. Sci. USA 2005, 102, 9741). The generality of reduced cluster stabilization has been examined with MoFe3S4 clusters. Reaction of single cubane [(Tp)MoFe3S4(PEt3)3]1+ and edge-bridged double cubane [(Tp)2Mo2Fe6S8(PEt3)4] with cyanide in acetonitrile affords [(Tp)MoFe3S4(CN)3]2− (2) and [(Tp)2Mo2Fe6S8(CN)4]4− (5), respectively. Reduction of 2 with KC14H10 yields [(Tp)MoFe3S4(CN)3]3− (3). Clusters were isolated in ca. 70–90% yields as Et4N+ or Bu4N+ salts; Clusters 3 and 5 contain all-ferrous cores; 3 is the first [MoFe3S4]1+ cluster isolated in substance. The structures of 2 and 3 are very similar; the volume of the reduced cluster core is slightly larger (2.5%), a usual effect upon reduction of cubane-type Fe4S4 and MFe3S4 clusters. Redox potentials and 57Fe isomer shifts of [(Tp)MoFe3S4L3]2−,3 and [(Tp)2Mo2Fe6S8L4]4−,3− clusters with L = CN, PhS, halide, and PEt3 are compared. Clusters with π-donor ligands (L = halide, PhS) exhibit larger isomer shifts and lower (more negative) redox potentials while π-acceptor ligands (L = CN, PEt3) induce smaller isomer shifts and higher (less negative) redox potentials. When potentials of 3/2 and [(Tp)MoFe3S4(SPh)3]3−/2− are compared, cyanide stabilizes 3 by 270 mV vs. the reduced thiolate cluster, commensurate with the 310 mV stabilization of [Fe4S4(CN)4]4− vs. [Fe4S4(SPh)4]4− where four ligands differ. These results demonstrate the efficacy of cyanide stabilization of lower cluster oxidation states. (Tp = hydrotris(pyrazolyl)borate(1−)). PMID:17279830

Stabilization of reduced molybdenum-iron-sulfur single- and double-cubane clusters by cyanide ligation.

PubMed

Pesavento, Russell P; Berlinguette, Curtis P; Holm, R H

2007-01-22

Recent work has shown that cyanide ligation increases the redox potentials of Fe(4)S(4) clusters, enabling the isolation of [Fe(4)S(4)(CN)4]4-, the first synthetic Fe(4)S(4) cluster obtained in the all-ferrous oxidation state (Scott, T. A.; Berlinguette, C. P.; Holm, R. H.; Zhou, H.-C. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 9741). The generality of reduced cluster stabilization has been examined with MoFe(3)S(4) clusters. Reaction of single-cubane [(Tp)MoFe(3)S(4)(PEt(3))3]1+ and edge-bridged double-cubane [(Tp)2Mo(2)Fe(6)S(8)(PEt(3))4] with cyanide in acetonitrile affords [(Tp)MoFe(3)S(4)(CN)3]2- (2) and [(Tp)2Mo(2)Fe(6)S(8)(CN)4]4- (5), respectively. Reduction of 2 with KC(14)H(10) yields [(Tp)MoFe(3)S(4)(CN)3]3- (3). Clusters were isolated in approximately 70-90% yields as Et(4)N+ or Bu(4)N+ salts; clusters 3 and 5 contain all-ferrous cores, and 3 is the first [MoFe(3)S(4)]1+ cluster isolated in substance. The structures of 2 and 3 are very similar; the volume of the reduced cluster core is slightly larger (2.5%), a usual effect upon reduction of cubane-type Fe(4)S(4) and MFe(3)S(4) clusters. Redox potentials and 57Fe isomer shifts of [(Tp)MoFe(3)S(4)L3]2-,3- and [(Tp)2Mo(2)Fe(6)S(8)L(4)]4-,3- clusters with L = CN-, PhS-, halide, and PEt3 are compared. Clusters with pi-donor ligands (L = halide, PhS) exhibit larger isomer shifts and lower (more negative) redox potentials, while pi-acceptor ligands (L = CN, PEt3) induce smaller isomer shifts and higher (less-negative) redox potentials. When the potentials of 3/2 and [(Tp)MoFe(3)S(4)(SPh)3]3-/2- are compared, cyanide stabilizes 3 by 270 mV versus the reduced thiolate cluster, commensurate with the 310 mV stabilization of [Fe(4)S(4)(CN)4]4- versus [Fe(4)S(4)(SPh)4]4- where four ligands differ. These results demonstrate the efficacy of cyanide stabilization of lower cluster oxidation states. (Tp = hydrotris(pyrazolyl)borate(1-)).

Electrochemical impedance spectroscopy study on polymerization of L-lysine on electrode surface and its application for immobilization and detection of suspension cells.

PubMed

Huang, Baozhen; Jia, Ningming; Chen, Lina; Tan, Liang; Yao, Shouzhuo

2014-07-15

Poly-L-lysine (PLL), which has been employed as a conductive polymer in the construction of some electrochemical sensors, can be prepared using L-lysine by cyclic voltammetry (CV) with a wide potential range. However, the presented explanation and description about its polymerization mechanism seems oversimplified because the self-reaction of electrode and the electrolysis of solvent at high potential are ignored. This work presents an intensive investigation on the relevant reactions during the process of PLL-polymerization using CV, X-ray photoelectron spectroscopy, Fourier transform-infrared spectroscopy, and electrochemical impedance spectroscopy. At a higher positive potential, the transfer from lysine molecules to cation radicals and the polymerization reaction on the glassy carbon electrode (GCE) could be achieved, accompanied by the activation of GCE, the formation of oxygen-containing functional groups, and the generation of oxygen derived from the oxidation of water. The adsorbed oxygen had a seriously negative effect on the formation of PLL unless it suffered reduction at a lower negative potential. The charge transfer through the electrochemical polymerized PLL film was seriously hindered by the immobilization of suspension cells due to the electrostatic interaction. The charge-transfer resistance difference (ΔR(ct)) was increased with the enhancement of the cell number (N(cells)) and the 1/ΔR(ct) value displayed a linear response with 1/N(cells) in the range of 5.0 × 10(2)-1.0 × 10(5) cells with a detection limit of 180 cells estimated at a signal-to-noise ratio of 3. A sensitive electrochemical sensor for the quantitative detection of suspension cells was developed.

The potential for iron reduction in upland soils in Calhoun Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Thompson, A.; Chen, C.; Noor, N.; Hodges, C. A.; Barcellos, D.; Richter, D. D., Jr.

2017-12-01

Fe redox cycling plays an important role in organic matter preservation and degradation, and the fate of nutrients and contaminants. Despite its importance, Fe redox cycling in non-flooded upland soils has been underappreciated, although many upland terrestrial ecosystems have episodes of low redox events and an abundance of anoxic microsites. Soil Fe reduction is generally constrained by C availability, the reactivity of Fe(III) oxyhydroxides, and the abundance of Fe reducing bacteria. The goal of this study was to determine the potential for Fe reduction in upland soils under varying land-uses (Hardwood, Pine and Cultivated soils) from Calhoun Critical Zone Observatory. Fresh field soils from multiple depths were incubated in the lab without amendments under anoxic conditions for 3 weeks to determine the native potential for soil Fe reduction and to assess the limiting factors, the soils were amended with factorial mixtures of the following: (1) organic substrates (glucose and alanine); (2) bioavailable Fe (ferrihydrite); and (3) Fe reducing bacteria (Shewanella oneidensis strain MR-1). Results showed that Fe reduction potential generally decreased with soil depth. Fe reduction potential is very minimal below 1m of soil profile. The availability of Fe(III) minerals did not constrain pine and hardwood soil Fe reduction potential. Fe(III) availability only slightly limited the potential for Fe reduction the cultivated soils, which have the lowest extractable Fe by ascorbate-citrate. Labile C constrained Fe reduction in the hardwood and cultivated soils, but not in the pine soils, which had the highest extractable C by K2SO4. In addition, we found the more energetic C source (glucose) facilitated more Fe reduction in the subsurface soil than did Alanine. Finally, the abundance of Fe-reducing bacteria limited Fe reduction potential in almost all of these soils, particularly the pine soils.

Thermodynamic Characterization of a Triheme Cytochrome Family from Geobacter sulfurreducens Reveals Mechanistic and Functional Diversity

PubMed Central

Morgado, Leonor; Bruix, Marta; Pessanha, Miguel; Londer, Yuri Y.; Salgueiro, Carlos A.

2010-01-01

Abstract A family of five periplasmic triheme cytochromes (PpcA-E) was identified in Geobacter sulfurreducens, where they play a crucial role by driving electron transfer from the cytoplasm to the cell exterior and assisting the reduction of extracellular acceptors. The thermodynamic characterization of PpcA using NMR and visible spectroscopies was previously achieved under experimental conditions identical to those used for the triheme cytochrome c7 from Desulfuromonas acetoxidans. Under such conditions, attempts to obtain NMR data were complicated by the relatively fast intermolecular electron exchange. This work reports the detailed thermodynamic characterization of PpcB, PpcD, and PpcE under optimal experimental conditions. The thermodynamic characterization of PpcA was redone under these new conditions to allow a proper comparison of the redox properties with those of other members of this family. The heme reduction potentials of the four proteins are negative, differ from each other, and cover different functional ranges. These reduction potentials are strongly modulated by heme-heme interactions and by interactions with protonated groups (the redox-Bohr effect) establishing different cooperative networks for each protein, which indicates that they are designed to perform different functions in the cell. PpcA and PpcD appear to be optimized to interact with specific redox partners involving e−/H+ transfer via different mechanisms. Although no evidence of preferential electron transfer pathway or e−/H+ coupling was found for PpcB and PpcE, the difference in their working potential ranges suggests that they may also have different physiological redox partners. This is the first study, to our knowledge, to characterize homologous cytochromes from the same microorganism and provide evidence of their different mechanistic and functional properties. These findings provide an explanation for the coexistence of five periplasmic triheme cytochromes in G. sulfurreducens. PMID:20655858

40 CFR 60.1935 - What equations must I use?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Percent reduction in potential hydrogen chloride emissions. Calculate the percent reduction in potential hydrogen chloride emissions (%PHC1) using equation 3 of this section: ER06DE00.005 Where: %PHC1 = percent reduction of the potential hydrogen chloride emissions Ei = hydrogen chloride emission concentration as...

40 CFR 60.1935 - What equations must I use?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Percent reduction in potential hydrogen chloride emissions. Calculate the percent reduction in potential hydrogen chloride emissions (%PHC1) using equation 3 of this section: ER06DE00.005 Where: %PHC1 = percent reduction of the potential hydrogen chloride emissions Ei = hydrogen chloride emission concentration as...

Potential negative consequences of non-consented switch of inhaled medications and devices in asthma patients.

PubMed

Björnsdóttir, U S; Gizurarson, S; Sabale, U

2013-09-01

Asthma requires individually tailored and careful management to control and prevent symptoms and exacerbations. Selection of the most appropriate treatment is dependent on both the choice of drugs and inhaler device; however, financial pressures may result in patients being switched to alternative medications and devices in an attempt to reduce costs. This review aimed to examine the published literature in order to ascertain whether switching a patient's asthma medications or device negatively impacts clinical and economic outcomes. A literature search of MEDLINE (2001-13 September 2011) was conducted to identify English-language articles focused on the direct impact of switching medications and inhaler devices and switching from fixed-dose combination to monocomponent therapy via separate inhalers in patients with asthma; the indirect impacts of switching were also assessed. Evidence showed that non-consented switching of medications and inhalers in patients with asthma can be associated with a range of negative outcomes, at both individual and organisational levels. Factors that reduce adherence may lead to compromised symptom control resulting in increased healthcare resource utilisation and poorer patient quality of life. The consequences of a non-consented switch should be weighed carefully against arguments supporting an inhaler switch without the patient's consent for non-medical/budgetary reasons, such as potential reductions in initial acquisition costs, which may be associated with subsequent additional healthcare needs. Given the increasing pressure for reduced costs and efficient allocation of limited healthcare resources, an additional investment in ensuring high medication adherence may lead to greater savings due to a potentially decreased demand for healthcare services. In contrast, savings achieved in acquisition costs may result in a greater net loss due to increased healthcare consumption caused by decreased asthma control. © 2013 The Authors. International Journal of Clinical Practice published by John Wiley & Sons Ltd.

Effects of aging on functional connectivity of the amygdala for subsequent memory of negative pictures: a network analysis of functional magnetic resonance imaging data.

PubMed

St Jacques, Peggy L; Dolcos, Florin; Cabeza, Roberto

2009-01-01

Aging is associated with preserved enhancement of emotional memory, as well as with age-related reductions in memory for negative stimuli, but the neural networks underlying such alterations are not clear. We used a subsequent-memory paradigm to identify brain activity predicting enhanced emotional memory in young and older adults. Activity in the amygdala predicted enhanced emotional memory, with subsequent-memory activity greater for negative stimuli than for neutral stimuli, across age groups, a finding consistent with an overall enhancement of emotional memory. However, older adults recruited greater activity in anterior regions and less activity in posterior regions in general for negative stimuli that were subsequently remembered. Functional connectivity of the amygdala with the rest of the brain was consistent with age-related reductions in memory for negative stimuli: Older adults showed decreased functional connectivity between the amygdala and the hippocampus, but increased functional connectivity between the amygdala and dorsolateral prefrontal cortices. These findings suggest that age-related differences in the enhancement of emotional memory might reflect decreased connectivity between the amygdala and typical subsequent-memory regions, as well as the engagement of regulatory processes that inhibit emotional responses.

Healthier side dishes at restaurants: an analysis of children’s perspectives, menu content, and energy impacts

PubMed Central

2014-01-01

Background Children consume restaurant-prepared foods at high rates, suggesting that interventions and policies targeting consumption of these foods have the potential to improve diet quality and attenuate excess energy intake. One approach to encouraging healthier dietary intake in restaurants is to offer fruits and vegetables (FV) as side dishes, as opposed to traditional, energy-dense accompaniments like French fries. The aims of the current study were to examine: children's views about healthier side dishes at restaurants; current side dish offerings on children's menus at leading restaurants; and potential energy reductions when substituting FV side dishes in place of French fries. Methods To investigate children’s attitudes, a survey was administered to a nationally representative sample of U.S. 8- to 18-year-olds (n = 1178). To examine current side dish offerings, children's menus from leading quick service (QSR; n = 10) and full service restaurant chains (FSR; n = 10) were analyzed. Energy reductions that could result from substituting commonly-offered FV side dishes for French fries were estimated using nutrition information corresponding to the children's menu items. Results Two-thirds of children reported that they would not feel negatively about receiving FV sides instead of French fries with kids' meals. Liking/taste was the most common reason that children gave to explain their attitudes about FV side dishes. Nearly all restaurants offered at least 1 FV side dish option, but at most restaurants (60% of QSR; 70% of FSR), FV sides were never served by default. Substituting FV side dishes for French fries yielded an average estimated energy reduction of at least 170 calories. Conclusions Results highlight some healthy trends in the restaurant context, including the majority of children reporting non-negative attitudes about FV side dishes and the consistent availability of FV side dish options at leading QSR and FSR. Yet the minority of restaurants offer these FV sides by default. Promoting creative, appealing FV side dishes can result in healthier, less energy-dense meals for children. Substituting or displacing energy-dense default side dishes with such FV dishes show promise as part of continued, comprehensive efforts to increase the healthfulness of meals consumed by children in restaurant settings. PMID:24996545

Recycled Archean sulfur in the mantle wedge of the Mariana Forearc and microbial sulfate reduction within an extremely alkaline serpentine seamount

NASA Astrophysics Data System (ADS)

Aoyama, Shinnosuke; Nishizawa, Manabu; Miyazaki, Junichi; Shibuya, Takazo; Ueno, Yuichiro; Takai, Ken

2018-06-01

The identification of microbial activity under extreme conditions is important to define potential boundaries of the habitable and uninhabitable zones of terrestrial and extraterrestrial living forms. The subseafloor regimes of serpentinite seamounts in the Mariana Forearc are among the most extreme environments for life on earth owing to the widespread presence of highly alkaline fluids with pH values greater than 12. The potential activity of sulfate-reducing microorganisms has been suggested within the South Chamorro serpentinite seamounts on the basis of depletion of sulfate and enrichment of dissolved sulfide in pore water. However, the vertical distribution of sulfate-reducing microorganisms and the origin of sulfate are still uncertain. To address these issues, we analyzed quadruple sulfur isotopes of sulfide minerals and pore water sulfate in the upper 56 m of sedimentary sequences at the summit of the S. Chamorro Seamount and those of dissolved sulfate in upwelling fluids collected as deep as 202 mbsf (meters below the seafloor) in a cased hole near the summit of the same seamount. The depth profiles of the concentrations and the δ34S and Δ33S‧ values of sulfide minerals and pore water sulfate indicate microbial sulfate reduction as deep as 30 mbsf. Further, apparent isotopic fractionations (34ε) and exponents of mass dependent relationships (33λ) during sulfate reduction are estimated to be 62 ± 14‰ and 0.512 ± 0.002, respectively. The upwelling fluids show both the chlorine depletion relative to seawater and the negative δ15N values of ammonia (-4‰). Although these signatures point to dehydration of the subducting oceanic plate, the negative Δ33S‧ values of sulfate (-0.16‰ to -0.26‰ with analytical errors of ±0.01‰) are unlikely to originate from surrounding modern crusts. Instead, sulfate in the upwelling fluid likely possess non-mass-dependent (NMD) sulfur. Because NMD sulfur was produced primarily in the Archean atmosphere, our results suggest that the presence of recycled Archean crust that could be incorporated into the upper mantle through subduction of Archean oceanic crusts or from the NMD-bearing OIB seamounts located in the southern margin of the Pacific Plate.

Does consideration of GHG reductions change local decision making? A Case Study in Chile

NASA Astrophysics Data System (ADS)

Cifuentes, L. A.; Blumel, G.

2003-12-01

While local air pollution has been a public concern in developing countries for some time, climate change is looked upon as a non-urgent, developed world problem. In this work we present a case study of the interaction of measures to abate air pollution and measures to mitigate GHG emissions in Santiago, Chile, with the purpose of determining if the consideration of reductions in GHG affects the decisions taken to mitigate local air pollution. The emissions reductions of both GHG and local air pollutants were estimated from emission factors (some derived locally) and changes in activity levels. Health benefits due to air pollution abatement were computed using figures derived previously for the cost benefit analysis of Santiago's Decontamination Plan, transferred to the different cities taking into consideration local demographic and income data. The Santiago estimates were obtained using the damage function approach, based on some local epidemiological studies, and on local health and demographic data. Unit social values for the effects were estimated locally (for cost of treatment and lost productivity values) or extrapolated from US values (mainly for WTP values) using the ratio of per-capita income and an income elasticity of 1. The average benefits of emission abatement (in 1997 US\\ per ton) are 1,800 (1,200-2300) for NOx, 3,000 (2,100-3900) for SO2, 31,900 (21,900 - 41,900) for PM, and 630 (430 - 830) for resuspended dust. Economic benefits due to carbon reduction were considered at 3.5, 10 and 20 UStCO2. Marginal abatement cost curves were constructed considering private and net costs (private less the potential sales of carbon credits) Due to the bottom-up approach to constructing the marginal cost curve, many abatement measures (like congestion tolls and CNG instead of diesel buses) amounting to 8% reduction of PM2.5 concentration, exhibit a negative private cost. If the health benefits are considered for the decision, a maximum reduction of 22% in PM2.5 levels is obtained. Although many measures have associated reductions in GHG, due to the relatively low price considered for carbon reductions, when the potential benefits of CO2 sales are considered, this number does not increases. Therefore, consideration of the CO2 benefits did not change the decision for any of the 36 measures analyzed. This confirms that the main driver for air pollution policy is likely to continue to be local concerns, like public health issues.

Evaluating confidence in the impact of regulatory nutrient reduction and assessing the competing impact of climate change

NASA Astrophysics Data System (ADS)

Irby, I.; Friedrichs, M. A. M.

2017-12-01

Human impacts on the Chesapeake Bay through increased nutrient run-off as a result of land-use change, urbanization, and industrialization, have resulted in a degradation of water quality over the last half-century. These direct impacts, compounded with human-induced climate changes such as warming, rising sea level, and changes in precipitation, have elevated the conversation surrounding the future of the Bay's water quality. As a result, in 2010, a Total Maximum Daily Load (TMDL) was established for the Chesapeake Bay that limited nutrient and sediment input in an effort to increase dissolved oxygen. This research utilizes a multiple model approach to evaluate confidence in the estuarine water quality modeling portion of the TMDL. One of the models is then used to assess the potential impact climate change may have on the success of currently mandated nutrient reduction levels in 2050. Results demonstrate that although the models examined differ structurally and in biogeochemical complexity, they project a similar attainment of regulatory water quality standards after nutrient reduction, while also establishing that meeting water quality standards is relatively independent of hydrologic conditions. By developing a Confidence Index, this research identifies the locations and causes of greatest uncertainty in modeled projections of water quality. Although there are specific locations and times where the models disagree, this research lends an increased degree of confidence in the appropriateness of the TMDL levels and in the general impact nutrient reductions will have on Chesapeake Bay water quality under current environmental conditions. However, when examining the potential impacts of climate change, this research shows that the combined impacts of increasing temperature, sea level, and river flow negatively affect dissolved oxygen throughout the Chesapeake Bay and impact progress towards meeting the water quality standards associated with the TMDL with increased temperature as the primary culprit. These results, having been continually shared with the regulatory TMDL modelers, will aid in the decision making for the 2017 TMDL Mid-Point Assessment.

Reductive dehalogenation of 5-bromouracil by aliphatic organic radicals in aqueous solutions; electron transfer and proton-coupled electron transfer mechanisms

NASA Astrophysics Data System (ADS)

Matasović, Brunislav; Bonifačić, Marija

2011-06-01

Reductive dehalogenation of 5-bromouracil by aliphatic organic radicals CO2-rad , rad CH 2OH, rad CH(CH 3)OH, and rad CH(CH 3)O - have been studied in oxygen free aqueous solutions in the presence of organic additives: formate, methanol or ethanol. For radicals production 60Co γ-radiolysis was employed and the yield of bromide was measured by means of ion chromatography. Both radical anions have reducing potential negative enough to transfer an electron to BrU producing bromide ion and U rad radical. High yields of bromide have been measured increasing proportional to the concentration of the corresponding organic additives at a constant dose rate. This is characteristic for a chain process where regeneration of radical ions occurs by H-atom abstraction by U rad radical from formate or ethanol. Results with the neutral radicals conformed earlier proposition that the reduction reaction of α-hydroxyalkyl radicals proceeds by the proton-coupled electron transfer mechanism ( Matasović and Bonifačić, 2007). Thus, while both rad CH 2OH and rad CH(CH 3)OH did not react with BrU in water/alcohol solutions, addition of bicarbonate and acetate in mmol dm -3 concentrations, pH 7, brought about chain debromination to occur in the case of rad CH(CH 3)OH radical as reactant. Under the same conditions phosphate buffer, a base with higher bulk proton affinity, failed to have any influence. The results are taken as additional proofs for the specific complex formation of α-hydroxyalkyl radicals with suitable bases which enhances radicals' reduction potential in comparison with only water molecules as proton acceptors. Rate constants for the H-atom abstraction from ethanol and formate by U rad radicals have been estimated to amount to about ≥85 and 1200 dm 3 mol -1 s -1, respectively.

Novel composite material polyoxovanadate@MIL-101(Cr): a highly efficient electrocatalyst for ascorbic acid oxidation.

PubMed

Fernandes, Diana M; Barbosa, André D S; Pires, João; Balula, Salete S; Cunha-Silva, Luís; Freire, Cristina

2013-12-26

A novel hybrid composite material, PMo10V2@MIL-101 was prepared by the encapsulation of the tetra-butylammonium (TBA) salt of the vanadium-substituted phosphomolybdate [PMo10V2O40](5-) (PMo10V2) into the porous metal-organic framework (MOF) MIL-101(Cr). The materials characterization by powder X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy confirmed the preparation of the composite material without disruption of the MOF porous structure. Pyrolytic graphite electrodes modified with the original components (MIL-101(Cr), PMo10V2), and the composite material PMo10V2@MIL-101 were prepared and their electrochemical responses were studied by cyclic voltammetry. Surface confined redox processes were observed for all the immobilized materials. MIL-101(Cr) showed one-electron reduction process due to chromium centers (Cr(III) → Cr(II)), while PMo10V2 presented five reduction processes: the peak at more positive potentials is attributed to two superimposed 1-electron vanadium reduction processes (V(V) → V(IV)) and the other four peaks to Mo-centred two-electron reduction processes (Mo(VI) → Mo(V)). The electrochemical behavior of the composite material PMo10V2@MIL-101 showed both MIL-101(Cr) and PMo10V2 redox features, although with the splitting of the two vanadium processes and the shift of the Mo- and Cr- centered processes to more negative potentials. Finally, PMo10V2@MIL-101 modified electrode showed outstanding enhanced vanadium-based electrocatalytic properties towards ascorbic acid oxidation, in comparison with the free PMo10V2, as a result of its immobilization into the porous structure of the MOF. Furthermore, PMo10V2@MIL-101 modified electrode showed successful simultaneous detection of ascorbic acid and dopamine.

Dissociable contributions of MRI volume reductions of superior temporal and fusiform gyri to symptoms and neuropsychology in schizophrenia.

PubMed

Nestor, Paul G; Onitsuka, Toshiaki; Gurrera, Ronald J; Niznikiewicz, Margaret; Frumin, Melissa; Shenton, Martha E; McCarley, Robert W

2007-03-01

We sought to identify the functional correlates of reduced magnetic resonance imaging (MRI) volumes of the superior temporal gyrus (STG) and the fusiform gyrus (FG) in patients with chronic schizophrenia. MRI volumes, positive/negative symptoms, and neuropsychological tests of facial memory and executive functioning were examined within the same subjects. The results indicated two distinct, dissociable brain structure-function relationships: (1) reduced left STG volume-positive symptoms-executive deficits; (2) reduced left FG-negative symptoms-facial memory deficits. STG and FG volume reductions may each make distinct contributions to symptoms and cognitive deficits of schizophrenia.

Safety behaviors and judgmental biases in social anxiety disorder.

PubMed

Taylor, Charles T; Alden, Lynn E

2010-03-01

Two experiments were conducted to examine the link between safety behaviors and social judgments in social anxiety disorder (SAD). Safety behaviors were manipulated in the context of a controlled laboratory-based social interaction, and subsequent effects of the manipulation on the social judgments of socially anxious participants (N = 50, Study 1) and individuals meeting diagnostic criteria for generalized SAD (N = 80, Study 2) were examined. Participants were randomly assigned to either a safety behavior reduction plus exposure condition (SB + EXP) or a graduated exposure (EXP) control condition, and then took part in a conversation with a trained experimental confederate. Results revealed across both studies that participants in the SB + EXP group were less negative and more accurate in judgments of their performance following safety behavior reduction relative to EXP participants. Study 2 also demonstrated that participants in the SB + EXP group displayed lower judgments about the likelihood of negative outcomes in a subsequent social event compared to controls. Moreover, reduction in safety behaviors mediated change in participant self-judgments and future social predictions. The current findings are consistent with cognitive theories of anxiety, and support the causal role of safety behaviors in the persistence of negative social judgments in SAD. 2009 Elsevier Ltd. All rights reserved.

40 CFR 60.1460 - What equations must I use?

Code of Federal Regulations, 2011 CFR

2011-07-01

... percent oxygen, dry basis (c) Percent reduction in potential hydrogen chloride emissions. Calculate the percent reduction in potential hydrogen chloride emissions (%PHC1) using equation 3 of this section: %PHC1 = (Ei − Eo) * (100/Ei) (Eq. 3) Where: %PHC1 = percent reduction of the potential hydrogen chloride...

40 CFR 60.1460 - What equations must I use?

Code of Federal Regulations, 2010 CFR

2010-07-01

... percent oxygen, dry basis (c) Percent reduction in potential hydrogen chloride emissions. Calculate the percent reduction in potential hydrogen chloride emissions (%PHC1) using equation 3 of this section: %PHC1 = (Ei − Eo) * (100/Ei) (Eq. 3) Where: %PHC1 = percent reduction of the potential hydrogen chloride...

Identifying external nutrient reduction requirements and potential in the hypereutrophic Lake Taihu Basin, China.

PubMed

Peng, Jiao-Ting; Zhu, Xiao-Dong; Sun, Xiang; Song, Xiao-Wei

2018-04-01

Reducing external nutrient loads is the first step for controlling eutrophication. Here, we identified external nutrient reduction requirements and potential of strategies for achieving reductions to remediate a eutrophic water body, Lake Taihu, China. A mass balance approach based on the entire lake was used to identify nutrient reduction requirements; an empirical export coefficient approach was introduced to estimate the nutrient reduction potential of the overall program on integrated regulation of Taihu Lake Basin (hereafter referred to as the "Guideline"). Reduction requirements included external total nitrogen (TN) and total phosphorus (TP) loads, which should be reduced by 41-55 and 25-50%, respectively, to prevent nutrient accumulation in Lake Taihu and to meet the planned water quality targets. In 2010, which is the most seriously polluted calendar year during the 2008-2014 period, the nutrient reduction requirements were estimated to be 36,819 tons of N and 2442 tons of P, and the potential nutrient reduction strategies would reduce approximately 25,821 tons of N and 3024 tons of P. Since there is a net N remaining in the reduction requirements, it should be the focus and deserves more attention in identifying external nutrient reduction strategies. Moreover, abatement measures outlined in the Guideline with high P reduction potential required large monetary investments. Achieving TP reduction requirement using the cost-effective strategy costs about 80.24 million USD. The design of nutrient reduction strategies should be enacted according to regional and sectoral differences and the cost-effectiveness of abatement measures.

Surface enhanced Raman spectroscopy of the silver/KCl, triethylenediamine (DABCO), water system

NASA Astrophysics Data System (ADS)

Irish, D. E.; Guzonas, D.; Atkinson, G. F.

1985-07-01

1,4-Diazabicyclo[2.2.2]octane, (N(CH 2CH 2) 3N), usually abbreviated DABCO or DBO, is a symmetric top molecule of point group D 3h. SERS experiments have been carried out in an optical electrochemical cell using a silver electrode roughened by a single oxidation-reduction cycle (ORC). The observed SERS spectra contained four strong bands at 624, 798, 990 and 1351 cm -1, all A' 1 totally symmetric modes. The same bands were also observed in SERS spectra of DABCO adsorbed on colloidal gold. In the electrochemical experiments, the maximum of SERS-intensity versus electrode potential plots was observed to shift to less negative potentials as the wavelength of the exciting line was shifted to the red. The radically-altered, relative intensities of the observed bands, as well as observed changes in relative intensity as a function of electrode potential, have been interpreted as a selective enhancement of those normal modes which have as a major component of vibrational motion the C-C stretch. These observations are correlated with current theories concerning the SERS mechanism, especially those involving charge transfer (CT).

Methadone maintenance treatment program in prisons from the perspective of medical and non-medical prison staff: a qualitative study in Iran

PubMed Central

Moradi, Ghobad; Farnia, Marzieh; Shokoohi, Mostafa; Shahbazi, Mohammad; Moazen, Babak; Rahmani, Khaled

2015-01-01

Background: As one of the most important components of harm reduction strategy for high-risk groups, following the HIV epidemics, Methadone Maintenance Treatment (MMT) has been initiated in prisoners since 2003. In this paper, we aimed to assess the advantages and shortcomings of the MMT program from the perspective of people who were involved with the delivery of prison healthcare in Iran. Methods: On the basis of grounded theory and through conducting 14 Focus Group Discussions (FGDs), 7 FGDs among physicians, consultants, experts, and 7 FGDs among directors and managers of prisons (n= 140) have been performed. The respondents were asked about positive and negative elements of the MMT program in Iranian prisons. Results: This study included a total of 48 themes, of which 22 themes were related to advantages and the other 26 were about shortcomings of MMT programs in the prisons. According to participants’ views "reduction of illegal drug use and high-risk injection", "reduction of potentially high-risk behaviors" and "making positive attitudes" were the main advantages of MMT in prisons, while issues such as "inaccurate implementation", "lack of skilled manpower" and "poor care after release from prison" were among the main shortcomings of MMT program. Conclusions: MMT program in Iran’s prisons has achieved remarkable success in the field of harm reduction, but to obtain much more significant results, its shortcomings and weaknesses must be also taken into account by policy-makers. PMID:26340487

Hydroxylamine addition impact to Nitrosomonas europaea activity in the presence of monochloramine.

PubMed

Wahman, David G; Speitel, Gerald E

2015-01-01

In drinking water, monochloramine may promote ammonia–oxidizing bacteria (AOB) growth because of concurrent ammonia presence. AOB use (i) ammonia monooxygenase for biological ammonia oxidation to hydroxylamine and (ii) hydroxylamine oxidoreductase for biological hydroxylamine oxidation to nitrite. In addition, monochloramine and hydroxylamine abiotically react, providing AOB a potential benefit by removing the disinfectant (monochloramine) and releasing growth substrate (ammonia). Alternatively and because biological hydroxylamine oxidation supplies the electrons (reductant) required for biological ammonia oxidation, the monochloramine/hydroxylamine abiotic reaction represents a possible inactivation mechanism by consuming hydroxylamine and inhibiting reductant generation. To investigate the abiotic monochloramine and hydroxylamine reaction's impact on AOB activity, the current study used batch experiments with Nitrosomonas europaea (AOB pure culture), ammonia, monochloramine, and hydroxylamine addition. To decipher whether hydroxylamine addition benefitted N. europaea activity by (i) removing monochloramine and releasing free ammonia or (ii) providing an additional effect (possibly the aforementioned reductant source), a previously developed cometabolism model was coupled with an abiotic monochloramine and hydroxylamine model for data interpretation. N. europaea maintained ammonia oxidizing activity when hydroxylamine was added before complete ammonia oxidation cessation. The impact could not be accounted for by monochloramine removal and free ammonia release alone and was concentration dependent for both monochloramine and hydroxylamine. In addition, a preferential negative impact occurred for ammonia versus hydroxylamine oxidation. These results suggest an additional benefit of exogenous hydroxylamine addition beyond monochloramine removal and free ammonia release, possibly providing reductant generation.

Phosphorus Amendment Efficacy for In Situ Remediation of ...

EPA Pesticide Factsheets

A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccesible Pb in P-treated soils. Two Pb-contaminated soils (790-1300 mg Pb kg-1), one from a garden and one from a city lot in Cleveland, OH, were incubated in a bench scale experiment for 1 yr. Six phosphate amendments, including bone meal, fish bone, poultry litter, monoammonium phosphate, diammonium phosphate, and triple superphosphate, were added to containers at two application rates. Lead IVBA was assessed using USEPA Method 1340 and three modified versions of this method. Modifications included using solutions with pH 1.5 and 2.5 as well as using solutions with and without 0.4 mol L-1 glycine. Soil amendments were effective in reducing IVBA Pb in these soils as measured by pH 1.5 with glycine buffer. The greatest reductions in IVBA Pb, from 5 to 26%, were found using pH 2.5 extractions. Lead mineral results showed several soil amendments promoted Pb phosphate formation, an indicator of remediation success. A significant negative linear relationship between reduction in IVBA Pb and Pb-phosphate formation was found only for pH 2.5 without glycine extraction solution. A modified USEPA Method 1340 without glycine and using pH 2.5 has the potential to predict P soil treatment efficacy and reductions in bioavailable Pb. Developing mana

Ziprasidone's effect on metabolic markers in patients with diabetes and chronic schizophrenia.

PubMed

Lindenmayer, Jean Pierre; Tedeschi, Frank; Yusim, Anna; Khan, Anzalee; Kaushik, Saurabh; Smith, Robert C; Parakadavil, Mohan

2012-01-01

Despite numerous studies of diabetes mellitus type II (DM-II) in schizophrenia and schizoaffective disorder, there have been no studies on the glycemic effects of switching patients with long-standing symptomatic DM-II from their current antipsychotic regimen to ziprasidone. An open-label, prospective inpatient study was conducted with 26 suboptimally responding inpatients with DSM-IV diagnoses of schizophrenia or schizoaffective disorder and comorbid DM-II who were switched to ziprasidone monotherapy and followed for 8 weeks. Outcome measures were fasting glucose, triglycerides, cholesterol, insulin levels, capillary blood glucose levels and weight. After a 3-week cross-titration period, patients were treated with ziprasidone up to a dose of 320 mg daily. Of the 26 study participants, 16 completed the entire study period of 63 days and 10 (38.46%) discontinued participation, primarily due to psychotic relapse. There was a statistically significant reduction in fasting glucose (F=4.43, p=0.05; 14.68 mg/dL mean reduction), capillary blood glucose levels (F=8.90, p=0.01; 25.36 mg/dL mean reduction), weight (F=4.46, p=0.05; 4.68 lb mean weight loss) and Body Mass Index (F=4.40, p=0.05; 3.62 kg/m(2) mean reduction). There was also a reduction in the use of antidiabetic medications after the switch to ziprasidone. Nine (34.62%) patients met criteria for metabolic syndrome (MetS) at baseline, as compared to 4 (15.38%) at endpoint. No change was observed in positive symptoms (F=0.62, p=0.44), negative symptoms (F=1.47, p=0.24) and in total PANSS score (F=0.12, p=0.74). This study suggests significant improvement in metabolic side effects and MetS in the subset of the patients who were able to tolerate switching from a polypharmacy regimen to ziprasidone. There was a large discontinuation rate, which limited the sustained beneficial effects of ziprasidone. The decision to switch to ziprasidone in patients with prior suboptimal response has to balance the potential metabolic benefits and the potential relapse risks of the individual patient first and foremost.

Know thy enemy: Education about terrorism improves social attitudes toward terrorists.

PubMed

Theriault, Jordan; Krause, Peter; Young, Liane

2017-03-01

Hatred of terrorists is an obstacle to the implementation of effective counterterrorism policies-it invites indiscriminate retaliation, whereas many of the greatest successes in counterterrorism have come from understanding terrorists' personal and political motivations. Drawing from psychological research, traditional prejudice reduction strategies are generally not well suited to the task of reducing hatred of terrorists. Instead, in 2 studies, we explored education's potential ability to reduce extreme negative attitudes toward terrorists. Study 1 compared students in a college course on terrorism (treatment) with wait-listed students, measuring prosocial attitudes toward a hypothetical terrorist. Initially, all students reported extremely negative attitudes; however, at the end of the semester, treatment students' attitudes were significantly improved. Study 2 replicated the effect within a sample of treatment and control classes drawn from universities across the United States. The present work was part of an ongoing research project, focusing on foreign policy and the perceived threat of terrorism; thus classes did not explicitly aim to reduce prejudice, making the effect of treatment somewhat surprising. One possibility is that learning about terrorists "crowds out" the initial pejorative associations-that is, the label terrorism may ultimately call more information to mind, diluting its initial negative associative links. Alternatively, students may learn to challenge how the label terrorist is being applied. In either case, learning about terrorism can decrease the extreme negative reactions it evokes, which is desirable if one wishes to implement effective counterterrorism policies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Regioselective electrochemical reduction of 2,4-dichlorobiphenyl - Distinct standard reduction potentials for carbon-chlorine bonds using convolution potential sweep voltammetry

NASA Astrophysics Data System (ADS)

Muthukrishnan, A.; Sangaranarayanan, M. V.; Boyarskiy, V. P.; Boyarskaya, I. A.

2010-04-01

The reductive cleavage of carbon-chlorine bonds in 2,4-dichlorobiphenyl (PCB-7) is investigated using the convolution potential sweep voltammetry and quantum chemical calculations. The potential dependence of the logarithmic rate constant is non-linear which indicates the validity of Marcus-Hush theory of quadratic activation-driving force relationship. The ortho-chlorine of the 2,4-dichlorobiphenyl gets reduced first as inferred from the quantum chemical calculations and bulk electrolysis. The standard reduction potentials pertaining to the ortho-chlorine of 2,4-dichlorobiphenyl and that corresponding to para chlorine of the 4-chlorobiphenyl have been estimated.

Harm reduction principles for healthcare settings.

PubMed

Hawk, Mary; Coulter, Robert W S; Egan, James E; Fisk, Stuart; Reuel Friedman, M; Tula, Monique; Kinsky, Suzanne

2017-10-24

Harm reduction refers to interventions aimed at reducing the negative effects of health behaviors without necessarily extinguishing the problematic health behaviors completely. The vast majority of the harm reduction literature focuses on the harms of drug use and on specific harm reduction strategies, such as syringe exchange, rather than on the harm reduction philosophy as a whole. Given that a harm reduction approach can address other risk behaviors that often occur alongside drug use and that harm reduction principles have been applied to harms such as sex work, eating disorders, and tobacco use, a natural evolution of the harm reduction philosophy is to extend it to other health risk behaviors and to a broader healthcare audience. Building on the extant literature, we used data from in-depth qualitative interviews with 23 patients and 17 staff members from an HIV clinic in the USA to describe harm reduction principles for use in healthcare settings. We defined six principles of harm reduction and generalized them for use in healthcare settings with patients beyond those who use illicit substances. The principles include humanism, pragmatism, individualism, autonomy, incrementalism, and accountability without termination. For each of these principles, we present a definition, a description of how healthcare providers can deliver interventions informed by the principle, and examples of how each principle may be applied in the healthcare setting. This paper is one of the firsts to provide a comprehensive set of principles for universal harm reduction as a conceptual approach for healthcare provision. Applying harm reduction principles in healthcare settings may improve clinical care outcomes given that the quality of the provider-patient relationship is known to impact health outcomes and treatment adherence. Harm reduction can be a universal precaution applied to all individuals regardless of their disclosure of negative health behaviors, given that health behaviors are not binary or linear but operate along a continuum based on a variety of individual and social determinants.

An experimental study on the bio-surfactant-assisted remediation of crude oil and salt contaminated soils.

PubMed

Zhang, Wen; Li, Jianbing; Huang, Guohe; Song, Weikun; Huang, Yuefei

2011-01-01

The effect of bio-surfactant (rhamnolipid) on the remediation of crude oil and salt contaminated soil was investigated in this study. The experimental results indicated that there was a distinct decline of total petroleum hydrocarbon (TPH) concentration within the soil when using rhamnolipid during a remediation period of 30 days, with maximum TPH reduction of 86.97%. The most effective remediation that was observed was with rhamnolipid at a concentration of 2 CMC in soil solution, and a first-order TPH degradation rate constant of 0.0866 d(-1). The results also illustrated that salts in soil had a negative impact on TPH reduction, and the degradation rate was negatively correlated with NaCl concentration in soil solution. The analysis of soil TPH fractions indicated that there was a significant reduction of C13-C30 during the remediation process when using bio-surfactant.

Sound reduction by metamaterial-based acoustic enclosure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Shanshan; Li, Pei; Zhou, Xiaoming

In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of themore » source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.« less

A Double-Negative Metamaterial-Inspired Mobile Wireless Antenna for Electromagnetic Absorption Reduction.

PubMed

Alam, Touhidul; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2015-07-29

A double-negative metamaterial-inspired antenna is presented for mobile wireless applications. The antenna consists of a semi-circular radiating patch and a 3 × 4 hexagonal shaped metamaterial unit cell array in the ground plane. The antenna is fed with a 50 Ω microstrip feed line. The electric dimensions of the proposed antenna are 0.20λ × 0.26λ × 0.004λ, at the low-end frequency. The proposed antenna achieves a -10 dB impedance with a bandwidth of 2.29 GHz at the lower band and 1.28 GHz at the upper band and can operate for most of the mobile applications such as upper GSM bands, WiMAX, Bluetooth, and wireless local area network (WLAN) frequency bands. The focused novelties of the proposed antenna are its small size, multi-standard operating bands, and electromagnetic absorption reduction at all the operating frequencies using the double-negative metamaterial ground plane.

Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs

NASA Astrophysics Data System (ADS)

Perry, C. T.; Morgan, K. M.

2017-01-01

Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO3 m-2 yr-1) to strongly net negative (mean -2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to -0.4 mm yr-1. Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability.

Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs.

PubMed

Perry, C T; Morgan, K M

2017-01-13

Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO 3 m -2 yr -1 ) to strongly net negative (mean -2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to -0.4 mm yr -1 . Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability.

Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs

PubMed Central

Perry, C. T.; Morgan, K. M.

2017-01-01

Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO3 m−2 yr−1) to strongly net negative (mean −2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to −0.4 mm yr−1. Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability. PMID:28084450

A novel hybrid tobacco product that delivers a tobacco flavour note with vapour aerosol (Part 2): In vitro biological assessment and comparison with different tobacco-heating products.

PubMed

Breheny, Damien; Adamson, Jason; Azzopardi, David; Baxter, Andrew; Bishop, Emma; Carr, Tony; Crooks, Ian; Hewitt, Katherine; Jaunky, Tomasz; Larard, Sophie; Lowe, Frazer; Oke, Oluwatobiloba; Taylor, Mark; Santopietro, Simone; Thorne, David; Zainuddin, Benjamin; Gaça, Marianna; Liu, Chuan; Murphy, James; Proctor, Christopher

2017-08-01

This study assessed the toxicological and biological responses of aerosols from a novel hybrid tobacco product. Toxicological responses from the hybrid tobacco product were compared to those from a commercially available Tobacco Heating Product (c-THP), a prototype THP (p-THP) and a 3R4F reference cigarette, using in vitro test methods which were outlined as part of a framework to substantiate the risk reduction potential of novel tobacco and nicotine products. Exposure matrices used included total particulate matter (TPM), whole aerosol (WA), and aqueous aerosol extracts (AqE) obtained after machine-puffing the test products under the Health Canada Intense smoking regime. Levels of carbonyls and nicotine in these matrices were measured to understand the aerosol dosimetry of the products. The hybrid tobacco product tested negative across the in vitro assays including mutagenicity, genotoxicity, cytotoxicity, tumour promotion, oxidative stress and endothelial dysfunction. All the THPs tested demonstrated significantly reduced responses in these in vitro assays when compared to 3R4F. The findings suggest these products have the potential for reduced health risks. Further pre-clinical and clinical assessments are required to substantiate the risk reduction of these novel products at individual and population levels. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Dust Acoustic Solitary Waves in Dusty Plasma with Trapped Electrons Having Different Temperature Nonthermal Ions

NASA Astrophysics Data System (ADS)

Deka, Manoj Kr.

2016-12-01

In this report, a detailed investigation on the study of dust acoustics solitary waves solution with negatively dust charge fluctuation in dusty plasma corresponding to lower and higher temperature nonthermal ions with trapped electrons is presented. We consider temporal variation of dust charge as a source of dissipation term to derive the lower order modified Kadomtsev-Petviashvili equation by using the reductive perturbation technique. Solitary wave solution is obtained with the help of sech method in presence of trapped electrons and low (and high) temperature nonthermal ions. Both nonthermality of ions and trapped state of the electrons are found to have an imperative control on the nonlinear coefficient, dissipative coefficient as well as height of the wave potential.

Health and Big Data: An Ethical Framework for Health Information Collection by Corporate Wellness Programs.

PubMed

Ajunwa, Ifeoma; Crawford, Kate; Ford, Joel S

2016-09-01

This essay details the resurgence of wellness program as employed by large corporations with the aim of reducing healthcare costs. The essay narrows in on a discussion of how Big Data collection practices are being utilized in wellness programs and the potential negative impact on the worker in regards to privacy and employment discrimination. The essay offers an ethical framework to be adopted by wellness program vendors in order to conduct wellness programs that would achieve cost-saving goals without undue burdens on the worker. The essay also offers some innovative approaches to wellness that may well better serve the goals of healthcare cost reduction. © 2016 American Society of Law, Medicine & Ethics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Zi-an; Ma, J. X., E-mail: jxma@ustc.edu.cn

Ion sheaths formed in the up- and downstream sides of a negatively biased metal plate/mesh in an ion-beam-background-plasma system were experimentally investigated in a double plasma device. Measured potential profiles near the plate exhibit asymmetric structure, showing thicker sheath in the downstream side. The presence of the ion beam causes the shrink of the sheaths on both sides. The sheath thickness decreases with the increase of beam energy and density. Furthermore, the sheaths near the mesh are substantially thinner than that near the plate because of the partial transmission of the mesh to the ions. In addition, the increase ofmore » neutral gas pressure leads to the reduction of the beam energy and density, resulting in the increase of the sheath thickness.« less

Electrochemistry and Spectroelectrochemistry of the Pu (III/IV) and (IV/VI) Couples in Nitric Acid Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lines, Amanda M.; Adami, Susan R.; Casella, Amanda J.

The solution chemistry of Pu in nitric acid is explored via electrochemistry and spectroelectrochemistry. By utilizing and comparing these techniques, an improved understanding of Pu behavior and its dependence on nitric acid concentration can be achieved. Here the Pu (III/IV) couple is characterized using cyclic voltammetry, square wave voltammetry, and a spectroelectrochemical Nernst step. Results indicate the formal reduction potential of the couple shifts negative with increasing acid concentration and reversible electrochemistry is no longer attainable above 6 M HNO3. Spectroelectrochemistry is also used to explore the irreversible oxidation of Pu(IV) to Pu(VI) and shine light on the mechanism andmore » acid dependence of the redox reaction.« less

Edge Plasma behavior during Improved Confinement by Lower Hybrid Wave Heating in HT-6M Tokamak

NASA Astrophysics Data System (ADS)

Li, Jian-gang; Bao, Yi; Luo, Jia-rong; Wan, Bao-nian; Liu, Yue-xiu; Gong, Xian-zu; Chen, Jun-ling; Liang, Yun-feng

2002-10-01

Lower hybrid heating (LHH) has been successfully carried out in the HT-6M tokamak. The H-mode has been obtained with a power threshold of 50 kW under a boronized wall condition. Both energy and particle confinements have been improved along with a dropped edge plasma density and an increase electron temperature during the LHH phase. A negative Er well plays a key role of triggering and sustaining the good confinement. Both electrostatic fluctuation of the plasma potential and the density fluctuations dropped to an ultra-low level. The observation of an enhanced Er shear before the reduction in turbulence level is consistent with an increased Er shear as the cause of turbulence suppression.

Linear and nonlinear dust ion acoustic solitary waves in a quantum dusty electron-positron-ion plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emadi, E.; Zahed, H.

2016-08-15

The behavior of linear and nonlinear dust ion acoustic (DIA) solitary waves in an unmagnetized quantum dusty plasma, including inertialess electrons and positrons, ions, and mobile negative dust grains, are studied. Reductive perturbation and Sagdeev pseudopotential methods are employed for small and large amplitude DIA solitary waves, respectively. A minimum value of the Mach number obtained for the existence of solitary waves using the analytical expression of the Sagdeev potential. It is observed that the variation on the values of the plasma parameters such as different values of Mach number M, ion to electron Fermi temperature ratio σ, and quantummore » diffraction parameter H can lead to the creation of compressive solitary waves.« less

Time course of emotion-related responding during distraction and reappraisal.

PubMed

Schönfelder, Sandra; Kanske, Philipp; Heissler, Janine; Wessa, Michèle

2014-09-01

Theoretical accounts of emotion regulation (ER) discriminate various cognitive strategies to voluntarily modify emotional states. Amongst these, attentional deployment (i.e. distraction) and cognitive change (i.e. reappraisal), have been shown to successfully down-regulate emotions. Neuroimaging studies found that both strategies differentially engage neural structures associated with selective attention, working memory and cognitive control. The aim of this study was to further delineate similarities and differences between the ER strategies reappraisal and distraction by investigating their temporal brain dynamics using event-related potentials (ERPs) and their patterns of facial expressive behavior. Twenty-one participants completed an ER experiment in which they had to either passively view positive, neutral and negative pictures, reinterpret them to down-regulate affective responses (reappraisal), or solve a concurrently presented mathematical equation (distraction). Results demonstrate the efficacy of both strategies in the subjective control of emotion, accompanied by reductions of facial expressive activity (Corrugator supercilii and Zygomaticus major). ERP results indicated that distraction, compared with reappraisal, yielded a stronger and earlier attenuation of the late positive potential (LPP) magnitude for negative pictures. For positive pictures, only distraction but not reappraisal had significant effect on LPP attenuation. The results support the process model of ER, separating subtypes of cognitive strategies based on their specific time course. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.