16 research outputs found
Distribution of Corbicula fluminea (Müller, 1774) in the invaded range: a geographic approach with notes on species traits variability
Corbicula fluminea is considered one of the
most important non-native invasive species (NIS) in
aquatic systems mainly due to its widespread distribution
and ecological and economic impacts. This species
is known to negatively affect native bivalves, also with
severe effects on biodiversity and ecosystem functioning.
Throughout an exhaustive bibliographic survey and
with the aid of Geographic Information Systems tools,
this study tracks the species dispersion from its native
range, including the description of important physical
and environmental barriers. Additional analyses were
conducted to examine possible influences of latitudinal/
temperature gradients on important traits (e.g. life span,
maximum and mean body length, growth at the end of
first year). Altitude and winter minimum temperature
appear to be delaying the invasion worldwide, but it
seems inevitable that the species will spread across the
globe. Latitude and summer temperature show a
relationship with growth and life span. Overall, the
information gathered in this review may be relevant to
forecast future distribution patterns of this NIS, and to
anticipate the possible implementation of effective
management measures. Moreover, it may constitute a
valuabletool inthe prediction of population responses to
an increasingly changing environment.This research was supported by FCT
(Portuguese Foundation for Science and Technology), through
a PhD grant attributed to D. Crespo (SFRH/BD/80252/2011), a
post-doc grant attributed to S. Leston (SFRH/BPD/91828/2012)
and M Dolbeth (SFRH/BPD/41117/2007) and BIOCHANGED
project (PTDC/MAR/111901/2009), subsidized by the
European Social Fund and MCTES (Ministério da Ciência,
Tecnologia e Ensino Superior) National Funds, through the
POPH (Human Potential Operational Programme), QREN
(National Strategic Reference Framework) and COMPETE
(Programa Operacional Factores de Competitividade).info:eu-repo/semantics/publishedVersio
Improving collection efforts to avoid loss of biodiversity: lessons from comprehensive sampling of lycophytes and ferns in the subtropical Atlantic Forest
Circulation and suspended sediment dynamics in a tropical estuary under different morphological setting
ABSTRACT Estuarine processes are directly related to the interaction of its forcing conditions with the local morphology. In this study we assess the implications of the opening of a new inlet on the hydrodynamics and suspended sediment concentration (SSC). A set of physical parameters have been measured in the Itanhém river estuary, a small, shallow and mangrove fringed tropical estuary in Northeastern Brazil. Field surveys have been conducted in August 2007 and January 2008, separated by an important morphological change. Our observations show that even shortening the lower estuary channel in 2 km, the inlet opening did not imply in changes in the estuarine circulation. However, SSC increased after the inlet opening. General estuarine circulation showed synodical modulation of tidal asymmetry and residual suspended sediment transport. The estuary showed flood dominance at spring tide and ebb dominance at neap tide. Although not directly changing the estuarine hydrodynamics, the morphological change resulted in an important increase in SSC. This increase might be related to a facilitated import of inner shelf sediment through a shorter channel, having important implications for the estuarine sedimentation processes
Paracoccidioidomicose com comprometimento do sistema nervoso central: revisão sistemática da literatura
Paracoccidioidomycosis case series with and without central nervous system involvement
INTRODUCTION: Paracoccidioidomycosis (PCM) is the most important systemic mycosis in South America. Central nervous system involvement is potentially fatal and can occur in 12.5% of cases. This paper aims to contribute to the literature describing eight cases of neuroparacoccidioidomycosis (NPMC) and compare their characteristics with patients without neurological involvement, to identify unique characteristics of NPCM. METHODS: A cohort of 213 PCM cases was evaluated at the Infectious Diseases Clinic of the University Hospital, Federal University of Minas Gerais, Brazil, from October 1976 to August 2008. Epidemiological, clinical, laboratory, therapeutic and follow-up data were registered. RESULTS: Eight patients presented NPCM. The observed NPCM prevalence was 3.8%. One patient presented the subacute form of PCM and the other seven presented the chronic form of the disease. The parenchymatous form of NPCM occurred in all patients. 60% of the patients who proceeded from the north/ northeast region of Minas Gerais State developed NPCM. The neurological involvement of a mother and her son was observed. NPCM patients exhibited demographical and clinical profiles similar to what is described in the literature. When NPCM cases were compared to PCM patients, there were differences in relation to origin and positive PCM family history. CONCLUSIONS: The results corroborate the clinical view that the neurological findings are extremely important in the evaluation of PCM patients. Despite the limitations of this study, the differences in relation to patient's origins and family history point to the need of further studies to determine the susceptibility factors involved in the neurological compromise
Global priorities for an effective information basis of biodiversity distributions
Gaps in digital accessible information (DAI) on species distributions hamper prospects of safeguarding biodiversity and ecosystem services, and addressing central ecological and evolutionary questions. Achieving international targets on biodiversity knowledge requires that information gaps be identified and actions prioritized. Integrating 157 million point records and distribution maps for 21,170 terrestrial vertebrate species, we find that outside a few well-sampled regions, DAI on point occurrences provides very limited and spatially biased inventories of species. Surprisingly, many large, emerging economies are even more under-represented in global DAI than species-rich, developing countries in the tropics. Multi-model inference reveals that completeness is mainly limited by distance to researchers, locally available research funding and participation in data-sharing networks, rather than transportation infrastructure, or size and funding of Western data contributors as often assumed. Our results highlight the urgent need for integrating non-Western data sources and intensifying cooperation to more effectively address societal biodiversity information needs
