233 research outputs found

    A Grounded Theory Approach to the Study of Open Source Software Development Process

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    Open source software is becoming increasingly important and popular. However, the process of open source software development (OSSD) is far less understood when compared to the prevalent final products of the process. The unique characteristics of OSSD imply that the traditional software development process can not be readily applied to OSSD. In addition, research on OSSD process is scanty at best and there are no comprehensive propositions on standardizing OSSD processes. In this research, we propose an in-depth grounded theory approach to understand open source software development process. We analyze the archives of an OSSD project’s mailing lists and we will also conduct online interviews with OSSD practitioners. The preliminary finding of this research is a Phase-Role-Skill-Responsibility (PRSR) OSSD process model. The proposed model consists of three OSSD process phases -- Launch Stage, Before the First Release, and Between Releases. These three phases address the characteristics of the OSSD process as well as the identified factors that influence the OSSD process. In the PRSR model, different roles/actors are required to have different skills and responsibilities corresponding to each of the three OSSD phases. This research contributes to the software development literature as well as to open source practice with the development of a comprehensive software development process model that depicts OSSD process

    A Semiotics View of Modeling Method Complexity - The Case of UML

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    Unified Modeling Language (UML) is the standard modeling language for object oriented system development. Despite its status as a standard, UML’s formal specification is fuzzy and its theoretical foundation is weak. Semiotics, the study of signs, provides us good theoretical foundation for UML research as UML graphical notations are some kinds of signs. In this research, we use semiotics to study the graphical notations in UML. We hypothesized that using iconic signs as UML graphical notations leads to more accurate representation and arouses fewer connotations than using symbolic signs. Since symbolic signs involve more learning efforts, we assume that expert users of UML will perform better with symbolic signs than novice users. We created an open-ended survey to test these hypotheses. The qualitative analysis of the survey process can help us gain in-depth understanding of the complexity of modeling language graphical notations. In addition, the introduction of semiotics in this research helps build a solid theoretical foundation of IS modeling method research

    The Complexity of Unified Modeling Language: A GOMS Analysis

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    Although the unified modeling language (UML) is becoming the de facto industry standard for object-oriented system development, it is not short of critics. Both researchers and practitioners have agreed that much work needs to be done to enhance UML. This research evaluates the nine UML diagrams using GOMS. GOMS, beginning as a theoretical model in HCI, describes the procedures required for accomplishing a general set of tasks by decomposing the tasks into four elements: Goals, Operators, Methods, and Selection rules. We use a special type of GOMS, NGOMSL, for analyzing UML. This research attempts to find ways to enhance the ease of use of UML diagrams and contribute to the evolution of UML

    Transcriptome analysis of the gene expression of M. iliotibialis lateralis affected by dietary methionine restriction

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    Introduction: Methionine (Met) is an important amino acid related to the development of skeletal muscle. This study investigated the effects of dietary Met restriction on the gene expression of M. iliotibialis lateralis.Methods: A total of 84 day-old broiler chicks (Zhuanghe Dagu) with a similar initial body weight (207.62 ± 8.54 g) were used in this study. All birds were divided into two groups (CON; L-Met) based on the initial body weight. Each group consisted of six replicates with seven birds per replicate. The experimental period was 63 days (phase 1, days 1-21; phase 2, days 22-63). According to the nutritional requirements of Zhuanghe Dagu chickens, we provided a basal diet (0.39% Met levels during phase 1 and 0.35% Met levels during phase 2, as-fed basis) to the birds in the CON group, while we provided a Met-restricted diet (0.31% Met levels during phase 1 and 0.28% Met levels during phase 2, as-fed basis) to the birds in the L-Met group. The growth performance of broiler chicks and their M. iliotibialis lateralis development parameters were measured on days 21 and 63.Results and Discussion: In this study, dietary Met restriction did not affect the growth performance of broiler chicks but hindered the development of M. iliotibialis lateralis at both sampling timepoints. On the final day, three birds selected from each group (three from CON and three from L-Met) were used to obtain M. iliotibialis lateralis samples from leg muscle for further transcriptome analysis. Transcriptome analysis revealed that dietary Met restriction significantly upregulated 247 differentially expressed genes (DEGs) and downregulated 173 DEGs. Additionally, DEGs were mainly enriched in 10 pathways. Among DEGs, we observed that dietary Met restriction downregulated the expression of CSRP3, KY, FHL1, LMCD1, and MYOZ2 in M. iliotibialis lateralis. Therefore, we considered that dietary Met restriction had negative effects on the development of M. iliotibialis lateralis, and CSRP3, KY, FHL1, LMCD1, and MYOZ2 may serve as potential functional genes involved in this process

    Epidemiological and virological characteristics of pandemic influenza A (H1N1) 2009 in school outbreaks in China

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    Background: During the 2009 pandemic influenza H1N1 (2009) virus (pH1N1) outbreak, school students were at an increased risk of infection by the pH1N1 virus. However, the estimation of the attack rate showed significant variability. Methods: Two school outbreaks were investigated in this study. A questionnaire was designed to collect information by interview. Throat samples were collected from all the subjects in this study 6 times and sero samples 3 times to confirm the infection and to determine viral shedding. Data analysis was performed using the software STATA 9.0. Findings: The attack rate of the pH1N1 outbreak was 58.3% for the primary school, and 52.9% for the middle school. The asymptomatic infection rates of the two schools were 35.8% and 37.6% respectively. Peak virus shedding occurred on the day of ARI symptoms onset, followed by a steady decrease over subsequent days (p = 0.026). No difference was found either in viral shedding or HI titer between the symptomatic and the asymptomatic infectious groups. Conclusions: School children were found to be at a high risk of infection by the novel virus. This may be because of a heightened risk of transmission owing to increased mixing at boarding school, or a lack of immunity owing to socioeconomic status. We conclude that asymptomatically infectious cases may play an important role in transmission of the pH1N1 virus

    Roadmap on semiconductor-cell biointerfaces.

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    This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world

    Association of hepatitis B virus infection status with outcomes of non-small cell lung cancer patients undergoing anti-PD-1/PD-L1 therapy

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    Background: The aim of this study was to evaluate the safety and survival outcomes of anti-programmed cell death (PD)-1/programmed cell death-ligand 1 (PD-L1) monotherapy in patients with advanced nonsmall cell lung cancer (NSCLC) and different hepatitis B virus (HBV) infection status. Methods: Patients with advanced NSCLC and both chronic and/or resolved HBV infection who were treated with anti-PD-(L)1 monotherapy were retrospectively enrolled. The primary endpoint was the safety of PD-1/PD-L1 monotherapy, while the secondary endpoints included the survival outcomes. Results: Of the 62 eligible patients, 10 (16.1%) were hepatitis B surface antigen (HBsAg) positive [chronic hepatitis B (CHB) infection] and 52 (83.9%) were HBsAg negative and HBcAb positive [resolved hepatitis B (RHB) infection]; 42 (67.7%) patients had at least 1 treatment-related adverse event (AE), with 4 patients (6.5%) developing grade 3 AEs and 6 (9.7%) developing hepatic AEs. One CHB patient experienced HBV reactivation during anti-PD-1 immunotherapy due to the interruption of antiviral prophylaxis. The objective response rate and durable clinical benefit (DCB) rate were 17.7% and 29.0%, respectively. Median overall survival (OS) and progression-free survival (PFS) were 23.6 months [95% confidence interval (CI): 14.432.8] and 2.1 months (95% CI: 1.2-3.0), respectively. The DCB rate was significantly higher in the CHB group than in the RHB group (60% vs. 23.1%; P=0.048). Patients with CHB experienced a longer PFS (8.3 vs. 2.0 months; P=0.103) and OS (35.0 vs. 18.2 months, P=0.119) than did RHB patients. Conclusions: Anti-PD-(L)1 monotherapy was safe and effective in patients with NSCLC and HBV infection. This population should not be excluded from receiving immunotherapy in routine clinical practice or within clinical trials if HBV biomarkers are monitored and antiviral prophylaxis is properly used

    Co<sub>3</sub>Mo<sub>3</sub>N—An efficient multifunctional electrocatalyst

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    Efficient catalysts are required for both oxidative and reductive reactions of hydrogen and oxygen in sustainable energy conversion devices. However, current precious metal-based electrocatalysts do not perform well across the full range of reactions and reported multifunctional catalysts are all complex hybrids. Here, we show that single-phase porous Co(3)Mo(3)N prepared via a facile method is an efficient and reliable electrocatalyst for three essential energy conversion reactions; oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) in alkaline solutions. Co(3)Mo(3)N presents outstanding OER, ORR, and HER activity with high durability, comparable with the commercial catalysts RuO(2) for OER and Pt/C for ORR and HER. In practical demonstrations, Co(3)Mo(3)N gives high specific capacity (850 mA h g(Zn)(−1) at 10 mA cm(−2)) as the cathode in a zinc-air battery, and a low potential (1.63 V at 10 mA cm(−2)) used in a water-splitting electrolyzer. Availability of Co and Mo d-states appear to result in high ORR and HER performance, while the OER properties result from a cobalt oxide-rich activation surface layer. Our findings will inspire further development of bimetallic nitrides as cost-effective and versatile multifunctional catalysts that will enable scalable usage of electrochemical energy devices
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