A bioassay method for the pheromone(s) of the bont tick Amblyomma hebraeum Koch.

A bioassay was developed which enabled the detection of the pheromones of the bont tick (Amblyomma hebraeum Koch) within 2 hours with a reproducibility of 82 +/- 13%. Dried, solvent-extracted ticks were glued onto the shaved backs of rabbits. Those ticks to which pheromone extract was subsequently applied strongly attracted females of the same species. In a 2-way choice test a cork disc impregnated with pheromone extract was even more attractive to female ticks than a treated dried tick.     

The localisation of beta-N-acetyl-glucosaminidase in the oviduct of the domestic fowl.

1. Beta-N-acetylglucosaminidase [EC 3.2.1.30] activity in the oviduct of the domestic fowl has been studied using biochemical and histochemical methods. 2. The principal source of the enzyme was the isthmus, where the enzyme was localised within the less dense region of the dual density granules which characterise this portion of the oviduct.     

Effect of environmental enrichment during the rearing phase on subsequent eggshell quality in broiler breeders

This study set out to investigate if access to an enriched environment during the rearing phase influences subsequent production and eggshell quality in broiler breeders. Broiler breeder pullets were reared under standard rearing conditions (control treatment) or under standard conditions with an environmental enrichment of bales of plastic-wrapped wood shavings (enriched treatment). At 19 weeks of age both groups were transported to a laying facility and housed in standard pens according to treatment type. Egg weight, shape, shell thickness, non-destructive deformation, breaking strength, stiffness and ultrastructural quality were compared at beginning of lay (25 weeks old), peak production (31 weeks old), mid-lay (45 weeks old) and end of lay (57 weeks old). Production and hatchery data were also collected throughout lay. Significant treatment-age interactions were detected for non-destructive deformation, breaking strength and stiffness, such that birds which had received prior enrichment went on to maintain a better shell quality with age. The measurements of total shell thickness, mammillary thickness and effective shell thickness all showed a trend for a treatment-age interaction. Significant age effects were found for weight, shape index, shell thickness, breaking strength and stiffness. All production and hatchery data also demonstrated significant changes with age. It is concluded that early enrichment with bales of wood shavings may provide a novel approach to the maintenance of eggshell quality at a time when calcium metabolism begins to reduce in efficiency.     

Use of a percutaneous atrial septal occluder device for complete acute occlusion of an intrahepatic portosystemic shunt in a dog

A 3-month-old sexually intact male German Shepherd Dog was evaluated because of signs of depression, ataxia, and collapse. Clinicopathologic abnormalities included low serum BUN and albumin concentrations and high serum liver enzyme activities and plasma ammonia and serum bile acids concentrations. Abdominal ultrasonography revealed an intrahepatic portosystemic shunt (PSS). The dog was anesthetized; via a transjugular approach, guidewires and catheters were directed with fluoroscopic guidance to locate the shunt and determine its anatomic features. Minimal changes in portal vein pressure during temporary shunt balloon occlusion enabled complete shunt attenuation, which was performed by use of a self-expanding septal occlusion device that is typically used for treatment of atrial septal defects in humans. Following initial misplacement of the device, the procedure was repeated successfully 2 months later and resulted in complete shunt occlusion. One year after this second procedure, the dog was clinically normal and serum bile acids concentration was within reference limits. In certain dogs with intrahepatic PSSs, treatment with minimally invasive interventional techniques involving fluoroscopy may reduce the morbidity and mortality rates associated with more invasive surgical procedures.     

An integrated logic circuit assembled on a single carbon nanotube

Single-walled carbon nanotubes (SWCNTs) have been shown to exhibit excellent electrical properties, such as ballistic transport over several hundred nanometers at room temperature. Field-effect transistors (FETs) made from individual tubes show dc performance specifications rivaling those of state-of-the-art silicon devices. An important next step is the fabrication of integrated circuits on SWCNTs to study the high-frequency ac capabilities of SWCNTs. We built a five-stage ring oscillator that comprises, in total, 12 FETs side by side along the length of an individual carbon nanotube. A complementary metal-oxide semiconductor-type architecture was achieved by adjusting the gate work functions of the individual p-type and n-type FETs used.     

Topography of the northern hemisphere of Mercury from MESSENGER laser altimetry

Laser altimetry by the MESSENGER spacecraft has yielded a topographic model of the northern hemisphere of Mercury. The dynamic range of elevations is considerably smaller than those of Mars or the Moon. The most prominent feature is an extensive lowland at high northern latitudes that hosts the volcanic northern plains. Within this lowland is a broad topographic rise that experienced uplift after plains emplacement. The interior of the 1500-km-diameter Caloris impact basin has been modified so that part of the basin floor now stands higher than the rim. The elevated portion of the floor of Caloris appears to be part of a quasi-linear rise that extends for approximately half the planetary circumference at mid-latitudes. Collectively, these features imply that long-wavelength changes to Mercury's topography occurred after the earliest phases of the planet's geological history.     

Effect of inclusion of tossign (Thymus serrulatus) in concentrate mix supplementation on performance and sensory quality of meat of Menz sheep

The experiment was conducted to determine feed intake, digestibility, body weight change, carcass characteristics, and sensory quality of meat of Menz sheep supplemented with a concentrate mix and combinations of different proportions of tossign (Thymus serrulatus). Twenty yearling intact male Menz sheep were divided according to their initial body weight into five blocks of four animals in a randomized block design, and treatments were assigned randomly to each sheep within each block. The treatments were a basal diet of hay alone (T1) and supplemented with 300 g concentrate mix (T2), 200 g concentrate mix?+?100 g tossign (T3), and 100 g concentrate mix?+?200 g tossign (T4) on a dry matter basis. The results indicated that supplementation of tossign together with concentrate mix significantly increased (P?<?0.001) feed intake and improved DM and nutrient digestibility compared to the non-supplemented group. Supplementation of tossign with concentrate significantly improved (P?<?0.001) daily weight gain, feed conversion efficiency, and carcass characteristics of sheep compared to the non-supplemented group. Flavor and aroma scores of meat samples of sheep in T3 and T4 were significantly higher (P?<?0.001) than the corresponding values in T1 and T2. The scores for tenderness, juiciness, and degree of marbling of meat samples of sheep were significantly higher (P?<?0.001) in T3 and T4 compared to meat samples of sheep in T1. Inclusion of small amounts of tossign as additive in concentrate mix supplementation can improve the sensory quality of meat of Menz sheep.     

Collection and ethnobotanical investigation of <Emphasis Type="Italic">Corchorus</Emphasis> species in Ethiopia: potential leafy vegetables for dry regions

Little information is available regarding the biodiversity and potential use of jute (Corchorus species) in Ethiopian agriculture. The present study summarizes species’ occurrence, use, geographical distribution, ecology, and ethnobotany of Corchorus species in Ethiopia. An ecogeographical study, conducted in the Amhara, Oromia and Gambella Regional States in 2005 and 2008 resulted in the collection of seven different species with more than 100 accessions. The study revealed low similarity in species composition between the Regional States, indicating that each region has its own unique set of species. Species numbers are higher in the north-eastern and south-western than the central part of the country. C. aestuans L. and C. tridens L. are restricted to humid lowlands of south-western part of Ethiopia, growing at elevations up to 490 m, whereas, C. urticifolius Wight et Arn., C. trilocularis L. and C. schimperi Cufod. were collected only in the north-eastern part of the country with elevation ranges of 1,380–2,130 m. The only species collected at a higher elevation (>2,100 m) was C. schimperi Cufod. Farmers’ perception, indigenous knowledge and folk taxonomy of jute species are better in Gambella than the other studied regions. Although several Corchorus species are reported from Ethiopia, these species are neither cultivated nor popularly used as leafy vegetables. This is mainly due to lack of awareness or knowledge about the species use, and abundant distribution of the species that allows gathering of edible leaves with little expenditure of time, labour and other resources. Our results revealed that some species are threatened, which necessitates highest priority for jute germplasm conservation in the country. In addition, creating public awareness about the use of jute species as a cheap source of leafy vegetable will play an important role to diversify food sources, reduce malnutrition, and contribute to household income generation of the farming community.     

Arbuscular mycorrhizal association of indigenous agroforestry tree species and their infective potential with maize in the rift valley, Ethiopia

Tree species in agroforestry are important source of inoculum for companion agricultural crops. Agroforestry trees can serve as a source of Arbuscular mycorrhiza (AM) inoculants to intercropped annuals. We studied spore abundance, root colonization of Albizia gummifera (J.F. Gmel.) and Croton macrostachyus (Hochst Ex Del.) trees and their effect on colonization of maize. Soil and root samples were collected from field standing trees from under and outside the canopy of trees and maize crops in the main rainy season. The number of spore count was significantly higher under the canopy of A. gummifera (791/100 g of dry soil) and C. macrostachyus (877/100 g of dry soil) trees than outside the canopy (547 and 588/100 g of dry soil, respectively). The level of root colonization of C. macrostachyus (45 %) was higher than A. gummifera (41 %). Root colonization of maize crops grown under the canopy of A. gummifera and C. macrostachyus trees was significantly higher than outside the canopy (P < 0.001). Maize seedlings grown on non-sterilized soils collected under and outside the canopy of A. gummifera and C. macrostachyus trees recorded higher root colonization, plant height, shoot and root dry weight than grown on sterilized soils (P < 0.001). The percentage of AM colonized roots of Zea mays seedlings was significantly positively correlated with the number of spore counts for field soils. The rhizospheres of indigenous agroforestry perennial species are important source of inoculum for annuals. The integration of perennials and annuals in an agroforestry system enhances the maintenance of soil quality in the tropics.