Cropping system effects on carbohydrate content and water-stable aggregates in a calcareous soil of Central Iran

The effect of humus, readily decomposable organic matter, and carbohydrates of a nonspecific nature on the formation of water-stable aggregates in field rotation members of a calcareous soil in central Iran, Isfahan (fine loamy mixed thermic typic haplargid) has been studied. The study was carried out at Lavark experimental farm in plots receiving 0 (T1), 25 (T2), 50 (T3) and 100 (T4) Mg/ha of manure for 5 years successively with a cropping rotation of wheat (Triticum aestivum L.)–corn (Zea mays L.) every year and plots under similar chemical fertilizer management but with three different cropping rotations (T5, T6 and T7) that has been the prevalent cropping systems. Three replications of soil sample in each treatment and at the depths of 0–5 and 5–15 cm were used to measure organic carbon (OC), hot-water-soluble carbohydrate, dilute acid hydrolysable carbohydrate, cold-water-soluble carbohydrate and mean weight diameter of water stable aggregates. The highest amount of carbohydrate (700 mg/kg) and aggregate stability (0.8 mm) were obtained in plots with 100 Mg/ha manure (T4). The amount of carbohydrate extracted from soil samples decreased in the order of hot water, dilute acid and cold water extracts.Aggregate stability had a better correlation with hot water (r = 0.74**) and dilute acid-soluble carbohydrate (r = 0.73**) than organic carbon (r = 0.62**) content of soil. This indicates that the carbohydrate extracted by hot water and dilute acid may be a suitable indicator for showing soil quality, particularly in relation to soil aggregation.     

Induction of humoral and cellular immunity against latent HSV-1 infections by DNA immunization in BALB/c mice

Previously, we have reported that the injection of an expression vector containing Herpes simplex virus (HSV) Glycoprotein D-1 (gD-1) generated a significant antibody response in mice and protected them against HSV lethal challenge. We tested its potential to induce antibody and cell mediated immune responses in latently infected mice. Positive control group (KOS) and HSV gD-1 vaccinated mice demonstrated protection against a lethal ocularly challenge of 10(5.5) plaque-forming units (pfu)/eye of wild HSV-1 versus negative control groups. For neutralizing antibody titers, delayed-type hypersensitivity (DTH), lymphocyte proliferation responses, clinical evaluation and survival following lethal challenge, no considerable difference was observed between mice vaccinated with DNA plasmid and those vaccinated with KOS. KOS-vaccinated mice demonstrated the ability to completely prevent latency whereas DNA vaccinated group showed some degree of protection and displayed less latency than negative control groups and had considerably high levels of IFN-gamma and strong CTL responses versus negative control groups. It can be concluded that although immunization with the DNA vaccine is more effective in both protecting mice and induction of immune response, however it could not completely block the latent infection in sensory nerves.     

Richesse spécifique des ennemis naturels associés aux vergers d'agrumes au Maroc: Intérêt et implication pour la lutte biologique

Ce travail a pour objectif de connaitre la richesse spécifique des ennemis naturels associés aux vergers d'agrumes au Maroc de 2001 à 2011. Les parasitoides Aphytis hispanicus Mercet, Aphytis lepidosaphes Compere, Aphytis melinus De Bach, Aphidius spp., Cales noacki Howard, Comperiella bifasciata Howard, Leptomastix dactylopii Howard, Citrostichus phyllocnistoides Narayanann et Semielacher petiolatus Girault, sont les plus abondants. Seules quatre espèces contribuent rèellement à la diminution de certains ravageurs du verger : A. melinus pour Aonidiella aurantii Maskell, C. noacki pour Aleurothrixus floccosus Maskell, et C. phyllocnistoides et S. petiolatus pour Phyllocnistis citrella Stainton. La cératite Ceratitis capitata Wiedemann est uniquement parasitée par Psyttalia concolor Szepligeti, mais sans avoir un impact réel de réduction de ses populations. Les prédateurs Adalia decempunctata L., Aphidoletes Aphidimyza Rondani, Chrysoperla carnea Stephens, Coccinella septempunctata L., Cybocephalus spp., Episyrphus balteatus DeGeer, Rodolia cardinalis Mulsant, Rhyzobius lophantae Blaisdell, Scymnus spp. et Stethorus punctillum Weise, sont les plus abondants. La coccinelle S. punctilllum et certaines espèces des genres Euseius, Iphiseius, Phytoseiulus, Neoseiulus, Typhlodromus, limitent essentiellement les populations des acariens. La conservation et la prise en compte de ces espèces bénéfiques dans les programmes de protection intégrée en vergers d'agrumes au Maroc est une nécessité. Certaines de ces espèces utiles inventoriées, en particulier celles introduites et reconnues comme efficaces en lutte biologique sur agrumes au Maroc, devraient êtres inscrites dans la Norme PM 6/3 de l'OEPP (Organisation Européenne et Méditerranéenne pour la Protection des Plantes).     

Detection and Molecular Characterization of Salmonella enterica Serovar Eppendorf Circulating in Chicken Farms in Tunisia

Salmonella enterica subsp. enterica serovar Eppendorf, with antigenic formula 1,4,12,[27]:d:1,5, is an infrequent serovar. However, 14% (20 of 142) of the isolates recovered during June–July 2012 in chicken farms in Tunisia belonged to S. Eppendorf. These isolates were analysed for resistance and virulence profiles. None of them were susceptible to all antimicrobials tested, while 70%, 60%, 50%, 50%, 20% and 5% were resistant to sulphonamides (sul1, sul2 and sul3), streptomycin (aadA1‐like), trimethoprim (dfrA1‐like), nalidixic acid (GyrA Asp₈₇→Asn and not identified), gentamicin (not identified) and ampicillin (bla_TEM‐1‐like). About 30% of the isolates showed decreased susceptibility to ciprofloxacin and carried the qnrB gene; 65% of the isolates were multidrug resistant and contained class 1 integrons with sul1 or sul3 in the 3′ conserved segment. The orgA, ssaQ, mgtC, siiD and sopB virulence genes located on SPI1 to SPI5 and the fimbrial bcfC gene were present in all isolates; the sopE1 and sodC1 carried by prophages were variably detected; however, the prophage gipA gene and the spvC gene of serovar‐specific virulence plasmids were absent. Altogether, ten resistance and three virulence profiles were identified. Typing of the isolates with XbaI‐ and BlnI‐PFGE supports a close relationship, although they appear to be evolving under selective pressure probably caused by antimicrobial use in chicken husbandry. As far as we know, this is the first study investigating the molecular bases of antimicrobial drug resistance, the virulence gene content and the PFGE profiles of S. Eppendorf. The epidemiological surveillance of this serovar would be necessary to evaluate its possible impact on human health, particularly in Tunisia and other African countries where it was already reported.     

Prediction of Repair and Maintenance Costs of Two-wheel Drive Tractors in Iran

Predicting of repair and maintenance （R＆M） costs of tractors in any mechanized farm is necessary for owners and managers to obtain information on overall costs and to control financial balance and production economy. In this context a study was conducted to predict accumulated R＆M costs （Y） of two-wheel drive （2WD） tractors based on accumulated usage hours （X） in Misagh-e-Sabz Agribusiness Company in Iran. Recorded data of the company were used to determine regression models for predicting accumulated R＆M costs （as percentage of initial purchase price） based on accumulated usage hours. The statistical results of the study indicated that in order to predict accumulated R＆M costs of 2WD tractors with accumulated usage hours of 2260 h or less the power regression model Y=0.013 （X/100）1.677 with R2=0.976, and to predict accumulated R＆M costs of 2WD tractors with accumulated usage hours of 2260 h or more the polynomial regression model Y=0.004 （X/100）2-0.181 （X/1 00）＋4.373 with R2=0.998 can be strongly suggested.     

Kinetics of Indigenous Isolated Bacteria used for Ex-Situ Bioremediation of Petroleum Contaminated Soil

The bioremediation of petroleum contaminated soil was investigated using a laboratory scale aerated reactor. The Indigenous bacteria, Stenotrophomonas multophilia, were isolated from the contaminated sites near to Jordan Petroleum Refinery and used further in the bioremediation experiments. First order kinetic equation has been proven to satisfactorily describe the biodegradation of petroleum contained in soil in the presence of the isolated bacteria. The results also showed that the first order kinetic constants for the different bioreactors vary between 0.041 and 0.0071/day. The overall kinetic constant k′ was determined based on food-to-microorganisms ratio and found to be 0.02/day.     

Effect of copper and nitrogen nutrients on diosgenin production in fenugreek

Different amounts of nitrogen (N) and copper (Cu) in the forms of urea and copper sulfate (CuSO₄·5H₂O) were applied and their effects on diosgenin production and dry matter yield in fenugreek were investigated under farm cultivation conditions. High-performance liquid chromatography (HPLC) was employed to analyze diosgenin content. Diosgenin contents were measured in 25, 45 and 65 day-old leaves and in leaves at flowering stage and in fruits. The maximum diosgenin content was obtained in 45 day-old leaves. The results showed that simultaneous addition of Cu and N and the level of supply had significant effects on diosgenin production in leaves, fruits and dry matter yield. Simultaneous use of urea (100 kg ha^?1) and copper sulfate (30 kg ha^?1) increased diosgenin production and dry matter yield in 45 day-old leaves for 7.72 and 1.32 times, respectively, compared to unfertilized control group. But, the use of higher amounts of urea and copper showed a decrease in diosgenin production.     

Interaction of Marek's disease virus and Cryptosporidium baileyi in experimentally infected chickens

Histocompatible B13/B13 white specific-pathogen-free leghorn chickens were used to investigate the effect of coinfection with Cryptosporidium baileyi and the HPRS 16 strain of Marek's disease virus (MDV) in chickens and to assess the pathogenicity of C. baileyi when MDV is given before or after the parasite. Groups of chickens concurrently infected with C. baileyi orally inoculated at day (D)4 and MDV inoculated at hatching (C4M0 group) or at D8 (C4M8 group) were compared with relevant control groups inoculated with only C. baileyi at D4 (C4 group), only MDV at hatching (M0 group) or at D8 (M8 group), and an uninoculated control group (UC group). The chickens were kept in isolator units until the end of the experiment at D62. Our results showed a considerable synergistic effect in concurrently infected chickens and more severe consequences when chickens received MDV before C. baileyi infection. In fact, except for a slight transitory weakness, the chickens in C4 group remained free of overt clinical signs and there was no mortality. However, coinfection with both pathogens induced more lasting or permanent oocyst shedding. Severe clinical cryptosporidiosis with weakness, anorexia, depression, growth retardation, and chronic and severe respiratory disease causing death occurred in all chickens in the C4M0 group between D12 and D43 and in 67% of the chickens in the C4M8 group between D17 and D57. Eighty-two percent and 33%, respectively, died before the development of specific Marek's disease lesions. Mortality rates were 27% and 33% in the M0 and M8 groups, respectively. The presence of MDV enhanced the establishment of more lasting cryptosporidial infection in the respiratory tract, esophagus, crop, proventriculus, and kidneys (only in C4M0 group) as well as in bursa of Fabricius, ceca, and cloaca. Serologic analysis showed that chickens with chronic cryptosporidiosis in the C4M8 group had an increased level of C. baileyi-specific immunoglobulin A. Our results may explain some cases of mortality in chickens naturally infected with MDV and Cryptosporidium.     

Renal Cryptosporidiosis (Cryptosporidium baileyi) in specific-pathogen-free chickens experimentally coinfected with Marek's disease virus

Renal Cryptosporidiosis was experimentally induced during a study to investigate the pathogenicity of Cryptosporidium baileyi in specific-pathogen-free (SPF) chickens coinfected with Marek's disease virus (MDV). Cryptosporidium baileyi was administered orally at 4 days of age to chickens previously infected at hatching (day 0) with the HPRS 16 strain of oncogenic MDV. Three control groups received MDV at hatching, C. baileyi on day 4, or placebo consisting of distilled water. Renal cryptosporidiosis lesions were induced in the group coinfected with MDV and C. baileyi. The kidneys were markedly swollen and pale, with visible urate crystals in the ureters and surface tubules. Oocysts of C. baileyi were demonstrated in six of seven cases tested by a scoring method with modified Sheather's sugar solution on renal tissue scrapings and were confirmed in three cases by histologic examination of paraffin-embedded kidney sections. Histologic study also revealed subacute interstitial nephritis, acute ureteritis, and attachment of cryptosporidia on the epithelial cell surface of the ureters and collecting ducts, collecting tubules, and distal convoluted tubules. Various developmental stages of the parasite were present in the kidney sections. To our knowledge, this is the first report of experimentally induced renal cryptosporidiosis in SPF chickens coinfected with MDV.