62 research outputs found
Effects of bud loading levels and nitrogen doses on yield, physical and chemical properties of brined grapeleaves
The aim of this study was to investigate the effects of several bud loading levels in winter pruning and nitrogen doses on yield and physical and chemical properties of fresh vine-leaves of grape cultivar “Narince”. Vines trained with bilateral cordon system was pruned to yield 35000 to 53000 buds/ha (16 or 24 buds/vine) above second bud in 2005 to 2006 growing season. Four nitrogen doses (0, 70, 140, 210 kg N /ha) were applied, in a completely randomized block with four replications. Brined-grape leaves were collected four times during growing season. Total fresh leaf yield (g/vine; kg/ha), number of leaves in 100 g samples, leaf area for physical properties; dry matter, ash, pH and titratable acidity for chemical properties were determined. Bud loading levels and N applications had significant effect (P<0.05) on fresh leaf yield. Fresh leaf yield varied from 2233 to 2978 kg/ha in 2005 and 3356 to 4221 kg/ha in 2006, respectively. Mean leaf area decreased with increasing of N doses and bud loading levels. Number of leaves in 100 g samples ranged from 33.3 to 38.9. Pruning and nitrogen doses had no effect on percent dry matter and ash ratio. Bud loading increased with pruning and N applications resulted in higher leaf yield which had no effect on total soluble solid (TSS), dry matter, ash ratio and decreased total leaf area. The results indicate that 140 kg N/ha and 40000 to 45000 buds/ha loading levels as vine growth is recommended.Keywords: Brined-grape leaves, nitrogen, bud loading level, narince grape cultivar, Turkey
The virial theorem and exact properties of density functionals for periodic systems
In the framework of density functional theory, scaling and the virial theorem
are essential tools for deriving exact properties of density functionals.
Preexisting mathematical difficulties in deriving the virial theorem via
scaling for periodic systems are resolved via a particular scaling technique.
This methodology is employed to derive universal properties of the
exchange-correlation energy functional for periodic systems.Comment: Accepted in PRB(R) 201
Some chemical and physical properties at physiological maturity and ripening period of kiwifruit (‘Hayward’)
This study was carried out to determine some chemical and physical properties at physiological maturity and ripening period of kiwifruit. The average geometric mean diameter, sphericity, bulk density, porosity, projected area along three axes (X, Y, Z) and colour characteristics (L*, a*, b*) were measured at physiological maturity and ripening period. Total soluble solid content, titratable acidity, pH, total phenolic, total antioxidant activity and total sugar of kiwifruit were also determined. The total antioxidant value was higher at physiological maturity than ripening period.Key words: Kiwifruit (Hayward), chemical properties, physical properties, physiological maturity, ripening period
Effects of shading and covering material application for delaying harvest on gray mold disease severity
To delay the harvest of Sultani Cekirdeksiz grape variety and to reduce pre and post-harvest botrytis bunch rot severity, shading and covering material application were tested in 2009 to 2010 growing periods. In this study, grape vines were shaded with shading materials which had three different shading densities (35, 55, and 75% shading density) from veraison period to harvest. The grape vines were also covered with four different covering materials (transparent polyethylene, mogul, polypropen cross-stich and lifepack) before rainfall, at the end of August until harvest. The gray mold severity was recorded three times (before shading at unriped grape stage, veraison period, shortly after shading and twice at 20 day interval) during growing period. Based on the results of this study, the highest gray mold (Botrytis cinerea) severity was obtained in the control (uncovered and unshaded) treatment and the lowest disease severity was observed in lifepack treatment with or without shading. Since gray mold disease of grape was the main factor affecting harvest date of the crop lifepack, + 35 or 55% shading could be recommended to delay harvest and reduce the gray mold severity of grape in Manisa province-Turkey.Key words: Sultani seedless, table grape, shading, cover material, delaying harvest disease severity, Botrytis cinerea
Electronic structure via potential functional approximations
The universal functional of Hohenberg-Kohn is given as a coupling-constant
integral over the density as a functional of the potential. Conditions are
derived under which potential-functional approximations are variational.
Construction via this method and imposition of these conditions are shown to
greatly improve the accuracy of the non-interacting kinetic energy needed for
orbital-free Kohn-Sham calculations
Electronic Density Response of Warm Dense Matter
Matter at extreme temperatures and pressures -- commonly known as warm dense
matter (WDM) in the literature -- is ubiquitous throughout our Universe and
occurs in a number of astrophysical objects such as giant planet interiors and
brown dwarfs. Moreover, WDM is very important for technological applications
such as inertial confinement fusion, and is realized in the laboratory using
different techniques. A particularly important property for the understanding
of WDM is given by its electronic density response to an external perturbation.
Such response properties are routinely probed in x-ray Thomson scattering
(XRTS) experiments, and, in addition, are central for the theoretical
description of WDM. In this work, we give an overview of a number of recent
developments in this field. To this end, we summarize the relevant theoretical
background, covering the regime of linear-response theory as well as nonlinear
effects, the fully dynamic response and its static, time-independent limit, and
the connection between density response properties and imaginary-time
correlation functions (ITCF). In addition, we introduce the most important
numerical simulation techniques including ab initio path integral Monte Carlo
(PIMC) simulations and different thermal density functional theory (DFT)
approaches. From a practical perspective, we present a variety of simulation
results for different density response properties, covering the archetypal
model of the uniform electron gas and realistic WDM systems such as hydrogen.
Moreover, we show how the concept of ITCFs can be used to infer the temperature
from XRTS measurements of arbitrarily complex systems without the need for any
models or approximations. Finally, we outline a strategy for future
developments based on the close interplay between simulations and experiments
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Enhanced water loss from the martian atmosphere during a regional-scale dust storm and implications for long-term water loss
Lower atmosphere variations in the martian water vapour and hydrogen abundance during the late southern summer regional-scale dust storm from LS= 326.1◦–333.5◦ Mars Year 34 (18th-31st January 2019) and their associated effect on hydrogen escape are investigated using a multi-spacecraft assimilation of atmospheric retrievals into a Martian global circulation model. The dusty conditions led to an elevation of the hygropause and associated increase in middle atmosphere hydrogen at the peak of the dust storm, which was particularly intense in Mars Year 34. This response has an important effect on water loss during this time period, quantification of which can provide a more robust calculation of the integrated loss of water through time on Mars and better insight to planetary evolution. The influx of water vapour to higher altitudes led to an associated increase in hydrogen through photolysis of water vapour and a hydrogen escape rate of around 1.0 ×109cm−2s−1, meaning the late southern summer regional-scale dust storm in Mars Year 34 enhanced water loss rates on Mars to levels observed during global-scale dust storms. The water loss rate during the late southern summer regional-scale dust storm, also known as a C storm, led to around 15% of the total annual water loss during only 5% of the year and was at least three times stronger than the much less dusty C storm event in Mars Year 30. These results demonstrate that interannual variations in the strength of the late southern summer regional-scale dust storm must be considered when calculating the integrated loss of water on Mars, an important quantity to constrain in relation to the potential habitability of Mar
Overexpression of CDC25B, CDC25C and phospho-CDC25C (Ser216) in vulvar squamous cell carcinomas are associated with malignant features and aggressive cancer phenotypes
<p>Abstract</p> <p>Background</p> <p>CDC25 phosphatases are important regulators of the cell cycle. Their abnormal expression detected in a number of tumors implies that their dysregulation is involved in malignant transformation. However, the role of CDC25s in vulvar cancer is still unknown. To shed light on their roles in the pathogenesis and to clarify their prognostic values, expression of CDC25A, CDC25B and CDC25C in a large series of vulvar squamous cell carcinomas were examined.</p> <p>Methods</p> <p>Expression of CDC25A, CDC25B, CDC25C and phosphorylated (phospho)-CDC25C (Ser216) were examined in 300 vulvar carcinomas using immunohistochemistry. Western blot analysis was utilized to demonstrate CDC25s expression in vulvar cancer cell lines. Kinase and phosphatase assays were performed to exclude cross reactivity among CDC25s isoform antibodies.</p> <p>Results</p> <p>High nuclear CDC25A and CDC25B expression were observed in 51% and 16% of the vulvar carcinomas, respectively, whereas high cytoplasmic CDC25C expression was seen in 63% of the cases. In cytoplasm, nucleus and cytoplasm/nucleus high phospho-CDC25C (Ser216) expression was identified in 50%, 70% and 77% of the carcinomas, respectively. High expression of CDC25s correlated significantly with malignant features, including poor differentiation and infiltration of vessel for CDC25B, high FIGO stage, presence of lymph node metastases, large tumor diameter, poor differentiation for CDC25C and high FIGO stage, large tumor diameter, deep invasion and poor differentiation for phospho-CDC25C (Ser216). In univariate analysis, high expression of phospho-CDC25C (Ser216) was correlated with poor disease-specific survival (p = 0.04). However, such an association was annulled in multivariate analysis.</p> <p>Conclusions</p> <p>Our results suggest that CDC25C and phospho-CDC25C (Ser216) play a crucial role and CDC25B a minor role in the pathogenesis and/or progression of vulvar carcinomas. CDC25B, CDC25C and phospho-CDC25C (Ser216) were associated with malignant features and aggressive cancer phenotypes. However, the CDC25s isoforms were not independently correlated to prognosis.</p
Cyclin A is a prognostic indicator in early stage breast cancer with and without tamoxifen treatment
Overexpression of G1-S regulators cyclin D1 or cyclin A is frequently observed in breast cancer and is also to result in ligand-independent activation of oestrogen receptor in vitro. This might therefore, provide a mechanism for failure of tamoxifen treatment. We examined by immunohistochemical staining the effect of deregulation of these, and other cell cycle regulators on tamoxifen treatment in a group of 394 patients with early stage breast cancer. In univariate analysis, expression of cyclin A, Neu, Ki-67 index, and lack of OR expression were significantly associated with worse prognosis. When adjusted by the clinical model (for lymph node status, age, performance status, T-classification, grade, prior surgery, oestrogen receptor status and tamoxifen use), only overexpression of cyclin A and Neu were significantly associated with worse prognosis with hazard ratios of, respectively, 1.709 (P=0.0195) and 1.884 (P=0.0151). Overexpression of cyclin A was found in 86 out of the 201 OR-positive cases treated with tamoxifen, and was the only independent marker associated with worse prognosis (hazard ratio 2.024, P=0.0462). In conclusion, cyclin A is an independent predictor of recurrence of early stage breast cancer and is as such a marker for response in patients treated with tamoxifen
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