A simple tentative model of the losses caused by the Senegalese grasshopper,Oedaleus senegalensis (Krauss 1877) to millet in the Sahel

Oedaleus senegalensis is a serious pest of millet in the Sahel, but the correlation to crop loss remains largely unknown. Therefore, the correlation between densities of O. senegalensis, defoliation level and millet yields was investigated in Niger in 2008, and a simple model to foresee the yield based on these parameters was developed. The yield was significantly correlated to both the density of O. senegalensis and the defoliation level on 17 September. The best model to foresee millet yield involved grasshopper density and cumulated rainfall and may be regarded a tentative method in O. senegalensis control.     

Experimental hyperkalaemia in rabbits: effects of salbutamol and norepinephrine treatments on blood biochemistry and electrocardiography

The effects of salbutamol and norepinephrine on the electrocardiogram (ECG), serum potassium level and enzyme activities were studied in rabbits with hyperkalaemia; norepinephrine and salbutamol may be therapeutically useful. For induction of hyperkalaemia, 300 mM KCl solution was used and then isotonic saline solution containing 6 microg salbutamol and 3.9 microg norepinephrine per ml were administered. Norepinephrine and salbutamol decreased the serum potassium from 7.36 +/- 0.26 and 7.21 +/- 0.31 mmol/L to 5.62 +/- 0.27 and 4.35 +/- 0.33 mmol/L, respectively, and caused the ECG changes (flatness of P wave, widening of QRS complex and bradycardia) to return to the control conditions (time 0). Norepinephrine, but not salbutamol, decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) to the control levels. These results suggest that monitoring of the enzyme activities might be useful as it yields indexes suitable for evaluating the therapeutic approach with norepinephrine in hyperkalaemia.     

Role of reactive oxygen species and antioxidants in plant disease resistance

Membrane damage caused by the non-specific fungal toxin fusaric acid was less on pretreated than on control leaves when tobacco leaves were pretreated with anti-senescence plant hormones, such as kinetin, benzyladenine or the anti-ozonant N-[2-(2-oxo-1-imidazolidinyl)]ethyl-N'-phenylurea. Similarly, the necrosis caused by mercuric chloride was reduced by the above anti-senescence agents. In addition, in in vitro tests, leaves from selected paraquat-tolerant tobacco plants were less sensitive to Alternaria alternata (Fr) Keissler infection than those of the control paraquat-sensitive tobacco leaves. Paraquat-tolerant Conyza canadensis (L) Cronq weeds naturally selected in vineyards in Hungary showed similar inhibition of senescence to paraquat-tolerant tobacco, expressed as more green leaves and slower development. In accordance with this, the paraquat-tolerant Conyza leaves remained almost symptomless, while paraquat-sensitive plants showed severe symptoms after infection with Botrytis cinerea Pers. Oxidative burst (accumulation of hydrogen peroxide) was attenuated in TMV-infected leaves of Xanthi-nc tobacco as a result of treatment with salicylic acid or in leaves where systemic acquired resistance (SAR) had been induced by a previous TMV infection. Accordingly, superoxide dismutase (SOD) activity was higher in Xanthi tobacco leaves with SAR than without SAR. However, in NahG tobacco, in which SAR cannot develop, there was no augmentation of SOD activity. All the above data support the significance of delayed senescence and antioxidants in the resistance of plants to biotic and abiotic necrosis-inducing agents.     

The effect of graduated radiation doses on the follicular apparatus of the ovaries and the adenohypophysis in sheep

Gradually increased radiation doses were applied directly to the ovaries of laparotomized ewes. The effect of these doses was studied as exerted on the qualitative and quantitative changes in the follicular apparatus of the ovaries and adenohypophysis of ewes in anoestrus and upon the recovery processes later on after irradiation. The ovaries irradiated with the dose of 4.79 Gy were found to be heavier when examined after some time from irradiation. The 10th and 30th day from irradiation the number of tertiary follicles decreased, the 100th day from irradiation their number increased to a four-fold level, as compared with the 10th day. Adenohypophysis showed a gradual growth of the number of PAS-positive cells. After the irradiation of ovaries with the dose of 9.57 Gy the ovaries showed the lowest rate of damage on the 10th day from irradiation; the 30th and 100th day from irradiation all the present tertiary follicles were in the state of atresia. In comparison with the control group, the amount of gonadotropic cells of adenohypophysis gradually increased, recovering from a rapid drop after irradiation. When the ovaries were irradiated with the dose of 19.14 Gy, all the tertiary follicles were in the state of atresia and the number of PAS-positive cells of adenohypophysis was lower in comparison with the control group.     

Forum: Social-Ecological System Archetypes for European Rangelands

Rangelands in Europe are imprinted by livestock production and embedded in mosaic landscapes of grasslands, croplands, woodlands, and settlements. They developed as social-ecological systems: People managed rangelands in order to maintain or enhance their ecosystem services, which in turn supported their well-being. The appreciation of ecosystem services provided by rangelands depends on the broad, socioeconomic aspirations and abilities of the managers and the capital available to achieve these aspirations. Here we propose four archetypical social-ecological system representations for European rangelands along the dimensions of socioeconomic aspirations (i.e., oriented toward conventional or sustainable production) and available financial capital (i.e., low or high) to employ farming technologies on rangelands. The four archetypes are aspiration misfit, pockets of sustainability, techno-dependence, and money dependent sustainability. We describe the landscape physiognomy, ecosystem service appreciation, and management-related synergies and trade-offs in ecosystem services supply related to each archetype and formulate a number of research questions to document and further understand them as social-ecological systems. We include the importance of urbanization, land grabbing, and institutional networks in shaping the social-ecological archetypes of rangelands and the relationship between our social-ecological archetypes and the resilience and transformability of rangelands.     

Changes of woody species diversity,horizontal and vertical distribution of stems across interior to outside within a primate rich habitat of Northeast India

The interior forest of protected area(PA)recover quickly in terms of greater diversity and structural complexity than peripheral and outsides, which may be due to high plant-frugivore interactions in the interior forest than the disturbed outsides. To describe the structural and functional differences in tree communities from interior to outside forests with in small PA, we quantitatively analyzed the vegetation of Trishna Wildlife Sanctuary, a rich primate habitat of Northeast India. Vegetation was sampled at C10 cm girth at breast height by 10 m 9 500 m sized20 line transects(10 ha) laid in the interior(N = 7),peripheral(N = 7) and outside(N = 6) zones of this sanctuary. All transects were ordinated by Principal Component Analysis based on correlation between diversity and existing disturbance indices. We found significant differences(P \ 0.05) in taxonomic richness and diversity indices between the habitat. Van diagram confirmed greater unique species richness in the interior zone(64) than peripheral(28) and outside(6) zones. Overall density(ha-1) did not differed across the zones, but basal area(m2ha-1) was significantly(P \ 0.01) high in peripheral zone. Vertical distribution of stem density was linearly declined across zones(r2adj[ 0.70; P \ 0.01) with increase in the canopy height. Horizontal distribution of adult stems showed significant inverse quadratic relationship(r2adj[ 0.80; P \ 0.001), which suggests very low density of canopy forming voluminous trees in the interior zone.Immediate protection, restoration and management of interior regions are required to preserve local plant genetic diversity and also to maintain suitable habitat for threatened wildlife.     

Facing the peat CO2 threat: digital mapping of Indonesian peatlands—a proposed methodology and its application

Journal of Soils and Sediments - We conducted this project to develop a feasible method for mapping tropical peat lands of Bengkalis Island—as a test site—in Indonesia. The method based...     

Partition of Cd,Cu, Pb and Zn among mineral particles during their sorption in soils

Journal of Soils and Sediments - Heterogeneity of soil mineral particles may lead to the misinterpretation of bulk sorption data on their role in metal sorption, which may be resolved through the...