Fat-tailed sheep production systems in the Khyber Pakhtunkhwa Province of Pakistan

Balkhi, Michni and Hashtnagri populations are the three fat-tailed phenotypes native to Khyber Pakhtunkhwa Province of Pakistan, harbouring the central valley. Their distribution, breeding trend and performances were evaluated through a survey using a pre-tested questionnaire during August, 2008. Out of the total populations, 70.7% were mixed flocks and 5.8%, 3.1% and 9.2% were purebred flocks belonging to Balkhi, Hashtnagri and Michni populations, respectively. Sheep flocks were reared under three different production systems, i.e. sedentary, transhumant and nomadic. Nomads keep Balkhi and are sole responsible for their development as a mutton breed. They practise autumn breeding only, for which they select the heaviest ram/s available within the community. Sedentary and transhumant shepherds had mixed flock, who were constantly replacing their native breed stock, i.e. Michni and Hashtnagri through outcrossing with Balkhi. The size of Balkhi and Michni populations warrants no immediate threat to their existence and diversity. However, in case of increased popularity of crossbreeding, Michni could pose threats of extinction. Hashtnagri on the other hand can be declared as breed at risk. Age at first lambing was significantly lower in Hashtnagri ewes, followed by Michni, crossbred and Balkhi. Hashtnagri ewes outperformed other populations in lambing twice per annum.     

Relationship between milk somatic cell count and postpartum ovarian cyclicity and fertility in dairy cows

The main objective of the study was to describe the relationship of high somatic cell count (SCC) with the incidence of abnormal postpartum resumption of ovarian cyclicity and reproductive performance in dairy cows. The factors influencing SCC were also investigated. Four hundred and forty-seven cows from six dairy herds in Japan were monitored for SCC and postpartum resumption of ovarian cyclicity. Cows with high SCC (200,000 to 500,000) had a higher incidence of prolonged luteal phase (P < 0.01) than cows with an SCC of 50,000 to 100,000. The high SCC cows (> 500,000) also showed a higher incidence of delayed first ovulation post partum than cows with an SCC ≤500,000 (P < 0.05) during the first month post partum. Cows with an SCC of 200,000 to 500,000 showed lower conception and pregnancy rates, and more days from calving to conception than cows with an SCC of less than 200,000 (P < 0.05). Cows in parity 5 or more had a higher incidence of high SCC than cows in the first and second parities (P < 0.05). It is concluded that cows with a high SCC have a higher incidence of abnormal postpartum resumption of ovarian cyclicity, leading to reduced reproductive performance.     

保水剂和负压供水对玉米生理生长及水分利用效率的影响

采用一种负水头供水控水系统,通过调节供水负压值来控制不同的土壤含水率,研究3种供水负压（3、6、9 kPa）下,保水剂对玉米生理、生长性状以及节水效果的影响。结果表明：在供水负压为3 kPa时,保水剂使玉米株高降低了7.4%,叶面积降低了14.9%,地上部干物质量降低了12.4%,地下部干物质量降低了7.3%,水分利用效率降低了12.6%。在供水负压为6 kPa和9 kPa时,保水剂使玉米株高分别增加了10.0%、37.9%,叶面积分别增加了14.2%、90.8%,地上部干物质量分别显著增加40.4%、104.6%,地下部干物质量分别增加了35.3%、83.8%,水分利用效率分别显著提高了26.9%、65.7%。同时,与无保水剂的相比,玉米叶片水势分别增加7.1%、19.2%,叶片相对含水率、净光合速率、胞间CO2浓度、蒸腾速率也较高。表明在水分受限制条件下,保水剂能够改善植株的生理生长特性,提高水分利用效率。     

The role of allelopathy in agricultural pest management

Allelopathy is a naturally occurring ecological phenomenon of interference among organisms that may be employed for managing weeds, insect pests and diseases in field crops. In field crops, allelopathy can be used following rotation, using cover crops, mulching and plant extracts for natural pest management. Application of allelopathic plant extracts can effectively control weeds and insect pests. However, mixtures of allelopathic water extracts are more effective than the application of single-plant extract in this regard. Combined application of allelopathic extract and reduced herbicide dose (up to half the standard dose) give as much weed control as the standard herbicide dose in several field crops. Lower doses of herbicides may help to reduce the development of herbicide resistance in weed ecotypes. Allelopathy thus offers an attractive environmentally friendly alternative to pesticides in agricultural pest management. In this review, application of allelopathy for natural pest management, particularly in small-farm intensive agricultural systems, is discussed.     

Co-relation of Growth and Yield as Affected by Va- rious Levels of Nitrogen Contents in the Leaves of Feutrell''''s Early ( Citrus reticula Blanco )

Research studies on the corelation of growth and yield as affected by different levels of Nitrogen in Feutrell's Early revealed that the yield is directly responsible for growth. Increasing nitrogen level increase the growth and yield of plants upto a certain limit but when this limit is cro ssed, the growth of tree may increase in terms of girth and height but the spread and yield of the tree is decreased. This indicates the effect of nitrogen in relation of growth and yield.     

One-third of reef-building corals face elevated extinction risk from climate change and local impacts

The conservation status of 845 zooxanthellate reef-building coral species was assessed by using International Union for Conservation of Nature Red List Criteria. Of the 704 species that could be assigned conservation status, 32.8% are in categories with elevated risk of extinction. Declines in abundance are associated with bleaching and diseases driven by elevated sea surface temperatures, with extinction risk further exacerbated by local-scale anthropogenic disturbances. The proportion of corals threatened with extinction has increased dramatically in recent decades and exceeds that of most terrestrial groups. The Caribbean has the largest proportion of corals in high extinction risk categories, whereas the Coral Triangle (western Pacific) has the highest proportion of species in all categories of elevated extinction risk. Our results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures.     

Epidermal electronics

We report classes of electronic systems that achieve thicknesses, effective elastic moduli, bending stiffnesses, and areal mass densities matched to the epidermis. Unlike traditional wafer-based technologies, laminating such devices onto the skin leads to conformal contact and adequate adhesion based on van der Waals interactions alone, in a manner that is mechanically invisible to the user. We describe systems incorporating electrophysiological, temperature, and strain sensors, as well as transistors, light-emitting diodes, photodetectors, radio frequency inductors, capacitors, oscillators, and rectifying diodes. Solar cells and wireless coils provide options for power supply. We used this type of technology to measure electrical activity produced by the heart, brain, and skeletal muscles and show that the resulting data contain sufficient information for an unusual type of computer game controller.     

Genetic variability in flooding tolerance of mungbean (Vigna radiata L. Wilczek) genotypes

The study was an exploratory in nature conducted using a large number of mungbean (Vigna radiata L. Wilczek) genotypes of diverse growth habit and adaptive characters. Soil flooding induced changes in eleven morpho-physiological characters of one-week old seedlings of 530 mungbean genotypes was compared in the study. The first and second principal components (PC) of principal component analysis (PCA) results accounted for 58 and 14%, respectively of the total variations of mungbean genotypes. The variation for first PC was composed mainly of relative dry weight (DW) of shoot and leaf as well as total DW. The second PC distinguished the genotypes that produced larger root system. There were seven clusters distinguished in the cluster analysis. The genotypes in cluster 4 and 6 performed better in respect of relative total DW and relative root DW, respectively and hence having flooding tolerance. The genotypes in clusters 7 and 1 performed very poorly and those of under clusters 3, 2 and 5 were moderate to poor. D² analysis indicated that the clusters differed significantly from each other. Discriminant function analysis (DFA) reaffirmed that more than 90% of the genotypes were correctly assigned to clusters. Both PCA and DFA confirmed that the relative total DW followed by shoot and leaf DW as well as leaf area were the major discriminatory variables and the root : shoot ratio and root DW were the secondary important variables to distinguish genotypes into groups. In this study, multivariate analyses were used in identifying the mungbean genotypes of desirable traits for flooding tolerance.     

The spread of highly pathogenic avian influenza (subtype H5N1) clades in Bangladesh, 2010 and 2011

Since the global spread of highly pathogenic avian influenza H5N1 during 2005–2006, control programs have been successfully implemented in most affected countries. HPAI H5N1 was first reported in Bangladesh in 2007, and since then 546 outbreaks have been reported to the OIE. The disease has apparently become endemic in Bangladesh. Spatio-temporal information on 177 outbreaks of HPAI H5N1 occurring between February 2010 and April 2011 in Bangladesh, and 37 of these outbreaks in which isolated H5N1 viruses were phylogenetically characterized to clade, were analyzed.