Iqbal N.,National University of Singapore |
Iqbal N.,Bahauddin Zakariya University |
Iqbal N.,Ghazi University |
Evans T.A.,National University of Singapore |
Evans T.A.,University of Western Australia
Bulletin of Entomological Research | Year: 2017
Fungus-growing termites (Macrotermitinae) are important pests in tropical countries. They are difficult to control with existing baiting methods, as chitin synthesis inhibitors are not effectual as active ingredients. We tested two neurotoxins, fipronil and imidacloprid, as potential bait active ingredients against Macrotermes gilvus (Hagen) in Singapore. In laboratory bioassays, M. gilvus showed no preference for doses of 0–64 ppm fipronil, or for doses of 0–250 ppm imidacloprid, indicating no repellence. We tested each insecticide in toilet paper as a bait matrix in a field experiment. After 28 days, termites had eaten 5–13% of the fipronil treated toilet paper, abandoned bait and monitoring stations, contacted no new stations, and repaired poorly their experimentally damaged mounds. Termites ate no imidacloprid treated toilet paper, abandoned bait stations although contacted new stations, and repaired fully their damaged mounds. Termites ate 60–70% of the control toilet paper, remained in bait stations, and fully repaired damaged mounds. After 56 days, all five fipronil colonies were eliminated, whereas all of the imidacloprid and control colonies were healthy. The results suggest that fipronil could be an effective active ingredient in bait systems for fungus-growing termites in tropical countries. Copyright © Cambridge University Press 2017
Darand M.,University of Kurdistan |
Dostkamyan M.,University of Zanjan |
Rehmanic M.I.A.,Ghazi University
Russian Meteorology and Hydrology | Year: 2017
Spatial variations in extreme precipitation events make hydrological, climatological, social, environmental and agricultural effects on a country. This study presents the spatiotemporal autocorrelation analysis of extreme precipitation events over Iran using gridded data on daily precipitation for the period 1961–2010. The 95th percentile is considered as extreme precipitation factor. The spatial autocorrelation of extreme precipitation is examined by three commonly used spatial autocorrelation statistics, the Gi statistic index, Moran’s I global index, and Local Moran’s I (LISA) index, at the 95 and 99% significant confidence level. The results showed a strong significant spatial autocorrelation for extreme precipitation events with the highest Moran’s I value in January. The positive significant autocorrelation of extreme precipitation is observed over the southern parts of the Caspian Sea and Zagros Mountains ranges, while the negative significant autocorrelation is observed over the central and eastern parts of country. In spring and summer the positive autocorrelation cores displace from the Zagros Mountains ranges to the northwestern and southeastern parts. © 2017, Allerton Press, Inc.
Liu H.,U.S. Department of Agriculture |
Atta S.,U.S. Department of Agriculture |
Atta S.,Ghazi University |
Hartung J.S.,U.S. Department of Agriculture
Protein Expression and Purification | Year: 2017
The citrus disease huanglongbing (HLB), which is caused by ‘Candidatus Liberibacter asiaticus’ (CaLas), is one of the most devastating pathogens of citrus, and with no effective method of control, poses a serious threat to citrus production throughout the world. In a previous study we described the production of single chain antibodies against several CaLas proteins that provide the basis for efficient and accurate detection of CaLas in citrus tissues. The isolation of a sufficient amount of purified antigen is a key step in the production of functional antibodies. The current report details purification procedures for six protein antigens used to select recombinant and produce polyclonal antibodies. These proteins include a flagellar biosynthesis protein (FlhA), a dinucleoside polyphosphate hydrolase (InvA), a portion of the major outer membrane protein (OmpA), a component of type IV pilus (CapB), the polysialic acid capsule expression protein (KpsA) and the outer membrane efflux protein (TolC). Results of purification under completely native or denatured conditions were not satisfactory. Therefore different hybrid purification conditions were optimized for each of the different proteins. The results of bioinformatic analysis also indicated that the six proteins contained a great diversity of potential antigenic epitopes, which varied in number, and that the antigenic clusters were not uniformly distributed throughout the proteins. The purified proteins are useful for the development of highly specific antibodies capable of differentiating specific strains of Liberibacter. © 2017
Yang S.,Southwest University |
Li C.,Southwest University |
Huang T.,Texas A&M University at Qatar |
Ahmad H.G.,Ghazi University
Neural Processing Letters | Year: 2017
This paper investigates the stability of TS fuzzy system via state-dependent impulsive control. Based on the Lyapunov stability theory, comparison theorem, and inequality techniques, the sufficient conditions with theoretical demonstration ensuring every solution of concerned models intersect each surface of the discontinuity exactly once are derived. Moreover, by applying B-equivalence method, the state-dependent impulsive TS fuzzy system can be reduced to the fixed-time impulsive ones, which can be analyzed via comparison method and mathematical induction. The control approach guarantees that the proposed state-dependent impulsive TS fuzzy system converge to zero. Finally, two numerical examples are carried out to demonstrate the effectiveness of the obtained results. © 2017 Springer Science+Business Media, LLC
PubMed | King Abdulaziz University, Islamia University of Bahawalpur, Northeast Agricultural University, China National Rice Research Institute and 18 more.
Type: | Journal: Environmental science and pollution research international | Year: 2017
Crop nutrient management is an essential component of any cropping system. With increasing concerns over environmental protection, improvement in fertilizer use efficiencies has become a prime goal in global agriculture system. Phosphorus (P) is one of the most important nutrients, and strategies are required to optimize its use in important arable crops like cotton (Gossypium hirsutum L.) that has great significance. Sustainable P use in crop production could significantly avoid environmental hazards resulting from over-P fertilization. Crop growth modeling has emerged as an effective tool to assess and predict the optimal nutrient requirements for different crops. In present study, Decision Support System for Agro-technology Transfer (DSSAT) sub-model CSM-CROPGRO-Cotton-P was evaluated to estimate the observed and simulated P use in two cotton cultivars grown at three P application rates under the semi-arid climate of southern Punjab, Pakistan. The results revealed that both the cultivars performed best at medium rate of P application (57kgha
PubMed | University of Paris Pantheon Sorbonne, Ghazi University, Czech University of Life Sciences, Free University of Colombia and 3 more.
Type: | Journal: Molecular biology and evolution | Year: 2016
The higher termites (Termitidae) are keystone species and ecosystem engineers. They have exceptional biomass and play important roles in decomposition of dead plant matter, in soil manipulation, and as the primary food for many animals, especially in the tropics. Higher termites are most diverse in rainforests, with estimated origins in the late Eocene (54Ma), postdating the breakup of Pangaea and Gondwana when most continents became separated. Since termites are poor fliers, their origin and spread across the globe requires alternative explanation. Here, we show that higher termites originated 42-54Ma in Africa and subsequently underwent at least 24 dispersal events between the continents in two main periods. Using phylogenetic analyses of mitochondrial genomes from 415 species, including all higher termite taxonomic and feeding groups, we inferred 10 dispersal events to South America and Asia 35-23Ma, coinciding with the sharp decrease in global temperature, sea level, and rainforest cover in the Oligocene. After global temperatures increased, 23-5Ma, there was only one more dispersal to South America but 11 to Asia and Australia, and one dispersal back to Africa. Most of these dispersal events were transoceanic and might have occurred via floating logs. The spread of higher termites across oceans was helped by the novel ecological opportunities brought about by environmental and ecosystem change, and led termites to become one of the few insect groups with specialized mammal predators. This has parallels with modern invasive species that have been able to thrive in human-impacted ecosystems.
News Article | December 16, 2015
In a study released yesterday in Proceedings of the National Academy of Sciences (PNAS), scientists at the University of New Mexico use biophysical models of thermoregulation in order to reveal multiple ways birds and mammals adapt to a wide range of temperatures. The Scholander-Irving model illustrates how warm-blooded birds and mammals maintain body temperature by balancing the rate of metabolic heat production with the rate of heat lost to the environment. Body size has been shown to affect both rates and, as a result, influences an organism's thermal limits – big species are generally able to deal with colder temperatures than smaller species and vice versa. This has been used to explain Bergmann's rule, the geographic pattern of increasing size with decreasing temperature that is seen in some groups of animals. However, after looking at the distribution of body sizes across temperatures on Earth, the scientists saw that birds and mammals of nearly every size live basically everywhere. Examples include tiny chickadees that can survive cold Alaskan winters, or elephants that live in some of the hottest parts of Africa. Clearly size isn't everything, the scientists hypothesized. The researchers extended the Scholander-Irving model to understand how species adapt to temperature without changing size. The research includes three graduate students from UNM: Trevor Fristoe, now a postdoc at Washington University in St. Louis, Mo., Robbie Burger, now a postdoc at the University of North Carolina, current UNM graduate student Meghan Balk, along with UNM Distinguished Professor James Brown. "We were interested in understanding ways other than body size that species can adapt their physiology and morphology in order to deal with environmental temperatures," Fristoe said, "So we developed a method of measuring adaptation to the thermal environment independent of body size. We incorporated changes in both the rate of heat production via a species' metabolism as well as thermal conductance - the loss of bodily heat to the environment." Thermal conductance could be affected by changes in insulation like developing thick fur or changes in body proportion like big ears or long legs that can help to dissipate heat. The scientists thought that if these types of adaptations are important, then a measure of their mass-independent adaptation should correlate with the temperatures that species experience in the wild. In order to test this, they collaborated with Imran Khaliq of Ghazi University in Pakistan and Christian Hof of the Senckenberg Biodiversity and Climate Research Centre in Frankfurt, Germany who compiled data on thermal physiology for hundreds of species of birds and mammals. "Our ideas build on the Scholander-Irving model of heat transfer, which has been around for over 60 years," said Fristoe, who is the lead author of the study. "However, it has only become recently possible to test these types of questions at such a large scale because of the growing availability of physiological data." Comparing physiological and environmental temperature data for 211 bird and 178 mammal species, the scientists demonstrated that birds and mammals have adapted to geographic variation in environmental temperature by concerted changes in both metabolic heat production and thermal conductance. Fristoe and colleagues found that species combined these traits in a number of ways. "It was possible to adapt to cold environments, for example, by either increasing metabolic heat production, decreasing thermal conductance, or both - the interaction between the two is what really mattered," Fristoe said. "Our study extends on a classic idea in thermal physiology in order to understand adaptations to temperatures across a global scale that goes beyond body size." "Unraveling these various avenues of adaptation to thermal environments has important implications for understanding how species respond to past, present and future climate change," he added.
PubMed | Islamia University of Bahawalpur, University of Agriculture at Faisalabad, Muhammad Nawaz Sharif University of Agriculture, Pmas Arid Agriculture University and Ghazi University
Type: | Journal: Journal of the science of food and agriculture | Year: 2016
Potato is an important vegetable; however, salt stress drastically affects its growth and yield. A pot experiment was therefore conducted to assess salicylic acid efficacy in improving performance of potato cultivars, grown under salt stress (50mmolLSalt stress effects were ameliorated by salicylic acid effectively in both the studied cultivars. N-Y LARA proved more responsive to salicylic acid application than 720-110 NARC, which confirmed genetic variation between cultivars. Salicylic acid scavenged reactive oxygen species by improving antioxidant enzyme activities (superoxide dismutase, catalase, peroxidases) and regulating osmotic adjustment (proline, phenolic contents), which led to enhanced water relation and gaseous exchange attributes, and thereby increased potassium availability and reduced sodium content in potato leaves. Moreover, potato tuber yield showed a positive correlation with potassium content, photosynthesis and antioxidant enzyme activities.Salt tolerance efficacy of salicylic acid is authenticated in improving potato crop performance under salt stress. Salicylic acid effect was more pronounced in N-Y LARA, reflecting greater tolerance than 720-110 NARC, which was confirmed as a susceptible cultivar. Hence salicylic acid at 0.5mmolL
PubMed | University of Punjab, University of Agriculture at Faisalabad and Ghazi University
Type: | Journal: Chemosphere | Year: 2016
Reduced sensitivity to insecticides in insect pests often results in control failures and increases in the dose and frequency of applications, ultimately polluting the environment. Reduced sensitivity to emamectin benzoate, a broad-spectrum agrochemical belonging to the avermectin group of pesticides, was reported in house flies (Musca domestica L.) collected from Punjab, Pakistan, in 2013. The aim of the present study was to investigate the risk for resistance development, biochemical mechanism, and cross-resistance potential to other insecticides in an emamectin benzoate selected (EB-SEL) strain of house flies. A field-collected strain showing reduced sensitivity to emamectin was re-selected in the laboratory for five consecutive generations and compared with a laboratory susceptible (Lab-Susceptible) reference strain, using bioassays. The field strain showed rapid development of resistance to emamectin (resistance ratio (RR) increased from 35.15 to 149.26-fold) as a result of selection experiments; however, resistance declined when the selection pressure uplifted. The EB-SEL strain showed reduction in resistance to abamectin, indoxacarb, and thiamethoxam. The results of synergism experiments using piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) enzyme inhibitors and biochemical analyses revealed that the metabolic resistance mechanism was not responsible in developing emamectin resistance in the EB-SEL strain. In conclusion, the risk for the rapid development of emamectin resistance under continuous selection pressure suggests using a multifaceted integrated pest management approach for house flies. Moreover, the instable nature of emamectin resistance in the EB-SEL strain and lack of cross-resistance to other insecticides provide windows for the rotational use of insecticides with different modes of action. This will ultimately reduce emamectin selection pressure and help improving management programs for house flies without polluting the environment.
PubMed | Hazara University, Ghazi University, King Saud University and Quaid-i-Azam University
Type: | Journal: Natural product research | Year: 2016
-Sitosterol-3-O-(6-O-13-octadecenoyl)--D-glucoside (1), a new acyl -sitosteryl glucoside, along with three known compounds -sitosterol-3-O--D-glucoside (2), -sitosterol (3) and methyl gallate (4) have been isolated from the ethyl acetate soluble fraction of methanolic extract of Ailanthus altissima fruits. Their structures were elucidated through spectroscopic data including 2D NMR, ESI-MS, methanolysis and oxidative cleavage of double bond. Antibacterial, antifungal, cytotoxic, phytotoxic and insecticidal activities were evaluated of compound 1, crude extract and its fractions so far for the first time. Pharmacological activities results showed that n-butanol fraction was good active against Pseudomonas aeruginosa and Salmonella typhi bacteria, and moderate active against Microsporum canis fungus. Crude extract, n-butanol and aqueous fractions showed good cytotoxicity. Moreover, compound 1, extract and all fractions showed notable phytotoxicity at higher concentrations, whereas all inactive against assayed insects.