Investigation of mechanical properties of developed antimicrobial PPsuture/Ag nanocomposite

In order to prevent surgical complications due to microbial infections, we have developed polypropylene suture grafted with silver nanoparticles (PPsuture/Ag nanocomposite) by a simple immersion procedure. Physical and mechanical properties of developed suture are investigated. Suture surface characteristics are examined by scanning electron microscopy (SEM) imaging and atomic force microscopy (AFM). Silver content on suture surface was determined by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). The mechanical properties of developed antibacterial PP suture/Ag were studied. We note that proposed silver coating method has not affected mechanical performances of suture. Antimicrobial performances of PP suture/Ag nanocomposites against S. aureus and E. coli colonies were also investigated.     

Latency sites and reactivation of duck enteritis virus

Duck virus enteritis (DVE) is a contagious disease caused by herpesvirus in waterfowl populations. Recovered birds become carriers and shed the virus periodically. Reactivation of latent duck enteritis virus (DEV) has been implicated in outbreaks of DVE in domestic and migrating waterfowl populations. In this study, the sites for virus latency were determined in white Pekin ducks infected with the DEV-97 strain. At 3 wk postinfection, infectious virus was not detectable in tissues or cloacal swabs (CSs). At 7 and 9 weeks postinfection, the viral DNA was detected by polymerase chain reaction in the trigeminal ganglia (TG), suggesting that the virus is latent. Viral DNA was detected in the peripheral blood lymphocytes (PBL), spleen, thymus, bursa, and CSs only after in vitro cocultivation. In vivo virus reactivation was demonstrated when dexamethasone or a combination of dexamethasone and cyclophosphamide was inoculated in latently infected ducks. The reactivation of DEV occurred without any clinical evidence of the disease, but the virus was detected in PBL and CSs. We conclude from this study that DEV establishes latency in TG and lymphoid tissues including PBL.     

Effect of gamma-irradiated entomopathogenic nematodeSteinernema carpocapsae (Fil.) on the larvae of the potato tuber moth,Phthorimaea operculella (Zell.)

The effect of gamma irradiation on the pathogenicity of the entomopathogenic nematodeSteinernema carposapsae was studied by infecting the larvae of the potato tuber moth,Phthorimaea operculella. Full grown larvae of the host were gamma-irradiated with different doses ranged from 2.5 to 160 Gray (Gy) and subsequently infected with either unirradiated or irradiated infective juveniles (IJs) ofS. carpocapsae using the same doses. For comparison, two groups of unirradiated and irradiated host larvae were left without nematode infection. Another group of larval host was also infected with nematodes either unexposed or exposed to the previous doses.The results revealed that there was a rapid mortality in the irradiated host infected with either unexposed nematodes or nematodes irradiated with different doses similar to the mortality in the nematode treatment alone. On the other hand, the pathogenicity of the nematodes was affected as a result of gamma irradiation with high doses, i. e. irradiation of nematodes delayed their efficiencyvis à vis the unirradiated host. However, lower doses of gamma irradiation exhibited worthily stimulating effect on the pathogenic nematodes, one week post irradiation, as it reduced by half the period of time required for killing all irradiated host larvae with regard to nematode treatment alone. Furthermore, nematode treatment whether applied alone or combined with gamma irradiation appears very promising as compared with single irradiation treatment of the host.With 3 tables     

Mild photochemical synthesis of the antioxidant hydroxytyrosol via conversion of tyrosol

Hydroxytyrosol, a naturally occurred orthodiphenolic antioxidant molecule found in olive oil and olive mill wastewaters, was obtained from the wet hydrogen peroxide photocatalytic oxidation of its monophenolic precursor tyrosol. The liquid-phase oxidation of tyrosol to hydroxytyrosol was performed by use of an iron-containing heterogeneous catalyst (Al-Fe)PILC with the assistance of UV irradiation at 254 nm and at room temperature. The spectroscopic and HPLC data of the synthesized compound proved to coincide fully with those of a pure sample obtained by continuous countercurrent extraction. This reaction was found to be light-induced. The hydroxytyrosol synthesis reaction reached its maximum yield of 64.36% under the optimized operating conditions of 3.6 mM tyrosol, 0.5 g L(-1) catalyst, and 10(-2) M H2O2 with the assistance of UV light. Increasing the initial hydrogen peroxide concentration more than 10(-2) M has a diminishing return on the reaction efficiency. Catalyst can be recuperated by means of filtration and then reused in a next run after regeneration since its activity did not significantly decrease (<10%). The reaction synthesis is operationally simple and could find application for industrial purposes.     

Developing scoring functions for soil quality to assess land suitability for irrigated wheat in Southern Algeria

Efficient land-use management could be optimized through appropriate advice regarding land suitability and achieving a reasonable yield while preserving soil and environmental conditions. The main objective of this study was to determine and define those locations capable of wheat cultivation with irrigation in the municipality of N’goussa (Southern Algeria). Expert opinion (EO) method was used for selecting minimum soil data set (MDS_-EO), where six influencing soil properties (sand, pH, salinity, organic matter, gypsum and lime) and other three key parameters (slope, land use/land cover, and proximity to roads and electricity network) were considered important for irrigated wheat cultivation in the study area. Indicators were weighted according to principal component analysis (PCA) loadings and summed. PCA revealed that the selected nine indicators are appropriate for accounting 73.63% of the total variance. Two maps of land suitability were created here (expressed as a soil quality index within a range from 0 to 1) from multivariate analysis and already known standard scoring functions (SSFs) by using two data sets (pure and scored). The distribution of soil quality index (IQI) showed that above 70% of the land was moderately (MS) to highly suitable (HS) for irrigated wheat. The estimation accuracy of soil quality classes has been evaluated using random forests (RF), having as a dependent variable the final class of land suitability used in each map. It was determined that estimation accuracy could reach 60% (pure data set) and 65% (scored data set) at 0.5 cut-off value for soil quality classes. Final prioritizing according to ranks of sensitivity index (SI) and efficiency ratio (ER) showed that IQI obtained from scored data set is the most suitable approach in soil quality assessment of arid areas. Therefore, it could be applied in southern Algeria for land management, integrated planning and environmental assessments.     

Performance and heterosis from crossing local cattle in the Sudan

Summary Local Sudanese breeds were crossbred at Ghazala Gawazat Research Station in western Sudan to utilise the advantage of heterosis. The breeds involved were Kenana (KK), Butana (BB), and Western (WW). Lactation milk yields were 277·7 and 252 kg/210 days from two teats for BB and WW respectively. Offspring from BB and KK sires bred to WW dams had 8·5% and 25% higher lactation milk yield respectively, than straightbred WW cows. The percentage heterosis for total milk yield was 3·3. The reproductive effectiveness of all breed types was below 100%; indicating that most cows did not calve at regular intervals of 365 days. The local crosses (Butana × Western [BW]) had an, earlier age at first calving and shorter calving interval, by 46 and 17% respectively below their respective straightbreds. Weaning weights (205-day) were 66·4, 58·5, 69·5 and 64·8 kg for BB, WW, BW and KW, respectively. The estimated heterosis for weaning weight was 16·1 per cent.

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Resumen En este ensayo, se cruzaron razas locales en la Estación Experimental de Ghazala Gawazat, en el occidente de Sudán, para expresar la heterosis. Las razas involucradas fueron la Kenana (KK), Butana (BB) y la Occidental (WW). Las producciones por lactación fueron de 277·7 y 252 kg en 210 días, tomada la medición de dos pezones, para BB y WW, respectivamente. Las hijas, de toros BB y KK que sirvieron hembras WW, tuvieron 8·5% y 25% producciones de leche mas altas respectivamente, que las vacas WW servidas con toros de la misma raza. El porcentaje de heterosis para producción de leche total fue 3·3. La efectivaded, reproductiva de todos los tipos cruzados fue monor del 100%; indicación ésta de que la mayoría de las vacas no parieron a intervalos regulares de 365 días. Los cruces locales (Butana × Western [BW]) tuvieron una minore edad más temprana a la primera parición e intervalos entre partos más cortos de 46 y 17% respectivamente, por debajo de las respectivas razas puras. Los pesos al destete (205 días) fueron 66·4, 58·5, 69·5 y 64·8 kg para BB, WW, BW, y KW, respectivamente. La heterosis estimada por peso al destete fue 10·1 por ciento.

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Résumé Des races bovines soudanaises locales ont été croisées à la station de recherche de Ghazala Gawazat, au Soudan occidental, pour tirer profit du phénomène d'hétérosis. Les races concernées étaient: la Kenana (KK), la Butana (BB) et la Western (WW). La production laitère, a été de 277,7 et 252 kg en 210 jours avec deux trayons pour la BB et la WW respectivement. Les animaux issus de pères BB et KK croisés avec des mères WW ont produit, respectivement, 8,5 et 25 p 100 de plus que les femelles WW non croisées. Le pourcentage d'hétérosis pour le rendement laitier total était de 3,3 p 100. La production significative, tous types de races confondus, était inférieure à 100p 100, indiquant ainsi que la plupart des vaches n'ont pas vêlé à un age moins avancé au premier vêlage, avec des inter-vêlages plus courts, de 46 et 17 p 100 respectivement inférieurs par rapport aux produits non croisés. Les poids au sevrage à 205 jours on été respectivement de 66,4, 58,5, 69,5 et 64,8 kg pour BB, WW, BW et KW. L'hétérosis estimé pour obtenir un gain de poids est de 10,1 p 100.

     

Do dogs use a mirror to find hidden food?

Dog (Canis familiaris) cognition research that examines whether dogs are able to use a mirror as a problem-solving tool is rare. The aim of this study was to explore whether dogs could find food that was visible only via a mirror at the beginning of the experiment. In a laboratory setting, we exposed 44 dogs to a large mirror, attached at a 90° angle to an opaque barrier for 10 minutes. Dogs were allowed complete freedom of movement. For the first minute of the exposure phase, the owner and experimenter stood against a wall, ignoring the dog; afterward, both walked around the room for 9 minutes. The dogs could observe their movements in the mirror. Then, dogs were taught to associate a bowl with food, after which the bowl was surreptitiously placed behind the barrier, and the dogs were positioned so that they could see the reflection of the food in the mirror. Dogs were pseudorandomly assigned to the experimental group (n = 22) as described or a control group (n = 22), which was identical except that the mirror was covered during the testing phase. In the testing phase, dogs that could see the mirror were more likely to find the treat than dogs that could not (P = 0.032). Although fewer dogs in the control condition found the food, those that did were just as likely as those in the mirror condition to locate it within 3 minutes. This suggests that, although dogs' food-searching behavior can be triggered by the mirror's visual cues to locate food, some dogs used other cues that we were unable to control.     

Evaluation of Water Stress Tolerance of Soybean Using Physiological Parameters and Retrotransposon-Based Markers

Drought is one of the most important environmental stresses that severely reduce plant growth and crop productivity. This study was carried out to investigate the difference in the response of six soybean cultivars (Giza 21, 22, 35, 82, 83 and 111) under water stress and the genetic difference between these cultivars using retroelements technique. The results showed that drought stress caused reduction in morphological criteria, photosynthetic pigments, starch, phospholipids, glycolipids, pectin, cellulose and lignin in shoots of all soybean cultivars except Giza 22 and Giza 83. On the other hand, there was a considerable increase in root length, soluble sugars, proline, glycine betaine, total lipids and hemicellulose contents in the shoots of the soybean cultivars in response to water stress. The soybean cultivars Giza 22 and 83 were more drought tolerant than the other cultivars while Giza 21 and Giza 111 were the most sensitive. Inter-primer binding sites (iPBS) and inter-retrotransposon amplified polymorphism (IRAP) techniques were used to fingerprint the six soybean cultivars using a set of eight primers. The techniques successfully tagged each cultivar with specific bands and detected molecular genetic markers related to drought tolerance in soybean.