Seasonal phenotypic flexibility in body mass, basal thermogenesis, and tissue oxidative capacity in the male Silky Starling (Sturnus sericeus)

Abstract Background Acclimatization to winter conditions is an essential prerequisite for the survival of small birds in the northern temperate zone. Changes in photoperiod, ambient temperature and food availability trigger seasonal physiological and behavioral acclimatization in many passerines. Seasonal trends in metabolic parameters are well known in avian populations from temperate environments; however, the physiological and biochemical mechanisms underlying these trends are incompletely understood. In this study, we used an integrative approach to measure variation in the thermogenic properties of the male Silky Starling (Sturnus sericeus) at different levels or organization, from the whole organism to the biochemical. We measured body mass (M b), basal metabolic rate (BMR), energy budget, the mass of selected internal organs, state 4 respiration and cytochrome c oxidase (COX) activity in the heart, liver and muscle. Methods Oxygen consumption was measured using an open-circuit respirometry system. The energy intake of the birds were then determined using an oxygen bomb calorimeter. Mitochondrial state 4 respiration and COX activity in heart, liver and pectoral muscle were measured with a Clark electrode. Results The results suggest that acclimatization to winter conditions caused significant change in each of the measured variables, specifically, increases in M b, organ mass, BMR, energy intake and cellular enzyme activity. Furthermore, BMR was positively correlated with body mass, energy intake, the mass of selected internal organs, state 4 respiration in the heart, liver and muscle, and COX activity in the heart and muscle. Conclusions These results suggest that the male Silky Starling’s enhanced basal thermogenesis under winter conditions is achieved by making a suite of adjustments from the whole organism to the biochemical level, and provide further evidence to support the notion that small birds have high phenotypic plasticity with respect to seasonal changes

Architecture and Performance Evaluation of a Novel Optical Packet Switch with Input Concentrators

In this paper, we propose a novel optical packet switch (OPS) architecture with input concentrators, which employ multi-input single-output optical buffers to aggregate all the incoming traffic into a small size switching fabric. Accordingly, the physical size, the number of the needed wavelength converters, and the economic cost of the total OPS node are decreased dramatically. However, the deployment of input concentrators introduces additional packet loss and delay, except from the contention at the switch output. A Markov model is presented to study the packet loss ratio (PLR) and average packet delay given by the input concentrators. The corresponding closed form expressions are given. The model also demonstrates that the system performance can be greatly improved by increasing the buffer size when the traffic load is not larger than 0.69315. The analytical values are compared with the simulation results. All the obtained results show that the proposed model provides satisfactory approximations under different network scenarios. Moreover, the economic cost savings of the proposed OPS node at the present time and its evolution as a function of time are also discussed in detail. The proposed architecture can also be applied in a packet enhanced optical transport network (OTN)

Architecture and Performance Evaluation of a Novel Optical Packet Switch with Input Concentrators

In this paper, we propose a novel optical packet switch (OPS) architecture with input concentrators, which employ multi-input single-output optical buffers to aggregate all the incoming traffic into a small size switching fabric. Accordingly, the physical size, the number of the needed wavelength converters, and the economic cost of the total OPS node are decreased dramatically. However, the deployment of input concentrators introduces additional packet loss and delay, except from the contention at the switch output. A Markov model is presented to study the packet loss ratio (PLR) and average packet delay given by the input concentrators. The corresponding closed form expressions are given. The model also demonstrates that the system performance can be greatly improved by increasing the buffer size when the traffic load is not larger than 0.69315. The analytical values are compared with the simulation results. All the obtained results show that the proposed model provides satisfactory approximations under different network scenarios. Moreover, the economic cost savings of the proposed OPS node at the present time and its evolution as a function of time are also discussed in detail. The proposed architecture can also be applied in a packet enhanced optical transport network (OTN)

Targeted Integration of siRNA against Porcine Cytomegalovirus (PCMV) Enhances the Resistance of Porcine Cells to PCMV

In the world’s first pig-to-human cardiac cytomegalovirus (PCMV), xenotransplant and elevated levels of porcine key factors contributing to patient mortality were considered. This has renewed attention on PCMV, a virus widely prevalent in pigs. Currently, there are no effective drugs or vaccines targeting PCMV, and its high detection difficulty poses challenges for prevention and control research. In this study, antiviral small hairpin RNA (shRNA) was selected and inserted into the Rosa26 and miR-17-92 loci of pigs via a CRISPR/Cas9-mediated knock-in strategy. Further in vitro viral challenge experiments demonstrated that these genetically edited pig cells could effectively limit PCMV replication. Through this process, we constructed a PCMV-infected cell model, validated partial viral interference sites, enhanced gene knock-in efficiency, performed gene editing at two different gene loci, and ultimately demonstrated that RNA interference (RNAi) technology combined with CRISPR/Cas9 has the potential to generate pig cells with enhanced antiviral infection capabilities. This opens up possibilities for the future production of pig populations with antiviral functionalities

The Dynamic Modulation Doping Effect of Gas Molecules on an AlGaN/GaN Heterojunction Surface

AlGaN/GaN high-electron-mobility transistors (HEMTs) are widely used in high-frequency and high-power applications owing to the high two-dimensional electron gas (2DEG) concentration. However, the microscopic origin of the 2DEG remains unclear. This hinders the development of device fabrication technologies, such as threshold voltage modulation, current collapse suppression, and 2DEG concentration enhancement technologies, as well as AlGaN/GaN sensors with very high sensitivity to polar liquids. To clarify the 2DEG microscopic origin, we studied the effects of gas molecules on AlGaN/GaN surfaces through various experiments and first-principles calculations. The results indicated that the adsorption of gas molecules on the AlGaN/GaN surface is an important phenomenon, clarifying the microscopic origin of the 2DEG. This study elucidates the properties of AlGaN/GaN heterojunctions and promotes the development of new fabrication technologies for AlGaN/GaN devices

Proneural and mesenchymal glioma stem cells display major differences in splicing and lncRNA profiles

Therapy resistance and recurrence in high-grade gliomas are driven by their populations of glioma stem cells (GSCs). Thus, detailed molecular characterization of GSCs is needed to develop more effective therapies. We conducted a study to identify differences in the splicing profile and expression of long non-coding RNAs in proneural and mesenchymal GSC cell lines. Genes related to cell cycle, DNA repair, cilium assembly, and splicing showed the most differences between GSC subgroups. We also identified genes distinctly associated with survival among patients of mesenchymal or proneural subgroups. We determined that multiple long non-coding RNAs with increased expression in mesenchymal GSCs are associated with poor survival of glioblastoma patients. In summary, our study established critical differences between proneural and mesenchymal GSCs in splicing profiles and expression of long non-coding RNA. These splicing isoforms and lncRNA signatures may contribute to the uniqueness of GSC subgroups, thus contributing to cancer phenotypes and explaining differences in therapeutic responses.This study was supported by a grant from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil to PAFG and LOFP and by NIH 7R21CA175875-03. This study was partially supported by grants from Serrapilheira foundation and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; 2018/15579-8) to PAFG. GDAG and BRC were supported by fellowships from FAPESP (2017/19541-2) and (2013/25483-4 and 2013/07159-5), respectively. PRA was supported by CPRIT Training Grant - RP14010