Irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn

The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. This study was conducted for 2 years (2005 and 2006) to establish optimal irrigation rates and plant population densities for corn (Zea mays L.) in sandy soils using drip irrigation system. The study aimed at achieving high yield and efficient irrigation water use (IWUE) simultaneously. A field experiment was conducted using a randomized complete block split plot design with three drip irrigation rates (I₁: 1.00, I₂: 0.80, and I₃: 0.60 of the estimated evapotranspiration), and three plant population densities (D₁: 48,000, D₂: 71,000 and D₃: 95,000 plants ha⁻¹) as the main plot and split plot, respectively. Irrigation water applied at I₁, I₂ and I₃ were 5955, 4762 and 3572 m³ ha⁻¹, respectively. A 3-day irrigation interval and three-way cross 310 hybrid corn were used. Results indicated that corn yield, yield components, and IWUE increased with increasing irrigation rates and decreasing plant population densities. Significant interaction effects between irrigation rate and plant population density were detected in both seasons for yield, selected yield components, and IWUE. The highest grain yield, yield components, and IWUE were found for I₁D₁, I₁D₂, or I₂D_1, while the lowest were found for I₃D₂ or I₃D₃. Thus, a high irrigation rate with low or medium plant population densities or a medium irrigation rate with a low plant population density are recommended for drip-irrigated corn in sandy soil. Crop production functions with respect to irrigation rates, determined for grain yield and different yield components, enable the results from this study to be extrapolated to similar agro-climatic conditions.     

Time-dependent changes in protein phosphorylation patterns in rat brain synaptosomes caused by deltamethrin

Effects of deltamethrin, a powerful pyrethroid insecticide, on the protein phosphorylation and dephosphorylation processes during depolarization in rat brain synaptosomes were studied by using [³²P]phosphoric acid as a starting radiotracer and high external concentration of potassium ions or veratridine (10^?-5 M) as depolarizing agents. At the onset of depolarization there was a quick rise in phosphorylation in various synaptic proteins for about 15–30 s followed by a gradual decline in levels of phosphorylation. The effect of deltamethrin (10^?-7 M) on this system was found to be dependent on the length of preincubation of the synaptosome with the pesticide prior to depolarization. At an early stage (0–3 min preincubation period) it caused a modest suppression of protein phosphorylation activities. When the period of deltamethrin preincubation was extended to 5–20 min, however, it caused a significant increase in protein phosphorylation throughout the depolarization period. At the later stage of the action of deltamethrin (e.g. preincubation period of 30–40 min), deltamethrin-treated synaptosomes no longer responded to the depolarization signal to raise the level of phosphorylation on many proteins. These results indicate that deltamethrin's actions on the synaptic process are complex. Depending on the length of exposure, its effects on protein phosphorylation responses in intact synaptosomes could be either stimulatory or inhibitory. To study the cause of deltamethrin-induced synaptic block at the later stage, effects of deltamethrin on protein kinases were studied by using lysed synaptic membranes with [gamma-³²P]ATP. Deltamethrin was shown to inhibit calcium–calmodulin-dependent protein phosphorylation activities at 10^?-7 M when given directly to the enzyme source 10 min prior to the addition of [³²P]ATP. Such an observation helps to explain the inhibitory action of deltamethrin on protein phosphorylation which occurs at the late stage of its action (i.e. preincubation time > 20 min).     

Towards sustainable control of Lepidopterous pests in olive cultivation

Zusammenfassung Traditionelle, extensiv bearbeitete Olivenhaine, aber auch moderne Intensiv-Plantagen mit künstlicher Bewässerung und hohem Einsatz von Düngern bzw. chemischen Pflanzenschutzmitteln kennzeichnen die derzeitigen verschiedenen Anbauformen der Olive im Mittelmeerraum. Schadlepidopteren wie die Olivenmotte (Prays oleae, Lep.: Yponomeutidae) und die Jasminmotte (Palpita unionalis, Lep.: Pyralidae) werden durch regelmässigen Insektizideinsatz bekämpft. Das von der EU geförderte internationale Forschungsprojekt TRIPHELIO zielte auf die Entwicklung insektizidfreier Alternativmethoden durch (1) die Optimierung der pheromongestützten Überwachung und Verwirrtechnik, (2) der Anwendung von Habitatmanagement-Strategien zur Förderung natürlicher Gegenspieler, und (3) dem Einsatz von Trichogramma-Schlupfwespen. Zusätzlich wurden Module für eine optimale Anwendung biotechnischer und biologischer Methoden bezüglich der Phänologie der Schadinsekten und möglicher Nebenwirkungen von Pestiziden erarbeitet. Die intensive Kooperation zwischen Wissenschaftlern und Praktikern aus mehreren Ländern Europas und Nordafrikas erlaubte den Entwurf möglicher Lösungsansätze für verschiedene Anbaubedingungen und klimatische Regionen des Mittelmeerraumes. Die wichtigsten Ergebnisse und Ausblicke für eine zukünftige praktische Umsetzung werden in dieser Veröffentlichung beschrieben.     

Radar soundings of the subsurface of Mars

The martian subsurface has been probed to kilometer depths by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument aboard the Mars Express orbiter. Signals penetrate the polar layered deposits, probably imaging the base of the deposits. Data from the northern lowlands of Chryse Planitia have revealed a shallowly buried quasi-circular structure about 250 kilometers in diameter that is interpreted to be an impact basin. In addition, a planar reflector associated with the basin structure may indicate the presence of a low-loss deposit that is more than 1 kilometer thick.     

Effect of dietary supplementation of Bacillus subtilis spores on growth performance,oxidative status,and digestive enzyme activities in Japanese quail birds

Tropical Animal Health and Production - The present trial investigated the feeding effect of B. subtilis spores on growth performance, blood metabolites, antioxidative status, and digestive enzyme...     

~(60)Co-γ射线在组织培养中对培养基的消毒作用

本文报道在植物组织培养中,~(60)Co_(-γ)射线对培养基的消毒作用,旨在探明,用~(60)Co_(-γ)射线消毒培养基的可行性及对培养效果的影响。结果表明,经~(60)Co_(-γ)射线600krad 处理培养基能达到灭菌。其培养基能促进愈伤组织的生长,而对绿苗分化率没有影响。辐射导致的茶色培养瓶可促进水稻愈伤组织根的分化和生长而抑制芽的分化。     

Alleviating effects of β‐glucan in Oreochromis niloticus on growth performance,immune reactions,antioxidant, transcriptomics disorders and resistance to Aeromonas sobria caused by atrazine

Three hundred Oreochromis niloticus were divided into five groups; the control fish (CNT) were fed a basal diet, beta glucan (βG) group was fed 0.5 g/kg^?1 βG, atrazine (ATZ) group was exposed to 1/5 96‐hr LC₅₀ (1.39 mg/L) ATZ, the (βG/ATZ) group was fed βG while being exposed to ATZ, and the (βG then ATZ) group was supplemented with βG for fifteen days before exposed to ATZ. ATZ exposure caused a decline in growth that was ameliorated by βG. ATZ reduced the levels of total and different types of leucocytes. Additionally, ATZ exposure caused reductions in total proteins, globulins, α 1‐globulin, α 2‐globulin, ?‐globulin, immunoglobulin M, lysozymes, superoxide dismutase, nitric oxide and catalase but increases in hepatic transaminases and malondialdehyde without any variations in albumin and β‐globulin. Exposure to ATZ also resulted in a rise in the mRNA level of IL‐8. In contrast, expression of IgM, SOD and CAT were decreased in the tilapias exposed to ATZ. Exposure to ATZ increases the susceptibility response to Aeromonas sobria challenge, as indicated by an increase in cumulative mortality post‐challenge. Supplementation with βG fifteen days before (βG then ATZ group), counteracted the adverse effects of ATZ on the immune, biochemical and antioxidants values, though only slight alleviation was observed with simultaneous treatment (βG/ATZ group). Our results established that ATZ has adverse impacts on immune responses, antioxidant equilibrium and its related genes. While, supplementation with βG before exposure to ATZ may be valuable for counteracting the possible damage caused by ATZ water pollution than its simultaneous treatment with ATZ.     

Diversity of bacterial pathogens and their antimicrobial resistance profile among commensal rodents in Qatar

Rodents are sources of many zoonotic pathogens that are of public health concern. This study investigated bacterial pathogens and assessed their antimicrobial resistance (AMR) patterns in commensal rodents in Qatar. A total of 148 rodents were captured between August 2019 and February 2020, and blood, ectoparasites, and visceral samples were collected. Gram-negative bacteria were isolated from the intestines, and blood plasma samples were used to detect antibodies against Brucella spp., Chlamydophila abortus, and Coxiella burnetii. PCR assays were performed to detect C. burnetii, Leptospira spp., Rickettsia spp., and Yersinia pestis in rodent tissues and ectoparasite samples. Antimicrobial resistance by the isolated intestinal bacteria was performed using an automated VITEK analyzer. A total of 13 bacterial species were isolated from the intestine samples, namely Acinetobacter baumannii, Aeromonas salmonicida, Citrobacter freundii, Citrobacter koseri, Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Hafnia alvei, Klebsiella pneumoniae, Providencia stuartii, Proteus mirabilis, Pseudomonas aeruginosa, and Salmonella enterica. The majority of them were E. coli (54.63%), followed by P. mirabilis (17.59%) and K. pneumoniae (8.33%). Most of the pathogens were isolated from rodents obtained from livestock farms (50.46%), followed by agricultural farms (26.61%) and other sources (22.94%). No antibodies (0/148) were detected against Brucella spp., C. abortus, or C. burnetii. In addition, 31.58% (6/19) of the flea pools and one (1/1) mite pool was positive for Rickettsia spp., and no sample was positive for C. burnetii, Leptospira spp., and Y. pestis by PCR. A total of 43 (38%) bacterial isolates were identified as multidrug resistant (MDR), whereas A. salmonicida (n?=?1) did not show resistance to any tested antimicrobials. Over 50% of bacterial MDR isolates were resistant to ampicillin, cefalotin, doxycycline, nitrofurantoin, and tetracycline. The presence of MDR pathogens was not correlated with rodent species or the location of rodent trapping. Seven (11.86%) E. coli and 2 (22.2%) K. pneumoniae were extended-spectrum beta-lactamases (ESBL) producers. These findings suggest that rodents can be a source of opportunistic bacteria for human and animal transmission in Qatar. Further studies are needed for the molecular characterization of the identified bacteria in this study.

     

Influence of uterine torsion in water buffaloes (Bubalus bubalis) with insights into the hematological and biochemical prognostic values regarding to manual correction

Bovine uterine torsion refers to the rotation of the gravid uterus around its longitudinal axis. It is the dominant cause of dystocia in buffaloes. A total of two hundred and seventeen dystocia’s Egyptian buffaloes were examined, and another twenty were apparently normal at the full term (healthy pregnant group). From the dystocia’s buffaloes, twenty-three percentage (n = 50) was uterine torsion after gynecology inspection at presentation (Ut group) and 5 days after the manual correction (Utc group). The buffaloes with uterine torsion exhibited loss of appetite, constipation, colic, and straining. The incidence of torsion was mostly at first parity that accounting for 50% of cases. Regarding to the pregnancy stage, torsion mostly occurred at full term, where it primarily occurred in buffaloes at 3 years of age. Right-sided torsion ensued in 90% of all cases. The survival rate of the pregnant buffaloes was 90% (45 buffaloes), and 10% (5 buffaloes) was directed to the culling. Regarding to the fetal survival outcome, 30% of fetuses was survived where the other 70% was died. The hematological results denoted leucocytosis in Ut and Utc groups that attributed to neutrophilia, monocytosis, and eosinophilia. Biochemical assessments were denoted an augments in the levels of serum AST, LDH, CPK, creatinine, blood urea nitrogen, progesterone, cortisol, MDA, NO, TAC, blood lactate (bLac), TNF-α, and IL-6. Where there were a non significant fluctuations in the ALT, GGT, calcium, and phosphorus levels in the torsion cases. The significant declines in 17-β-oestradiol, total proteins, albumin, magnesium, and GSH levels in the dams suffering from Ut were observed. The robust elevations in AST (156 ± 3.47) and bLac (16.12 ± 0.18) with severe hypomagnesaemia (2.69 ± 0.15) were evident in 10% of the torsion cases that directed to the culling. This can conclude that robust elevations in AST and bLac with severe hypomagnesaemia are factors denoting a poor prognosis for uterine torsion in the buffaloes.

     

Pathology and molecular diagnosis of paratuberculosis of camels

Camels are the prime source of meat and milk in many desert regions of the world including Saudi Arabia. Paratuberculosis of camels, locally called Silag, is a serious and invariably fatal disease in the Arabian camel. Six camels were used in this study. Five camels with clinical paratuberculosis were used to study the pathology of the disease and confirm its aetiology. The sixth camel was clinically healthy and used as a control. The camels were examined clinically and bled for haematological and blood chemistry analysis. They were then humanely killed with a high intravenous dose of thiopental sodium (10 mg/kg) for pathological studies as well as obtaining tissues for microbiological and molecular studies. The clinical signs of the disease were emaciation, diarrhoea, alopecia, wry neck and pale mucous membranes. Laboratory diagnosis showed reduced haemoglobin concentration, low haematocrit and high activity of the serum enzyme alanine aminotransferase. Serum creatinine concentration was normal. These results indicated the infected camels were anaemic and the function of their livers was affected. Postmortem examination showed thickened and corrugated intestinal mucosa, enlarged granulomatous mesenteric lymph nodes, miliary and diffuse granulomas in the liver (in four camels), generalized lymph node granulomas (in one camel), splenic granuloma (in one camel) and mediastinal lymph node granuloma (in two camels). Histopathological examination showed diffuse infiltration of macrophages in all organs showing lesions. Ziehl–Neelsen staining of tissue scraping and tissue sections showed masses of acid fast bacilli, except for the spleen. Infection with Mycobacterium avium subsp. paratuberculosis was confirmed by PCR by targeting the IS900 gene.