Plan nacional para mejorar el manejo del cultivo de arroz en Colombia :proyecto para reducir los costos de producción

Colombia ha sido tal vez el país más beneficiado al aumentar su producción desde cuando se inició la introducción de variedades de alto rendimiento durante los últimos años de la década de los 60. En 1965 su área arrocera fué de 375.000 has, sembradas con un rendimiento de 1.8 Tm/ha resultando con una producción total de 675.000 toneladas. La producción aumentó hasta 753.000 toneladas en 1970 debido principalmente al aumento de rendimiento a 3.2 Tm/ha no obstante que el área sembrada había disminuido a 235.300 hectáreas. En los 5 años de 1970 a 1975 fué una verdadera revolución verde de arroz en Colombia, en la cual la producción fue de 1.622.000 toneladas con un rendimiento promedio de 4.3 Tm/ha, debido principalmente a la introducción y creación de variedades de alto rendimiento denominadas IR-22 y CICA 4Arroz-Oryza sativ

Mechanisms explaining transitions between tonic and phasic firing in neuronal populations as predicted by a low dimensional firing rate model

Several firing patterns experimentally observed in neural populations have been successfully correlated to animal behavior. Population bursting, hereby regarded as a period of high firing rate followed by a period of quiescence, is typically observed in groups of neurons during behavior. Biophysical membrane-potential models of single cell bursting involve at least three equations. Extending such models to study the collective behavior of neural populations involves thousands of equations and can be very expensive computationally. For this reason, low dimensional population models that capture biophysical aspects of networks are needed. \noindent The present paper uses a firing-rate model to study mechanisms that trigger and stop transitions between tonic and phasic population firing. These mechanisms are captured through a two-dimensional system, which can potentially be extended to include interactions between different areas of the nervous system with a small number of equations. The typical behavior of midbrain dopaminergic neurons in the rodent is used as an example to illustrate and interpret our results. \noindent The model presented here can be used as a building block to study interactions between networks of neurons. This theoretical approach may help contextualize and understand the factors involved in regulating burst firing in populations and how it may modulate distinct aspects of behavior.Comment: 25 pages (including references and appendices); 12 figures uploaded as separate file

Maternal super-obesity and perinatal outcomes in Australia: A national population-based cohort study

© 2015 Sullivan et al. Background: Super-obesity is associated with significantly elevated rates of obstetric complications, adverse perinatal outcomes and interventions. The purpose of this study was to determine the prevalence, risk factors, management and perinatal outcomes of super-obese women giving birth in Australia. Methods: A national population-based cohort study. Super-obese pregnant women (body mass index (BMI) >50 kg/m2 or weight >140 kg) who gave birth between January 1 and October 31, 2010 and a comparison cohort were identified using the Australasian Maternity Outcomes Surveillance System (AMOSS). Outcomes included maternal and perinatal morbidity and mortality. Prevalence estimates calculated with 95 % confidence intervals (CIs). Adjusted odds ratios (ORs) were calculated using multivariable logistic regression. Results: 370 super-obese women with a median BMI of 52.8 kg/m2 (range 40.9-79.9 kg/m2) and prevalence of 2.1 per 1 000 women giving birth (95 % CI: 1.96-2.40). Super-obese women were significantly more likely to be public patients (96.2 %), smoke (23.8 %) and be socio-economically disadvantaged (36.2 %). Compared with other women, super-obese women had a significantly higher risk for obstetric (adjusted odds ratio (AOR) 2.42, 95 % CI: 1.77-3.29) and medical (AOR: 2.89, 95 % CI: 2.64-4.11) complications during pregnancy, birth by caesarean section (51.6 %) and admission to special care (HDU/ICU) (6.2 %). The 372 babies born to 365 super-obese women with outcomes known had significantly higher rates of birthweight ≥4500 g (AOR 19.94, 95 % CI: 6.81-58.36), hospital transfer (AOR 3.81, 95 % CI: 1.93-7.55) and admission to Neonatal Intensive Care Unit (NICU) (AOR 1.83, 95 % CI: 1.27-2.65) compared to babies of the comparison group, but not prematurity (10.5 % versus 9.2 %) or perinatal mortality (11.0 (95 % CI: 4.3-28.0) versus 6.6 (95 % CI: 2.6- 16.8) per 1 000 singleton births). Conclusions: Super-obesity in pregnancy in Australia is associated with increased rates of pregnancy and birth complications, and with social disadvantage. There is an urgent need to further address risk factors leading to super-obesity among pregnant women and for maternity services to better address pre-pregnancy and pregnancy care to reduce associated inequalities in perinatal outcomes

Evaluation of NHMRC funded research completed in 1992, 1997 and 2003: gains in knowledge, health and wealth

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Objective: To report on strategies for, and outcomes of, evaluation of knowledge (publications), health and wealth (commercial) gains from medical research funded by the Australian Government through the National Health and Medical Research Council (NHMRC). Design and methods: End-of-grant reports submitted by researchers within 6 months of completion of NHMRC funded project grants which terminated in 2003 were used to capture self-reported publication number, health and wealth gains. Self-reported gains were also examined in retrospective surveys of grants completed in 1992 and 1997 and awards primarily supporting people (“people awards”) held between 1992 and 2002. Results: The response rate for the 1992 sample was too low for meaningful analysis. The mean number of publications per grant in the basic biomedical, clinical and health services research areas was very similar in 1997 and 2003. The publication output for population health was somewhat higher in the 2003 than in the 1997 analysis. For grants completed in 1997, 24% (31/131) affected clinical practice; 14% (18/131) public health practice; 9% (12/131) health policy; and 41% (54/131) had commercial potential with 20% (26/131) resulting in patents. Most respondents (89%) agreed that NHMRC people awards improved their career prospects. Interpretation is limited by the relatively low response rates (50% or less). Conclusions: A mechanism has been developed for ongoing assessment of NHMRC funded research. This process will improve accountability to the community and to government, and refine current funding mechanisms to most efficiently deliver health and economic returns for Australia.Bronwyn A Kingwell, Gary P Anderson, Stephen J Duckett, Elizabeth A Hoole, Lisa R Jackson-Pulver, Levon M Khachigian, Meg E Morris, David M Roder, Jan Rothwell-Short and Andrew J Wilson for the National Health and Medical Research Council Evaluations and Outcomes Working Committe

Eclampsia in Australia and New Zealand: A prospective population-based study

Background: Eclampsia is a serious consequence of pre-eclampsia. There are lim-ited data from Australia and New Zealand (ANZ) on eclampsia.Aim: To determine the incidence, management and perinatal outcomes of women with eclampsia in ANZ.Materials and Methods: A two-year population-based descriptive study, using the Australasian Maternity Outcomes Surveillance System (AMOSS), carried out in 263 sites in Australia, and all 24 New Zealand maternity units, during a staggered implementation over 2010-2011. Eclampsia was defined as one or more seizures during pregnancy or postpartum (up to 14 days) in any woman with clinical evi-dence of pre-eclampsia.Results: Of 136 women with eclampsia, 111 (83%) were in Australia and 25 (17%) in New Zealand. The estimated incidence of eclampsia was 2.2 (95% confidence inter-val (CI) 1.9-2.7) per 10 000 women giving birth. Aboriginal and Torres Strait Islander women were over-represented in Australia (n = 9; 8.1%). Women with antepartum eclampsia (n = 58, 42.6%) were more likely to have a preterm birth (P = 0.04). Sixty-three (47.4%) women had pre-eclampsia diagnosed prior to their first eclamptic seizure of whom 19 (30.2%) received magnesium sulphate prior to the first seizure. Nearly all women (n = 128; 95.5%) received magnesium sulphate post-seizure. No woman received prophylactic aspirin during pregnancy. Five women had a cer-ebrovascular haemorrhage, and there were five known perinatal deaths.Conclusions: Eclampsia is an uncommon consequence of pre-eclampsia in ANZ. There is scope to reduce the incidence of this condition, associated with often cata-strophic morbidity, through the use of low-dose aspirin and magnesium sulphate in women at higher risk.Funding for AMOSS was through the National Health and Medical Research Council (App ID 510298). In NZ, AMOSS is supported and funded by the Perinatal and Maternal Mortality Review Committee

parkin-induced defects in neurophysiology and locomotion are generated by metabolic dysfunction and not oxidative stress

Parkinson's disease (PD) is characterized by movement disorders, including bradykinesia. Analysis of inherited, juvenile PD, identified several genes linked via a common pathway to mitochondrial dysfunction. In this study, we demonstrate that the larva of the Drosophila parkin mutant faithfully models the locomotory and metabolic defects of PD and is an excellent system for investigating their inter-relationship. parkin larvae displayed a marked bradykinesia that was caused by a reduction in both the frequency of peristalsis and speed of muscle contractions. Rescue experiments confirmed that this phenotype was due to a defect in the nervous system and not in the muscle. Furthermore, recordings of motoneuron activity in parkin larvae revealed reduced bursting and a striking reduction in evoked and miniature excitatory junction potentials, suggesting a neuronal deficit. This was supported by our observations in parkin larvae that the resting potential was depolarized, oxygen consumption and ATP concentration were drastically reduced while lactate was increased. These findings suggest that neuronal mitochondrial respiration is severely compromised and there is a compensatory switch to glycolysis for energy production

Evidence that duplications of 22q11.2 protect against schizophrenia.

A number of large, rare copy number variants (CNVs) are deleterious for neurodevelopmental disorders, but large, rare, protective CNVs have not been reported for such phenotypes. Here we show in a CNV analysis of 47 005 individuals, the largest CNV analysis of schizophrenia to date, that large duplications (1.5-3.0 Mb) at 22q11.2--the reciprocal of the well-known, risk-inducing deletion of this locus--are substantially less common in schizophrenia cases than in the general population (0.014% vs 0.085%, OR=0.17, P=0.00086). 22q11.2 duplications represent the first putative protective mutation for schizophrenia

Protein kinase A-mediated CREB phosphorylation is an oxidant-induced survival pathway in alveolar type II cells

Oxidant stress plays a role in the pathogenesis of pulmonary diseases, including fibrotic lung disease and cancer. We previously found that hydrogen peroxide (H2O2) initiates an increase in Ca2+/cAMP-response element binding protein (CREB) phosphorylation in C10 alveolar type II cells that requires activation of extracellular regulated kinases 1/2 (ERK1/2). Here, we investigated the role of crosstalk between protein kinase A (PKA) and epidermal growth factor receptor (EGFR) in oxidant-induced signaling to ERK1/2 and CREB in C10 cells. Application of H2O2 increased nuclear accumulation of PKA, and inhibition of PKA with H89 reduced oxidant-mediated phosphorylation of both CREB and ERK1/2. Single cell measurements of cAMP and redox status, using a FRET-based biosensor and a redox-sensitive GFP, respectively, indicated that H2O2 increases production of cAMP that correlates with redox state. Inhibition of EGFR activity decreased both H2O2-induced CREB phosphorylation and translocation of PKA to the nucleus, suggesting that crosstalk between PKA and EGFR underlies the oxidant-induced CREB response. Furthermore, knockdown of CREB expression using siRNA led to a decrease in bcl-2 and an increase in oxidant-induced apoptosis. Together these data reveal a novel role for crosstalk between PKA, ERK1/2 and CREB that mediates cell survival during oxidant stress