Land Management Decisions and Agricultural Productivity in the Hillsides of Honduras

Increasing land degradation and concomitant low agricultural productivity are important determinants of rural poverty in the hillside areas of Honduras. Using data at the levels of the farm household, parcel and plot, we develop an econometric modeling framework to analyze land management decisions and their impact on crop productivity. Our econometric model allows for endogenous household decisions regarding livelihood strategy choice, use of labor and external inputs, and participation in organizations. We found support for the inverse farm size-land productivity relationship which suggests that improved land access could increase total crop production. Land tenure has no impact on crop productivity, but adoption of soil conservation practices is higher on owner-operated than leased plots. Ownership of machinery and equipment and livestock ownership both positively influence crop productivity. Education positively affects perennial crop productivity. The gender of the household head has no significant effect on crop productivity, but does influence some land management and input use decisions. Even though household participation in training programs and organizations has only limited effects on crop productivity, agricultural extension plays a key role in promoting adoption of soil conservation practices. Location assets have limited impacts on crop productivity but do influence land management decisions. Road density and better market access have a positive effect on perennial crop productivity. Population density has limited direct impact on crop productivity, though it may have indirect effects by affecting farm size and livelihood strategies.agricultural productivity, hillsides, Honduras, land management, soil conservation, Land Economics/Use, Productivity Analysis,

Optical modulation spectroscopy of hydrogenated microcrystalline silicon

The properties of microcrystalline silicon thin films prepared by RF sputtering were investigated by optical modulation spectroscopy at room temperature and the results were correlated with Raman and conductivity measurements. For comparative purposes, a number of good quality PECVD microc-Si:H samples were also investigated. For PECVD samples the OMS signal is very weak, and only measurable for probe beam energies comparable to the gap of amorphous silicon. This indicates the absence of gap states and therefore a very high crystalline fraction, as confirmed by Raman and TEM measurements. In what concerns RF-sputtered samples, different behaviors can be distinguished: Some samples show a low OMS signal which can be attributed either to a high crystallinity (low density of gap states) or to high recombination rates. These two cases can be distinguished by electrical conductivity values and analysis of the Raman spectra. Other samples exhibit a OMS signal similar to a-Si:H and have low conductivity values, consistent with a Raman spectrum typical of a-Si:H.FCT-grant from PRAXIS XX

Turbulent boundary layer with strong favorable pressure gradient and curvature effects: Streamline coordinate and scaling analysis

Direct numerical simulation (DNS) of a turbulent boundary layer over the Gaussian (Boeing) bump is performed. This boundary layer exhibits a series of adverse and favorable pressure gradients and convex and concave curvature effects before separating. These effects on turbulent boundary layers are characterized and compared to a lower Reynolds number flow over the same geometry. The momentum budgets are analyzed in the streamline-aligned coordinate system upstream of the separation region. These momentum budgets allow the simplification of equations to facilitate an integral analysis. Integral analysis-based scalings for Reynolds stresses in the inner and outer regions of the boundary layer are also formulated. These proposed scalings exhibit a better collapse of Reynolds stress profiles compared to friction velocity scaling and Zagarola-Smits scaling in the strong favorable pressure gradient region and in the mild adverse pressure region that precedes it in this flow

The story against smoking:An exploratory study into the processing and perceived effectiveness of narrative visual smoking warnings

Objectives: This study compared the effects of two types of health warnings on cigarette packages: 'narrative visual warnings', showing an image portraying people plus a corresponding slogan that could evoke a story-like interpretation, and 'non-narrative visual warnings' with non-narrative content (i.e. body parts). Moreover, the mechanisms underlying the effects of these health warnings were explored. Design: A within-participants experiment was conducted comparing narrative and non-narrative visual warnings. Path analyses were performed to investigate the relationship between the narrative concepts transportation and identification, the emotions evoked by the health warning and the perceived effectiveness of the message. Method: Participants (N = 200) were presented with one narrative warning and one non-narrative warning. After each warning, they answered questions on narrative perception, transportation, identification, emotions and perceived effectiveness. Results: The narrative warnings were seen as more story-like than the non-narrative warnings. There was a statistical trend for narrative warnings to be perceived as more effective than the non-narratives. The narrative warnings caused more transportation, fear, sadness, compassion and anger; the non-narrative warnings evoked more disgust and surprise. For the narrative warnings, both narrative concepts of transportation and identification were directly related to perceived effectiveness, and also indirectly via sadness. For the non-narrative warnings, transportation was related to perceived effectiveness, both directly and indirectly via disgust. Conclusion: Seeing a story in a still picture with a slogan helps to increase the effectiveness of the antismoking message. Both narrative and non-narrative visual warnings may persuade receivers directly, but also by the evoking of emotions, although the specific emotions responsible for the persuasive effects may differ