Quantitative Mapping and Assessment of Environmentally Sensitive Areas to Desertification in Central Iran

Desertification is one of the main environmental and also social and economic problems facing Iran. Seventeen out of 31 Iranian provinces, which are home to approximately 70% of the total population, are affected by desertification. This study aimed to use geographic information system (GIS) and fuzzy logic for mapping environmentally sensitive areas to desertification based on Mediterranean Desertification and Land Use approach in Isfahan province, central Iran. Six desertification indicators including climate, soil, vegetation, soil erosion, groundwater, and management and policy quality were used to determine various types of environmentally sensitive areas to desertification. Seventeen desertification indices affecting the quality of each indicator were spatially mapped and assigned a value between 0 and 1 using a fuzzy logic option of ArcSDM3 software in GIS environment. Results showed that a 21·7% of the study area was classified as critical, 70% as fragile and 5·5% as potential, and 2·9% of the area was not affected by desertification. In the town of Borkhar, 64·2% of the area was classified as critical, followed by the towns of Isfahan and Nayin with 40·2% and 31·8%, respectively. Results at provincial scale indicated that the climate indicator and humidity index with a weighting mean of 0·71 and 0·77 were the most affective factors in the desertification of the study area. The developed model in this study can be used for mapping desertification status in other 16 provinces that contain desert areas. These assessments provide a GIS‐based desertification database that Iran as a member of the United Nation Convention to Combat Desertification can use to report the condition of desertification at national scale. Copyright © 2013 John Wiley & Sons, Ltd.     

Study on the effect of nano-silver impregnation on mechanical properties of heat-treated <Emphasis Type="Italic">Populus nigra</Emphasis>

The present study is aimed at investigating the effect of heat treatment of nano-silver-impregnated Populus nigra on weight loss, modulus of rupture (MOR), modulus of elasticity (MOE), and compression parallel to grain. Specimens were impregnated with 200 PPM water-based solution of nano-silver particles at 2.5 bar in a pressure vessel. For heat treatment, both nano-silver-impregnated and simple specimens were kept for 24 h at 45°C and then further for 24 h at 145°C and finally for 4 h at 185°C. MOR decreased from 529 to 461 kg/cm² in heat-treated specimens; MOE and compression parallel to grain were though improved. Also, comparison between heat-treated and nano-silver-impregnated heat-treated specimens showed that there was a decrease in MOR and MOE in nano-silver-impregnated heat-treated specimens. This shows that nano-silver impregnation facilitates transfer of heat in wood and it may increase the process of degradation and pyrolysis of wood structures in deeper parts of specimens.     

Comparison of genetic variation among accessions of <Emphasis Type="Italic">Aegilops tauschii</Emphasis> using AFLP and SSR markers

Genetic diversity of 54 accessions of Aegilops tauschii from five countries was assessed using sequence-tagged microsatellites (or simple sequence repeats, SSRs) and amplified fragment length polymorphisms (AFLPs). In the case of AFLP analysis, a total of 256 amplification products obtained, 234 of them were polymorphic across all the 54 accessions. A total of 224 fragments were obtained from the 24 SSR primers and 219 of fragments were polymorphic across all the genotypes screened. Based on both AFLP and SSR markers, the highest percentage of polymorphisms were obtained in Iranian and accessions of unknown origin. The highest polymorphic information content (PIC) value was observed for SSRs (0.82) while the highest marker index (MI) value was for AFLPs (8.5) reflecting the hyper-variability of the first and the distinctive nature of the second system. Principal co-ordinate analysis (PCO) revealed congruent patterns of genetic relationships for both data sets, but did not group accessions strictly according to their geographical origins. Poor correlation was found between AFLP and SSR marker loci. This low association may be due to low number of AFLP and SSR markers. These results show that molecular markers can help to organize the genetic variability and expose useful diversity for breeding purposes.     

CoRoT measures solar-like oscillations and granulation in stars hotter than the Sun

Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars.     

Foliar application of iron,zinc, and manganese nano-chelates improves physiological indicators and soybean yield under water deficit stress

Abstract

To investigate the effect of foliar application of nano-chelates of iron, zinc, and manganese subjected to different irrigation conditions on physiological traits, and yield of soybean (cultivar M9), a split plot experiment was conducted in a completely randomized block design with three replications in two crop years (2016–2017). The main plot included four levels of irrigation (I): full irrigation (I ₁), irrigation withhold at flowering stage (I ₂), irrigation withhold at podding stage (I ₃), and irrigation withhold during the grain filling period (I ₄). Also, the subplot included eight levels of foliar application with Fe, Zn, Mn, Fe?+?Zn, Fe?+?Mn, Zn?+?Mn, Fe?+?Zn?+?Mn nano-chelates, and distilled water (control). The results of combined analysis of variance suggested that the effect of irrigation and foliar application of nano-chelate was significant on all traits. Water deficit stress significantly reduced the grain yield. The minimum numbers of pods per plant, number of grains per plant, 100-seed weight per plant, leaf area index, leaf chlorophyll concentration, total dry weight of plant, and the grain yield were obtained by irrigation withhold at podding stage. Foliar application of combined nano-chelates increased the soybean resistance against water shortage more considerably than the separate consumption of these elements. Under drought stress in podding stage, the application of Fe?+?Zn led to the highest yield with a mean of 2613.84?kg ha^?1 where this increase was 61.1% higher than control.     

Effect of Bacillus thuringiensis var. kurstaki on survival and mortality of immature and mature stages of Diadegma insulare parasitizing Plutella xylostella

Effects of Bacillus thuringiensis (Bt) on immature stages of Diadegma insulare (Cresson) (Hym., Ichneumonidae) within larvae of diamondback moth (DBM), Plutella xylostella (L.) (Lep., Plutellidae), and on the adult stage as a Bt-honey solution were evaluated at 25?±?1?°C, 65?±?10% r.h. and 16:8?h (L:D) photoperiod. P. xylostella and D. insulare pupae were collected from cabbage fields in Karaj, Iran. A commercial wettable powder formulation of Bt (var. kurstaki, serotype H-3a3b, strain Z-52) was used in these experiments. The value of LC₅₀ for third instar larvae of P. xylostella was 210?ppm. Parasitoid??s adult mortality at field rate of Bt was not significantly different from that of control. Formation of parasitoid??s pupae in Bt-parasitoid combined treatments was significantly lower than parasitoid alone. Formation of parasitoid??s pupae in larvae treated with LC₁₀, LC₃₀ and LC₅₀ of Bt and then exposed to parasitoids after 48?h was 5%, 3% and 2%, respectively, which was significantly lower than that of the parasitoid alone (41%). Mean percentage mortality of larvae of DBM in LC₃₀ and LC₅₀ concentrations of Bt combined with the parasitoid was approximately 100%. Our results showed that B. thuringiensis kills D. insulare larvae indirectly by killing susceptible hosts in which they are developing. Successful use of multiple biological control agents will depend on close monitoring of their compatibility in the field. Our results could be useful in this purpose.     

Compatible Puccinia hordei infection in barley induces basal defense to subsequent infection by Blumeria graminis

Rusts and powdery mildews employ different strategies to suppress defense during penetration. We observed that a compatible interaction of barley-Puccinia hordei induced increased penetration resistance to a challenge infection by powdery mildew. This induced resistance is local and its level is not determined by the virulence spectrum of the challenger isolate. Our data suggest that the inducer effect is due to rust-stoma communication during penetration, to the presence of the rust hyphae in the apoplast, or to penetration resistance mounted by the rust attacked mesophyll cells. We hypothesized that the rust “primes” the basal defense prior to the mildew infection.     

Highly conserved protective epitopes on influenza B viruses

Identification of broadly neutralizing antibodies against influenza A viruses has raised hopes for the development of monoclonal antibody-based immunotherapy and "universal" vaccines for influenza. However, a substantial part of the annual flu burden is caused by two cocirculating, antigenically distinct lineages of influenza B viruses. Here, we report human monoclonal antibodies, CR8033, CR8071, and CR9114, that protect mice against lethal challenge from both lineages. Antibodies CR8033 and CR8071 recognize distinct conserved epitopes in the head region of the influenza B hemagglutinin (HA), whereas CR9114 binds a conserved epitope in the HA stem and protects against lethal challenge with influenza A and B viruses. These antibodies may inform on development of monoclonal antibody-based treatments and a universal flu vaccine for all influenza A and B viruses.