We examined stand dynamics and biomass along an altitudinal gradient in a tropical montane forest (TMF) in the disturbance-prone Cordillera Central, Dominican Republic. We tested the general hypothesis that chronic disturbance by fire, wind, floods and landslides results in a landscape of relatively low above-ground biomass with high rates of mortality, recruitment and growth as compared with o...

the expanding phenomenon of dieback is caused by the reaction of trees against the harmful biotic and a biotic factor that lead to dying of shoots and branches of trees from upper crown to lower crown. this phenomenon spreads throughout the leaves and branches and all parts of the plant and may finally lead to the death of the plant. this study aimed to identify species dieback especially carpi...

BACKGROUND Differentiation of pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PVH) often requires right heart catheterization (RHC). We sought to determine whether a combination of clinical and echocardiographic variables could predict the pulmonary diastolic to wedge (PAd-PWP) gradient and thus differentiate patients with PAH and PVH. METHODS We prospectively enrolle...

The southern Andes create a variety of atmospheric phcromena, b:* &ese have not been well studied. In this paper, we describe our preliminary observations and modeling of a few of these phenomena including: the sharp vegetation gradient on the eastern slopes, orographic triggering ofroll convection, foehn wall and short lee-wave trains, liquid clouds capping ice clouds, "bullef' clouds, and iso...

OBJECTIVE Income and regional gradients in being without a regular family doctor have been reported. The study objective was to assess the extent to which the slopes of both income and regional gradients vary by individuals' health needs. METHOD Using the Canadian Community Health Survey and multivariate regression analyses, the study examined the income and interprovincial variations in pote...

We present a generalized method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object but rather its local slope. These sensors display several advantages, including high information efficiency, sensitivity, and robustness. For many applications, however, it is necessary to acquire the shape, which must ...

Convergent evolution is characterized by the independent evolution of similar phenotypes within similar selective environments. Previous work on Trinidadian killifish, Rivulus hartii, demonstrated repeatable life-history differences across communities that differ in predation intensity. These studies were performed in rivers located on the south slope of Trinidad's Northern Range Mountains. The...