Neutralization of the AIDS retrovirus by antibodies to a recombinant envelope glycoprotein

Mammalian cell lines have been engineered to produce a secreted form of the AIDS retrovirus envelope glycoprotein. The recombinant protein has been isolated from growth-conditioned culture media and used to immunize animals. Antibodies directed against the recombinant molecule were found to react with the envelope glycoprotein produced in virus-infected cells. Furthermore, these antibodies were able to directly inactivate the AIDS retrovirus in a neutralization assay in vitro. The expression system reported here should provide sufficient quantities of the AIDS retrovirus envelope protein for biological and vaccination studies.     

Anthelmintic efficacy of ivermectin against immature gastrointestinal pulmonary nematodes of calves

Anthelmintic efficacy of ivermectin (greater than or equal to 80% 22,23-dihydroavermectin B1a and less than or equal to 20% 22,23-dihydroavermectin B1b) was evaluated in a controlled experiment against immature nematodes. Twenty calves raised to about 8 weeks of age under nematode-free conditions were allocated into 4 groups. Infective larvae of Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia oncophora, C punctata, Oesophagostomum radiatum, and Dictyocaulus viviparus were given orally to each calf on a staggered schedule 6 to 14 days before treatments. The drug was given subcutaneously when the nematodes were in the early 4th stage of development, and the calves were killed 23 or 24 days later. Group 1 nonmedicated control calves had a geometric mean of 25,102 nematodes; groups 2, 3, and 4 calves given ivermectin at dose rates of 50, 100, or 200 micrograms/kg had reductions of 88.2%, 98.0%, and 99.8%, respectively.     

Histopathologic and histochemic changes in the small intestine of calves infected with Trichostrongylus colubriformis

The pathologic effects of Trichostrongylus colubriformis on the small intestine of 8-week-old calves were studied. Morphologic and enzymic alterations were confined to the proximal third of the small intestine, which was shown to be the principal habitat of the nematode. Changes in the mucosa varied according to the acuteness of the infection rather than the duration. Villous atrophy, infiltrations of the lamina propria with plasma cells and lymphocytes, infiltrations of glandular tissue with eosinophils, and necrosis and erosions of the surface epithelial cells were present. Enzymic changes were related to the extent of cellular injury. Alkaline phosphatase and leucine aminopeptidase were more severely reduced, while nonspecific esterase and succinic dehydrogenase were less affected. Enzymic activities in the distal areas were nor influenced by the lesions in the proximal region.     

Anthelmintic activities of B1a fraction of avermectin against gastrointestinal nematodes in calves

Anthelmintic activities of the B1a fraction of avermectin were evaluated in a controlled experiment. Twenty 12-week-old calves artificially infected with gastrointestinal nematodes were allotted to four groups. Calves in group 1 were used as nonmedicated controls; other calves in groups 2, 3, and 4 were given (orally) B1a avermectin at dosage levels of 50, 100, and 200 microgram/kg of body weight, respectively. These treatments were given 35 days after calves were inoculated with infective nematode larvae. In groups 2, 3, and 4, overall reductions (based on geometric means) were 98.6%, 98.7%, and 98.4%, respectively. These reductions were highly significantly different (P less than 0.01) from the control calves. Nematodes in the calves were Haemonchus contortus. Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia oncophora, C punctata, and Oesophagostomum radiatum.     

Towards commercial aquaponics: a review of systems,designs, scales and nomenclature

Aquaponics is rapidly developing as the need for sustainable food production increases and freshwater and phosphorous reserves shrink. Starting from small-scale operations, aquaponics is at the brink of commercialization, attracting investment. Arising from integrated freshwater aquaculture, a variety of methods and system designs has developed that focus either on fish or plant production. Public interest in aquaponics has increased dramatically in recent years, in line with the trend towards more integrated value chains, greater productivity and less harmful environmental impact compared to other production systems. New business models are opening up, with new customers and markets, and with this expansion comes the potential for confusion, misunderstanding and deception. New stakeholders require guidelines and detail concerning the different system designs and their potentials. We provide a definitive definition of aquaponics, where the majority (>?50%) of nutrients sustaining the optimal plant growth derives from waste originating from feeding aquatic organisms, classify the available integrated aquaculture and aquaponics (open, domestic, demonstration, commercial) systems and designs, distinguish four different scales of production (≤?50, >?50–≤?100 m², >?100–≤?500 m², >?500 m²) and present a definite nomenclature for aquaponics and aquaponic farming allowing distinctions between the technologies that are in use. This enables authorities, customers, producers and all other stakeholders to distinguish between the various systems, to better understand their potentials and constraints and to set priorities for business and regulations in order to transition RAS or already integrated aquaculture into commercial aquaponic systems.     

Anthropogenic sediments and soils of tells of the Balkans and Anatolia: Composition,genesis, and relationships with the history of landscape and human occupation

Soils and sediments composing Tell Körtik Tepe (Epipaleolithic, Turkey) and Tell Yunatsite (Chalcolithic (Eneolithic), Bulgaria) have been studied with the aim to gain a better insight into their microfabrics, determine the composition of anthropogenic artifacts, and, on this basis, to analyze similarities and distinctions between these objects and the modern soils of urban areas. The methods of micromorphology, scanning electron microscopy with an energy dispersive X-ray microanalyzer, X-ray fluorometry, and other techniques to determine the chemical and physical properties of the soils and sediments have been applied. Two paleosols have been identified in Tell Yunatsite with a total thickness of 9 m: the paleosol buried under the tell and the paleosol in its middle part. Sediments of Tell Körtik Tepe have a total thickness of up to 5 m; their accumulation began at the end of Pleistocene over the surface of buried paleosol. The cultural layer of the tells consists of construction debris mainly represented by a mixture of clay and sand and of domestic wastes with the high content of phosphorus. The major source of phosphorus is calcium phosphate (apatite) of bone tissues. The abundance of various anthropogenic materials in the sediments is clearly seen in thin sections. Even in the paleosols developed within the cultural layer (the mid-profile paleosol in Tell Yunatsite), the amount of microinclusions of bone fragments, charcoal, and burnt clay (ceramics) is very high. Micromorphological data indicate that up to 50% of the layered material filling an Epipaleolithic construction in Tell Körtik Tepe consists of the anthropogenic inclusions: bone fragments, charcoal, etc. The features of pedogenic transformation are present in the sediments. Such sediments can be classified as synlithogenic soils similar to the modern Urbic Technosols. It is shown that the formation of paleosols and sediments of Tell Körtik Tepe took place under extreme environmental conditions—arid climate of the latest Pleistocene climate cooling phase (the Younger Dryas, Tell Körtik Tepe)—and intensive anthropogenic loads (tells Körtik Tepe and Yunatsite).     

Planting materials for warm tropic potato production: growth and yield of transplanted seedlings or rooted cuttings and tuber materials in the field

Expansion of potato production in lowland tropical regions has been constrained by the lack of planting materials, given that adapted genotypes and suitable field management practices now exist.

The respective performance of transplanted materials (i.e., true potato seed (TPS) seedlings or rooted stem cuttings) produced in situ in the warm tropics were compared with that of genetically identical seedling tubers (tubers produced from seedlings) or seed tubers. Seed and seedling tubers had been previously produced under optimal cool conditions. Transplanted materials achieved lower maximum leaf area index than did tuber materials (1.3–2.2 vs. 2.7) but relative growth rates of cuttings and seedlings were greater. This was in part due to the greater net assimilation rate of cuttings and to greater leaf:stem ratio for both compared with plants originating from tubers. Stolon and tuber formation were greater in seed tubers than in cuttings and in seedlings versus seedling tubers. On average, seedlings produced 14 tubers per plant, apical cuttings 12, seedling tubers 8, and stem cuttings 6.

Tuber yields within a genotype were statistically similar for crops from seed tubers or cuttings and for crops from seedling tubers or seedlings. However, the proportion of marketable (i.e., > 3.5 cm diameter) tubers was approximately 12% less in the crops from seed tuber and seedlings compared with those from cuttings and seedling tubers, respectively. Within a genotype, the crop duration in the field was similar whatever the type of planting material. Maximum yields, at 23 t/ha in warm sites, were still below those of temperate potato crops, but could be achieved equally well with transplanted in situ-produced materials or imported cool-climate seed tubers.     

Spinnen als Prädatoren von landwirtschaftlich schädlichen Blattläusen

Direct observations in grasslands and cereal fields near Zurich (Switzerland) have shown that aphids constitute an essentiel component in many spiders' prey. Spiders were observed to be predators of the agricultural harmful aphidsRhopalosiphum padi L.,Sitobion avenae F.,Metopolophium dirhodum Walck.,Hyalopterus pruni Geoffr.,Myzus persicae Sulz. andAphis fabae Scop.     

Effects of increasing choice white grease in corn- and sorghum-based diets on growth performance, carcass characteristics, and fat quality characteristics of finishing pigs

A total of 120 pigs (60 barrows and 60 gilts; TR4 × PIC 1050; 54.4 kg initial BW) were used in an 83-d study to evaluate the effects of added fat in corn- and sorghum-based diets on growth performance, carcass characteristics, and carcass fat quality. Treatments were arranged in a 2 × 3 factorial with grain source (corn or sorghum) and added fat (0, 2.5, or 5% choice white grease; CWG) as factors. There were 2 pigs (1 barrow and 1 gilt) per pen and 10 replicate pens per treatment. Pigs and feeders were weighed on d 14, 22, 39, 53, 67, and 83 to calculate ADG, ADFI, and G:F. At the end of the trial, pigs were slaughtered and jowl fat and backfat samples were collected and analyzed for fatty acid profile. No interactions were observed for growth performance. Pigs fed sorghum-based diets had greater (P < 0.01) ADG than pigs fed corn-based diets. Adding CWG improved (linear, P < 0.01) ADG. Pigs fed corn-based diets tended to have greater (P < 0.09) carcass yield, 10th-rib backfat, and percentage lean than pigs fed sorghum-based diets. Adding CWG increased (linear, P = 0.02) 10th-rib backfat, tended to increase (linear, P = 0.08) HCW, and tended to decrease (linear, P = 0.07) percentage lean. There was no grain source × fat level interaction for iodine value (IV) in backfat, but an interaction (P = 0.03) was observed for IV in jowl fat. Adding CWG increased (P < 0.01) IV in jowl fat for pigs fed sorghum- and corn-based diets; however, the greatest increase was between 0 and 2.5% CWG in sorghum-based diets and between 2.5 and 5% CWG in corn-based diets. Pigs fed corn-based diets had less (P = 0.01) C18:1 cis-9 and MUFA but greater (P = 0.01) C18:2n-6, PUFA, and backfat IV than pigs fed sorghum-based diets. Increasing CWG in the diet increased (linear, P = 0.01) backfat IV. Of the 2 fat depots, backfat generally had a reduced IV than jowl fat. In summary, feeding sorghum-based diets reduced carcass fat IV and unsaturated fats compared with corn-based diets. As expected, adding CWG increased carcass fat IV regardless of the cereal grain in the diet.