29 research outputs found
Effect of defoliation on leaf physiology of sugar beet cultivars subjected to water stress and re-watering
Abstract Water stress causes defoliation, which can reduce yield and root quality of sugar beets (Beta vulgaris L.) through altered gas exchange characteristics of the leaves. In a two-year experiment, three sugar beet cultivars (Europa, Rival and Corsica) were subjected to three defoliation levels (control-C, moderate-MD, severe-SD) and re-watering after their exposition to drought for a month. Leaf physiological traits including net photosynthesis (A), transpiration rate (E), stomatal conductance (g s ), intracellular CO 2 (C i ), water use efficiency (WUE L -A/E and WUE i -A/g s ), leaf N concentration, petiole NO 3 -N concentration, specific leaf area (SLA), leaf water potential (WP) and leaf water content (LWC), were determined before defoliation and 15, 30 and 40 days after defoliation (DAD). On contrary to previous reports, water-stressed cultivars differed significantly in their leaf physiology; the late-season cultivar Corsica had the lowest E and g s values without any significant reduction in A. Thus, Corsica was the most water-conservative cultivar. Re-watering rapidly restored leaf physiology but a gradual decline, with the progress of DAD, was evident for A, E, g s and C i . After re-growth, cultivars differed only in WP and LWC with Europa, the early-harvested cultivar, to have the highest values. Thus, the better response (higher yield increase and lower root quality degradation) of Corsica to re-watering and the subsequent re-growth, as reported b
Acoustic emission behavior of steel fibre reinforced concrete under bending
a b s t r a c t The present paper describes the acoustic emission (AE) behavior of concrete under four-point bending. Steel fibres of varying content were used as reinforcement in concrete slabs and their influence on the fracture process and the acoustic activity was investigated. The total acoustic emission (AE) activity was found to be directly proportional to the fibre content. Analysis revealed that particular AE parameters change monotonically with the progress of damage and can be used for the characterization of the failure process
Global Geographic Distribution and Host Range of Fusarium circinatum, the Causal Agent of Pine Pitch Canker
Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen
Genotypic response to re-growth of defoliated sugar beets after re-watering in a water-limited environment: effects on yield and quality.
Abstract Defoliation produced by abiotic factors and the subsequent re-growth can reduce sugar beet (Beta vulgaris L.) sucrose content and final sugar yield. Field experiments were conducted during 2003 and 2004 growing seasons in the farm of Hellenic Sugar Industry SA, Larissa factory, central Greece. Three sugar beet cultivars (Rival, Europa and Corsica) were ordinary irrigated till the beginning of July and then left without irrigation for a month. Three defoliation levels (control-C, moderate-MD and severe-SD) were performed at early August and irrigation was simultaneously started to promote re-growth. Four samplings were conducted (before defoliation, 15, 30 and 40 days after defoliation) to determine the changes in physiological and productive traits. Yields were lower in 2003 compared to 2004 because sugar beets were grown under more stressful conditions due to the delayed sowing, the higher temperatures and the lower rainfall. Both defoliation level and cultivar had significant effects on physiological and productive traits after re-growth only in 2003. The late-season cultivar, Corsica, showed better LAI maintenance compared to Europa and Corsica and had the greatest performance after re-growth in regard to fresh root weight and sugar yield. Also, this cultivar showed the least decrease of sucrose percentage in fresh root weight and juice purity mainly due to the stable potassium (K) concentration and limited increase of sodium (Na) accumulation in roots. Corsica consumed the least root α-amino N for its re-growth. Quantitative and qualitative traits were negatively affected only by the SD treatment. Plants suffered from MD treatment gradually recovered during growing season. This study demonstrates that under Mediterranean conditions, the adverse effects of re-growth on sugar beet yield and quality depend on the growing conditions and they can be restricted by the selection of an appropriate cultivar
Opioid-Free Anesthesia and Postoperative Cognitive Dysfunction After Minor Urological Surgery: A Case Series Study
Background: Postoperative cognitive dysfunction (POCD) is a complication that mainly occurs in adult patients and refers to a new-onset decline in cognitive function after anesthesia and surgery. The literature lacks evidence regarding opioid-free anesthesia and its impact on mental function postoperatively. Objectives: The effect of opioid-free anesthesia on POCD following urological surgery has not been previously reported. Accord-ingly, we present a case series of 15 adult patients undergoing transurethral urological surgery under general anesthesia using an opioid-free protocol with dexmedetomidine, ketamine, and lidocaine. Methods: Patients that underwent simple transurethral elective urological procedures under general opioid-free anesthesia were included. This case series is part of a prospective clinical study regarding opioid-free anesthesia and served as a pilot sample. The mini-mental state examination (MMSE) test, performed preoperatively and 12 hours postoperatively, was applied to assess POCD. Results: Fifteen patients with a mean age of 68 years old were included in the study. The opioid-free protocol was associated with non-statistically significant changes of the MMSE test after minor urological procedures. Conclusions: In our study, an opioid-free protocol of general anesthesia, using a mixture of dexmedetomidine, ketamine, and lido-caine, did not seem to have a negative impact on postoperative cognitive function in patients undergoing transurethral urological surgery. Further studies specifically designed to identify this effect are certainly required to further prove such an effect. © 2022, Author(s)
The relationship of internet addiction with anxiety and depressive symptomatology
Article in Greek.
Title on PDF: Η σχέση της εξάρτησης από το διαδίκτυο με την αγχώδη και καταθλιπτική συμπτωματολογί
Lessons learned from first case of Cesarean delivery in a COVID-19 positive parturient in Greek region
We report the successful anesthetic management of a 24-year-old patient, with an active COVID-19 viral infection, scheduled for elective Cesarean section at 40th week of pregnancy. This was the first case in Greek region, and we report and discuss the difficulties and safety issues regarding a COVID-19 positive patient during an elective cesarean delivery. Regional anesthesia with full protective equipment for health personnel involved, along with careful planning and adherence to guidelines achieved safe completion of the operation. © 2020 Wolters Kluwer Medknow Publications. All rights reserved