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3714. Evaluating the bio-hydrological impact of a cloud forest in Central America using a semi-distributed water balance model

Creator:
Caballero, Luis A., Easton, Zachary M., Richards, Brian K., and Steenhuis, Tammo S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
central america, rainfall-runoff, thornthwaite-mather, water balance model, cloud forest, and monsoonal climate
Language:
Slovak
Description:
Water scarcity poses a major threat to food security and human health in Central America and is increasingly recognized as a pressing regional issues caused primarily by deforestation and population pressure. Tools that can reliably simulate the major components of the water balance with the limited data available and needed to drive management decision and protect water supplies in this region. Four adjacent forested headwater catchments in La Tigra National Park, Honduras, ranging in size from 70 to 635 ha were instrumented and discharge measured over a one year period. A semi-distributed water balance model was developed to characterize the bio-hydrology of the four catchments, one of which is primarily cloud forest cover. The water balance model simulated daily stream discharges well, with Nash Sutcliffe model efficiency (E) values ranging from 0.67 to 0.90. Analysis of calibrated model parameters showed that despite all watersheds having similar geologic substrata, the bio-hydrological response the cloud forest indicated less plantavailable water in the root zone and greater groundwater recharge than the non cloud forest cover catchments. This resulted in watershed discharge on a per area basis four times greater from the cloud forest than the other watersheds despite only relatively minor differences in annual rainfall. These results highlight the importance of biological factors (cloud forests in this case) for sustained provision of clean, potable water, and the need to protect the cloud forest areas from destruction, particularly in the populated areas of Central America.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3715. Evaluating the link between photosynthetic capacity and leaf vascular organization with principal component analysis

Creator:
Polutchko, S. K., Stewart, J. J., Demmig-Adams, Barbara, and Adams, William W.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, growth temperature, high light, low light, phloem parenchyma cells, xylem, 2, and 581
Language:
Multiple languages
Description:
Significant linear relationships between photosynthetic capacity and principal components loaded by phloem cell numbers and tracheary elements per minor vein as well as the latter two normalized for vein density (proxy for apoplastic phloem loading capacity involving membrane transporters) were revealed for all apoplastic loaders (summer annuals and winter annual Arabidopsis thaliana). In addition, significant linear relationships between photosynthetic capacity and a principal component loaded by tracheary element cross-sectional areas and volumes per unit of leaf area (water flux capacity proxy) was present for symplastic and apoplastic loaders. Lastly, a significant linear relationship between photosynthetic capacity and a principal component loaded by phloem cell cross-sectional areas and volumes per unit of leaf area (proxy for symplastic loading capacity involving cytosolic enzymes for companion cells) was revealed for summer annual symplastic loaders as well as for A. thaliana (in the case of sieve elements, a proxy for sugar export capacity from the leaves)., S. K. Polutchko, J. J. Stewart, B. Demmig-Adams, W. W. Adams., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3716. Evaluating the superoxide dismutase activity and chlorophyll fluorescence in Picea abies leaves growing at different altitudes

Creator:
Miszalski, Z., Niewiadomska, E., Kępa, E., and Skawiński, P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
CuZnSOD, pine, and SOD isoforms
Language:
Multiple languages
Description:
Superoxide dismutase (SOD) activity and parameters of chlorophyll fluorescence, the ratio of maximal to variable fluorescence (Fv/Fm), maximal fluorescence (Fm), and minimal fluorescence (F0) were determined on Picea abies growing at different altitudes. The decreases of Fv/Fm and Fm, in comparison to samples from the lower stands (control), were found on trees from the highest stands. The decrease of fluorescence parameters was reversible, at least partly, after keeping branches for some days in the laboratory. Fv/Fm measured in spring when trees were partially covered with snow revealed greater degree of photoinactivation in branches collected from above the snow in comparison to those from below the snow. In samples collected from above snow also slower recovery from stress was observed. Two main SOD isoforms were determined in needles of P. abies, and classified as CuZnSODs. The activity of both SOD isoforms was increasing with the altitude, thus indicating the highest level of oxidative stress at the timberline zone. and Z. Miszalski ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3717. Evaluation and validation of the ASCE standardized reference evapotranspiration equations for a subhumid site in northeastern Austria

Creator:
Nolz, Reinhard and Rodný, Marek
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
weighing lysimeter, calculations, hourly, sum-of-hourly, and daily time steps
Language:
Slovak
Description:
Employing evapotranspiration models is a widely used method to estimate reference evapotranspiration (ETREF) based on weather data. Evaluating such models considering site-specific boundary conditions is recommended to interpret ETREF-calculations in a realistic and substantiated manner. Therefore, we evaluated the ASCE standardized ETREF-equations at a subhumid site in northeastern Austria. We calculated ETREF-values for hourly and daily time steps, whereof the former were processed to sum-of-hourly values. The obtained data were compared to each other and to ETvalues measured by a weighing lysimeter under reference conditions. The resulting datasets covered daily data of the years 2004 to 2011. Sum-of-hourly values correlated well (r2 = 0.978) with daily values, but an RMSE of 0.27 mm specified the differences between the calculation procedures. Comparing the calculations to lysimeter measurements revealed overestimation of small ETREF-values and underestimation of large values. The sum-of-hourly values outperformed the daily values, as r2 of the former was slightly larger and RMSE was slightly smaller. Hence, sum-of-hourly computations delivered the best estimation of ETREF for a single day. Seasonal effects were obvious, with computations and measurements being closest to each other in the summer months.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3718. Evaluation of a leaf area prediction model proposed for sunflower

Creator:
Tsialtas, J. T. and Maslaris, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Helianthus annuus, leaf length, leaf width, and non-destructive methods
Language:
Multiple languages
Description:
Six leaf samplings were conducted in two sunflower (Helianthus annuus L.) hybrids during the 2006 growing season in order to evaluate a simple model proposed for leaf area (LA) estimation. A total of 144 leaves were processed using an image analysis system and LA, maximum leaf width (W) [cm], and midvein length (L) [cm] were measured. Also, LA was estimated using the model proposed by Rouphael et al. (2007). Measured LA was exponentially related with L and W, and the W-LA relationships showed higher r2. Estimated LA was strongly and exponentially related with L. Strong, linear relationships with high r2 between estimated and measured LA confirmed the high predictability of the proposed model. and J. T. Tsialtas, N. Maslaris.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3719. Evaluation of anti-leishmanial effects of killed Leishmania vaccine with BCG adjuvant in BALB/c mice infected with Leishmania major MRHO/IR/75/ER

Creator:
Nahrevanian, Hossein, Jafary, Seyedeh Parisa, Nemati, Sara, Farahmand, Mahin, and Omidinia, Eskandar
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
vaccine, KLV, adjuvant, Leishmania major, immunization, and Iran
Language:
English
Description:
There are many strategies to control leishmaniasis, but majority of them are inadequate. Killed Leishmania vaccine (KLV) has been applied for its immunogenicity in human and mouse model. Bacillus Calmette-Guerin (BCG) as adjuvant is an immunemodulator inducing humoral and cellular immune responses during zoonotic cutaneous leishmaniasis (ZCL). Both KLV and BCG have been applied for their immune responses in hosts for controlling leishmaniasis. In this study, KLV and BCG were applied to inhibit replication and visceralization of Leishmania major in BALB/c mice. Mice were injected with KLV and BCG, followed by infection with promastigotes of L. major. Six weeks after infection, a small nodule appeared, which was followed by development of a large lesion and visceralization. Effects of KLV and BCG, physiopathological changes, lesion size, delay of lesion formation, proliferation of amastigotes inside macrophages and detection of amastigotes in target organs were studied. Results showed that the KLV had anti-leishmanial activity by reducing lesion size on late infection. In KLV and BCG group, the average number of amastigotes in macrophages was lower than in other groups. Significant reductions in number of amastigotes in both spleen and lymph node were observed, indicating lower visceralization of Leishmania parasites in these target organs. No significant changes were presented in body weights, survival rates and degrees of splenomegaly in test group. It can be concluded that application of KLV and BCG had acceptable efficacy in reduction of skin lesions size and proliferation of parasites, even though a few side-effects were observed. It is indicated that KLV/BSG may have ability to modulate host immune responses against Leishmania parasites and to reduce pathophysiology of the disease during infection.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3720. Evaluation of calcium channel blockers as potential hepatoprotective agents in oxidative stress injury of perfused hepatocytes

Creator:
Hassan Farghali, Eva Kmoníčková, Halka Lotková, and Martínek, J.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, verapamil, diltiazem, Tertbutyl hydroperoxide, hepatoprotection, ATPase, 14, and 612
Language:
English
Description:
The aim of this study was to investigate the effects of calcium channel blockers on tertbutyl hydroperoxide (TBH) induced liver injury using isolated perfused rat hepatocytes. Rat hepatocytes were immobilized in agarose threads and perfused with Williams E medium. Hepatocyte injury was induced by the addition of tertbutyl hydroperoxide (1 mM) to the perfusion medium 30 min after the addition of either verapamil or diltiazim. Hepatocyte injury was observed by monitoring the functional and metabolic competence of hepatocytes or by ultrastructural morphological examination of hepatocytes. Verapamil (0.5 mM) reduced lactate dehydrogenase leakage in TBH-injured hepatocytes as compared to the controls (154± 11 % vs. 247± 30 %). Lipid peroxides production was reduced after verapamil pretreatment as compared to the controls and oxygen consumption was increased by pretreatment of hepatocytes with verapamil. Verapamil pretreatment increased the protein synthesis activity at both levels of granular endoplasmic reticulum and free polysomes in cytoplasm and decreased ATPase activity. Diltiazem was qualitatively effective as verapamil. It is concluded that in hepatocyte oxidative injury, calcium channel blockers exhibited hepatoprotective properties. The hepatoprotective effect of calcium channel blockers was accompanied by a decrease in ATPase activity, which may implicate a normalization of Ca2+i after TBH intoxication., H. Farghali, E. Kmoníčková, H. Lotková, J. Martínek., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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