Determination of unifloral honey volatiles from Centaurea iberica and Zizyphus spina-christi by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

The volatiles of two different unifloral Palestinian honeys from botanical species Centaurea iberica and Zizyphus spina-christi have been investigated for the first time. They were isolated, identified, and quantitatively analyzed using Headspace Solid-Phase Microextraction and Gas Chromatography Mass Spectrometry (HS-SPME-GCMS) methodology. The resulted total ion current (TIC) chromatographic profiles reflected the uniqueness of each type of honey and therefore the proposed procedure can be used to characterize each kind of honey by revealing the absence or presence of certain volatile constituents. A total of 18 compounds were seen in Centaurea iberica honey with phenylacetaldehyde, phenylethylalcohol, 2-ethyl hexanoic acid, 2,4,6-trimethylphenol and nonanoic acid as the principal components, whereas 25 compounds were seen in Zizyphus spinachristi honey with benzaldehyde, phenylacetaldehyde, phenylethylalcohol, benzeneacetonitrile, 2-ethyl hexanoic acid, octanoic acid, 2-methoxy-4-(1-propanol)-6-acetate phenol, nonanoic acid, decanoic acid, 1-hydroxy 2,4,6-trimethylbenzene, and 5-hydroxymethyl- 2-furaldehyde as the principal constituents. Ziziphus spina-christi honey was found to have two unequivocal potential markers: phenylacetonitrile and 5-hydroxymethyl-2-furancarboxaldehyde, while Centaurea Italica honey has only one representative floral origin marker compound: the 2,4,6-trimethylphenol

A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply

This paper elucidates one of the tracking schemes for a photovoltaic (PV) systems using Cuk converter operating in discontinuous inductor current mode (DICM) as an interface. A method for efficiently maximizing the output power of a solar panel supplying a load or battery bus under varying meteorological conditions is investigated and results presented therein. The incremental conductance (InCond) method of maximum power point tracking (MPPT) using the Cuks dc to dc converter operating in a discontinuous inductor current mode (DICM) was modeled and studied in relation to PV system interface. Also, laboratory setup was implemented based on the model. This was the main objective of the research. Similarly, the PV simulator was also modeled alongside with Cuk converter operating in DICM. MATLAB/SIMULINK software was used to carry out simulation test. With the incremental conductance method, the problem of sustained oscillation around the maximum power point of the solar panel which is the usual characteristic of the perturbation and observation method is essentially absent. The result disclosed that the power available for the load when MPPT was applied was 1.1 kW which gives a tolerance of 0.1% to the load it powers. But without MPPT, the available power is 0.9 kW using the same number of PV panels and batteries as back up. Hence, MPPT has 17.65% edge in power delivery over non-MPPT PV powered energy supply. An experimental prototype of a 1kW, 230V, 50Hz stand-alone solar based power supply with the incremental conductance scheme was successfully implemented using PIC 16F877 microcontroller, tested and results presented therein. The experimental results agreed with the simulated results.Keywords: Maximum Power point tracking, Cuk converter, Photovoltaic system, PIC 16F877A micro-controller, inverter, batteries

WWOX, the common fragile site FRA16D gene product, regulates ATM activation and the DNA damage response

Genomic instability is a hallmark of cancer. The WW domaincontaining oxidoreductase (WWOX) is a tumor suppressor spanning the common chromosomal fragile site FRA16D. Here, we report a direct role ofWWOXin DNA damage response (DDR) and DNA repair. We show that Wwox deficiency results in reduced activation of the ataxia telangiectasia-mutated (ATM) checkpoint kinase, inefficient induction and maintenance of γ-H2AX foci, and impaired DNA repair. Mechanistically, we show that, upon DNA damage, WWOX accumulates in the cell nucleus, where it interacts with ATM and enhances its activation. Nuclear accumulation of WWOX is regulated by its K63- linked ubiquitination at lysine residue 274, which is mediated by the E3 ubiquitin ligase ITCH. These findings identify a novel role for the tumor suppressor WWOX and show that loss of WWOX expression may drive genomic instabilityWe thank Dr. Eugenio Gaudio and Dr. Sonja Matt for technical help, Dr. Yossi Shiloh for the ataxia telangiectasia-mutated inhibitor, and Dr. Kay Huebner for the rabbit polyclonal WW domaincontaining oxidoreductase antibody. This study was supported by a German Israeli Foundation Joint Grant (to T.G.H. and R.I.A.), Israeli Cancer Research Funds (to Z.S. and R.I.A.), Deutsche Forschungsgemeinschaft Grant SFB1036 (to T.G.H.), and the Deutsche Krebshilfe (T.G.H.)

Effect of Harvesting Date and Variety of Date Palm on Antioxidant Capacity, Phenolic and Flavonoid Content of Date Palm (Phoenix Dactylifera)

The effect of date palm variety and harvesting date on total phenolic content, total flavonoid content, and antioxidant capacity of seven varieties of date palm fruits collected at different maturation stages obtained from date palm farms located in the Jericho area of the Jordan valley was investigated in this study. During different harvesting times (from June to September 2011), total phenolic content, total flavonoid content, and antioxidant capacity varied between 13.75-231.40 mg gallic acid equivalents (GAE), 1.72-9.6 mg catechin equivalents, and 142.0-719.3 μmol Trolox equivalents per 100 g dry weight sample for the seven varieties of date palm, respectively. Pearson correlation indicated that there is a strong significant correlation between antioxidant capacity and total phenolic content, as well as between antioxidant capacity and total flavonoid content for all date palm varieties investigated in this study. It is expected that these results will be useful to farmers particularly in their selection of harvesting time of the date palm fruits with high content of the bioactive compounds to meet the increasing demand on such healthy products.We are grateful to Beit Jala pharmaceutical company for performing HPLC analyses in their laboratories

Combating viral mosaic disease of cassava in the Lake Zone of Tanzania by intercropping with legumes

Cassava (Manihot esculenta Crantz) production is constrained by many factors, including the viral cassava mosaic disease (CMD). This study was conducted to explore the potential of intercropping cassava with legumes to reduce CMD effects on cassava production. Local (Lyongo Kwimba) and improved (Suma) cassava varieties were intercropped with three types of grain legumes (groundnut, Arachis hypogea L. var. Upendo; cowpea, Vigna unguiculata (L.) Walp. var. Vuli; and green gram, Vigna radiata (L.) R. Wilczek var. Imara). Monocrops of cassava with and without NPK fertilizer were included as controls. The experiment was established using a randomized complete block design with four replications in a split-plot arrangement for three seasons. Cassava varieties intercropped with cowpeas, green gram, and groundnuts and cassava monocrops with and without NPK fertilizer constituted the main plot and sub-plots, respectively. Whitefly population counts and CMD severity and incidence were measured at regular intervals. Cropping system had a significant effect (P < 0.05) on whitefly populations and CMD severity. Small whitefly populations (0–7.5 individuals per leaf) and low CMD severity (1–2.4 on a 5-point scale) were recorded in improved and local cassava varieties intercropped with green gram. The local cassava variety intercropped with green gram showed low CMD incidences (0%–40%) in all seasons. Generally, growing cassava with green gram proved effective in reducing whitefly populations and CMD incidence and severity. Intercropping cassava with grain legumes may improve cassava production and food security in CMD-prone areas of the Lake Zone of Tanzania and areas with similar environments

Nitrogen mineralization dynamics of different valuable organic amendments commonly used in agriculture

Published online: 27 February 2016This is an open access article under the CC BY-NC-ND licenseSustainable agriculture requires the careful optimization of the use of organic amendments to improve soil fertility while minimizing any harmful environmental effects. To understand the events that occur in soil after the addition of different organic amendments, we evaluated the nitrogen (N) mineralization dynamics in soil after adding organic amendments, and evaluated changes in the microbial population. The four organic amendments were fresh dairy cattle manure, fresh white clover, vegetable, fruit, and yard waste compost, and poplar tree compost. The N mineralization potential of each organic amendment was determined by analyzing total mineral nitrogen during a 97-day laboratory incubation experiment. Soils amended with clover released 240 μg N g−1 soil during the 97-day incubation, more than twice as much as that released from soils amended with manure or composts (76–100 μg N g−1 soil). At the end of the incubation, the net N mineralization in clover-amended soils was 54%, more than five times higher than that in soils amended with composts or manure (4%–9%). Nitrogen was mineralized faster in clover-amended soil (1.056 μg N g−1 soil day−1) than in soil amended with composts (0.361–0.417 μg N g−1 soil day−1). The microbial biomass carbon content was higher in clover-amended soil than in the soils amended with manure or composts. We monitored changes in the microbial population in amended soils by a phospholipid fatty acid (PLFA) analysis. On day 97, there were higher concentrations of total PLFAs in soils with organic amendments (e.g., 14.41 nmol g−1 in clover-amended soil) than in control soil without amendments (9.84 nmol g−1). Bacteria (Gram-positive and Gram-negative), actinomycetes, and fungi were more abundant in clover-amended soils than soils amended with manure or composts. The N mineralization potential varied among the four organic amendments. Therefore, the timing of application and the type of organic amendment should be matched to the nutrient needs of the crop

Use of hybrid solar-wind energy generation for remote area electrification in South-Eastern Nigeria

This paper presents simulated hybridized solar-wind generation as an alternative for rural dwellers that do not have access to a conventional grid connection. Solar and wind were used as the main sources of energy with battery storage. Each power source has a DC-DC converter to control the power flow. An axial flux permanent magnet generator, which is suitable for a location with a low wind speed, was driven by the wind turbine. By using this generator, the efficiency of the system increased since certain losses were removed. The perturbation and observation method of MPPT is used to achieve maximum power extraction from the solar panel. The hybrid system was modelled in Matlab/Simulink software. A squirrel cage induction motor was used as the electrical load to the system load. The results obtained for the proposed hybrid system indicates that it can be used as an isolated power supply. By doing so, it improves the standard of living and hence, increasing total number of citizens using energy in the country

Use of hybrid solar-wind energy generation for remote area electrification in South-Eastern Nigeria

This paper presents simulated hybridized solar-wind generation as an alternative for rural dwellers that do not have access to a conventional grid connection. Solar and wind were used as the main sources of energy with battery storage. Each power source has a DC-DC converter to control the power flow. An axial flux permanent magnet generator, which is suitable for a location with a low wind speed, was driven by the wind turbine. By using this generator, the efficiency of the system increased since certain losses were removed. The perturbation and observation method of MPPT is used to achieve maximum power extraction from the solar panel. The hybrid system was modelled in Matlab/Simulink software. A squirrel cage induction motor was used as the electrical load to the system load. The results obtained for the proposed hybrid system indicates that it can be used as an isolated power supply. By doing so, it improves the standard of living and hence, increasing total number of citizens using energy in the country