The emergence of SARS-CoV-2 into a highly susceptible global population was primarily driven by human mobility-induced introduction events. Especially in the early stages, understanding mobility was vital to mitigating the pandemic prior to widespread vaccine availability. We conducted a systematic review of studies published from January 1, 2020, to May 9, 2021, that used population-level human mobility data to understand SARS-CoV-2 transmission.
View Article and Find Full Text PDFMorphometric analyses of male genitalia are routinely used to distinguish genera and species in beetles, butterflies, and flies, but are rarely used in ants, where most morphometric analyses focus on the external morphology of the worker caste. In this work, we performed linear morphometric analysis of the male genitalia to distinguish and in Madagascar. For 80 specimens, we measured 10 morphometric characters, especially on the paramere, volsella, and penisvalvae.
View Article and Find Full Text PDFCricket Frass Fertilizer (CFF) was tested for its efficiency and potential as a fertilizer on the growth of green beans (Phaseolus vulgaris L.) in central Madagascar from April 2020 to October 2020. We grew green beans experimentally for 93 days with seven different fertilizer treatments: NPK 200 kg/ha (0.
View Article and Find Full Text PDFDisturbances are ubiquitous in ecological systems, and species have evolved a range of strategies to resist or rebound following disturbance. Understanding how the presence and complementarity of regeneration traits will affect community responses to disturbance is increasingly urgent as disturbance regimes shift beyond their historical ranges of variability. We define "disturbance niche" as a species' fitness across a range of disturbance sizes and frequencies that can reflect the fundamental or realized niche, that is, whether the species occurs alone or with other species.
View Article and Find Full Text PDFFor emerging epidemics such as the COVID-19 pandemic, quantifying travel is a key component of developing accurate predictive models of disease spread to inform public health planning. However, in many LMICs, traditional data sets on travel such as commuting surveys as well as non-traditional sources such as mobile phone data are lacking, or, where available, have only rarely been leveraged by the public health community. Evaluating the accuracy of available data to measure transmission-relevant travel may be further hampered by limited reporting of suspected and laboratory confirmed infections.
View Article and Find Full Text PDFA surprising feature of the SARS-CoV-2 pandemic to date is the low burdens reported in sub-Saharan Africa (SSA) countries relative to other global regions. Potential explanations (for example, warmer environments, younger populations) have yet to be framed within a comprehensive analysis. We synthesized factors hypothesized to drive the pace and burden of this pandemic in SSA during the period from 25 February to 20 December 2020, encompassing demographic, comorbidity, climatic, healthcare capacity, intervention efforts and human mobility dimensions.
View Article and Find Full Text PDFObjectives: Quantitative estimates of the impact of infectious disease outbreaks are required to develop measured policy responses. In many low- and middle-income countries, inadequate surveillance and incompleteness of death registration are important barriers.
Design: Here, we characterize how large an impact on mortality would have to be for being detectable using the uniquely detailed mortality notification data from the city of Antananarivo, Madagascar, with application to a recent measles outbreak.
Pulsed fluxes of organisms across ecosystem boundaries can exert top-down and bottom-up effects in recipient food webs, through both direct effects on the subsidized trophic levels and indirect effects on other components of the system. While previous theoretical and empirical studies demonstrate the influence of allochthonous subsidies on bottom-up and top-down processes, understanding how these forces act in conjunction is still limited, particularly when an allochthonous resource can simultaneously subsidize multiple trophic levels. Using the Lake Mývatn region in Iceland as an example system of allochthony and its potential effects on multiple trophic levels, we analyzed a mathematical model to evaluate how pulsed subsidies of aquatic insects affect the dynamics of a soil-plant-arthropod food web.
View Article and Find Full Text PDFMultiple abrupt and sometimes near-synchronous declines in tree populations have been detected in the temperate forests of eastern North America and Europe during the Holocene. Traditional approaches to understanding these declines focus on searching for climatic or other broad-scale extrinsic drivers. These approaches include multi-proxy studies that match reconstructed changes in tree abundance to reconstructed changes in precipitation or temperature.
View Article and Find Full Text PDFTheor Popul Biol
December 2018
Empirical studies have shown that, unlike species with specialized resource requirements, generalist species may benefit from habitat destruction. We use a family of models to probe the causes of the contrasting responses of these two types of species to habitat destruction. Our approach allows a number of mechanisms to be switched on and off, thereby making it possible to study their marginal and joint effects.
View Article and Find Full Text PDFTrends Ecol Evol
July 2018
Background: Malaria is one of the primary health concerns in Madagascar. Based on the duration and intensity of transmission, Madagascar is divided into five epidemiological strata that range from low to mesoendemic transmission. In this study, the spatial and temporal dynamics of malaria within each epidemiological zone were studied.
View Article and Find Full Text PDFIn biodiversity conservation, habitat corridors are assumed to increase landscape-level connectivity and to enhance the viability of otherwise isolated populations. While the role of corridors is supported by empirical evidence, studies have typically been conducted at small spatial scales. Here, we assess the quality and the functionality of a large 95-km long forest corridor connecting two large national parks (416 and 311 km2) in the southeastern escarpment of Madagascar.
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