The Effect of Detoxification of Lignocellulosic Biomass for Enhanced Methane Production

The aim of this research is to examine the effect of lignocellulosic biomass detoxification on the efficiency of the methane fermentation process. Both for corn straw and rye straw, the methane yield was expressed per volume of fermentation medium and per mass of volatile solids (VS) added. Lignocellulosic biomass was subjected of thermo-chemical and enzymatic sequential pretreatments. It was found that methane yield was higher by 22% when using the detoxification process. In these variants, CH4 yield was 18.86 L/L for corn straw and 17.69 L/L for rye straw; while methane yield expressed per mass of VS added was 0.31 m3/kg VS for corn straw and 0.29 m3/kg VS for rye straw. The inclusion of a detoxification step in pretreatments of biomass lignocellulosic increases the degree of organic substance decomposition and enhances methane yield. The results show that a two-step pretreatment, alkaline/enzymatic with a detoxification process, is necessary for the effective generation of high methane concentration biogas.

Clothing and identity: Chinese rural students’ embodied transformations in the urban university

In the context of enduring urban–rural inequality in China, attention has been drawn to rural students’ encounters in the urban university. In this research, I elicit rural students’ narratives about their (classed) perceptions of clothing and style, as well as the bodily practices embedded in their subjective social mobility experiences in the unique social milieu of China’s context. I argue that participants’ transforming practices entail a nexus of challenge to and also compliance with the urban field. Through the theoretical lens of habitus, I illustrate how rural students strategically transform their ‘style’, as dispositions of habitus, in the urban field to obtain valued forms of embodied capital. At the same time, I emphasise the importance of viewing rural students’ embodied transformations critically, as it entails both their effective generation of valued capital to actively adapt to the urban field and their (involuntary) compliance to the oppressive social relations.

Study of the Vernier Effect Based on the Fabry–Perot Interferometer: Methodology and Application

The optical Vernier effect is a powerful tool for improving the sensitivity of an optical sensor, which relies on the use of two sensor units with slightly detuned frequencies. However, an improper amount of detuning can easily cause the Vernier effect to be unusable. In this work, the effective generation range of the Vernier effect and the corresponding interferometer configuration are suggested and experimentally demonstrated through a tunable cascaded Fabry–Perot interferometer structure. We further demonstrate a practical method to increase the magnification factor of the Vernier effect based on the device bandwidth. Only the optical path length of an interferometer probe and the sensitivity of the measurement parameters are needed to design this practical interferometer based on the Vernier effect. Our results provide potential insights for the sensing applications of the Vernier effect.

Emergent evolutionary forces in spatial models of luminal growth in the human gut microbiota

The genetic composition of the gut microbiota is constantly reshaped by ecological and evolutionary forces. These strain-level dynamics can be challenging to understand because they emerge from complex spatial growth processes that take place within a host. Here we introduce a mathematical framework to predict how stochastic evolutionary forces emerge from simple models of microbial growth in the intestinal lumen. Our framework shows how fluid flow and longitudinal variation in growth rate combine to shape the frequencies of genetic variants in sequenced fecal samples, yielding analytical expressions for the effective generation times, selection coefficients, and rates of genetic drift. We find that the emergent evolutionary dynamics can often be captured by well-mixed models that lack explicit spatial structure, even when there is substantial spatial variation in species-level composition. By applying these results to the human colon, we find that continuous fluid flow is unlikely to create sufficient bottlenecks to allow large fluctuations in mutant frequencies within a host, while the effective generation times may be significantly shorter than expected from traditional average growth rate estimates. Our results provide a starting point for quantifying genetic turnover in the gut microbiota, and may be relevant for other microbial ecosystems where unidirectional fluid flow plays an important role.

Tailored generation of insulin producing cells from canine mesenchymal stem cells derived from bone marrow and adipose tissue

The trend of regenerative therapy for diabetes in human and veterinary practices has conceptually been proven according to the Edmonton protocol and animal models. Establishing an alternative insulin-producing cell (IPC) resource for further clinical application is a challenging task. This study investigated IPC generation from two practical canine mesenchymal stem cells (cMSCs), canine bone marrow-derived MSCs (cBM-MSCs) and canine adipose-derived MSCs (cAD-MSCs). The results illustrated that cBM-MSCs and cAD-MSCs contain distinct pancreatic differentiation potential and require the tailor-made induction protocols. The effective generation of cBM-MSC-derived IPCs needs the integration of genetic and microenvironment manipulation using a hanging-drop culture of PDX1-transfected cBM-MSCs under a three-step pancreatic induction protocol. However, this protocol is resource- and time-consuming. Another study on cAD-MSC-derived IPC generation found that IPC colonies could be obtained by a low attachment culture under the three-step induction protocol. Further, Notch signaling inhibition during pancreatic endoderm/progenitor induction yielded IPC colonies through the trend of glucose-responsive C-peptide secretion. Thus, this study showed that IPCs could be obtained from cBM-MSCs and cAD-MSCs through different induction techniques. Also, further signaling manipulation studies should be conducted to maximize the protocol’s efficiency.

Tailor-made generation of insulin-producing cells from canine mesenchymal stem cells derived from bone marrow and adipose tissue

Trend of regenerative therapy for diabetes in human and veterinary practice has conceptually been proven according to Edmonton protocol and animal models. Establishing an alternative insulin-producing cell (IPC) resource is a challenge task for further clinical application. In this study, IPC generation from two practical canine mesenchymal stem cells(cMSCs), canine bone marrow-derived MSCs (cBM-MSCs) and canine adipose-derived MSCs(cAD-MSCs), was of interest. The results illustrated that cBM-MSCs and cAD-MSCs contained distinct pancreatic differentiation potential and required the tailor-made induction protocols. Effective generation of cBM-MSC-derived IPCs needed an integration of genetic and microenvironment manipulation using hanging-drop culture of PDX-1-transfected cBM-MSCs under three-step pancreatic induction protocol. However, this protocol was resource- and time-consumed. Another study on cAD-MSC-derived IPC generation found that IPC colonies could be obtained by low attachment culture under three-step induction protocol. Further Notch signaling inhibition during pancreatic endoderm/progenitor induction yielded IPC colonies with trend of glucose-responsive C-peptide secretion. Thus, this study showed that IPCs could be obtained from cBM-MSCs and cAD-MSCs by different induction techniques, and further signaling manipulation study should be conducted to maximize the protocol efficiency.