Efficiency of tree-based water status indicators at the onset of water deficit in citrus

5 páginas.-- 3 figuras.-- 5 tablas.-- 18 referenciasThis experiment evaluates the potential of using parameters based on tree trunk fluctuations for detecting water deficit in citrus trees under two different water saving-irrigation strategies: sustained deficit irrigation and partial root-zone drying. Three irrigation treatments were applied: 1) Control: trees were irrigated with 100% of their evapotranspirative needs (ETc); 2) 60 sustained deficit irrigation (SDI): 60% ETc; and 3) partial root-zone drying (PRD): 100% ETc needs, applied to only one-half of root zone. Maximum daily shrinkage (MDS), trunk growth rate (TGR), and MDS ratio (ratio between MDS of stressed trees and control trees) were determined. Day-to-day MDS values varied largely and could not be used to determine tree water deficit. TGR did not show significant differences among treatments at this level of stress. Nevertheless, the MDS ratio was a reliable indicator to measure tree water status, and it was more sensitive for detecting water deficit at the onset of a water deficit in trees under SDI than in trees under PRD.The authors thank the Consejo Superiorde Investigaciones Científicas (CSIC) for funding the stay of S. Elsayed-Farag at the Texas A&M University-Kingsville Citrus Center and her JAE-predoc fellowship and Ayako Kusakabe, research associate at the Citrus Center, for her technical support.Peer reviewe

Assessment of left ventricular function by global longitudinal strain in patients with non-ST elevation myocardial infarction: Comparative study with conventional method

Background: Left ventricular ejection fraction (LVEF) is a strong prognostic parameter in patients with heart disease. The assessment of global longitudinal strain (GLS) from speckle-tracking analysis of 2-dimensional echocardiography has become a clinically feasible alternative to LVEF for the measurement of myocardial function.Objective: The aim of the current work was to compare between GLS speckle tracking echocardiography and Simpson’s biplane methods for assessment of left ventricular function in non-STEMI patients.Patients and methods: This study was carried out in Cardiology Department, Faculty of Medicine, Zagazig University on 44 non‐ST‐elevation myocardial infarction (NSTEMI) patients scheduled for assessment of Left ventricular function by GLS and biplane Simpson method.Result: Mean systolic blood pressure was 122.05±18.37 mmHg. No statistically significant difference in systolic blood pressure was found across GLS groups (P= 0.17). Mean diastolic blood pressure was 73.41±12.00 mmHg. No statistically significant difference in diastolic blood pressure was found across GLS groups (P= 0.35). Mean heart rate was 68.84±7.13 bpm, and a statistically significant difference was found in heart rate across GLS groups (P= 0.039).Conclusion: It could be concluded that GLS speckle tracking echocardiography and Simpson’s biplane methods can be used as alternative different parameters for assessment of left ventricular function in non-STEMI patients

Role of ankle-brachial pressure index as a predictor of coronary artery disease severity in diabetic and non-diabetic patients

PurposeThe aim of the study was to estimate the role of ankle-brachial pressure index (ABI) in predicting severity of coronary artery disease (CAD) in patients with or without diabetes mellitus.MethodsThis study included 120 patients with CAD proved by coronary angiography and ABI was measured for all of them. They were divided into 4 groups; Group (A): Non-diabetic patients without peripheral arterial disease (PAD) (ABI < or =0.9) , Group (B):diabetic patients without PAD (ABI < or =0.9), Group (C):Non-diabetic patients with PAD (ABI>0.9) and Group (D):diabetic patients with PAD (ABI>0.9).ResultsHypertension was more prevalent in group (D) (p value>0.05). Group (C) had the highest mean age and the highest percentage of smokers, after normalization of the effects of the risk factors mean Gensini score, mean number of affected coronary vessels, mean number of coronary artery lesions and the percentage of coronary artery chronic total occlusions (CTO) were significantly higher in groups (C & D) (p>0.001) (Table 1).ConclusionABI had a significant relationship with the degree of CAD severity. Therefore ABI seems to be a reliable independent prognostic marker of CAD severity in patients with or without diabetes mellitus

An index from sap flow records to schedule irrigation in super-high density olive orchards

8 pages, 5 figures, 11 references.-- IX International Workshop on Sap Flow, celebrado del 4-7 de junio 2013, en Gante, Bélgica.Regulated deficit irrigation (RDI), recommended for super-high density (SHD) olive orchards, requires a precise control of irrigation. Water must be supplied on the phenological stages when the plant is most sensitive to water stress, but irrigation promotes plant vigour, and excessive growth hampers management in SHD orchards. A reliable water stress indicator is needed, therefore, for the proper management of RDI. Here we present an evaluation of the performance of DEp, an index previously reported by Cuevas et al. (2012). The index is derived from sap flow measurements in RDI trees and in fully irrigated trees used as a reference. We evaluated the index during the irrigation seasons of 2011 and 2012, in an 'Arbequina' olive orchard with 1667 trees ha-1 close to Seville, southwest Spain. The index showed a potential for scheduling RDI strategies, although its reliability decreased on periods of fluctuating atmospheric demand. The required data analyses and data interpretation make the DEp index suitable for well-trained users only.This work was funded by the Spanish Ministry of Science and innovation (research project AGL2009-11310/AGR), by the Junta de Andalucía (research project AGR-6456-2010) and by the FEDER programme.Peer Reviewe

Variabilidad radial y acimutal del flujo de savia en olivos plantados en seto

5 páginas.-- 4 figuras.-- Comunicación oral presentada en el XI Simposio Hispano-Portugués de Relaciones Hídricas en las Plantas, Sevilla 17-20 Sep. (2012)La heterogeneidad de densidad de flujo de savia tanto alrededor del tronco como en profundidad respecto al cambium es un hecho bien conocido que requiere ser analizado para un correcto uso e interpretación de las estimas de transpiración a partir de las medidas de flujo de savia. Por ello, se hizo un experimento en olivos ‘Arbequina’ de 5 años de edad en una plantación en seto (4 m x 1.5 m) donde se instalaron cuatro sondas por árbol, en tres árboles representativos de la plantación. Los resultados han mostradoque se puede reducir el número de sondas hasta una para estimar el flujo de savia en olivos plantados en seto de esta edad. La correlación obtenida para la densidad de flujo de savia relativa entre la sección más externa del xilema conductor y las interiores frente a la conductancia estomática relativa medida en hojas jóvenes y viejas aportó evidencias sobre la hipótesis de que los vasos exteriores están preferentemente conectados a las hojas jóvenes del año.N

Sap flow response to olive water stress: a comparative study with trunk diameter variations and leaf turgor pressure

11 pages, 3 figures, 19 references.-- VIII International Symposium on Sap Flow, celebrado del 8-12 de mayo 2011, en Volterra, Italia.The aim of this work was to evaluate the potential of used sap flow (SF), trunk diameter variation (TDV) and leaf turgor (LT) sensors for assessing water stress in a `Arbequina¿ hedgerow olive orchard with 1667 trees ha-1. Measurements were made in control trees irrigated to replace 100% of the crop water needs, and in trees under two regulated deficit irrigation strategies, 60RDI and 30RDI, in which irrigation replaced ca. 60% and 30% of the control, respectively. From the SF and TDV measurements we calculated the daily difference, both for tree water consumption (DEp) and maximum trunk diameter (DMXTD), between RDI trees and control trees. With the LT sensors we recorded the leaf patch output pressure (Pp), which is related to the leaf turgor pressure. Both DEp and DMXTD responded quickly and markedly to changes in water stress. The seasonal dynamics of both indices agreed with that of the stem water potential. A decrease in the reliability of DEp was recorded on days of highly variable atmospheric demand. The LT sensors also showed to be highly sensitive to changes on water stress. Any of the three methods have a potential as indicators for precise irrigation in hedgerow olive orchards with high plant density and low soil water-holding capacity.This experiment was funded by the Spanish Ministry of Science and Innovation, research project AGL2009-11310/AGR.Peer Reviewe

Using a process-based stomatal model in olive and its potential application to deficit irrigation studies

Over the last years modeling plant transpiration has been pointed out as a powerful tool to optimize the management of irrigation in fruit trees. In this study we tested the hydromechanical model of stomata functioning proposed by Buckley et al. (2003), a model with a strong physiological basis. The great contribution of this model is that its parameters have direct physiological meaning. Firstly, the model was simplified to make its parameters estimation friendly and easy. Secondly, the model was fitted to data obtained in a hedgerow olive orchard under regulated deficit irrigation. The hydromechanical model fitted our data satisfactorily and allowed us to analyze the physiological parameters obtained.Ministerio de Ciencia e Innovación español AGL2009-11310/AGRJunta de Andalucí

Unveiling the therapeutic potential of exogenous β-hydroxybutyrate for chronic colitis in rats: novel insights on autophagy, apoptosis, and pyroptosis

Ulcerative colitis (UC) is a chronic relapsing inflammatory disease of the colorectal area that demonstrates a dramatically increasing incidence worldwide. This study provides novel insights into the capacity of the exogenous β-hydroxybutyrate and ketogenic diet (KD) consumption to alleviate dextran sodium sulfate (DSS)-induced UC in rats. Remarkably, both interventions attenuated disease activity and colon weight-to-length ratio, and improved macro and microstructures of the damaged colon. Importantly, both β-hydroxybutyrate and KD curbed the DSS-induced aberrant NLRP3 inflammasome activation as observed in mRNA and protein expression analysis. Additionally, inhibition of the NLRP3/NGSDMD-mediated pyroptosis was detected in response to both regimens. In parallel, these modalities attenuated caspase-1 and its associated consequences of IL-1β and IL-18 overproduction. They also mitigated apoptosis as indicated by the inactivation of caspase-3. The anti-inflammatory effects of BHB and KD were confirmed by the reported decline in the levels of inflammatory markers including MPO, NFκB, IL-6, and TNF-α. Moreover, these interventions exhibited antioxidative properties by reducing ROS production and improving antioxidative enzymes. Their effectiveness in mitigating UC was also evident in the renovation of normal intestinal epithelial barrier function, as shown by correcting the discrepancies in the levels of tight junction proteins ZO-1, OCLN, and CLDN5. Furthermore, their effects on the intestinal microbiota homeostasis were investigated. In terms of autophagy, exogenous β-hydroxybutyrate upregulated BECN-1 and downregulated p62, which may account for its superiority over KD in attenuating colonic damage. In conclusion, this study provides experimental evidence supporting the potential therapeutic use of β-hydroxybutyrate or β-hydroxybutyrate-boosting regimens in UC

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Association between Multimorbidity and COVID-19 Mortality in Qatar: A Cross-Sectional Study

This study assessed the association between multimorbidity and mortality from COVID-19 in the Middle East and North Africa region, where such data are scarce. We conducted a cross-sectional study using data of all cases with COVID-19 reported to the Ministry of Public Health of Qatar from March to September 2020. Data on pre-existing comorbidities were collected using a questionnaire and multimorbidity was defined as having at least two comorbidities. Proportions of deaths were compared by comorbidity and multimorbidity status and multivariable logistic regression analyses were carried out. A total of 92,426 participants with a mean age of 37.0 years (SD 11.0) were included. Mortality due to COVID-19 was associated with gastrointestinal diseases (aOR 3.1, 95% CI 1.16–8.30), respiratory diseases (aOR 2.9, 95% CI 1.57–5.26), neurological diseases (aOR 2.6, 95% CI 1.19–5.54), diabetes (aOR 1.8, 95% CI 1.24–2.61), and CVD (aOR 1.5, 95% CI 1.03–2.22). COVID-19 mortality was strongly associated with increasing multimorbidity; one comorbidity (aOR 2.0, 95% CI 1.28–3.12), two comorbidities (aOR 2.8, 95% CI 1.79–4.38), three comorbidities (aOR 6.0, 95% 3.34–10.86) and four or more comorbidities (aOR 4.15, 95% 1.3–12.88). This study demonstrates a strong association between COVID-19 mortality and multimorbidity in Qatar