Ultimate Strength Characteristics of Switchgrass Stem Cross-Sections at Representative Processing Conditions

Switchgrass stem cross-sections were failed with ultimate shearing stresses that were one-fifth the magnitude of ultimate tensile stresses, thereby indicating that shear- dominant size reduction equipment would be much more efficient than tensile-dominant size reduction processes. Individual tensile strength measures ranged from 28 to 205 MPa and shear strength ranged from 6.9 to 38 MPa for all test conditions. Tests were conducted throughout a cropping season to obtain a range of switchgrass properties representative of those available for typical biomass processing. Representative processing conditions were organized and statistically tested based on switchgrass variety, maturity, elapsed time after harvest, moisture content, stem diameter, and stem thickness. Significant differences were detected among tensile and among shear strength measures for switchgrass lowland varieties of Alamo and Kanlow. Mean tensile strength increased as mean moisture content decreased from about 60 to 10 % wet basis, and tensile strength increased two-fold with a corresponding increase in elapsed time after harvest ranging from 2 to 386 h. This indicated that tensile-dominant size reduction should be conducted early in the harvest process and at a high moisture content to minimize energy consumption for grinding. Mean shear strength was relatively unaffected by moisture content and elapsed time after harvest. Data analyses also provided indicators of consistency and validity of the test method. For example, desiccation of stem samples for tensile and shear tests occurred at the same statistical rate even though a slightly offset testing schedule was a necessary strategy to accommodate coincident measures. Mean stem moisture was statistically consistent throughout the study. Diameter and thickness of stems slightly decreased as time after harvest increased, possibly due to a stem shrinkage phenomena associated with desiccation. Switchgrass stem diameter and thickness were directly proportional to moisture content, with Pearson correlation coefficients of 0.24 (P = 0.0) and 0.30 (P = 0.0), respectively. Test cross section widths of samples were consistent among varieties and maturity class, thereby indicating uniform sample preparation throughout the experiment

Business Values of Community Source: The Construct and a Research Framework

Community source development has emerged as a new way of developing enterprise applications, leading to a unique type of open source development involving collaborative investment decisions by multiple institutional partners. But research on the business value of community source is lacking. In this paper, we classify the adopters of community source into four types according to the degree of involvement in community source: founding partners, development partners, deployment members and non members. We further identify the dimensions of business values of community source for each type of adopters. A research framework is developed to explicate the varying levels of institutional benefits by adopting community source for the four types of adopters, and several propositions are also generated. Our framework demonstrates the relationship between the business value dimensions and different degree of involvement in community source. This study should help institutions to make more informed decisions in IT investment

Inflating bacterial cells by increased protein synthesis.

Understanding how the homeostasis of cellular size and composition is accomplished by different organisms is an outstanding challenge in biology. For exponentially growing Escherichia coli cells, it is long known that the size of cells exhibits a strong positive relation with their growth rates in different nutrient conditions. Here, we characterized cell sizes in a set of orthogonal growth limitations. We report that cell size and mass exhibit positive or negative dependences with growth rate depending on the growth limitation applied. In particular, synthesizing large amounts of "useless" proteins led to an inversion of the canonical, positive relation, with slow growing cells enlarged 7- to 8-fold compared to cells growing at similar rates under nutrient limitation. Strikingly, this increase in cell size was accompanied by a 3- to 4-fold increase in cellular DNA content at slow growth, reaching up to an amount equivalent to ~8 chromosomes per cell. Despite drastic changes in cell mass and macromolecular composition, cellular dry mass density remained constant. Our findings reveal an important role of protein synthesis in cell division control

On Assessment of Project Success in Community Source Development

Community source has emerged as a unique way of developing enterprise software systems that require significant investments from partnering organizations. This new way of software engineering raises new questions on the issue of successful project development, which are significantly different from previous studies. The objective of this study is to develop a model for assessing project success under community source development. In this paper, we present a case of community source project called Kuali to understand the research questions, propose a unique research model for a survey study, outline the related hypotheses, and discuss our data collection methodology. We believe that our study is unique and will have significant impact on the successful introduction of the community source approach to enterprise application development

A Cooporative Analysis Framework for Investment Decisions in Community Source Partnerships

Community source development has emerged as a new way of developing enterprise applications, leading to a unique type of open source practice involving partnership and investments from multiple organizations. A critical research question in community source development is concerned with the rationale and the economic incentives behind investments from partnering organizations. In this paper, we examine a real world case, the Kuali community source project, and propose a cooperative decision framework to analyze investment decisions made by various types of organizations involved in community source. We analyze joint investment decisions and adopt the Black-Scholes model to capture individual organizations’ decision-making in risky environments. Our analytical results are able to explain an array of observed investment behavior from community-source partners and reveal useful insights to help these organizations make decisions. Our results also facilitate a general understanding of the emerging community source development landscape

Analysis of the Market Structure and Shift-effects in North China Ports

ABSTRACTThis study divides the foreign trade traffic of major North China ports into export and import cargoes for the past 10 years. Then, the concentration ratios and shift effects are analyzed in order to determine their relationships with the ports’ competition structures. Here, the HHI, a BCG matrix analysis, and the shift effects are applied as study methods. The results indicate that the oligopoly market structure of major North China ports has gradually decreased. Furthermore, the concentration ratios of import cargoes are higher than those of export cargoes, indicating that competition to attract import cargoes will intensify. Therefore, the effects of the South Korea–China FTA mean that the competition structures of these ports with regard to export and import cargoes are highly likely to be differentiated further over time

Time-slot based architecture for power beam-assisted relay techniques in CR-WSNs with transceiver hardware inadequacies

Over the past two decades, numerous research projects have concentrated on cognitive radio wireless sensor networks (CR-WSNs) and their benefits. To tackle the problem of energy and spectrum shortfall in CR-WSNs, this research proposes an underpinning decode-&-forward (DF) relaying technique. Using the suggested time-slot architecture (TSA), this technique harvests energy from a multi-antenna power beam (PB) and delivers source information to the target utilizing energy-constrained secondary source and relay nodes. The study considers three proposed relay selection schemes: enhanced hybrid partial relay selection (E-HPRS), conventional opportunistic relay selection (C-ORS), and leading opportunistic relay selection (L-ORS). We present evidence for the sustainability of the suggested methods by examining the outage probability (OP) and throughput (TPT) under multiple primary users (PUs). These systems leverage time switching (TS) receiver design to increase end-to-end performance while taking into account the maximum interference constraint and transceiver hardware inadequacies. In order to assess the efficacy of the proposed methods, we derive the exact and asymptotic closed-form equations for OP and TPT & develop an understanding to learn how they affect the overall performance all across the Rayleigh fading channel. The results show that OP of the L-ORS protocol is 16% better than C-ORS and 75% better than E-HPRS in terms of transmitting SNR. The OP of L-ORS is 30% better than C-ORS and 55% better than E-HPRS in terms of hardware inadequacies at the destination. The L-ORS technique outperforms C-ORS and E-HPRS in terms of TPT by 4% and 11%, respectively

Central Aortic Systolic Blood Pressure Exhibits Advantages Over Brachial Blood Pressure Measurements in Chronic Kidney Disease Risk Prediction in Women

Background/Aims: To investigate whether the invasively obtained central aortic systolic blood pressure (CSBP) predicts chronic kidney disease (CKD) better than brachial systolic blood pressure (SBP), brachial diastolic blood pressure (DBP) and brachial pulse pressure (PP) in the middle-aged Chinese population. Methods: A cross-sectional study was carried out across China in 2009-2010 among the subjects aged 35-64 years. CSBP was measured non-invasively by radial artery applanation tonometry B-pro (A-PULSE CASP and corresponding software). CSBP, SBP, DBP and PP were standardized with Z-score and the odds ratios were calculated with multivariable logistic regression model. Results: Data of 10197 participants were analyzed. The multivariable logistic regression after adjusting for possible confounders showed that a 1-standard deviation increment in each blood pressure measurement was associated with greater risk of CKD in both men and women (P < 0.05). The association of CSBP with CKD was stronger than SBP, DBP and PP in women, while in men the association of CSBP with CKD was stronger only than PP. With CSBP and SBP entering into the multivariable logistic regression models jointly, the odds ratio (95% confidence interval) for CSBP and SBP was 1.57 (1.39-1.79) and 1.22 (1.07-1.38) in women and 1.20 (1.03-1.39) and 1.48 (1.28-1.72) in men, respectively. With CSBP and DBP entering into the multivariable logistic regression models jointly, the odds ratio (95% confidence interval) for CSBP and DBP was 1.68 (1.52-1.84) and 1.15 (1.04-1.27) in women and 1.30 (1.15-1.46) and 1.45 (1.29-1.63) in men, respectively. With CSBP and PP entering into the multivariable logistic regression models jointly, the odds ratio (95% confidence interval) for CSBP and PP was 1.75 (1.58-1.94) and 1.06 (0.96-1.17) in women and 1.58 (1.41-1.77) and 1.04 (0.93-1.17) in men, respectively. Conclusion: CSBP and brachial blood pressure measurements are all predictors of CKD, however the non-invasively obtained CSBP may offer advantages over brachial blood pressure measurements in CKD risk prediction in women

Functional metagenomic and metabolomics analysis of gut dysbiosis induced by hyperoxia

BackgroundInhaled oxygen is the first-line therapeutic approach for maintaining tissue oxygenation in critically ill patients, but usually exposes patients to damaging hyperoxia. Hyperoxia adversely increases the oxygen tension in the gut lumen which harbors the trillions of microorganisms playing an important role in host metabolism and immunity. Nevertheless, the effects of hyperoxia on gut microbiome and metabolome remain unclear, and metagenomic and metabolomics analysis were performed in this mouse study.MethodsC57BL/6 mice were randomly divided into a control (CON) group exposed to room air with fractional inspired oxygen (FiO2) of 21% and a hyperoxia (OXY) group exposed to FiO2 of 80% for 7 days, respectively. Fecal pellets were collected on day 7 and subjected to metagenomic sequencing. Another experiment with the same design was performed to explore the impact of hyperoxia on gut and serum metabolome. Fecal pellets and blood were collected and high-performance liquid chromatography with mass spectrometric analysis was carried out.ResultsAt the phylum level, hyperoxia increased the ratio of Firmicutes/Bacteroidetes (p = 0.049). At the species level, hyperoxia reduced the abundance of Muribaculaceae bacterium Isolate-037 (p = 0.007), Isolate-114 (p = 0.010), and Isolate-043 (p = 0.011) etc. Linear discriminant analysis effect size (LEfSe) revealed that Muribaculaceae and Muribaculaceae bacterium Isolate-037, both belonging to Bacteroidetes, were the marker microbes of the CON group, while Firmicutes was the marker microbes of the OXY group. Metagenomic analysis using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Carbohydrate-Active enZYmes (CAZy) revealed that hyperoxia provoked disturbances in carbohydrate and lipid metabolism. Fecal metabolomics analysis showed hyperoxia reduced 11-dehydro Thromboxane B2-d4 biosynthesis (p = 1.10 × 10−11). Hyperoxia blunted fecal linoleic acid metabolism (p = 0.008) and alpha-linolenic acid metabolism (p = 0.014). We showed that 1-docosanoyl-glycer-3-phosphate (p = 1.58 × 10−10) was the most significant differential serum metabolite inhibited by hyperoxia. In addition, hyperoxia suppressed serum hypoxia-inducible factor-1 (HIF-1, p = 0.007) and glucagon signaling pathways (p = 0.007).ConclusionHyperoxia leads to gut dysbiosis by eliminating beneficial and oxygen strictly intolerant Muribaculaceae with genomic dysfunction of carbohydrate and lipid metabolism. In addition, hyperoxia suppresses unsaturated fatty acid metabolism in the gut and inhibits the HIF-1 and glucagon signaling pathways in the serum