Se evaluaron los datos climáticos para el valle de Jauja, región Junín, sierra central del Perú para el siglo xxi, como lo simulan los modelos climáticos utilizados en la fase 5 por la ...intercomparación de modelos acoplados (CMP5). Los modelos utilizados fueron tres: CSIRO Mk 3.6, MIROC-ESM y CNRM-CM5, respectivamente, a una resolución espacial de 1,875 × 1,86°, 2,81 × 1,87° y 1,41 × 1,40°, construidos con data meteorológica observada en el valle de Jauja durante el periodo 1975-2005, empleando el escenario RCP2.6 y 8.5 del IPCC. El objetivo del presente trabajo es proporcionar proyecciones climáticas locales para esta área, generando una primera base de datos climáticos futura de la región, como herramienta de toma de decisiones por parte de agricultores y otros usuarios de la cuenca. Las proyecciones climáticas muestran un calentamiento significativo desde 2,0 grados de temperatura para el escenario RCP2.6 hasta 3,5 grados de temperatura para el escenario RCP8.5, esperado en toda el área evaluada del valle de Jauja para los próximos cincuenta años, junto con una disminución de la precipitación. Las proyecciones de precipitación dependen de la resolución horizontal, lo que sugiere la necesidad de simulaciones adicionales con una resolución más alta, especialmente para una representación adecuada de eventos climáticos extremos.
RESUMEN El incremento de la evapotranspiración debido al calentamiento global del planeta hace que la permanencia en el tiempo del cultivo de arroz se vea amenazada por la alta demanda de agua que ...implica su producción. Por ello, este estudio tiene como objetivo estimar el índice de estrés hídrico foliar (Crop Water Stress Index - CWSI) a partir del procesamiento de imágenes térmicas obtenidas por sensores remotos, como herramienta para pasar de una escala de planta (dosel) a una mayor escala. La investigación se realizó en La Molina, Perú, en el periodo de otoño-invierno del 2017 (febrero-agosto), en el cultivo de arroz variedad IR 43 bajo riego por goteo. Se colectó información de la temperatura del dosel medida con una cámara térmica FLIR ajustada con información de termopares, y se correlacionó con información de humedad volumétrica del suelo medida con sensores FDR. El CWSI se obtuvo a partir de la temperatura foliar ajustada a las condiciones atmosféricas, la temperatura seca que representa la mínima transpiración (estomas cerrados) y la temperatura húmeda que representa la máxima transpiración (estomas totalmente abiertos). En la fase reproductiva y de maduración del cultivo se determinó que la temperatura húmeda fue de 15,2 °C y 15,4 °C y la temperatura seca de 33,7 °C y 36 °C, respectivamente. Finalmente se obtuvo una correlación significativa de Pearson de -0,522 entre el CWSI y la humedad volumétrica del suelo, para un nivel de significancia del 5%, a 0,3 m de profundidad del suelo. Se recomienda monitorear variables fisiológicas del cultivo para viabilizar el uso del CWSI e implementar calendarios de riego óptimos y, por lo tanto, una reducción en el consumo del agua.
Abstract Water scarcity threatens agriculture in California. During the last two decades, historically severe droughts have led to severe water shortages. Under projected changes in climate, droughts ...of greater severity and duration will exacerbate this situation. California produces 80% of the world’s almonds, which require consistent water supplies for irrigation. Almonds are the most commonly grown crop in California, covering nearly 1.4 million acres over about 8,000 farms. In response to these challenges, almond growers are considering a myriad of management strategies to save water and mitigate climate change. The Tree-Crop Remote Sensing of Evapotranspiration Experiment (T-REX) aims to identify water and orchard management opportunities to maximize water use efficiency and carbon sequestration in almonds and other woody perennial tree crops. The project combines satellite, uncrewed aerial vehicles, and proximal sensing technologies to retrieve key variables used to model surface fluxes and biophysical properties. We aim to advance our understanding of water management and cultural practices on water–carbon relationships in tree-perennial agroecosystems. Through new methods, such as evapotranspiration-based irrigation scheduling, even a modest 10% decrease in almond orchard irrigation across the state equates to about a third of the water in Lake Oroville, California’s second-largest reservoir, at average levels. From a carbon perspective, almond orchards could sequester 8% of the state’s current greenhouse gas emissions by transitioning toward climate-smart practices. As such, the almond industry is uniquely positioned to curb water use and contribute to climate change mitigation while maintaining economic viability of almond production. An overview of initial results related to evapotranspiration observational and modeling uncertainty and carbon sequestration potential are presented in this article.
Non-alcoholic fatty liver disease (NAFLD) could play a catalytic role in the development of metabolic comorbidities, although the magnitude of this effect in metabolically healthy patients with NAFLD ...remains unclear. We assessed the role of biopsy-proven NAFLD on the risk of developing type 2 diabetes mellitus (T2DM) and other metabolic comorbidities (arterial hypertension AHT, and dyslipidemia) in metabolically healthy patients.
We included 178 metabolically healthy—defined by the absence of baseline T2DM, AHT, dyslipidemia—patients with biopsy-proven NAFLD from the HEPAmet Registry (N = 1,030). Hepamet fibrosis score (HFS), NAFLD fibrosis score, and Fibrosis-4 were calculated. Follow-up was computed from biopsy to the diagnosis of T2DM, AHT, or dyslipidemia.
During a follow-up of 5.6 ± 4.4 years, T2DM occurred in 9% (16/178), AHT in 8.4% (15/178), low HDL in 9.6% (17/178), and hypertriglyceridemia in 23.6% (42/178) of patients. In multivariate analysis, significant fibrosis predicted T2DM and AHT. Independent variables related to T2DM appearance were significant fibrosis (HR 2.95; 95% CI 1.19–7.31; p = 0.019), glucose levels (p = 0.008), age (p = 0.007) and BMI (p = 0.039). AHT was independently linked to significant fibrosis (HR 2.39; 95% CI 1.14–5.10; p = 0.028), age (p = 0.0001), BMI (p = 0.006), glucose (p = 0.021) and platelets (p = 0.050). The annual incidence rate of T2DM was higher in patients with significant fibrosis (4.4 vs. 1.2 cases per 100 person-years), and increased in the presence of obesity, similar to AHT (4.6 vs. 1.1 cases per 100 person-years). HFS >0.12 predicted the risk of T2DM (25% 4/16 vs. HFS <0.12 4.5% 4/88; logRank 6.658, p = 0.010).
Metabolically healthy patients with NAFLD-related significant fibrosis were at greater risk of developing T2DM and AHT. HFS >0.12, but not NAFLD fibrosis score or Fibrosis-4, predicted the occurrence of T2DM.
Patients with biopsy-proven non-alcoholic fatty liver disease and significant fibrosis were at risk of developing type 2 diabetes mellitus and arterial hypertension. The risk of metabolic outcomes in patients with significant fibrosis was increased in the presence of obesity. In addition to liver biopsy, patients at intermediate-to-high risk of significant fibrosis by Hepamet fibrosis score were at risk of type 2 diabetes mellitus.
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•NAFLD-related significant fibrosis predicts the occurrence of type 2 diabetes mellitus and arterial hypertension.•The annual incidence of metabolic outcomes is four-times higher in the presence of significant fibrosis.•Neither steatosis nor NASH predict the appearance of metabolic outcomes.•Hepamet fibrosis score >0.12 is associated with the risk of developing type 2 diabetes mellitus.
Background/Aims To investigate the effect of sustained virological response (SVR) on impaired fasting glucose (IFG) and/or type 2 diabetes (T2DM); to assess the influence of glucose abnormalities on ...the SVR rate. Methods 1059 patients with chronic HCV; normal glucose (< 100 mg/dl) in 734, IFG (between 100 and 125 mg/dl) in 218, and T2DM (⩾126 mg/dl) in 107 cases, were treated with interferon plus ribavirin over 24 or 48 weeks, depending on viral genotype. Results The SVR rate was lower in patients with IFG and/or T2DM than in patients with normal glucose concentrations 143/325 (44%) vs. 432/734 (58.8%); P = 0.002. In the follow-up, abnormal glucose concentrations were observed in 74 of 304 (24.3%) non-responders and in 49 of 430 (11.4%) sustained responders (log-rank: 13.8; P = 0.00002). Reverse stepwise logistic regression analysis identified the independent variables predictive of IFG or T2DM development as: sustained response (OR: 0.44; 95%CI = 0.20–0.97; P = 0.004) and fibrosis stage (OR: 1.46; 95%CI = 1.06–2.01; P = 0.02). Family history of DM, steatosis, gender, HCV viral load, genotype, triglycerides, cholesterol and BMI did not enter the multivariate analysis equation. Conclusions SVR reduces the risk of IFG and/or T2DM development in patients with chronic hepatitis C while altered glucose metabolism impairs sustained response to viral treatment.
Background
MASLD can manifest as hepatocellular damage, which can result in mild elevation of aminotransferases. However, in some patients, MASLD presents with cholestatic pattern.
Objective
To ...assess the impact of the biochemical pattern on the natural course of MASLD, including liver damage in histology, the accuracy of non-invasive tests(NITs), and prognosis.
Methods
Multicenter study enrolling 2156 patients with biopsy-proven MASLD, who were classified based on theirALT/ULN)/(ALP/ULN) levels at the time of biopsy: (a) hepatocellular pattern(H), > 5; (b) mixed pattern(M),2–5; (c) cholestatic pattern(C), < 2. Outcomes: (a) histological evaluation of the single components of NAS, MASH, and fibrosis; (b) NITs and transient elastography assessing advanced fibrosis; (c) prognosis determined by the appearance of decompensated cirrhosis and death.
Results
Out of the 2156 patients, 22.9% exhibited the H-pattern, whilst 31.7% exhibited the C-pattern. Severe steatosis, ballooning, lobular inflammation, and MASH (56.4% H
vs.
41.9% M
vs.
31.9% C) were more common in H-pattern (
p
= 0.0001),whilst C-pattern was linked to cirrhosis (5.8% H
vs.
5.6% M
vs.
10.9% C;
p
= 0.0001). FIB-4(0.74(95% CI 0.69–0.79)
vs.
0.83 (95% CI 0.80–0.85);
p
= 0.005) and Hepamet Fibrosis Score(0.77 (95% CI 0.69–0.85)
vs.
0.84 (95% CI 0.80–0.87);
p
= 0.044)exhibited lower AUROCs in the H-pattern. The C-patternHR 2.37 (95% CI 1.12–5.02);
p
= 0.024, along with age, diabetes, and cirrhosis were independently associated with mortality. Most patients maintained their initial biochemical pattern during the second evaluation.
Conclusions
The H-pattern exhibited greater necro-inflammation in the histology than the C-pattern, whereas the latter showed more cirrhosis. The accuracy of NITs in detecting fibrosis was decreased in H-pattern. The occurrence of decompensated events and mortality was predominant in C-pattern. Therefore, identifying MASLD phenotypes based on the biochemical presentation could be relevant for clinical practice.
Insulin resistance affects sustained virological response (SVR) in chronic hepatitis C. To know whether adding metformin to standard antiviral treatment improves SVR, we conducted a prospective, ...multicentered, randomized, double‐blinded, placebo‐controlled trial in 19 Spanish hospitals, including 123 consecutive patients with genotype 1 chronic hepatitis C and insulin resistance. Patients were randomized to receive either metformin (arm A; n = 59) or placebo (arm B; n = 64) in addition to peginterferon alfa‐2a (180 μg/week) and ribavirin (1000–1200 mg/day). The primary end point was SVR, and secondary endpoints were viral clearance at weeks 12, 24, and 48, and changes in the homeostasis model assessment (HOMA) index over the first 24 weeks. There were no differences between arms at baseline. In the intent‐to‐treat analysis, SVR was observed in 53% versus 42% in arm A and arm B, respectively (P = NS). In the subgroup analyses, SVR was higher in females (n = 54) receiving metformin: arm A, 58% (15/26) versus 29% (8/28) arm B (P = 0.03). In the per protocol analysis (PPA; n = 101), SVR was 67% in arm A and 49% in arm B (P = 0.06). Viral decline during the first 12 weeks was greater in females receiving metformin: −4.88 (1.18) versus −4.0 (1.44) (P = 0.021), whereas no differences were seen in males. The triple therapy was well tolerated, but diarrhea was more often seen in arm A (34% versus 11%; P < 0.05). Conclusion: Adding metformin to peginterferon and ribavirin was safe and improved insulin sensitivity. Although the study failed to show a statistically significant difference between arms, it did show an improved SVR in females. (HEPATOLOGY 2009.)
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