An assessment of road-verge grass as a feedstock for farm-fed anaerobic digestion plants

Cuttings from road-verge grass could provide biomass for energy generation, but currently this potential is not exploited. This research assessed the technical, practical and financial feasibility of using grass harvested from road verges as a feedstock in farm-fed anaerobic digestion (AD) plants. The methane potential (191 mL CH4 gDM−1) and digestion characteristics of verge grass were similar to those of current farm feedstocks; indicating suitability for AD. Ensiling had no significant impact on the biomethane generated. Testing co-digestions of verge grass with current farm feedstocks showed enhanced methane yields, suggesting that verge grass could be a valuable addition to AD feedstock mixes. In a case study of the UK county of Lincolnshire, potential volumes and locations of verge grass biomass were estimated, with capacities and locations of existing AD plants, to assess the potential to supply practical grass volumes. Grass harvesting costs were modelled and compared with other feedstock costs. Finally, the attitudes of AD operators to using verge grass were investigated to understand whether a market for verge grass exists. In a small survey all operators were willing to use it as a feedstock and most were prepared to pay over the estimated harvesting cost. If verge grass was legally recognised as a waste product it could be attractive to AD operators especially where financial incentives to use waste feedstocks are in place. In rural areas, verge grass could be harvested and co-digested by existing farm-fed AD plants, potentially reducing the cost of road verge maintenance and increasing biodiversity

Careers of an elite cohort of U.S. basic life science postdoctoral fellows and the influence of their mentor's citation record

<p>Abstract</p> <p>Background</p> <p>There is general agreement that the number of U.S. science PhDs being trained far exceeds the number of future academic positions. One suggested approach to this problem is to significantly reduce the number of PhD positions. A counter argument is that students are aware of the limited academic positions but have chosen a PhD track because it opens other, non-academic, opportunities. The latter view requires that students have objective information about what careers options will be available for them.</p> <p>Methods</p> <p>The scientific careers of the 1992-94 cohort of NIH National Institute of General Medical Sciences (NIGMS) Kirchstein-NRSA F32 postdoctoral fellows (PD) was determined by following their publications (PubMed), grants (NIH and NSF), and faculty and industry positions through 2009. These basic life science PDs receive support through individual grant applications and represent the most successful class of NIH PDs as judged by academic careers and grants. The sex dependence of the career and grant success and the influence of the PD mentor's citation record were also determined</p> <p>Results</p> <p>Of the 439 1992-94 NIGMS F32 fellows, the careers of 417 could be determined. Although females had significantly higher rates of dropping out of science (22% females, 9% males) there was no significant difference in the fraction of females that ended up as associate or full professors at research universities (22.8% females, 29.1% for males). More males then females ended up in industry (34% males, 22% females). Although there was no significant correlation between male grant success and their mentor's publication record (h index, citations, publications), there was a significant correlation for females. Females whose mentor's h index was in the top quartile were nearly 3 times as likely to receive a major grant as those whose mentors were in the bottom quartile (38.7% versus 13.3%).</p> <p>Conclusions</p> <p>Sixteen years after starting their PD, only 9% of males had dropped out of science. More females (28%) have dropped out of science, primarily because fewer went into industry positions. The mentor's publication record does not affect the future grant success of males but it has a dramatic effect on female grant success.</p

Ross, Macdonald, and a Theory for the Dynamics and Control of Mosquito-Transmitted Pathogens

Ronald Ross and George Macdonald are credited with developing a mathematical model of mosquito-borne pathogen transmission. A systematic historical review suggests that several mathematicians and scientists contributed to development of the Ross-Macdonald model over a period of 70 years. Ross developed two different mathematical models, Macdonald a third, and various “Ross-Macdonald” mathematical models exist. Ross-Macdonald models are best defined by a consensus set of assumptions. The mathematical model is just one part of a theory for the dynamics and control of mosquito-transmitted pathogens that also includes epidemiological and entomological concepts and metrics for measuring transmission. All the basic elements of the theory had fallen into place by the end of the Global Malaria Eradication Programme (GMEP, 1955–1969) with the concept of vectorial capacity, methods for measuring key components of transmission by mosquitoes, and a quantitative theory of vector control. The Ross-Macdonald theory has since played a central role in development of research on mosquito-borne pathogen transmission and the development of strategies for mosquito-borne disease prevention

Fenretinide induces mitochondrial ROS and inhibits the mitochondrial respiratory chain in neuroblastoma

Fenretinide induces apoptosis in neuroblastoma by induction of reactive oxygen species (ROS). In this study, we investigated the role of mitochondria in fenretinide-induced cytotoxicity and ROS production in six neuroblastoma cell lines. ROS induction by fenretinide was of mitochondrial origin, demonstrated by detection of superoxide with MitoSOX, the scavenging effect of the mitochondrial antioxidant MitoQ and reduced ROS production in cells without a functional mitochondrial respiratory chain (Rho zero cells). In digitonin-permeabilized cells, a fenretinide concentration-dependent decrease in ATP synthesis and substrate oxidation was observed, reflecting inhibition of the mitochondrial respiratory chain. However, inhibition of the mitochondrial respiratory chain was not required for ROS production. Co-incubation of fenretinide with inhibitors of different complexes of the respiratory chain suggested that fenretinide-induced ROS production occurred via complex II. The cytotoxicity of fenretinide was exerted through the generation of mitochondrial ROS and, at higher concentrations, also through inhibition of the mitochondrial respiratory chain

Blunted Neuronal Calcium Response to Hypoxia in Naked Mole-Rat Hippocampus

Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6) and older (postnatal day 20) age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals

The programming of sequences of saccades

Saccadic eye movements move the high-resolution fovea to point at regions of interest. Saccades can only be generated serially (i.e., one at a time). However, what remains unclear is the extent to which saccades are programmed in parallel (i.e., a series of such moments can be planned together) and how far ahead such planning occurs. In the current experiment, we investigate this issue with a saccade contingent preview paradigm. Participants were asked to execute saccadic eye movements in response to seven small circles presented on a screen. The extent to which participants were given prior information about target locations was varied on a trial-by-trial basis: participants were aware of the location of the next target only, the next three, five, or all seven targets. The addition of new targets to the display was made during the saccade to the next target in the sequence. The overall time taken to complete the sequence was decreased as more targets were available up to all seven targets. This was a result of a reduction in the number of saccades being executed and a reduction in their saccade latencies. Surprisingly, these results suggest that, when faced with a demand to saccade to a large number of target locations, saccade preparation about all target locations is carried out in paralle

The Impact of Fuelwood Moisture Content on the Emission of Gaseous and Particulate Pollutants from a Wood Stove

The amount of moisture in wood fuel has a significant influence on the emissions of particulate matter (PM) and gaseous pollutants when burned in small-scale domestic appliances. Previous studies have shown that higher moisture content generally produces higher particulate emissions factors. As well as quantity of material emitted, it is also important to understand the effects of moisture on particle qualities including size, composition and morphology – since these can influence the human-toxicity and environmental impacts of the particles. In this study, emissions were quantified and the particulate qualities were also examined using chemical, optical and thermogravimetric analysis as well as size-graded sampling. By comparing the results from the use of batches of beech wood fuel with differing moisture content, it was shown that there are consistent and significant differences in both the quantity and qualities of the resulting emissions when burned under the same conditions. This has important consequences for emission inventories which currently only assume an emission factor from a proscribed combustion situatio

Children’s perceptions of dissimilarity in parenting styles are associated with internalizing and externalizing behavior

The purpose of this study was to examine the relationship between children’s perception of dissimilarity in parenting styles, and internalizing and externalizing problems in children. Children from the general population (n = 658) reported on the level of emotional warmth, rejection, and overprotection of both parents by filling out the child version of the Egna Minnen Beträffande Uppfostran (EMBU-C) and mothers completed the child behavior checklist (CBCL). Intraclass correlations were computed as measures of dissimilarity between parenting styles of mothers and fathers. Children’s perceived dissimilarity in parental emotional warmth is associated with internalizing and externalizing problems (β = 0.092, p < 0.05; β = 0.091, p < 0.05). Perceived dissimilarity between parents’ overprotection is associated with externalizing problems (β = 0.097, p < 0.05). Perceived dissimilarity between parenting styles is associated with externalizing and internalizing problems, over and above the effects of the level of the parenting styles. The results highlight the negative consequences of perceived dissimilarity between parents. To conclude, children have more internalizing and externalizing problems when they perceive their parents as more dissimilar in parenting styles

Establishment of one-step SYBR green-based real time-PCR assay for rapid detection and quantification of chikungunya virus infection

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus and one of the prevalent re-emerging arbovirus in tropical and subtropical regions of Asia, Africa, and Central and South America. It produces a spectrum of illness ranging from inapparent infection to moderate febrile illness as well as severe arthralgia or arthritis affecting multiple joints. In this study, a quantitative, one-step real-time SYBR Green-based RT-PCR system for the non-structural protein 2 (nsP2) of CHIKV that can quantify a wide range of viral RNA concentrations was developed. Comparisons between the conventional semi-quantitative RT-PCR assay, immunofluorescence detection method and the one-step SYBR Green-based RT-PCR assay in the detection of CHIKV infection revealed much rapid and increase sensitivity of the latter method. Furthermore, this newly developed assay was validated by in vitro experiments in which ribavirin, a well-known RNA virus inhibitor, showed a dose-dependent inhibition of virus replication on cells that was assessed by viral infectivity and viral RNA production. Our results demonstrate the potential of this newly developed one-step SYBR Green I-based RT-PCR assay may be a useful tool in rapid detection of CHIKV and monitoring the extent of viral replication possibly in patients' samples