923 resultados para ligules and style branch under SEM


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The sensitivity of copepods to ocean acidification (OA) and warming may increase with time, however, studies >10 days and on synergistic effects are rare. We therefore incubated late copepodites and females of two dominant Arctic species, Calanus glacialis and Calanus hyperboreus, at 0 °C at 390 and 3000 µatm pCO2 for several months in fall/winter 2010. Respiration rates, body mass and mortality in both species and life stages did not change with pCO2. To detect synergistic effects, in 2011 C. hyperboreus females were kept at different pCO2 and temperatures (0, 5, 10 °C). Incubation at 10 °C induced sublethal stress, which might have overruled effects of pCO2. At 5 °C and 3000 µatm, body carbon was significantly lowest indicating a synergistic effect. The copepods, thus, can tolerate pCO2 predicted for a future ocean, but in combination with increasing temperatures they could be sensitive to OA.

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This paper describes and analyzes the major features of economic development and poverty reduction in Egypt during its transition to a market Economy. It focuses on the changes in the situation of poverty and economic policies pursued as remedies by the government of Egypt and the ruling NDP. Sustainable development and poverty reduction is the core of the President Mubarak’s election campaign for his fifth term for the presidency. We attempt to explain the obstacles encountered by the Egyptian economy in terms of adjustments and general economic arguments on poverty. Finally, we refer to the necessity for enhanced accountability in the society to accomplish the goal.

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The international garment trade was liberalized in 2005 following the termination of the MFA (Multifibre Arrangement) and ever since then, price competition has intensified. Employing a unique firm dataset collected by the authors, this paper examines the changes in the performance of Cambodian garment firms between 2002/03 and 2008/09. During the period concerned, frequent firm turnover led to an improvement of the industry’s productivity, and the study found that the average total-factor productivity (TFP) of new entrants was substantially higher than that of exiting firms. Furthermore, we observed that thanks to productivity growth, an improvement in workers’ welfare, including a rise in the relative wages of the low-skilled, was taking place. These industrial dynamics differ considerably from those indicated by the “race to the bottom” argument as applied to labor-intensive industrialization in low income countries.

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In arid countries worldwide, social conflicts between irrigation-based human development and the conservation of aquatic ecosystems are widespread and attract many public debates. This research focuses on the analysis of water and agricultural policies aimed at conserving groundwater resources and maintaining rurallivelihoods in a basin in Spain's central arid region. Intensive groundwater mining for irrigation has caused overexploitation of the basin's large aquifer, the degradation of reputed wetlands and has given rise to notable social conflicts over the years. With the aim of tackling the multifaceted socio-ecological interactions of complex water systems, the methodology used in this study consists in a novel integration into a common platform of an economic optimization model and a hydrology model WEAP (Water Evaluation And Planning system). This robust tool is used to analyze the spatial and temporal effects of different water and agricultural policies under different climate scenarios. It permits the prediction of different climate and policy outcomes across farm types (water stress impacts and adaptation), at basin's level (aquifer recovery), and along the policies’ implementation horizon (short and long run). Results show that the region's current quota-based water policies may contribute to reduce water consumption in the farms but will not be able to recover the aquifer and will inflict income losses to the rural communities. This situation would worsen in case of drought. Economies of scale and technology are evidenced as larger farms with cropping diversification and those equipped with modern irrigation will better adapt to water stress conditions. However, the long-term sustainability of the aquifer and the maintenance of rurallivelihoods will be attained only if additional policy measures are put in place such as the control of illegal abstractions and the establishing of a water bank. Within the policy domain, the research contributes to the new sustainable development strategy of the EU by concluding that, in water-scarce regions, effective integration of water and agricultural policies is essential for achieving the water protection objectives of the EU policies. Therefore, the design and enforcement of well-balanced region-specific polices is a major task faced by policy makers for achieving successful water management that will ensure nature protection and human development at tolerable social costs. From a methodological perspective, this research initiative contributes to better address hydrological questions as well as economic and social issues in complex water and human systems. Its integrated vision provides a valuable illustration to inform water policy and management decisions within contexts of water-related conflicts worldwide.

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The pattern of damage localization and fracture under uniaxial and biaxial tension was studied in glass–fiber nonwoven felts. The analyses were carried out within the framework of the finite-element simulation of plain and notched specimens in which the microstructure of the felt, made up of fiber bundles connected at the cross point through an organic binder, was explicitly represented. Following previous experimental observations, fracture by interbundle decohesion and energy dissipation by frictional sliding between the bundles were included in the model. It was found that the failure path in these materials was controlled by the maximum applied normal stress, regardless of the loading path, and that the failure locus under biaxial tension was well represented by the von Mises failure criteria. The notch sensitivity of the nonwoven felts was limited and the presence of a notch did not modify the failure path.

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Field studies were conducted in walk-in tunnels to determine the flying capacity in the presence and absence of crop, of the parasitoid Psyttalia concolor and the predator Chrysoperla carnea under a UV-absorbent net (Bionet®). Yellow sticky cards were used for insect recovery but neither P. concolor nor C. carnea were very attracted to them, thus captures were too low to permit any meaningful comparisons. Bionet® did not seem to affect the mobility of any natural enemy irrespective of the trap location and monitoring hour. Climatic conditions inside nets were very extreme (average temperatures very high and relative humidity very low) threatening insect survival. New experiments are being developed, trying to find new attractants that permit a significant capture of both natural enemies.