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In this study, we use deterministic and stochastic models to analyze the demography of Verreaux’s sifaka ( Propithecus verreauxi verreauxi) in a fluctuating rainfall environment. The model is based on 16 years of data from Beza Mahafaly Special Reserve, southwest Madagascar. The parameters in the stage-classified life cycle were estimated using mark-recapture methods. Statistical models were evaluated using information-theoretic techniques and multi-model inference. The highest ranking model is time-invariant, but the averaged model includes rainfall-dependence of survival and breeding. We used a time-series model of rainfall to construct a stochastic demographic model. The time-invariant model and the stochastic model give a population growth rate of about 0.98. Bootstrap confidence intervals on the growth rates, both deterministic and stochastic, include 1. Growth rates are most elastic to changes in adult survival. Many demographic statistics show a nonlinear response to annual rainfall but are depressed when annual rainfall is low, or the variance in annual rainfall is high. Perturbation analyses from both the time-invariant and stochastic models indicate that recruitment and survival of older females are key determinants of population growth rate. [ABSTRACT FROM AUTHOR]

Examines the effect of medication status on prepulse inhibition in schizophrenic subjects. Inhibition of the acoustic startle response when startling stimulus is preceded by a weaker non-startling acoustic stimulus; Concept of prepulse inhibition of acoustic startle; Impairment of the prepulse inhibition acoustic startle in schizophrenics.

Aims: Understanding the belowground interactions in multi-species intercropping agroecosystems is critical to improving the cropping system’s sustainability. This study aims to assess the sugarcane root colonization of the soil in plant crops when intercropped with legumes or spontaneous weeds in the inter-row.Roots were studied in the setting of three inter-row conditions: sugarcane with full chemical weed control, sugarcane-jack bean (Canavalia ensiformis) intercropping, and sugarcane with spontaneous weeds in the inter-row. Root mappings were conducted at 3.5, 6, 8, and 11 months after sugarcane planting in two vertical trenches per age and experimental condition (width 1.5 m x depth 1.2 m). Fine root distribution, root length densities, and a soil colonization index were estimated from the root intersects, in relation to plant root co-occurrence.We found that both legumes and weeds in the inter-row decreased the total sugarcane fine root length by 17 to 30% compared to situation of chemical weed control from 6 months onwards. From 3.5 months, legumes or weeds impacted vertical and horizontal sugarcane root distribution, mainly in the topsoil. Consequently, the soil volume colonized by sugarcane roots decreased by 27% in both inter-row conditions throughout the crop cycle. This decrease was due to changes in root distribution and the co-occurrence of multi-species plant roots but not to changes in total root length.Our study pointed out the need to consider how the presence of other plant roots affects sugarcane root extension to understand and simulate the competition processes influencing intercropping performances.Methods: Understanding the belowground interactions in multi-species intercropping agroecosystems is critical to improving the cropping system’s sustainability. This study aims to assess the sugarcane root colonization of the soil in plant crops when intercropped with legumes or spontaneous weeds in the inter-row.Roots were studied in the setting of three inter-row conditions: sugarcane with full chemical weed control, sugarcane-jack bean (Canavalia ensiformis) intercropping, and sugarcane with spontaneous weeds in the inter-row. Root mappings were conducted at 3.5, 6, 8, and 11 months after sugarcane planting in two vertical trenches per age and experimental condition (width 1.5 m x depth 1.2 m). Fine root distribution, root length densities, and a soil colonization index were estimated from the root intersects, in relation to plant root co-occurrence.We found that both legumes and weeds in the inter-row decreased the total sugarcane fine root length by 17 to 30% compared to situation of chemical weed control from 6 months onwards. From 3.5 months, legumes or weeds impacted vertical and horizontal sugarcane root distribution, mainly in the topsoil. Consequently, the soil volume colonized by sugarcane roots decreased by 27% in both inter-row conditions throughout the crop cycle. This decrease was due to changes in root distribution and the co-occurrence of multi-species plant roots but not to changes in total root length.Our study pointed out the need to consider how the presence of other plant roots affects sugarcane root extension to understand and simulate the competition processes influencing intercropping performances.Results: Understanding the belowground interactions in multi-species intercropping agroecosystems is critical to improving the cropping system’s sustainability. This study aims to assess the sugarcane root colonization of the soil in plant crops when intercropped with legumes or spontaneous weeds in the inter-row.Roots were studied in the setting of three inter-row conditions: sugarcane with full chemical weed control, sugarcane-jack bean (Canavalia ensiformis) intercropping, and sugarcane with spontaneous weeds in the inter-row. Root mappings were conducted at 3.5, 6, 8, and 11 months after sugarcane planting in two vertical trenches per age and experimental condition (width 1.5 m x depth 1.2 m). Fine root distribution, root length densities, and a soil colonization index were estimated from the root intersects, in relation to plant root co-occurrence.We found that both legumes and weeds in the inter-row decreased the total sugarcane fine root length by 17 to 30% compared to situation of chemical weed control from 6 months onwards. From 3.5 months, legumes or weeds impacted vertical and horizontal sugarcane root distribution, mainly in the topsoil. Consequently, the soil volume colonized by sugarcane roots decreased by 27% in both inter-row conditions throughout the crop cycle. This decrease was due to changes in root distribution and the co-occurrence of multi-species plant roots but not to changes in total root length.Our study pointed out the need to consider how the presence of other plant roots affects sugarcane root extension to understand and simulate the competition processes influencing intercropping performances.Conclusions: Understanding the belowground interactions in multi-species intercropping agroecosystems is critical to improving the cropping system’s sustainability. This study aims to assess the sugarcane root colonization of the soil in plant crops when intercropped with legumes or spontaneous weeds in the inter-row.Roots were studied in the setting of three inter-row conditions: sugarcane with full chemical weed control, sugarcane-jack bean (Canavalia ensiformis) intercropping, and sugarcane with spontaneous weeds in the inter-row. Root mappings were conducted at 3.5, 6, 8, and 11 months after sugarcane planting in two vertical trenches per age and experimental condition (width 1.5 m x depth 1.2 m). Fine root distribution, root length densities, and a soil colonization index were estimated from the root intersects, in relation to plant root co-occurrence.We found that both legumes and weeds in the inter-row decreased the total sugarcane fine root length by 17 to 30% compared to situation of chemical weed control from 6 months onwards. From 3.5 months, legumes or weeds impacted vertical and horizontal sugarcane root distribution, mainly in the topsoil. Consequently, the soil volume colonized by sugarcane roots decreased by 27% in both inter-row conditions throughout the crop cycle. This decrease was due to changes in root distribution and the co-occurrence of multi-species plant roots but not to changes in total root length.Our study pointed out the need to consider how the presence of other plant roots affects sugarcane root extension to understand and simulate the competition processes influencing intercropping performances. [ABSTRACT FROM AUTHOR]