3,386 research outputs found

    ANÃLISIS DE FACTIBILIDAD PARA LA INTRODUCCIÓN DEL BIODIESEL EN ECUADOR

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    Increases in petroleum prices have affected the prices of its derived products. In addition, the interest in issues related to the environment and energy security at world-wide level has been increased. All of these factors have contributed to the development of alternative fuel such as the ethanol, biodiesel and natural gas. This study analyzes the main agricultural products used to produce biodiesel, their production costs and the utilization of those inputs in other industries. This study will also include a brief summary of different legislations in those countries under analysis. On the other hand, we will find break-even points and apply a sensibility analysis associated with distinct scenarios in terms of input-output prices.Biofuels, biodiesel, feasibility, legislations, break-even points., Agribusiness,

    Size-Controlled Water-Soluble Ag Nanoparticles

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    Ag nanoparticles of two different sizes (1 and 4 nm) were prepared within an apoferritin cavity by using an Ag+-loaded apoferritin as a nanoconfined environment for their construction. The initial amount of Ag' ions injected in the apoferritin cavity dictates the size of the final Ag particles. The protein shell prevents bulk aggregation of the metal particles, which renders them water soluble and extremely stable

    Pion form factor in the Kroll-Lee-Zumino model

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    The renormalizable Abelian quantum field theory model of Kroll, Lee, and Zumino is used to compute the one-loop vertex corrections to the tree-level, Vector Meson Dominance (VMD) pion form factor. These corrections, together with the known one-loop vacuum polarization contribution, lead to a substantial improvement over VMD. The resulting pion form factor in the space-like region is in excellent agreement with data in the whole range of accessible momentum transfers. The time-like form factor, known to reproduce the Gounaris-Sakurai formula at and near the rho-meson peak, is unaffected by the vertex correction at order O\cal{O}(g_\rpp^2).Comment: Revised version corrects a misprint in Eq.(1

    Differences in Prenatal Tobacco Exposure Patterns among 13 Race/Ethnic Groups in California.

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    Prenatal tobacco exposure is a significant, preventable cause of childhood morbidity, yet little is known about exposure risks for many race/ethnic subpopulations. We studied active smoking and environmental tobacco smoke (ETS) exposure in a population-based cohort of 13 racially/ethnically diverse pregnant women: white, African American, Hispanic, Native American, including nine Asian/Pacific Islander subgroups: Chinese, Japanese, Korean, Filipino, Cambodian, Vietnamese, Laotian, Samoan, and Asian Indians (N = 3329). Using the major nicotine metabolite, cotinine, as an objective biomarker, we analyzed mid-pregnancy serum from prenatal screening banked in 1999⁻2002 from Southern California in an effort to understand differences in tobacco exposure patterns by race/ethnicity, as well as provide a baseline for future work to assess secular changes and longer-term health outcomes. Prevalence of active smoking (based on age- and race-specific cotinine cutpoints) was highest among African American, Samoan, Native Americans and whites (6.8⁻14.1%); and lowest among Filipinos, Chinese, Vietnamese and Asian Indians (0.3⁻1.0%). ETS exposure among non-smokers was highest among African Americans and Samoans, followed by Cambodians, Native Americans, Vietnamese and Koreans, and lowest among Filipinos, Japanese, whites, and Chinese. At least 75% of women had detectable cotinine. While for most groups, levels of active smoking corresponded with levels of ETS, divergent patterns were also found. For example, smoking prevalence among white women was among the highest, but the group's ETS exposure was low among non-smokers; while Vietnamese women were unlikely to be active smokers, they experienced relatively high ETS exposure. Knowledge of race/ethnic differences may be useful in assessing disparities in health outcomes and creating successful tobacco interventions

    Are hierarchically formed embedded star clusters surviving gas expulsion depending on their initial conditions?

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    We investigate the dissolution process of young embedded star clusters with different primordial mass segregation levels using fractal distributions by means of N-body simulations. We combine several star clusters in virial and subvirial global states with Plummer and uniform density profiles to mimic the gas. The star clusters have masses of M-stars = 500 M-circle dot that follow an initial mass function where the stars have maximum distance from the centre of r = 1.5 pc. The clusters are placed in clouds that at the same radius have masses of M-cloud = 2000 M-circle dot, resulting in star formation efficiency of 0.2. We remove the background potential instantaneously at a very early phase, mimicking the most destructive scenario of gas expulsion. The evolution of the fraction of bound stellar mass is followed for a total of 16 Myr for simulations with stellar evolution and without. We compare our results with previous works using equal-mass particles where an analytical physical model was used to estimate the bound mass fraction after gas expulsion. We find that independent of the initial condition, the fraction of bound stellar mass can be well predicted just right after the gas expulsion but tends to be lower at later stages, as these systems evolve due to the stronger two-body interactions resulting from the inclusion of a realistic initial mass function. This discrepancy is independent of the primordial mass segregation level

    The Importance of User in ISD. Do We Really Teach?

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    In 1999, the European Higher Education Area (EHEA) defined the framework that regulates all degrees, including Computer Engineering (CE), within the environment of the European Union. Each country, in turn, regulated each of these studies on the basis of that common framework.In the case of Computer Engineering, among the specific competencies the profession entails, there are concrete references to the effective incorporation of user and need for IT (Information Technology) professionals to learn how to manage and work in multidisciplinary environments. However, these competencies are difficult to teach to students. This paper presents a critical view of the way we are teaching future developers of information systems to work with user. Besides, it analyses the consequences that it may bring to future professionals. The paper also offers some considerations and intends to motivate a future discussion on this topic

    The meaning of postpartum sexual health for women living in Spain : a phenomenological inquiry

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    Sexual health is a multidimensional phenomenon constructed by personal, social, and cultural factors but continues to be studied with a biomedical approach. During the postpartum period, a woman transitions to mother, as well as partner-to-parent and couple-to-family. There are new realities in life in the postpartum period, including household changes and new responsibilities that can impact the quality of sexual health. This phenomenon is understudied especially in the context of Spain. The purpose of this study was to describe the lived experience of postpartum sexual health among primiparous women giving birth in Catalonia (Spain). This was a phenomenological study with a purposive sample of primiparous women. Data was collected through semi-structured interviews until saturation. Analysis followed Colaizzi's seven-step process with an eighth translation step added to limit cross-cultural threats to validity. Also, the four dimensions of trustworthiness were established through strategies and techniques during data collection and analysis. Ten women were interviewed from which five themes emerged, including: Not feeling ready, inhibiting factors, new reality at home, socio-cultural factors, and the clinician within the health system. Returning to sexual health led women to engage in experiential learning through trial and error. Most participants reported reduced libido, experienced altered body image, and recounted resumption of sexual activity before feeling ready. A common finding was fatigue and feeling overloaded by the demands of the newborn. Partner support was described as essential to returning to a meaningful relationship. Discussions about postpartum sexual health with clinicians were described as taboo, and largely absent from the care model. Evidence-based practices should incorporate the best evidence from research, consider the postpartum sexual health experiences and preferences of the woman, and use clinician expertise in discussions that include the topic of postpartum sexual health to make decisions. As such, human caring practices should be incorporated into clinical guidelines to recognize the preferences of women. Clinicians need to be authentically present, engage in active communication, and individualize their care. More qualitative studies are needed to understand postpartum sexual health in different contexts, cultures, and countries and to identify similarities and differences through meta-synthesis

    Non-Alcoholic Fatty Liver Disease in Patients with Polycystic Ovary Syndrome : A Systematic Review, Meta-Analysis, and Meta-Regression

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    Background: The metabolic effects of polycystic ovary syndrome (PCOS) may increase the risk of non-alcoholic fatty liver disease (NAFLD). However, the burden of NAFLD in PCOS has not been unequivocally defined. This systematic review (SR), meta-analysis (MA) assessed NAFLD's prevalence, and risk factors in patients with PCOS. Methods: A literature search was performed in MEDLINE, Scopus, and Scielo. First, we performed a MA of proportions to estimate the prevalence of NAFLD in PCOS. Second, we performed meta-analyses of precalculated adjusted odds ratios to examine NAFLD risk factors. Finally, we performed a meta-regression to model how the estimated prevalence changed with changes in prespecified variables. Results: We identified 817 articles from the database searches. Thirty-six were included. MA of proportions found a pooled NAFLD prevalence of 43% (95% CI, 35-52%) with high heterogeneity (I 2 = 97.2%). BMI, waist circumference, ALT values, HOMA-IR values, free androgen index levels, hyperandrogenism, and triglycerides were associated with significantly higher risk-adjusted odds of NAFLD among patients with PCOS. Meta-regression showed that rises in NAFLD prevalence were mediated through increases in metabolic syndrome prevalence and higher levels of HOMA-IR, free androgen index, and total testosterone. Conclusion: The prevalence of NAFLD (43%) among PCOS patients is high despite their average young age, with several metabolic and PCOS-specific factors influencing its occurrence. Screening programs may aid in detecting metabolic-associated fatty liver disease and prevent its consequences. Further work is required to establish the burden of liver-related outcomes once NAFLD has progressed in the PCOS population

    Safety and efficacy of asciminib treatment in chronic myeloid leukemia patients in real-life clinical practice

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    Chronic myeloid leukemia; Asciminib; TreatmentLeucemia mieloide crónica; Asciminib; TratamientoLeucèmia mieloide crònica; Asciminib; TractamentDespite the excellent overall survival (OS) of chronic myeloid leukemia (CML) patients, a significant proportion will fail currently available tyrosine-kinase inhibitors (TKIs) due to resistance or intolerance. Intolerant patients are usually managed successfully with alternative second-generation tyrosine-kinase inhibitors (2GTKIs). However, more than half of the patients will eventually discontinue second-line treatment due to loss of response or toxicity. Ponatinib is an effective drug in the setting of resistance to 2GTKIs, however with life-threatening side effects and varying responses. Asciminib is a first-in-class STAMP (Specifically Targeting the ABL Myristoyl Pocket) inhibitor that potently and specifically inhibits BCR-ABL1 via binding to a pocket distinct from the ATP binding site of the kinase. Asciminib has the potential to overcome resistance to prior TKIs, and also offers the possibility of dual inhibition of BCR-ABL1 in combination with ATP-binding TKIs. Asciminib has been evaluated in a phase I study in patients with Ph-positive leukemia failing prior TKIs, with promising results. Our aim is to share the first data on the use of asciminib in CML patients in clinical practice, allowed by Novartis under a managed-access program (MAP)
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