Contribution of phytoecological data to spatialize soil erosion: Application of the RUSLE model in the Algerian atlas

Among the models used to assess water erosion, the RUSLE model is commonly used. Policy makers can act on cover (C-factor) and conservation practice (P-factor) to reduce erosion, with less costly action on soil surface characteristics. However, the widespread use of vegetation indices such as NDVI does not allow for a proper assessment of the C-factor in drylands where stones, crusted surfaces and litter strongly influence soil protection. Two sub-factors of C, canopy cover (CC) and soil cover (SC), can be assessed from phytoecological measurements that include gravel-pebbles cover, physical mulch, annual and perennial vegetation. This paper introduces a method to calculate the C-factor from phytoecological data and, in combination with remote sensing and a geographic information system (GIS), to map it over large areas. A supervised classification, based on field phytoecological data, is applied to radiometric data from Landsat-8/OLI satellite images. Then, a C-factor value, whose SC and CC subfactors are directly derived from the phytoecological measurements, is assigned to each land cover unit. This method and RUSLE are implemented on a pilot region of 3828 km² of the Saharan Atlas, composed of rangelands and steppe formations, and intended to become an observatory. The protective effect against erosion by gravel-pebbles (50%) is more than twice that of vegetation (23%). The C-factor derived from NDVI (0.67) is higher and more evenly distributed than that combining these two contributions (0.37 on average). Finally, priorities are proposed to decision-makers by crossing the synthetic map of erosion sensitivity and a decision matrix of management priorities.     

Different Eucalyptus Species Show Different Mechanisms of Tolerance to Salinity and Salinity × Hypoxia

ABSTRACT

We studied the effect of sodium chloride (NaCl) salinity and oxygen deficiency stress on growth and leaf ionic composition of three Eucalyptus species [E. tereticornis, E. camaldulensis (Silverton), and E. camaldulensis (Local)]. Species were grown with control (no NaCl) and salinity (150 mol m^?3 NaCl) under hypoxic and non-hypoxic conditions in nutrient solution with five replications following CRD. Species differed significantly in their response to salinity and hypoxia. Absolute shoot dry matter was significantly better in E. camaldulensis (Silverton) in salinity and in E. camaldulensis (Local) in saline hypoxic treatment. E. tereticornis was the most sensitive species to salinity and salinity × hypoxia in the root environment. Sodium (Na⁺) and chloride (Cl^?) concentrations were significantly lower in E. camaldulensis (Local) in non-hypoxic saline treatment compared to the other two species. E. camaldulensis (Silverton) seems to have better tissue compartmentalization, whereas E. camaldulensis (local) seems to have better exclusion of Na⁺ at the root level.     

Vorratsschädllche Insekten in Saudi-Arabien

A survey of insect pests of stored products in three main regions of Saudi Arabia was carried out during two successive years, 1978 und 1979. Randomized samples of different commodities were collected for inspection from 13 localities four times a year. Thirty six species of insect pests belonging to 12 families and 4 orders in addition to 2 hymenopterous parasites were recorded.     

Enhanced Biodegradation of Used Engine Oil in Soil Amended with Organic Wastes

Three organic wastes (banana skin (BS), brewery spent grain (BSG), and spent mushroom compost (SMC)) were used for bioremediation of soil spiked with used engine oil to determine the potential of these organic wastes in enhancing biodegradation of used oil in soil. The rates of biodegradation of the oil were studied for a period of 84 days under laboratory conditions. Hydrocarbon-utilizing bacterial counts were high in all the organic waste-amended soil ranging between 10.2?×?10⁶ and 80.5?×?10⁶?CFU/g compared to unamended control soil throughout the 84 days of study. Oil-contaminated soil amended with BSG showed the highest reduction in total petroleum hydrocarbon with net loss of 26.76% in 84 days compared to other treatments. First-order kinetic model revealed that BSG was the best of the three organic wastes used with biodegradation rate constant of 0.3163 day^?1 and half-life of 2.19 days. The results obtained demonstrated the potential of organic wastes for oil bioremediation in the order BSG?>?BS?>?SMC.     

利用微量元素来最大限度地促进生产

在过去的15年中,肉鸡养殖业中的遗传改良是显著的.一个领先的种鸡公司声称仅在这一时期其产品的饲料转化率就提高了35个百分点,活重肉产量提高了4.5%.实际生产中这些遗传改良有可能还在继续.这些改善是合乎人们需要的,因此,通过营养和管理手段,特别是在亲本饲养方面,来充分发挥这种遗传潜力,就非常有挑战性.     

Medial patellar ligament splitting for the treatment of upward fixation of the patella in 7 equids

OBJECTIVE: To describe a surgical technique for splitting the proximal third of the medial patellar ligament (MPL) in horses and ponies with upward fixation of the patella (UFP), and to report outcome. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Four horses and 3 Shetland ponies. METHODS: With ultrasound guidance, the proximal third of the MPL was split by percutaneous use of a no. 15 scalpel blade. The rationale for this surgical procedure was to induce a localized desmitis with subsequent ligament thickening. No anti-inflammatory drugs were administered, and horses and ponies were exercised the day after surgery. Clinical, radiographic and ultrasonographic follow-up evaluation was obtained. RESULTS: No short-term or long-term complications were observed, and no patients had clinical signs of UFP after surgery. This clinical effect was attributed to a 2- to 3-fold increase in size of the proximal part the MPL from an induced localized desmitis. CONCLUSIONS-Percutaneous splitting of the proximal third of the MPL resolved UFP in equids. CLINICAL RELEVANCE: Splitting of the proximal third of the MPL is effective for treatment of UFP and allows rapid return to normal activity.     

Ultrasonograhic and histopathological features of atypical interstitial (Leydig) cell tumors in two cryptorchid horses

This article describes atypical interstitial (Leydig) cell tumors in two cryptorchid horses. Ultrasonography allowed accurate localization of the cryptorchid testicles. Ultrasonographic features of the tumor are also presented and may be of value for the clinical diagnosis.Histopathological evaluation of testicular tissue after cryptorchidectomy revealed atypical evolving interstitial (Leydig) cell tumors. Clinically, the tumors reported here appear to have several similarities with the interstitial (Leydig) cell tumors described in the literature, which in most cases appear to be (1) cryptorchidism–induced tumors, (2) often benign and not enlarged, and (3) often associated with aggressive behavior. Although generally considered to be uncommon, equine testicular neoplasms may occur more frequently than previously thought. The use of ultrasonography may improve diagnosis.     

Cholinergic receptors of the central nervous system of insects

Concentrated particulate preparations were made from housefly heads and the nerve cords of the American and Madagascar cockroaches. Macromolecules present in these preparations bound ³H-nicotine reversibly and with high affinities (3, 1.1, and 1.5 μM, respectively). Binding of ACh to the macromolecules in the preparation of houseflies and Madagascar cockroach was determined by inhibition of ³H-nicotine binding, and was found to be of much lower affinity than that of nicotine.There was a 2 × purification of the nicotine-binding macromolecules in this particulate preparation of housefly heads as compared to an earlier preparation of supernatant of 100,000g. Nicotine binding to this particulate preparation was blocked also by d-tubocurarine and atropine demonstrating the nicotinic and muscarinic nature of these nicotine-binding macromolecules. Prior exposure of the preparation to trypsin and chymotrypsin reduced nicotine binding by 58 and 68%, respectively.The relationship of these nicotine and ACh binding macromolecules to ACh-receptors is discussed.