bluuebunny/crossref_metadata_2025 huggingface dataset:
The Networked Naturalist: Mobile phone data collection for citizen science and education
Authors: Graham Eric
Published: November 2010

Background/Question/Methods

Citizen science projects engage individual volunteers or groups to observe, measure, and contribute data to scientific studies. CENS is building a collection of mobile phone and web-based tools to make the citizen scientist experience more engaging and flexible. CENS is an NSF-funded Information and Technology Center that employs graduate students from Computer Science and Electrical Engineering at UCLA to create open-source software that is environmentally and socially responsible. The overarching goal of the Networked Naturalist project is to enhance participatory learning experiences through citizen science campaigns and help transform the associated learning process. We are collaborating with national field campaigns, such Project BudBurst, and also with the National Park Service to increase participation and retention in citizen scientist campaigns through two main avenues afforded by the use of new technologies: (1) to offer new methods for data collection, primarily using mobile phones, through text, picture, and smart-phone applications, and (2) to provide immediate feedback and automated, engaging analysis of data for informal learning opportunities. We are working to create a robust data collection system to enhance citizen science by ensuring data quality and improving data submission, and to transform participation into an active learning, engaging experience.

Results/Conclusions

Our experience with volunteers for software testing at UCLA and at the National Park Service has indicated that using mobile phones is an efficient method for collecting environmental and location data and raises public awareness of environmental issues through attracting the attention of the mass media. Individual participation in the What’s Invasive! project by volunteer citizen scientists seems to have been limited by smartphone application availability (iPhone app is currently only available for Santa Monica), although methods for making observations based on text and picture messaging are also available. We have found that running short-term "campaigns" partnered with NPS officials and groups such as schools has been the most effective in not only education-related efforts but also in efficiently identifying and locating species and objects of interest using mobile phones.
Does accounting for imperfect detection improve species distribution models?
Authors: Rota Christopher , Fletcher Robert , Evans Jason , Hutto Richard
Published: November 2010

Background/Question/Methods

Models of species distributions are increasingly being used to address a variety of problems in ecology and conservation biology. In many applications, perfect detectability of species, given presence, is assumed. While this problem has been acknowledged and addressed through the development of occupancy models, we still know little regarding whether or not addressing the potential for imperfect detection improves the predictive performance of species distribution models in nature. Here, we ask if explicitly accounting for imperfect detection improves predictive performance of species distribution models relative to approaches that assume perfect detection. We contrast logistic regression models of species occurrence that do not correct for detectability to hierarchical occupancy models that explicitly estimate and adjust for detectability, and maximum entropy models that circumvent the detectability problem by using data from known presence locations only. We use a large-scale, long-term monitoring database across western Montana and northern Idaho to contrast these models for nine landbird species that cover a broad spectrum in detectability.

Results/Conclusions

Overall, occupancy models were similar to or better than other approaches in terms of predictive accuracy, as measured by the Area Under the ROC Curve (AUC) and Kappa, with maximum entropy tending to provide the lowest predictive accuracy. Models varied in the types of errors associated with predictions, such that some model approaches may be preferred over others in certain situations. As expected, predictive performance varied across a gradient in species detectability, with logistic regression providing lower relative performance for less detectable species and Maxent providing lower performance for highly detectable species. Occupancy models showed no strong relationship with detection probability and any source of predictive error, suggesting this approach can perform as well for highly detectable species as for difficult to detect species. We conclude by suggesting that occupancy modeling approaches hold promise for improving models of species distributions. However, occupancy models did not always significantly improve predictive performance of species distribution models. In these instances, issues of sampling design other than imperfect detection may be of greater importance for inference, and the onus is on ecologists to address the detection issue and other problems in sampling design in rigorous ways to evaluate potential biases in inference.
Recasting spatial food web ecology as an ecosystem science
Authors: Massol François , Gravel Dominique , Mouquet Nicolas , Cadotte Marc , Fukami Tadashi , Leibold Mathew
Published: November 2010

Background/questions/methods

Food webs are complex systems in which organisms interact with each other and with the abiotic aspects of their environment, thus acting as the conduit for transfers of energy and nutrients through ecosystems. Classical approaches to food webs focus strongly on patterns and processes occurring at the community level rather than at the broader ecosystem scale. Recent developments in community ecology suggest that spatial processes may be important in affecting food web dynamics and affect ecosystems as well, thus leading to the idea of meta-ecosystems. Here, we make a synthesis on how the links between food web dynamics and spatial ecosystem dynamics may be studied through (i) identifying differences between metacommunity and landscape ecology approaches when dealing with food webs, (ii) arguing that a tighter synthesis of the two approaches is needed for a good understanding of how diversity, ecosystem process and trait distributions in landscapes are related, and (iii) laying out how this gap can be efficiently bridged under the framework of meta-ecosystems.

Results/conclusions

We identify two possible sets of processes that drive spatial food webs and the ecosystems they occur in: trait-dependent processes and material-dependent processes. Both of these have been shown to be important in affecting various aspects of food web ecology and we ask how they may compare to each other and how they may interact. We argue that interactions between them, while complex, are likely and depend strongly on the size of the meta-ecosystem and its connectivity. A more integrative framework to the study of spatial food webs, which takes into account both approaches, might be key in better understanding the links between ecosystem and community dynamics at large spatial scales.
Cross-Frequency Integration for Consonant and Vowel Identification in Bimodal Hearing
Authors: Kong Ying-Yee , Braida Louis D.
Published: November 2010

Purpose

Improved speech recognition in binaurally combined acoustic–electric stimulation (otherwise known as
bimodal hearing
) could arise when listeners integrate speech cues from the acoustic and electric hearing. The aims of this study were (a) to identify speech cues extracted in electric hearing and residual acoustic hearing in the low-frequency region and (b) to investigate cochlear implant (CI) users' ability to integrate speech cues across frequencies.

Method

Normal-hearing (NH) and CI subjects participated in consonant and vowel identification tasks. Each subject was tested in 3 listening conditions: CI alone (vocoder speech for NH), hearing aid (HA) alone (low-pass filtered speech for NH), and both. Integration ability for each subject was evaluated using a model of optimal integration—the PreLabeling integration model (Braida, 1991).

Results

Only a few CI listeners demonstrated bimodal benefit for phoneme identification in quiet. Speech cues extracted from the CI and the HA were highly redundant for consonants but were complementary for vowels. CI listeners also exhibited reduced integration ability for both consonant and vowel identification compared with their NH counterparts.

Conclusion

These findings suggest that reduced bimodal benefits in CI listeners are due to insufficient complementary speech cues across ears, a decrease in integration ability, or both.
Enhancement of random lasing through fluorescence resonance energy transfer and light scattering mediated by nanoparticles
Authors: Wang C. S. , Chen Y. L. , Lin H. Y. , Chen Y. T. , Chen Y. F.
Published: November 2010

A simple approach for the enhancement of random lasing based on fluorescence resonance energy transfer and light scattering mediated by nanoparticles is reported. To illustrate our working principle, ZnO nanorods decorated with TiO2 nanoparticles were chosen as an example. It is shown that the random laser action of ZnO nanorods can be significantly improved by the assistance of TiO2 nanoparticles. Moreover, due to the inherent nature of higher refractive index of TiO2 than ZnO, the TiO2 nanoparticles can serve efficiently as better nanoscatterers, which can promote the formation of closed-loop paths. Our strategy provided here is very useful for the future development of high efficiency optoelectronic devices.
The effect of drug and sexual risk behaviours with social network and non-network members on homeless youths' sexually transmissible infections and HIV testing
Authors: Tyler Kimberly , Melander Lisa
Published: November 2010

Background: The study examined whether engaging in drug and sexual risk behaviours with social network and non-network members (strangers) differentially affected the decision to test for sexually transmissible infections (STIs) and HIV. Methods: A cross-sectional survey was conducted among 249 homeless youths aged 14–21 years. Results: Multivariate analyses revealed that females were over three times more likely than males to test for STIs (adjusted odds ratio (AOR) = 3.34; 95% confidence interval (CI) = 1.54–7.25). For every one unit increase in age, there was a 37% increase in the likelihood of having tested for STIs (AOR = 1.37; 95% CI = 1.12–1.68). Youths who had sex after using alcohol and drugs with strangers were approximately 3.5 times more likely to have tested for STIs (AOR = 3.45; 95% CI = 1.38–8.61). For every one unit increase in age, there was a 26% increase in the likelihood of having tested for HIV (AOR = 1.26; 95% CI = 1.05–1.51). Youths who had sex with a stranger after using alcohol or drugs were over three times more likely to test for HIV (AOR = 3.22; 95% CI = 1.42–7.31). No social network variables reached significance for STI or HIV testing. Conclusions: Being older and engaging in drug and sexual risk behaviours with strangers are important correlates of STI and HIV testing. Females are more likely than males to be tested for STIs. Engaging in risky behaviours with social network members was not a key factor in deciding whether to be tested.
Geoengineering potential of artificially enhanced silicate weathering of olivine
Authors: Köhler Peter , Hartmann Jens , Wolf-Gladrow Dieter A.
Published: November 2010

Geoengineering is a proposed action to manipulate Earth’s climate in order to counteract global warming from anthropogenic greenhouse gas emissions. We investigate the potential of a specific geoengineering technique, carbon sequestration by artificially enhanced silicate weathering via the dissolution of olivine. This approach would not only operate against rising temperatures but would also oppose ocean acidification, because it influences the global climate via the carbon cycle. If important details of the marine chemistry are taken into consideration, a new mass ratio of CO
2
sequestration per olivine dissolution of about 1 is achieved, 20% smaller than previously assumed. We calculate that this approach has the potential to sequestrate up to 1 Pg of C per year directly, if olivine is distributed as fine powder over land areas of the humid tropics, but this rate is limited by the saturation concentration of silicic acid. In our calculations for the Amazon and Congo river catchments, a maximum annual dissolution of 1.8 and 0.4 Pg of olivine seems possible, corresponding to the sequestration of 0.5 and 0.1 Pg of C per year, but these upper limit sequestration rates come at the environmental cost of
p
H values in the rivers rising to 8.2. Open water dissolution of fine-grained olivine and an enhancement of the biological pump by the rising riverine input of silicic acid might increase our estimate of the carbon sequestration, but additional research is needed here. We finally calculate with a carbon cycle model the consequences of sequestration rates of 1–5 Pg of C per year for the 21st century by this technique.
Role of antigen persistence and dose for CD4+T-cell exhaustion and recovery
Authors: Han Shaobo , Asoyan Ayuna , Rabenstein Hannah , Nakano Naoko , Obst Reinhard
Published: November 2010

It is currently not understood how some chronic infections exhaust antigen-specific T cells over time and which pathogen components contribute to exhaustion. Here, we dissected the behavior of primed CD4+T cells exposed to persistent antigen using an inducible transgenic mouse system that allowed us to control antigen presentation as the only experimental variable, independent of the persistent inflammation and disease progression that complicate infectious models. Moreover, this system restricted antigen presentation to dendritic cells (DCs) and avoided confounding B, CD8+T, or innate cell responses. When antigen presentation was extended beyond the expansion phase, primed CD4+T cells survived, but exhibited reduced memory functionality in terms of their proliferative capacity and cytokine expression potential. The effect was antigen dose and time dependent, not associated with increased PD-1 expression or reduced calcium influx, but impaired Jun phosphorylation in response to TCR engagement. Upon antigen removal, the cells regained the ability to proliferate, but remained unable to produce high levels of IL-2 and TNF-α. These data show that persistent antigen by itself rapidly induces a dysfunctional state in CD4+T cells that is only partially reversible upon antigen removal. These findings have implications for vaccine optimization and for the possible reinvigoration of CD4+T cells during chronic infection.
Plant-derived human butyrylcholinesterase, but not an organophosphorous-compound hydrolyzing variant thereof, protects rodents against nerve agents
Authors: Geyer Brian C. , Kannan Latha , Garnaud Pierre-Emmanuel , Broomfield Clarence A. , Cadieux C. Linn , Cherni Irene , Hodgins Sean M. , Kasten Shane A. , Kelley Karli , Kilbourne Jacquelyn , Oliver Zeke P. , Otto Tamara C. , Puffenberger Ian , Reeves Tony E. , Robbins Neil , Woods Ryan R. , Soreq Hermona , Lenz David E. , Cerasoli Douglas M. , Mor Tsafrir S.
Published: November 2010

The concept of using cholinesterase bioscavengers for prophylaxis against organophosphorous nerve agents and pesticides has progressed from the bench to clinical trial. However, the supply of the native human proteins is either limited (e.g., plasma-derived butyrylcholinesterase and erythrocytic acetylcholinesterase) or nonexisting (synaptic acetylcholinesterase). Here we identify a unique form of recombinant human butyrylcholinesterase that mimics the native enzyme assembly into tetramers; this form provides extended effective pharmacokinetics that is significantly enhanced by polyethylene glycol conjugation. We further demonstrate that this enzyme (but not a G117H/E197Q organophosphorus acid anhydride hydrolase catalytic variant) can prevent morbidity and mortality associated with organophosphorous nerve agent and pesticide exposure of animal subjects of two model species.
Molecular chaperone function of Mia40 triggers consecutive induced folding steps of the substrate in mitochondrial protein import
Authors: Banci Lucia , Bertini Ivano , Cefaro Chiara , Cenacchi Lucia , Ciofi-Baffoni Simone , Felli Isabella Caterina , Gallo Angelo , Gonnelli Leonardo , Luchinat Enrico , Sideris Dionisia , Tokatlidis Kostas
Published: November 2010

Several proteins of the mitochondrial intermembrane space are targeted by internal targeting signals. A class of such proteins with α-helical hairpin structure bridged by two intramolecular disulfides is trapped by a Mia40-dependent oxidative process. Here, we describe the oxidative folding mechanism underpinning this process by an exhaustive structural characterization of the protein in all stages and as a complex with Mia40. Two consecutive induced folding steps are at the basis of the protein-trapping process. In the first one, Mia40 functions as a molecular chaperone assisting α-helical folding of the internal targeting signal of the substrate. Subsequently, in a Mia40-independent manner, folding of the second substrate helix is induced by the folded targeting signal functioning as a folding scaffold. The Mia40-induced folding pathway provides a proof of principle for the general concept that internal targeting signals may operate as a folding nucleus upon compartment-specific activation.
Human tumor virus utilizes exosomes for intercellular communication
Authors: Meckes David G. , Shair Kathy H. Y. , Marquitz Aron R. , Kung Che-Pei , Edwards Rachel H. , Raab-Traub Nancy
Published: November 2010

The Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) is expressed in multiple human malignancies and has potent effects on cell growth. It has been detected in exosomes and shown to inhibit immune function. Exosomes are small secreted cellular vesicles that contain proteins, mRNAs, and microRNAs (miRNAs). When produced by malignant cells, they can promote angiogenesis, cell proliferation, tumor-cell invasion, and immune evasion. In this study, exosomes released from nasopharyngeal carcinoma (NPC) cells harboring latent EBV were shown to contain LMP1, signal transduction molecules, and virus-encoded miRNAs. Exposure to these NPC exosomes activated the ERK and AKT signaling pathways in the recipient cells. Interestingly, NPC exosomes also contained viral miRNAs, several of which were enriched in comparison with their intracellular levels. LMP1 induces expression of the EGF receptor in an EBV-negative epithelial cell line, and exosomes produced by these cells also contain high levels of EGF receptor in exosomes. These findings suggest that the effects of EBV and LMP1 on cellular expression also modulate exosome content and properties. The exosomes may manipulate the tumor microenvironment to influence the growth of neighboring cells through the intercellular transfer of LMP1, signaling molecules, and viral miRNAs.
Visualizing electron rearrangement in space and time during the transition from a molecule to atoms
Authors: Li Wen , Jaroń-Becker Agnieszka A. , Hogle Craig W. , Sharma Vandana , Zhou Xibin , Becker Andreas , Kapteyn Henry C. , Murnane Margaret M.
Published: November 2010

Imaging and controlling reactions in molecules and materials at the level of electrons is a grand challenge in science, relevant to our understanding of charge transfer processes in chemistry, physics, and biology, as well as material dynamics. Direct access to the dynamic electron density as electrons are shared or transferred between atoms in a chemical bond would greatly improve our understanding of molecular bonding and structure. Using reaction microscope techniques, we show that we can capture how the entire valence shell electron density in a molecule rearranges, from molecular-like to atomic-like, as a bond breaks. An intense ultrashort laser pulse is used to ionize a bromine molecule at different times during dissociation, and we measure the total ionization signal and the angular distribution of the ionization yield. Using this technique, we can observe density changes over a surprisingly long time and distance, allowing us to see that the electrons do not localize onto the individual Br atoms until the fragments are far apart (∼5.5 
Å
), in a region where the potential energy curves for the dissociation are nearly degenerate. Our observations agree well with calculations of the strong-field ionization rates of the bromine molecule.
Racial/ethnic differences in menthol cigarette smoking, population quit ratios and utilization of evidence‐based tobacco cessation treatments
Authors: Stahre Mandy , Okuyemi Kolawole S. , Joseph Anne M. , Fu Steven S.
Published: November 2010

Aims This study examines the relationship between menthol cigarette smoking and the population quit ratio and whether menthol smokers differ in utilization of evidence‐based smoking cessation aids among a nationally representative sample of US adult smokers.

Design, setting and particiants Secondary data analysis of cross‐sectional data from the 2005 National Health Interview Survey (NHIS) Cancer Control Supplement. The NHIS is a nationally representative survey of US households conducted annually.

Measurements The main outcome variables of interest were (1) the population quit ratio and (2) use of smoking quit aids. All analyses were conducted using SAS version 9.2 with SUDAAN, which corrects for the complex sampling design of the study. Univariate analyses were used to determine variables that differed significantly by menthol status and utilization of types of quit aids. Multiple logistic regression analysis modeled the relationship between menthol smoking status, demographic characteristics and smoking‐related characteristics on the population quit ratio and utilization of quit aids.

Findings We observed significant differences in the population quit ratio for menthol versus non‐menthol among African American smokers (34% versus 49%,P < 0.001), but not among whites (52% versus 50%). In multiple logistic regression analysis, there was a significant interaction between race and menthol smoking status. African American menthol smokers were significantly less likely than white non‐menthol smokers to have quit smoking (adjusted odds ratio: 0.72, 95% confidence interval: 0.53, 0.97) after controlling for age group, sex, marital status, region and average number of cigarettes smoked per day. Menthol smoking status was not associated with differences in utilization of quit aids.

Conclusions African Americans have the highest rates of menthol cigarette smoking of all racial and ethnic groups in the United States. Menthol cigarette smoking is associated negatively with successful smoking cessation among African Americans.
The analysis of immunological profiles in wild animals: a case study on immunodynamics in the field vole, Microtus agrestis
Authors: JACKSON JOSEPH A. , BEGON MICHAEL , BIRTLES RICHARD , PATERSON STEVE , FRIBERG IDA M. , HALL AMY , LOWE ANN , RALLI CATRIONA , TURNER ANDREW , ZAWADZKA MALGORZATA , BRADLEY JANETTE E.
Published: November 2010

A revolutionary advance in ecological immunology is that postgenomic technologies now allow molecular mediators defined in laboratory models to be measured at the mRNA level in field studies of many naturally occurring species. Here, we demonstrate the application of such an approach to generate meaningful immunological profiles for wild mammals. We sampled a natural field vole population across the year (n = 307) and developed a battery of cellular assays in which functionally different pro‐ and anti‐inflammatory signalling responses (transcription factors and cytokines) were activated and quantified by Q‐PCR. Temporal trends were the strongest feature in the expression data, although some life history stages (mating vs. nonmating males and pregnant females) were also associated with significant variation. There was a striking set of significant negative associations between inflammatory mediators and condition indices reflecting packed erythrocyte volume and relative liver size, spleen size and splenocyte count. Grouped (principal component) measures of inflammatory and anti‐inflammatory expression were high in winter, with minima in the breeding season that occurred earlier for grouped anti‐inflammatory responses than for grouped inflammatory responses. Some individual immunological mediators also showed patterns unrelated to the breeding season or annual periodic cues. For example, interferon regulatory factor 5 (IRF5) expression declined throughout the study period, indicating a systematic trend in antimicrobial defences. Pinpointing the causes and consequences of such variation may help identify underlying environmental drivers of individual fitness and demographic fluctuation.
Effect of electrical stimulation on gastric electrical activity, motility and emptying
Authors: EAGON J.C. , KELLY K. A.
Published: November 2010

Abstract The aim was to measure the effect of gastric electrical stimulation on the frequency of canine antral pacesetter potentials (PPs), the strength of antral contractions, and the rate of gastric emptying while fasting, after feeding and with pentagastrin stimulation. Four conscious dogs with a stimulating electrode placed 10 cm proximal to the pylorus and recording electrodes and strain gauges placed 7, 5 and 3 cm proximal to the pylorus underwent myoelectric and strain gauge recordings while fasting, after feeding (250 ml 5% dextrose labelled with polyethylene glycol), and during pentagastrin infusion (0.5 μg kg−1 min−1) on four separate days. On each day, electrical stimulation was done using one of four stimulation frequencies (0, 6, 30 and 1200 stimuli per minute ***[s.p.m.]). Stimulation at 6 and 30 s.p.m. increased the fasting and fed PP frequency, whereas 1200 s.p.m. stimulation did not. Feeding decreased the maximum driven frequency, and pentagastrin increased it. Neither the motility index nor the gastric emptying rate were consistently changed by stimulation at any frequency. In conclusion, canine proximal antral stimulation at 6 and 30 s.p.m. sped PP frequency during fasting and after feeding, but stimulation over a wide range of frequencies had little effect on gastric contractions and emptying.
Gastric but not duodenal motor effects of oral erythromycin are dose related
Authors: MATHIS C. , MALBERT C. H.
Published: November 2010

AbstractThere has been increasing interest in the potential use of erythromycin as a prokinetic agent, despite limited data on the effect of oral administration on gastrointestinal motility. We have now evaluated, in 15 conscious pigs fitted with strain gauges, the response of (i) basal gastric motility and (ii) gastric motility during inhibition with intraduodenal triglycerides in fusion to increasing doses of oral erythromycin. In the basal state, erythromycin led to dose‐dependent increases in both the amplitude (10–30 mg kg−1) and the frequency (10–55 mg kg−1) of gastric contractions. The corpus was more responsive than the antrum, with an increase in amplitude at lower doses. The amplitude of the duodenal contractions was also improved but not in a dose‐dependent manner. Gastroduodenal coordination was unchanged regardless of the dose of erythromycin. Following inhibition of gastric motility, a dose of erythromycin below 45 mg kg−1increased both the amplitude of gastric contractions and the gastroduodenal coordination, although individual doses produced smaller increases in amplitude than in the basal state. These results suggest that erythromycin has a different mechanism of action in the stomach compared with the duodenum. The reduced effectiveness of large doses of erythromycin has important therapeutic implications.
Effects of CCK‐receptor antagonist on colonic motor activity in dogs
Authors: KARAUS M. , NIEDERAU C.
Published: November 2010

AbstractThis study employed a cholecystokinin (CCK) antagonist to evaluate whether endogenous CCK regulates fasted and fed motor patterns of the colon. Experiments were performed in six conscious dogs, each in duplicate. Motor activity was recorded by four strain gauge transducers implanted on the colon. The effects of the CCK‐analogue caerulein and the CCK‐antagonist loxiglumide (Rotta, Italy) were studied in fasted and fed states. The motor activity was computed for the area under contractions. Caerulein given as an intravenous bolus of 50 ng kg−1during a quiescent state caused a burst of phasic and tonic contractions resembling a regular non‐migrating motor complex. Physiological doses of 10 ng kg−1caerulein, which increases plasma CCK‐immunoreactivity to postprandial levels, had no effect. Continuous intravenous infusion of 10 mg kg−1h−1loxiglumide completely abolished the effects of 50 ng kg−1caerulein. The motor activity stimulated by the cholinesterase inhibitor neostigmine (10 μg kg−1) was not altered by loxiglumide. Loxiglumide given in the fasted state reduced the area under contractions in the proximal colon by 26.8 ± 12.8% compared to the control without loxiglumide (P < 0.05). The postprandial increase in motor activity in the distal colon, the gastrocolonic response, was significantly inhibited by loxiglumide. Moreover, loxiglumide reduced the area under contractions in the fed state by 25.4 ± 10.7% and 19 ± 7.2% in the proximal and distal colon, respectively (P < 0.05). The present results show that loxiglumide acts as a specific antagonist of the actions of CCK on colonic motor activity in the dog. Only supraphysiological concentrations of caerulein affect colonic motor activity. Loxiglumide, at a dose which abolishes the effects of exogenous CCK, significantly decreases fasting motor activity in the proximal colon. Loxiglumide also significantly reduces colonic motor activity after a meal. Therefore, CCK plays a physiological role in the regulation of fasting and fed motor activity of the canine colon as a neurotransmitter but not as a hormone.
Evidence for mast cell, leukotriene and nitric oxide involvement in the regulation of the adrenoceptor number of inflamed small intestine in guinea pigs
Authors: MARTINOLLE I.‐P. , GARCIA‐VILLAR R. , MORE J. , BUENO L.
Published: November 2010

Changes in the populations of neurotransmitter receptors involved in the control of intestinal smooth muscle function have been associated with the altered motility of the inflamed gut. Thus, trinitroben‐zenesulphonic acid (TNBS)‐induced gut inflammation is accompanied by an increase in α‐ and a decrease in β‐adrenoceptor numbers in guinea pig small intestine. In the present study, we investigated the effects of anti‐inflammatory compounds (cyclooxygenase inhibitor indomethacin, lipooxygenase inhibitor MK‐886, nitric oxide synthase inhibitor NG‐nitro‐l‐arginine methyl‐ester (l‐NAME), mast cell stabilizer doxantrazole) on TNBS‐induced adrenoceptor changes. Smooth muscle adrenoceptor populations, labelled by subtype‐specific radioligands 6 days after TNBS, were significantly different from those of sham‐treated controls: α1‐ and α2‐adrenoceptor numbers increased by more than 50%, while β‐adrenoceptor numbers decreased by more than 50%. These changes, associated with severe inflammation as assessed histologically and by myeloperoxidase assay, were prevented by doxantrazole orl‐NAME, and only partly by MK‐886. In contrast, indomethacin did not prevent these changes. It appears then that: (a) mast cell mediators, nitric oxide and leukotrienes are likely to contribute to TNBS‐induced changes in adrenoceptor populations in the guinea pig inflamed intestine; (b) there is no evidence for prostanoid involvement in this process. It was suggested that changes in smooth muscle adrenoceptor populations may be an important mechanism by which gut inflammation alters intestinal motility.
Contribution of acetylcholine, vasoactive intestinal polypeptide and nitric oxide to CNS‐evoked vagal gastric relaxation in the rat
Authors: KROWICKI Z. K. , HORNBY P. J.
Published: November 2010

AbstractSeveral in vitro models of gastric relaxation have elucidated a role of nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) in non‐adrenergic, non‐cholinergic (NANC) vagally mediated gastric relaxation. However, these models do not necessarily mimic the events leading to gastric relaxation in the whole animal. We have recently described a vagally mediated gastric relaxation evoked by micro‐injection of substance P (SP) into the nucleus raphe obscurus (NRO). The present study was performed to elucidate whether this CNS‐stimulated in vivo gastric relaxation involved acetylcholine, NO and VIP.

Atropine (1 mg kg−1i.v.), reduces both the rapid nadir and sustained gastric relaxation evoked by SP in the NRO, and the residual responses are abolished by NG‐Nitro‐L‐arginine methyl ester hydrochloride (L‐NAME, 10 mg kg−1i.v.), an NO synthase inhibitor. Blockade of NO synthase alone is not sufficient to abolish the effect of SP into the NRO on intragastric pressure. A VIP antagonist, [p‐chloro‐D‐Phe6, Leu17]VIP (32 μg i.v.) alone, or with the addition of L‐NAME, does not affect the nadir of the gastric relaxation in response to SP microinjected into the NRO; however, both antagonists reduce the CNS‐evoked sustained intragastric pressure relaxation. We conclude that, in CNS‐evoked gastric relaxation, inhibition of cholinergic pathways is potentially important for both the rapid nadir and sustained gastric relaxation, and both NO and VIP contribute to sustained gastric relaxation.
5‐Hydroxytryptamine and functional bowel disorders
Authors: SANGER G. J.
Published: November 2010

AbstractThe possibility that 5‐hydroxytryptamine (5‐HT) acts as a key sensitising agent in the aetiology of irritable bowel syndrome (IBS) is reviewed. The strategic locations of 5‐HT and its receptors are described, the most dominant being the 5‐HT3and 5‐HT4type. 5‐HT, acting mostly at 5‐HT3or 5‐HT3‐like receptors, enhances the sensitivity of visceral neurones projecting between the gut and the central nervous systems. 5‐HT, acting at 5‐HT4receptors promotes the sensitivity of enteric neurones that react to luminal stimuli. 5‐HT4and 5‐HT3receptors also mediate, respectively, sensitzsing and physiological actions of 5‐HT on gastrointestinal motor and secretory functions. This distribution implies that some 5‐HT3receptor antagonists might reduce certain symptoms of IBS, such as pain, by reducing the reactivity of the visceral afferent neurones linking the gut with the brain and spinal cord. However, such antagonists are not likely to find widespread clinical acceptance because they can also affect normal lower bowel function and promote constipation. 5‐HT4receptor antagonists, by contrast, reduce 5‐HT‐induced enteric nerve hypersensitivity without notably affecting the function of the normal bowel. Accordingly, these agents may reduce the symptoms of IBS directly, by reducing the incidence of defecation and diarrhoea and indirectly, by reducing both ‘rebound’ constipation and the post‐prandial discomfort and pain associated with gastrointestinal hyper‐reactivity.
Abscisic Acid and the Germination of Thermodormant Lettuce Fruits (Lactuca sativa cv. Grand Rapids). The Fate of Isotopically Labelled Abscisic Acid
Authors: ROBERTSON J. , BERRIE A. M. M.
Published: November 2010

ABA inhibits the germination of Grand Rapids lettuce seeds at a temperature at which photoblastism is not observed. This ABA inhibition can be overcome by GA, or cytokinin, or red light acting alone or in concert. At high levels of ABA the ameliorative effects of GA, cytokinin or red light are not manifest and it is suggested that lettuce seeds' response to a given level of ABA is temperature dependent, and any interaction which may be observed between ABA and other regulators, or red light, likewise is temperature dependent.

Seeds only actively metabolize ABA after germination is complete though ABA does influence the germination process proper. Some radioactivity, originally applied as 14C ABA, cannot be extracted from 14C ABA treated seeds by methanol, and this “fixed” ABA can constitute more than 50% of the activity taken up by the seeds. High levels of “fixed” ABA are found in seeds which do not germinate. As well as this “fixed” ABA two labelled metabolites arise in seeds treated with 14C ABA. The levels of these rise in seed extracts as the level of extractable ABA decreases.

Whilst ABA can affect germination our results do not allow us to assign a specific regulatory role to ABA in seed germination.
Getting on Target with Community Health Advisors (GOTCHA): an innovative stroke prevention project
Authors: Story Lachel , Mayfield‐Johnson Susan , Downey Laura H , Anderson‐Lewis Charkarra , Young Rebekah , Day Pearlean
Published: November 2010

STORY L, MAYFIELD‐JOHNSON S, DOWNEY LH, ANDERSON‐LEWIS C, YOUNG R and DAY P. Nursing Inquiry 2010; 17: 373–384 Getting on Target with Community Health Advisors (GOTCHA): an innovative stroke prevention project

Health disparities along with insufficient numbers of healthcare providers and resources have created a need for effective and efficient grassroots approaches to improve community health. Community‐based participatory research (CBPR), more specifically the utilization of community health advisors (CHAs), is one such strategy. The Getting on Target with Community Health Advisors (GOTCHA) project convened an interdisciplinary team to answer the call from 10 counties in the rural Mississippi Delta area of ‘The Stroke Belt’ to meet the region’s identified health needs, and to impact the health of a disparaged state. This article explores this CBPR project including the community involvement strategies, innovative CHA training curriculum, evaluation plan, and implications to healthcare professionals, particularly nurses.
Are corporate governance attributes associated with accounting conservatism?
Authors: Lim Roslinda
Published: November 2010

This article investigates the association between the board of directors, the audit committee and the external auditor (as well as an aggregate governance index) and the extent of conservatism evident in Australian firms’ financial reporting. Overall, the results provide only weak evidence that firms with certain governance characteristics report more conservatively. Evidence of any such link is restricted to measures of board composition and leadership, and even then the results are sensitive to the method used to measure the extent of conservatism in financial reporting.
Red blood cell (RBC) survival determined in humans using RBCs labeled at multiple biotin densities
Authors: Mock Donald M. , Matthews Nell I. , Zhu Shan , Strauss Ronald G. , Schmidt Robert L. , Nalbant Demet , Cress Gretchen A. , Widness John A.
Published: November 2010

BACKGROUND: Safe, accurate methods permitting simultaneous and/or repeated measurement of red blood cell (RBC) survival (RCS) are important to investigate pathophysiology and therapy of anemia. Methods using chromium 51 (51Cr)‐labeled RBCs are unacceptable for infants, children, and pregnant women. We report RCS measured in vivo using RBCs labeled with several densities of biotin (BioRBCs).

STUDY DESIGN AND METHODS: Aliquots of autologous RBCs from eight healthy adult subjects were labeled separately at four discrete biotin densities, mixed, and infused. The proportion of each population of BioRBCs circulating was determined serially by flow cytometry over 20 weeks. For each population, RCS was assessed by the following: 1) posttransfusion BioRBC recovery at 24 hours (PTR24); 2) time to decrease to 50% of the enrichment at 24 hours (T50); and 3) mean potential lifespan (MPL).

RESULTS: Among the four BioRBC densities, no significant differences in PTR24 were observed. T50 and MPL were similar for the two lowest BioRBC densities. In contrast, the two highest BioRBC densities demonstrated progressively decreased T50 and MPL.

CONCLUSIONS: RBCs labeled at four biotin densities can be used to independently and accurately measure PTR24 and two lowest biotin densities can accurately quantitate long‐term RCS. This method provides a tool for investigating anemia in infants, fetuses, and pregnant women with the following advantages over the standard 51Cr method: 1) study subjects are not exposed to radiation; 2) small blood volumes (e.g., 20 µL) are required; and 3) multiple independent RCS measurements can be made simultaneously in the same individual.
Corporate Fraud and Business Conditions: Evidence from IPOs
Authors: WANG TRACY YUE , WINTON ANDREW , YU XIAOYUN
Published: November 2010

We examine how a firm's incentive to commit fraud when going public varies with investor beliefs about industry business conditions. Fraud propensity increases with the level of investor beliefs about industry prospects but decreases when beliefs are extremely high. We find that two mechanisms are at work: monitoring by investors and short‐term executive compensation, both of which vary with investor beliefs about industry prospects. We also find that monitoring incentives of investors and underwriters differ. Our results are consistent with models of investor beliefs and corporate fraud, and suggest that regulators and auditors should be vigilant for fraud during booms.
Collateral, Risk Management, and the Distribution of Debt Capacity
Authors: RAMPINI ADRIANO A. , VISWANATHAN S.
Published: November 2010

Collateral constraints imply that financing and risk management are fundamentally linked. The opportunity cost of engaging in risk management and conserving debt capacity to hedge future financing needs is forgone current investment, and is higher for more productive and less well‐capitalized firms. More constrained firms engage in less risk management and may exhaust their debt capacity and abstain from risk management, consistent with empirical evidence and in contrast to received theory. When cash flows are low, such firms may be unable to seize investment opportunities and be forced to downsize. Consequently, capital may be less productively deployed in downturns.
The financial crisis and its impacts on global agriculture
Authors: Lin Justin Yifu , Martin Will
Published: November 2010

The financial crisis arose in the industrial countries, but has affected developing countries through higher interest rates, sharp changes in commodity prices, and reductions in investment, trade, migration, and remittances. For most low‐income countries, shocks that affect food prices or wage rates for unskilled workers seem likely to have the biggest impact on poverty, with the declines in key food prices associated with the crisis helping to reduce poverty. Policies to address the crisis must include measures to deal with: financial sector problems; the resulting reductions in aggregate demand; and the particular vulnerabilities of poor people.
Infant‐feeding practices and associated factors of HIV‐positive mothers at Gert Sibande, South Africa
Authors: Ladzani Rendani , Peltzer Karl , Mlambo Motlatso G. , Phaweni Khanyisa
Published: November 2010

Aim:  To assess knowledge, infant‐feeding education and practices, factors that affect choice of infant feeding option, determinants of mixed feeding, psychosocial challenges and attitudes of HIV‐positive women with infants between ages 3–6 months who attended prevention of mother‐to‐child transmission of HIV services in Gert Sibande district.

Methods:  A cross‐sectional study was conducted with 815 HIV‐positive mothers at 47 postnatal clinics. Trained field workers collected data at health facilities, using structured questionnaires. HIV‐infected women who were at least 18 years of age were interviewed.

Results:  The mean age was 27.7 years (SD 6.4). Seventy‐eight percent agreed that HIV could be transmitted by breastfeeding. Fifty per cent were exclusively formula feeding, 35.6% breastfed exclusively and 12.4% mixed fed. In multivariate analysis, having a vaginal delivery, infant hospital admissions, and currently pregnant were associated with mixed feeding. Being older, knowing the HIV status of the infant and higher knowledge on HIV transmission through breastfeeding were associated with formula feeding.

Conclusion:  The study identified gaps in prevention of mother‐to‐child transmission (PMTCT) knowledge and infant feeding policy which seem to affect appropriate infant feeding. Various determinants of mixed feeding and exclusive formula feeding in the context of PMTCT were identified that can guide infant feeding counselling and support services of PMTCT programmes.
Decriminalization of Cannabis – potential risks for children?
Authors: Amirav Israel , Luder Anthony , Viner Yuri , Finkel Martin
Published: November 2010

The legalization of cannabis for medicinal purposes is becoming increasingly widespread worldwide. The anticipated growing ease of access to cannabis may create an increased risk for passive and/or active ingestion by children. We report a case of a 1.5‐year‐old infant who presented with unexplained coma that was later proved to be associated with the ingestion of cannabis. This case highlights the importance of considering cannabis ingestion in the differential diagnosis of infantile and toddler coma and the need for public education regarding the risks of childhood exposure in the light of the legalization of cannabis for medical purposes and its greater availability.
Fatty acid omega‐oxidation as a rescue pathway for fatty acid oxidation disorders in humans
Authors: Wanders Ronald J. A. , Komen Jasper , Kemp Stephan
Published: November 2010

Fatty acids (FAs) can be degraded via different mechanisms including α‐, β‐ and ω‐oxidation. In humans, a range of different genetic diseases has been identified in which either mitochondrial FA β‐oxidation, peroxisomal FA β‐oxidation or FA α‐oxidation is impaired. Treatment options for most of these disorders are limited. This has prompted us to study FA ω‐oxidation as a rescue pathway for these disorders, based on the notion that if the ω‐oxidation of specific FAs could be upregulated one could reduce the accumulation of these FAs and the subsequent detrimental effects in the different groups of disorders. In this minireview, we describe our current state of knowledge in this area with special emphasis on Refsum disease and X‐linked adrenoleukodystrophy.
The role of cytochrome P450 monooxygenases in microbial fatty acid metabolism
Authors: Van Bogaert Inge N. A. , Groeneboer Sara , Saerens Karen , Soetaert Wim
Published: November 2010

Cytochrome P450 monooxygenases (P450s) are a diverse collection of enzymes acting on various endogenous and xenobiotic molecules. Most of them catalyse hydroxylation reactions and one group of possible substrates are fatty acids and their related structures. In this minireview, the significance of P450s in microbial fatty acid conversion is described. Bacteria and yeasts possess various P450 systems involved in alkane and fatty acid degradation, and often several enzymes with different activities and specificities are retrieved in one organism. Furthermore, P450s take part in the formation of fatty acid‐based secondary metabolites. Finally, there are a substantial number of microbial P450s displaying activity towards fatty acids, but to which no biological role could be assigned despite the often quite intense research.