Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ∼10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50°C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme

Why have asset price properties changed so little in 200 years

We first review empirical evidence that asset prices have had episodes of large fluctuations and been inefficient for at least 200 years. We briefly review recent theoretical results as well as the neurological basis of trend following and finally argue that these asset price properties can be attributed to two fundamental mechanisms that have not changed for many centuries: an innate preference for trend following and the collective tendency to exploit as much as possible detectable price arbitrage, which leads to destabilizing feedback loops.Comment: 16 pages, 4 figure

Prevalence of positive depression screen among post miscarriage women- A cross sectional study

Background: Miscarriages are a common pregnancy complication affecting about 10–15% of pregnancies. Miscarriages may be associated with a myriad of psychiatric morbidity at various timelines after the event. Depression has been shown to affect about 10–20% of all women following a miscarriage. However, no data exists in the local setting informing on the prevalence of post-miscarriage depression. We set out to determine the prevalence of positive depression screen among women who have experienced a miscarriage at the Aga Khan University hospital, Nairobi. Methods: The study was cross-sectional in design. Patients who had a miscarriage were recruited at the post-miscarriage clinic review at the gynecology clinics at Aga Khan University Hospital, Nairobi. The Edinburgh postpartum depression scale was used to screen for depression in the patients. Prevalence was calculated from the percentage of patients achieving the cut –off score of 13 over the total number of patients. Results: A total of 182 patients were recruited for the study. The prevalence of positive depression screen was 34.1% since 62 of the 182 patients had a positive depression screen. Moreover, of the patients who had a positive depression screen, 21(33.1%) had thoughts of self-harm. Conclusion: A positive depression screen is present in 34.1% of women in our population two weeks after a miscarriage. Thoughts of self-harm are present in about a third of these women (33.1%) hence pointing out the importance of screening these women using the EPDS after a miscarriage

A Combination of Dopamine Genes Predicts Success by Professional Wall Street Traders

What determines success on Wall Street? This study examined if genes affecting dopamine levels of professional traders were associated with their career tenure. Sixty professional Wall Street traders were genotyped and compared to a control group who did not trade stocks. We found that distinct alleles of the dopamine receptor 4 promoter (DRD4P) and catecholamine-O-methyltransferase (COMT) that affect synaptic dopamine were predominant in traders. These alleles are associated with moderate, rather than very high or very low, levels of synaptic dopamine. The activity of these alleles correlated positively with years spent trading stocks on Wall Street. Differences in personality and trading behavior were also correlated with allelic variants. This evidence suggests there may be a genetic basis for the traits that make one a successful trader

Years working as a trader correlates with DA levels as determined by COMT alleles (r

<p> = <b>.19>0, one-tailed t-test P</b> = <b>.05).</b> Those with the lowest COMT-related synaptic DA category (G/G) averaged 6.5 years of trading experience, while those in the highest category (A/A) averaged 10.6 years trading stocks (one tailed t-test P = .05).</p

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme