Mass Scales and Stability of the Proton in [SU(6)]3×^{3}\timesZ3_{3}

We proof that the proton is stable in the left-right symmetric gauge model [SU(6)]$^3\times$Z$_3$, which unifies nongravitational forces with flavors, broken spontaneously by a minimal set of Higgs Fields and Vacuum Expectation Values down to SU(3)$_{c}\otimes$U(1)$_{EM}$\hspace{0.2cm} . We also compute the evolution of the gauge coupling constants and show how agreement with precision data can be obtained.Comment: 14 page

Biofuels and Rural Economic Development in Latin America and the Caribbean

Biofuel expansion is seen as a way to reduce dependence on fossil fuels, as an alternative energy source for transportation and other uses, as a way to reduce Green House Gases, and as way to revitalize the agricultural sector. Very little discussions have been focused on Latin America, except for Brazil. Potential negative impacts re-enforce the need of performing more in depth analysis of the potential impact of biofuels expansion in Latin America and the Caribbean (LAC). Paper estimates biofuels production potential based on current production situation and develops a forward-looking analysis of the long-term impact of biofuels expansion in Latin America and its effects on prices, trade, food security, malnutrition and other indicators using the IMPACT-WATER model developed by IFPRI. The analysis conducted for this paper of potential crops in the region show that from a technical and productivity standpoint in which to base biofuels expansion continues to be sugarcane and palm oil trees. Most countries in Latin America will not have a production constraint in terms of meeting existing and projected mandatory blends requirements. However, if the goal is to obtain energy independence, this result only holds for a few countries, with obvious food security implications as countries dedicate higher shares of their agricultural land to biofuels expansion. Our analysis, and those made in other studies, show that biofuels expansion is not likely to have a binding land production constraint in Latin America, with a few exceptions. The forward-looking estimations from the IMPACT-WATER model show that Brazil will continue to be the major player in the ethanol market. Brazil will expand its ethanol exports to meet growing demand in other countries including some in Latin America. Other countries such as Argentina and Colombia will likely continue their biofuels expansion plans, although our estimate show that they will not likely meet their demand based on current production potential. The IMPACT-WATER simulations also show that biofuels impacts on food security and malnutrition will likely happen in those countries where the feedstock used for biofuels production is a critical component of a major share of the population, other things equal. An example of this potential is Mexico and most of the Central America region, where a high proportion of the diet is composed of maize. The extent to which biofuels efforts can contribute towards addressing or affecting all broader contextual issues depend on a series of strategic determinants of impact success, ranging from the characteristics of installed capacity and industrial organization and coordination to whether any nascent market for biofuels will be economically sustainable and financially viable without continuous government support or interventions.Community/Rural/Urban Development, Resource /Energy Economics and Policy,

Longitudinal assessment of high blood pressure in children with nonalcoholic fatty liver disease.

ObjectiveNonalcoholic fatty liver disease (NAFLD) affects 9.6% of children and may put these children at elevated risk of high blood pressure and subsequent cardiovascular morbidity and mortality. Therefore, we sought to determine the prevalence of and risk factors for high blood pressure in children with NAFLD.MethodsCohort study performed by the NIDDK NASH Clinical Research Network. There were 484 children with NAFLD ages 2 to 17 at enrollment; 382 children were assessed both at enrollment and 48 weeks afterwards. The main outcomes were high blood pressure at baseline and persistent high blood pressure at both baseline and 48 weeks.ResultsPrevalence of high blood pressure at baseline was 35.8% and prevalence of persistent high blood pressure was 21.4%. Children with high blood pressure were significantly more likely to have worse steatosis than children without high blood pressure (mild 19.8% vs. 34.2%, moderate 35.0% vs. 30.7%, severe 45.2% vs. 35.1%; P = 0.003). Higher body mass index, low-density lipoprotein, and uric acid were independent risk factors for high blood pressure (Odds Ratios: 1.10 per kg/m2, 1.09 per 10 mg/dL, 1.25 per mg/dL, respectively). Compared to boys, girls with NAFLD were significantly more likely to have persistent high blood pressure (28.4% vs.18.9%; P = 0.05).ConclusionsIn conclusion, NAFLD is a common clinical problem that places children at substantial risk for high blood pressure, which may often go undiagnosed. Thus blood pressure evaluation, control, and monitoring should be an integral component of the clinical management of children with NAFLD

Momento Económico (38)

Temas de hoy. 2/ De la ganaderización de la agricultura a la desganaderización actual. Retos y perspectivas Rosario Pérez Espejo. 3/ El mejoramiento en el transporte colectivo. una necesidad insoslayable Bernardo Navarro Benitez. 8/ La reconversión industrial también afecta al sector educativo Leticia Campos, 10/ México y el marco internacional de la inflación Mario J. Zepeda M. 12/ El petróleo y el conflicto del Medio Oriente Arturo Bonilla. 13

Policy recommendations from the 13th ICABR conference on the emerging bioeconomy

The International Consortium on Agricultural Biotechnology Research held its 13th annual conference in Ravello, Italy in June 2009. The theme of the conference was the bioeconomy,and this topic was addressed through research presentations from academia, government, and industry. Numerous presentations from developing countries highlighted the benefits of agricultural biotechnology in these nations. The broad range of presentations provided a wealth of insights, resulting in three policy recommendations regarding future funding, international regulation, and technology transfer.global food crisis, biofuels, food safety, innovation

Fourier Method for Approximating Eigenvalues of Indefinite Stekloff Operator

We introduce an efficient method for computing the Stekloff eigenvalues associated with the Helmholtz equation. In general, this eigenvalue problem requires solving the Helmholtz equation with Dirichlet and/or Neumann boundary condition repeatedly. We propose solving the related constant coefficient Helmholtz equation with Fast Fourier Transform (FFT) based on carefully designed extensions and restrictions of the equation. The proposed Fourier method, combined with proper eigensolver, results in an efficient and clear approach for computing the Stekloff eigenvalues.Comment: 12 pages, 4 figure

Acclimatization to chronic intermittent hypoxia in mine workers: a challenge to mountain medicine in Chile

In the past two decades, Chile has developed intense mining activity in the Andes mountain range, whose altitude is over 4,000 meters above sea level. It is estimated that a workforce population of over 55,000 is exposed to high altitude hypobaric hypoxia. The miners work under shift systems which vary from 4 to 20 days at the worksite followed by rest days at sea level, in a cycle repeated for several years. This Chronic Intermittent Hypoxia (CIH) constitutes an unusual condition for workers involving a series of changes at the physiological, cellular and molecular levels attempting to compensate for the decrease in the environmental partial pressure of oxygen (PO2). The mine worker must become acclimatized to CIH, and consequently undergoes an acute acclimatization process when he reaches the worksite and an acute reverse process when he reaches sea level. We have observed that after a period of 3 to 8 years of CIH exposure workers acclimatize well, and evidence from our studies and those of others indicates that CIH induces acute and chronic multisystem adjustments which are effective in offsetting the reduced availability of oxygen at high altitudes. The aims of this review are to summarize findings of the physiological responses to CIH exposure, highlighting outstanding issues in the field

Vitreous Bands Identified by Handheld Spectral-Domain Optical Coherence Tomography Among Premature Infants

Importance: Handheld spectral-domain optical coherence tomography (SD-OCT) can provide insights into the complex interactions occurring at the vitreoretinal interface in retinopathy of prematurity (ROP) to enhance our understanding of ROP pathology. Objective: To characterize vitreous bands in premature infants with use of handheld SD-OCT. Design, Setting, and Participants: Prospective cohort study conducted from July 7, 2015, to February 28, 2017, at 2 university-based neonatal intensive care units. Seventy-three premature infants who required routine ROP screening examination were recruited. Informed consent was obtained from all legal guardians. Trained graders who were masked to the clinical assessment analyzed each SD-OCT scan of the right eye for vitreoretinal findings. A third trained grader mediated disagreements. Main Outcomes and Measures: Associations between the presence of vitreous bands in premature infants with ROP diagnoses and the presence of other vitreoretinal SD-OCT findings were investigated. Results: Of the 73 infants recruited, 6 infants\u27 parents withdrew their children from the study, and 2 infants were too hemodynamically unstable for imaging, leaving a total of 65 participants. Of these, 32 (49%) were female, 36 (55%) were white, 10 (15%) were Hispanic, 3 (5%) were Native American, 4 (6%) were African American, 4 (7%) were Asian/Pacific Islander, and 8 (12%) were other. The mean (SD) gestational age was 28 (2.7) weeks, the mean (SD) birth weight was 997 g (286 g), and the mean (SD) postmenstrual age at imaging was 34 (3) weeks (mean [SD] total of 3 [2] imaging sessions). Comparing the 24 infants (37%) who had a right eye vitreous band at any time with the 41 (63%) who did not, no difference in mean birth weight, gestational age, postmenstrual age at imaging, sex, or race/ethnicity was identified. No associations with ROP stage (eg, in 6 [25%] infants with vitreous bands vs 4 [9.8%] in those without; P = .23), presence of plus disease (2 [8%] vs 2 [5%]; P = .84), or type 1 ROP (3 [12%] vs 3 [7%]; P = .66) were identified. Vitreous bands were associated with epiretinal membrane detected on SD-OCT (P = .001) with an odds ratio of 9.4 (95% CI, 2.8-31.3) in 15 [62%] infants with vitreous bands vs 6 [15%] in those without. Vitreous bands were also associated with cystoid macular edema (in 15 [62%] infants with vitreous bands vs 1 [27%] in those without; P = .005) with an odds ratio of 4.5 (95% CI, 1.5-13.3). Conclusions and Relevance: In this study, the development of vitreous bands was associated with both cystoid macular edema and epiretinal membrane. These findings suggest a tractional pathogenesis to these entities among premature infants. This study did not find a direct association between vitreous bands and severe ROP. Additional study is needed to determine whether vitreous bands represent subclinical hyaloidal organization leading to retinal detachment in advanced ROP