ΧΡΗΣΗ ΜΗΝΙΑΙΩΝ ΔΕΔΟΜΕΝΩΝ ΓΙΑ ΤΗΝ ΕΚΤΙΜΗΣΗ ΤΗΣ ΕΞΑΤΜΙΣΟΔΙΑΠΝΟΗΣ ΑΝΑΦΟΡΑΣ ΜΕ ΒΑΣΗ ΤΗ ΘΕΡΜΟΚΡΑΣΙΑ ΣΕ ΔΑΣΟΣ

Σκοπός της εργασίας είναι η διερεύνηση της ακρίβειας εκτίμησης της εξατμισοδιαπνοής αναφοράς (ΕΤο) των μεθόδων Hargreaves (HAR), Hargreaves-Samani (H-S) και τεσσάρων τροποποιήσεών της (HS1, HS2, HS3, HS4) με μηνιαία δεδομένα εισόδου 23 ετών (1996-2018), σε σχέση με την FAO56 Penman-Monteith (PM) σε δασικό περιβάλλον. Τα αποτελέσματα υποδεικνύουν ότι όλες οι μέθοδοι και κυρίως οι HAR, HS2 και H-S, εμφανίζουν ικανοποιητική ακρίβεια και συστήνεται η χρήση τους για την εκτίμηση της μηνιαίας ΕΤο σε δασικό μεσογειακό περιβάλλον. Παρόλα αυτά η εποχικότητα, το χρονικό βήμα και η ύπαρξη ξηρών ή υγρών ετών επηρεάζει την αποτελεσματικότητα των μεθόδων και πρέπει να λαμβάνονται υπόψη κατά την υιοθέτηση της κατάλληλης μεθόδου

Infiltration under Ponded Conditions

Ponded infiltration processes occur in agricultural lands irrigated by flooding of their soil surface or under insufficient drainage conditions. The existing equations describing the phenomenon of vertical infiltration under ponded conditions have not considered the actual contribution of the pressure head gradient to the flow. In this study, simple equations are proposed to describe the horizontal and vertical infiltration under various ponding heads incorporating the actual contribution of the pressure head gradient to the flow. Six soils with known hydraulic properties, covering a wide range of soil textures, were used. Horizontal and vertical infiltration data are obtained by numerical simulation for all soils studied using the Hydrus-1D code. To validate the accuracy of the proposed equations, the solutions of horizontal and vertical infiltrations provided by the proposed equations were compared with numerically simulated ones provided by the Hydrus 1-D. The analysis of the results showed a very good agreement in all soils studied. The proposed vertical infiltration equation was also compared to a simple and accurate equation which does not incorporate the actual contribution of the pressure head gradient to the flow and differences between them were observed in all soils studied

Infiltration under Ponded Conditions

Ponded infiltration processes occur in agricultural lands irrigated by flooding of their soil surface or under insufficient drainage conditions. The existing equations describing the phenomenon of vertical infiltration under ponded conditions have not considered the actual contribution of the pressure head gradient to the flow. In this study, simple equations are proposed to describe the horizontal and vertical infiltration under various ponding heads incorporating the actual contribution of the pressure head gradient to the flow. Six soils with known hydraulic properties, covering a wide range of soil textures, were used. Horizontal and vertical infiltration data are obtained by numerical simulation for all soils studied using the Hydrus-1D code. To validate the accuracy of the proposed equations, the solutions of horizontal and vertical infiltrations provided by the proposed equations were compared with numerically simulated ones provided by the Hydrus 1-D. The analysis of the results showed a very good agreement in all soils studied. The proposed vertical infiltration equation was also compared to a simple and accurate equation which does not incorporate the actual contribution of the pressure head gradient to the flow and differences between them were observed in all soils studied

Applicability of an empirical runoff estimation method in central Greece

In order to assess the water runoff on the sloping cultivated fields of Central Greece, an experiment was carried out from 1997 to 2000. The following treatments were used: three tillage methods, viz. conventional tillage, reduced tillage with heavy cultivator and disk-harrow: two with or without winter cover crop, two parallel and perpendicular to the contour tillage and planting directions. An existing methodology for predicting runoff was evaluated and improved, which is based on the estimation of pending time for the different tillage systems in the study area under rainfall. An equation predicting the time to ponding was used obtaining data from infiltration experiments using double-cylinder infiltrometers in the field. The surface runoff of each rain storm was estimated by combining the appropriate infiltration equation with the rain intensity data, taking into consideration not only the excess rainfall rate over the infiltration rate, but also the surface detention. Measured runoff was used to test the validity of the USDA-Soil Conservation Service (SCS) curve number method in the region. The results from this test indicated that this prediction runoff method may not be used in the region without the proper modifications to suit the rainfall in the region. The developed model could be used to successfully estimate runoff and erosion in the area. It was found that the combination of equations of time to incipient ponding and the maximum surface storage capacity of topsoil, could explain about 85% of the existing runoff variation. (c) 2006 Elsevier B.V. All rights reserved

Isolation, characterization, and sequencing of nodavirus in sturgeon (Acipenser gueldestaedi L.) reared in freshwater facilities

The study demonstrates the presence of a nodavirus that affected sturgeon in fresh water, causing disease with neurological signs. The virus was isolated and inoculated onto SSN-1 (striped snakehead, Channa striatus) cell cultures where cytopathic effects (CPE) of the virus included vacuolation of the cells and degeneration of the monolayer. A 255 bp amplicon from nucleic acid preparations of brain tissue from infected sturgeon was detected by PCR (RT-PCR and nested-PCR) and compared with corresponding amino acid sequences of other infected species. The sequences from the sturgeon were similar to those of sea bass, red spotted grouper, and European eel, supporting the hypothesis that the virus originated in marine fish and was horizontally transmitted to freshwater sturgeon

Cloning and functional characterization of the ovine Hormone Sensitive Lipase (HSL) full-length cDNAs: An integrated approach

Hormone Sensitive Lipase (HSL) is a highly regulated enzyme that mediates lipolysis in adipocytes. HSL enzymatic activity is increased by adrenergic agonists, such as catecholamines and glucagons, which induce cyclic AMP (cAMP) intracellular production, subsequently followed by the activation of Protein Kinase A (PKA) and its downstream signalling cascade reactions. Since HSL constitutes the key enzyme in the regulation of lipid stores and the only enzyme being subjected to hormonal regulation [in terms of the recently identified Adipose Triglyceride Lipase (ATGL)], the ovine Hormone Sensitive Lipase (ovHSL) full-length cDNA clones were isolated, using a Polymerase Chain Reaction-based (PCR) strategy. The two isolated isoforms ovHSL-A and ovHSL-B contain two highly homologous Open Reading Frame (ORF) regions of 2.089 Kb and 2.086 Kb, respectively, the latter having been missed the 688th triplet coding for glutamine (ΔQ688). The putative 695 and 694 amino acid respective sequences bear strong homologies with other HSL protein family members. Southern blotting analysis revealed that HSL is represented as a single copy gene in the ovine genome, while Reverse Transcription-PCR (RT-PCR) approaches unambiguously dictated its variable transcriptional expression profile in the different tissues examined. Interestingly, as undoubtedly corroborated by both RT-PCR and Western blotting analysis, ovHSL gene expression is notably enhanced in the adipose tissue during the fasting period, when lipolysis is highly increased in ruminant species. Based on the crystal structure of an Archaeoglobus fulgidus enzyme, a three-dimensional (3D) molecular model of the ovHSL putative catalytic domain was constructed, thus providing an inchoative insight into understanding the enzymatic activity and functional regulation mechanisms of the ruminant HSL gene product(s). © 2008 Elsevier B.V. All rights reserved

Map integration at human chromosome 10: molecular and cytogenetic analysis of a chromosome-specific somatic cell hybrid panel and genomic clones, based on a well-supported genetic map

Well-characterized, chromosome-specific somatic cell hybrid panels are powerful tools for the analysis of the human genome. We have characterized a panel of human x hamster somatic cell hybrids retaining fragments of human chromosome 10 by fluorescence in situ hybridization and associated them to genetic markers. Most of the hybrids were generated by the radiation-reduction method, starting from a chromosome 10-specific monochromosomal hybrid, whereas some were collected from hybrids retaining chromosome 10-specific fragments as a result of spontaneous in vitro rearrangements. PCR was used to score the retention of 57 microsatellite markers evenly distributed along a well-supported framework genetic map containing 149 loci uniquely placed at 69 anchor points (odds exceeding 1,000:1), with an average spacing of 2.8 cM. As an additional resource for genomic studies involving human chromosome 10, we report the cytogenetic localization of a series of YAC and PAC clones recognized by at least one genetic marker. Somatic cell hybrids provide a powerful source of partial chromosome paints useful for detailed clinical cytogenetic and primate chromosome evolution investigations. Furthermore, correlation of the above physical, genetic, and cytogenetic data contribute to an emerging consensus map of human chromosome 10