Batch and continuous biogas production from grass silage liquor

Herein batch and continuous mesophilic anaerobic digestion of grass silage liquor was studied. The continuous process was carried out in Armfield digesters with an OLR ranging from 0.851 to 1.77 kg COD m-3 day-1. The effect of recirculation of effluent from the digester was investigated using different OLRs of grass silage liquor feed. These results showed that as the OLR increased, the methane yield decreased for the reactor with no recycle and increased for the reactor with recycle. However, the COD removal for both digesters was nearly the same at the same OLR. Overall these studies show that grass silage liquor can produce a high quality methane steam between 70% and 80% and achieve methane yields of 0.385 m3 kg-1 COD.

An eye on RNAi in nematode parasites

RNA interference (RNAi) has revolutionised approaches to gene function determination. From a parasitology perspective, gene function studies have the added dimension of providing validation data, increasingly deemed essential to the initial phases of drug target selection, pre-screen development. Notionally advantageous to those working on nematode parasites is the fact that Caenorhabditis elegans research spawned RNAi discovery and continues to seed our understanding of its fundamentals. Unfortunately, RNAi data for nematode parasites illustrate variable and inconsistent susceptibilities which undermine confidence and exploitation. Now well-ensconced in an era of nematode parasite genomics, we can begin to unscramble this variation.

Acid-catalyzed hydrolysis of cellulose and cellulosic waste using a microwave reactor system

A microwave reactor system was investigated as a potential technique to maximize sugar yield for the hydrolysis of municipal solid waste for ethanol production. Specifically, dilute acid hydrolysis of a-cellulose and waste cellulosic biomass (grass clippings) with phosphoric acid was undertaken within the microwave reactor system. The experimental data and reaction kinetic analysis indicate that the use of a microwave reactor system can successfully facilitate dilute acid hydrolysis of cellulose and waste cellulosic biomass, producing high yields of total sugars in short reaction times. The maximum yield of reducing sugars was obtained at 7.5% (w/v) phosphoric acid and 160 degrees C, corresponding to 60% of the theoretical total sugars, with a reaction time of 5 min. When using a very low acid concentration (0.4% w/v) for the hydrolysis in the microwave reactor, it was found that 10 g of total sugars/100 g dry mass was produced, which is significant considering the low acid concentration. When hydrolyzing grass clippings using the microwave reactor, the optimum conditions were an acid concentration of 2.5% (w/v), 175 degrees C with a 15 min reaction time, giving 18 g/100 g dry mass of total sugars, with xylose being the sugar with the highest yield. It was observed that pentose sugars were more easily formed but also more easily degraded, these being significantly affected by increases in acid concentration and temperature. Kinetic modeling of the data indicated that the use of microwave heating may account for an increase in reaction rate constant, k(1), found in this study in comparison with conventional systems described in the literature.

Management of long-term sickness absence: a systematic realist review

Purpose
The increasing impact and costs of long term sickness absence have been well documented. However, the diversity and complexity of interventions and of the contexts in which these take place makes a traditional review problematic. Therefore, we undertook a systematic realist review to identify the dominant programme theories underlying best practice, to assess the evidence for these theories, and to throw light on important enabling or disabling contextual factors.

Method
A search of the scholarly literature from 1950 to 2011 identified 5,576 articles, of which 269 formed the basis of the review.

Results
We found that the dominant programme theories in relation to effective management related to: early intervention or referral by employers; having proactive organisational procedures; good communication and cooperation between stakeholders; and workplace-based occupational rehabilitation. Significant contextual factors were identified as the level of support for interventions from top management, the size and structure of the organisation, the level of financial and organisational investment in the management of long-term sickness absence, and the quality of relationships between managers and staff.

Conclusions
Consequently, those with responsibility for managing absence should bear in mind the contextual factors that are likely to have an impact on interventions, and do what they can to ensure stakeholders have at least a mutual understanding (if not a common purpose) in relation to their perceptions of interventions, goals, culture and practice in the management of long term sickness absence.

Ran Is a Potential Therapeutic Target for Cancer Cells with Molecular Changes Associated with Activation of the PI3K/Akt/mTORC1 and Ras/MEK/ERK Pathways

Purpose: Cancer cells have been shown to be more susceptible to Ran knockdown than normal cells. We nowinvestigate whether Ran is a potential therapeutic target of cancers with frequently found mutations that lead to higher Ras/MEK/ERK [mitogen-activated protein/extracellular signal-regulated kinase (ERK; MEK)] and phosphoinositide 3-kinase (PI3K)/Akt/mTORC1 activities.