Weighted Gini-Simpson Quadratic Index of Biodiversity for Interdependent Species

The weighted Gini-Simpson quadratic index is the simplest measure of biodiversity which takes into account the relative abundance of species and some weights assigned to the species. These weights could be assigned based on factors such as the phylogenetic distance between species, or their relative conservation values, or even the species richness or vulnerability of the habitats where these species live. In the vast majority of cases where the biodiversity is measured the species are supposed to be independent, which means that the relative proportion of a pair of species is the product of the relative proportions of the component species making up the respective pair. In the first section of the paper, the main versions of the weighted Gini-Simpson index of biodiversity for the pairs and triads of independent species are presented. In the second section of the paper, the weighted Gini-Simpson quadratic index is calculated for the general case when the species are interdependent. In this instance, the weights reflect the conservation values of the species and the distribution pattern variability of the subsets of species in the respective habitat induced by the inter-dependence between species. The third section contains a numerical example.

Numerical Study of Highly Nonlinear Photonic Crystal Fiber with Tunable Zero Dispersion Wavelengths

Solid-core silica photonic crystal fiber is proposed borrowing the concept of golden ratio (1.618) and keeping it between pitch and air hole diameter Λ/d in a subset of six rings of air-holes with hexagonal arrangement. In the case when we have a pitch equal to one micron (Λ = 1 μm), we need air-holes diameters d = 0.618 μm in order to achieve two zero dispersion wavelength (ZDW) points at 725 nm and 1055 nm;this gives us the possibility to use the fiber for supercontinuum generation, by pumping close to that points, pulse compression or reshaping. We analyzed a series of fibers using this relation and showed the possibilities of tunable ZDW in a wide range of wavelengths from 725 nm to 2000 nm, with low losses and small effective area. In agreement with the ZDW point needed, the geometry of the structure can be modified to the point of having only three rings of air holes that surround the solid core with low losses and good confinement mode. The design proposed here is analyzed using the finite element method with perfectly matched layers, including the material dispersion directly into the model applying the Sellmeier’s equation.

Comparison of gastrointestinal parasite communities in vervet monkeys

Globally,habitat degradation is accelerating,especially in the tropics.Changes to interface habitats can increase environmental overlap among nonhuman primates,people,and domestic animals and change stress levels in wildlife,leading to changes in their risk of parasite infections.However,the direction and consequences of these changes are unclear,since animals may benefit by exploiting human resources(e.g.,improving nutrition­al health by eating nutritious crops)and decreasing susceptibility to infection,or interactions with humans may lead to chronic stress and increased susceptibility to infection.Vervet monkeys are an excellent model to under­stand parasitic disease transmission because of their tolerance to anthropogenic disturbance.Here we quantify the gastrointestinal parasites of a group of vervet monkeys(Chlorocebus aethiops)near Lake Nabugabo,Ugan­da,that frequently overlaps with people in their use of a highly modified environment.We compare the parasites found in this population to seven other sites where vervet monkey gastrointestinal parasites have been identi­fied.The vervets of Lake Nabugabo have the greatest richness of parasites documented to date.We discuss how this may reflect differences in sampling intensity or differences in the types of habitat where vervet parasites have been sampled.