As modalidades esportivas coletivas de invasão (MECi) despertam grande interesse aos envolvidos com esporte no Brasil, mas o olhar dado à formação não é o mesmo dado ao alto rendimento, muitas vezes desconsiderando-se as características desse grupo de modalidades no processo de iniciação. Com o fim de valorizar essas características, há disponível na literatura diversas propostas de iniciação nas MECi. Considerando essas propostas e modelos de formação esportiva em longo prazo, esse estudo objetivou verificar a possibilidade de uma prática transferível na iniciação nas MECi, avaliando se o desempenho de praticantes de uma MECi é semelhante em outra MECi. Foi realizada uma pesquisa descritiva observacional, com jovens atletas de handebol e de basquetebol do sexo masculino. Cada jogador foi avaliado ao realizar jogos das duas modalidades, através do Game Performance Assessment Instrument. A partir dessa avaliação, o desempenho que os jogadores tiveram nas duas modalidades foi comparado. Os resultados mostraram que o desempenho dos sujeitos em ambas as modalidades foi semelhante, ou seja, o desempenho que os jogadores tiveram na modalidade que não praticavam foi tão bom quanto na sua modalidade de origem. Esses resultados, aliados a outros estudos e projetos disponíveis na literatura, indicam que é possível adotar a prática transferível como estratégia para iniciação nas MECi, explorando suas similaridades e deixando a cargo de uma etapa de especialização futura, o aprofundamento nas questões específicas da modalidade escolhida / The invasion games (IG) arouse great interest to those involved with sport in Brazil, however view about sports learning process is not the same as at performance training, often disregarding the characteristics of this group of games in the learning process. In order to value these characteristics, there are several proposals for the IG learning process available in the literature. Considering these proposals and long-term sports training models, this study aimed on verifying the possibility of the transfer practice into the IG learning, then evaluating if the practitioners performance of a specific game would be similar to their performance in another game. A descriptive observational research with young male athletes of handball and basketball was performed. Each player was assessed by performing games on both sports through the Game Performance Assessment Instrument. Based on this assessment, the players performance on both sports was compared. The results showed that subjects\' performance in both were similar: the performance that players had in the sport they did not use to practice, was as good as in their sport of origin. These results, allied with other studies and projects available in the literature indicate that it is possible to adopt the transfer practice as a strategy to IG learning, exploring their similarities and leaving to a future specialization, the deepening in specific issues of the chosen sport

As modalidades esportivas coletivas de invasão (MECi) despertam grande interesse aos envolvidos com esporte no Brasil, mas o olhar dado à formação não é o mesmo dado ao alto rendimento, muitas vezes desconsiderando-se as características desse grupo de modalidades no processo de iniciação. Com o fim de valorizar essas características, há disponível na literatura diversas propostas de iniciação nas MECi. Considerando essas propostas e modelos de formação esportiva em longo prazo, esse estudo objetivou verificar a possibilidade de uma prática transferível na iniciação nas MECi, avaliando se o desempenho de praticantes de uma MECi é semelhante em outra MECi. Foi realizada uma pesquisa descritiva observacional, com jovens atletas de handebol e de basquetebol do sexo masculino. Cada jogador foi avaliado ao realizar jogos das duas modalidades, através do Game Performance Assessment Instrument. A partir dessa avaliação, o desempenho que os jogadores tiveram nas duas modalidades foi comparado. Os resultados mostraram que o desempenho dos sujeitos em ambas as modalidades foi semelhante, ou seja, o desempenho que os jogadores tiveram na modalidade que não praticavam foi tão bom quanto na sua modalidade de origem. Esses resultados, aliados a outros estudos e projetos disponíveis na literatura, indicam que é possível adotar a prática transferível como estratégia para iniciação nas MECi, explorando suas similaridades e deixando a cargo de uma etapa de especialização futura, o aprofundamento nas questões específicas da modalidade escolhida / The invasion games (IG) arouse great interest to those involved with sport in Brazil, however view about sports learning process is not the same as at performance training, often disregarding the characteristics of this group of games in the learning process. In order to value these characteristics, there are several proposals for the IG learning process available in the literature. Considering these proposals and long-term sports training models, this study aimed on verifying the possibility of the transfer practice into the IG learning, then evaluating if the practitioners performance of a specific game would be similar to their performance in another game. A descriptive observational research with young male athletes of handball and basketball was performed. Each player was assessed by performing games on both sports through the Game Performance Assessment Instrument. Based on this assessment, the players performance on both sports was compared. The results showed that subjects\' performance in both were similar: the performance that players had in the sport they did not use to practice, was as good as in their sport of origin. These results, allied with other studies and projects available in the literature indicate that it is possible to adopt the transfer practice as a strategy to IG learning, exploring their similarities and leaving to a future specialization, the deepening in specific issues of the chosen sport

O câncer de mama é uma das principais causas de morte por câncer em mulheres em todo o mundo, apresentando-se como uma doença heterogênea composta por distintos subtipos associados a diferentes prognósticos clínicos, mas as bases moleculares que sustentam sua progressão tumoral ainda não estão completamente elucidadas. Evidências de estudos em larga escala apontam uma potencial participação da proteína EMC1 no desenvolvimento do câncer de mama, mas falham em avaliam seu papel específico na progressão e manutenção deste tipo de tumor. EMC1 faz parte de um complexo definido por dez proteínas presente no retículo endoplasmático denominado Endoplasmic Reticulum Membrane Complex, caracterizado recentemente com potencial papel no enovelamento e maturação de proteínas de membrana e na via secretória. Investimos deste modo na caracterização de EMC1 e no seu envolvimento com o câncer de mama. Utilizando um pequeno painel de linhagens tumorais de mama, mostramos por meio de qPCR que os níveis de RNAm de EMC1 estavam aumentados em linhagens consideradas mais agressivas. Duas linhagens tumorais de mama, MCF-7 e SKBR-3 foram utilizadas para expressão estável de EMC1 mediada pelo vetor plasmidial pcDNA3.1. Os efeitos foram notáveis apenas para a linhagem SKBR-3, que apresenta amplificação no locus HER-2, um receptor do tipo tirosina quinase da família EGFR envolvido em vias de invasão e proliferação celular. Observamos uma nítida alteração morfológica após a superexpressão de EMC1 nesta linhagem, sugerindo uma reprogramação para um fenótipo mesenquimal. As células adquiriram filopódios mais proeminentes e mostraram aumento em sua capacidade proliferativa e crescimento clonogênico, sob condições adesivas ou não, bem como aumento nas capacidades invasiva (transwell) e migratória (wound healing). Análises do ciclo celular por iodeto de propídeo indicaram um ligeiro aumento nas populações celulares nas fases S e G2/M em células superexpressando EMC1, corroborando os ensaios funcionais. Notamos também após a superexpressão de EMC1 um aumento na liberação de MMP-2, justificando o aumento na capacidade invasiva destas células. Os resultados dos ensaios funcionais comprovam as análises in silico realizadas nas quais identificamos uma correlação da expressão de EMC1 com proteínas envolvidas em funções no retículo endoplasmático e no processo de transição epitélio-mesenquimal. Avaliamos ainda o metabolismo celular quanto a funções mitocondriais como consumo de oxigênio utilizando um oxígrafo e quanto a geração de espécies reativas de oxigênio (EROs) através da marcação por DHE. A superexpressão de EMC1 levou à diminuição da respiração, ou seja, no consumo de oxigênio e também da produção de EROs, ao passo que os níveis de lactato foram aumentados, características associadas a maior malignidade de células tumorais de mama. Por fim, mostramos através de ensaio de tumorigênese in vivo utilizando camundongos nude que a superexpressão de EMC1 conduziu a formação de tumores mais agressivos e de maior volume. Em conjunto os dados sugerem um importante papel de EMC1 na progressão tumoral do câncer de mama, sobretudo na transição para estágios mais invasivos, servindo como potencial marcador diagnóstico e alvo para terapias futuras. / Breast cancer is a leading cause of cancer death in women worldwide. It presents as a heterogeneous disease composed of distinct subtypes associated with different clinical prognoses, but the molecular basis underlying their tumor progression are not yet fully comprehended. Evidence from large-scale studies suggests a potential involvement of EMC1 protein in the development of breast cancer, but fail to assess its specific role in the progression and maintenance of this type of tumor. EMC1 is part of a protein complex composed of ten different subunits associated to the endoplasmic reticulum (ER) and recently proposed to play a potential role in the folding and maturation of membrane proteins in the secretory pathway. Thus, our aim here was to do a functional characterization of EMC1 in breast cancer. Using a small panel of breast cancer cell lines, we showed higher EMC1 mRNA expression levels in the most aggressive cell lines, by qPCR. Two breast tumor cell lines, MCF - 7 and SKBR -3 were used for stable expression of EMC1 mediated by the plasmidial vector pcDNA3.1. The effects were remarkable only for the SKBR-3 cell line, which carries an amplification of the HER-2 locus, a tyrosine kinase receptor of the EGFR family, involved in cell proliferation and invasion. We observed a clear morphological change after overexpression of EMC1 in this cell line, suggesting a reprogramming to a mesenchymal phenotype. The cells acquired more prominent filopodia and showed an increase of their proliferative capacity and clonogenic growth upon adhesive and non-adhesive conditions, as well as an increase of invasive (collagen-coated transwell) and migratory (wound healing) properties. Analysis of the cell cycle by propidium iodide showed a slight increase in the cell population in S phase and G2/M for EMC1-overexpressing cells, corroborating other functional assays. Also, EMC1-overexpressing cells showed an increase in the release of MMP-2, which could explain the increase in the invasive capacity of these cells. The results of the functional assays confirm the in silico analysis performed in which we identified a correlation between the EMC1 expression with proteins involved in functions in the endoplasmic reticulum and in the epithelial-mesenchymal transition. We also evaluated the cellular metabolism and mitochondrial functions such as oxygen consumption using an oxygraph and the generation of reactive oxygen species (ROS) with DHE dye. Overexpression of EMC1 led to decreased respiration, i.e. oxygen consumption and also ROS production whereas lactate was increased, characteristics associated with increased malignancy of breast tumor cells. Finally, we show through in vivo tumorigenesis assay using nude mice that overexpression of EMC1 led to formation of more aggressive tumors. Together the data suggest an important role of EMC1 in tumor progression of breast cancer, especially in the transition to more invasive stages, serving as a potential prognostic marker and target for future therapies.

As radiografias intraorais ilustram bem os estágios de reabsorção periodontal nas regiões interproximais. Entretanto, a sobreposição de estruturas dificulta avaliação da perda óssea nas corticais vestibular e lingual. A tomografia computadorizada por feixe cônico (TCFC) é de elevada importância em várias especialidades odontológicas, tais como implantodontia, avaliação de lesões ósseas, estudo da articulação têmporo-mandibular e cirurgia buco-maxilo-facial. A TCFC também tem tido crescente indicação em outras áreas, como a periodontia e endodontia. O objetivo no presente estudo foi a) estabelecer o protocolo de aquisição mais adequado para a detecção de lesões incipientes de furca simuladas quimicamente; e b) avaliar a reprodutibilidade, sensibilidade e especificidade da TCFC, para a finalidade previamente citada. No presente estudo, foram utilizadas 15 mandíbulas suínas maceradas, que apresentavam o segundo molar íntegro e as corticais adjacentes preservadas As simulações de lesões em região de furca foram feitas com aplicação de ácido perclórico a 70%, em até quatro sítios possíveis em cada mandíbula (vestibular do lado direito, lingual do lado direito, vestibular do lado esquerdo, lingual do lado esquerdo) por um examinador participante que não avaliou as imagens. Nos 60 sitios possíveis, foram escolhidos aleatoriamente 20 para as simulações das lesões. Posteriormente, as mandíbulas foram submetidas à TCFC (i-CAT Next Generation) em dois. protocolos de aquição: voxel 0,2 mm e 0,25 mm, ambos com FOV de 6 cm de altura por 16 cm de diâmetro e com 26,9 segundos de tempo. Dois observadores (radiologistas previamente calibrados) avaliaram os exames duas vezes, em ordem aleatória, sob iluminação controlada. Os observadores foram orientados a direcionar a avaliação das regiões dos segundos molares, e questionados se havia lesão ou não nos sítios avaliados. A interpretação das imagens foi realizada em uma estação de trabalho independente localizada no Laboratório de Imagem em Terceira Dimensão da Faculdade de Odontologia da Universidade de São Paulo, utilizando o software Xoran (Xoran Technologies). A sensibilidade, especificidade e reprodutibilidade da TCFC foram avaliadas nos dois protocolos. A TCFC apresentou especificidade alta, sensibilidade baixa e reprodutibilidade moderada na detecção de lesões incipientes de furca. A influência do tamanho do voxel não foi estatisticamente significativa na detecção destas lesões. / Intraoral radiographs illustrate the stages of resorption in periodontal interproximal regions. However, overlapping structures hinders evaluation of bone loss in the buccal and lingual cortical plates. The cone beam computed tomography (CBCT) is of high importance in various dental specialties such as implantology, evaluation of bone lesions, the study of temporomandibular joint and maxillo-facial surgery. The CBCT has also been increasing indications in other areas, such as periodontics and endodontics. The aim of this study was to establish a) the acquisition protocol most suitable for the detection of incipient furcation invasion chemically simulated and b) assess the reproducibility, sensitivity and specificity of CBCT for the purpose previously mentioned. In this study, 15 pigs macerated mandibles were used, which showed the second molar and the adjacent cortical integrity preserved. Simulated lesions in the furcation area were made with application of 70% perchloric acid, up to four possible sites in each jaw (the right buccal, the right lingual, the left buccal, and left lingual side) by an examiner participant who did not evaluate the images. In the 60 possible sites, 20 were randomly chosen for the simulated lesions. Subsequently, the mandibles underwent cone beam computed tomography (Next Generation i-CAT) in two acquisition protocols: at 0.2 mm and 0.25 mm voxel, both with FOV of 6 cm height by 16 cm in diameter and 26.9 seconds of time. Two observers (calibrated radiologists) evaluated the examinations twice, in random order under controlled lighting. Observers were instructed to direct the evaluation to the regions of the second molars, and they were asked if there were or not injuries on those avaluated sites. Image interpretation was performed on an independent workstation located at the Third Dimension Laboratory of Image in the School of Dentistry, University of São Paulo, using the software Xoran (Xoran Technologies). The sensitivity, specificity and reproducibility of CBCT were assessed in both trials. The CBCT showed high specificity, low sensitivity and moderate reproducibility in the detection of incipient lesions, furcation. The influence of voxel size was not statistically significant in detecting these lesions.

Research in the biomedical sciences is incredibly diverse and often involves the interaction of specialists in a variety of fields. In particular, quantitative, mathematical, and computational methods are increasingly playing significant roles in studying problems arising in biomedical science. This is particularly exciting for mathematical modeling as the complexity of biological systems poses new challenges to modelers and leads to interesting mathematical problems. On the other hand mathematical modeling can provide considerable insight to laboratory and clinical researchers. In this thesis we develop mathematical representations for three biological processes that are of current interest in biomedical science. A deeper understanding of these processes is desirable not only from the standpoint of basic science, but also because of the connections these processes have with certain diseases. The processes we consider are collective cell motility, bone remodeling, and injury response in articular cartilage. Our goals are to develop mathematical representations of these processes that can provide a conceptual framework for understanding the processes at a fundamental level, that make rigorous the intuition biological researchers have developed about these processes, and that help to translate theoretical and experimental work into information that can be used in clinical settings where the primary concern is in treating diseases associated with the process.

Introduced species are the greatest threat to biodiversity after habitat loss. Understanding the processes that permit organisms to become successful invaders may provide opportunities to prevent or limit their dispersal and establishment and thereby alleviate some of their harmful effects. The goal of my dissertation research has been to investigate whether invasive species have distinctive interactions with parasites, and some of the mechanisms that may underlie that variation. I used one of the world's most successful vertebrate invaders as a case study: the house sparrow (Passer domesticus; Introduction). Previous research in the house sparrow suggested that loss of parasite diversity may contribute to invasion success. However, my work demonstrates that infection with common avian malaria parasites is primarily a function of environmental heterogeneity and is not a predictor of time since introduction for house sparrows that are currently expanding their range in Kenya (Chapter 1). Interestingly, in spite of a large proportion of the population being infected with avian malaria, a state that should reduce competitive ability of house sparrow populations, this species is still able to establish themselves among native competitors. Though there are a number of potential mechanisms that could explain this pattern, one of the most convincing explanations is that house sparrows, and perhaps other introduced species, have adaptive differences in immunity. As such, the findings of Chapter 1 inspired two studies in which my collaborators and I showed that house sparrows from two non-native populations seem capable of maintaining normal health, performance and behavior during immune challenge, a response often referred to as parasite tolerance. Specifically, in Chapter 2, we found that when Floridian house sparrows, established since ~1870, were challenged with synthetic pathogens that mimicked infection with a fungi, an RNA virus or Gram-negative bacteria, only individuals challenged by the synthetic bacteria showed measurable sickness behaviors and secretion of an inflammatory protein. In Chapter 3, we compared parasite tolerance in Kenyan house sparrows (introduced in ~2000) and a native congener, the grey-headed sparrow (P. griseus) to a common intestinal parasite of songbirds. We found that both species were tolerant in that they were able to maintain fat reserves, protein reserves and vertical flight ability during infection. However, house sparrows maintained burdens that were, on average, more than 10x those of grey-headed sparrows. Moreover, when examining nutrient allocation in the two species, house sparrows appeared to assimilate nutrients more efficiently than grey-headed sparrows and did not change how nutrients were allocated among immune and reproductive organs during experimental infection. Grey-headed sparrows, however, did shift nutrient allocation among immune and reproductive organs during experimental infection. Together, the larger nutrient pool and maintenance of nutrient allocation patterns in challenged house sparrows suggests that no physiological trade-offs occurred and that house sparrows experienced a lower cost of parasite exposure. In the fourth Chapter, I explored why house sparrows had such high coccidia burdens in comparison to their congeners. We suspected burden was a function of the frequency of exposure to coccidia. Consequently, we explored heterogeneity in foraging preferences and other behaviors in Floridian house sparrows and their role in coccidia burden. As expected, we found that house sparrows did not avoid contaminated food. In fact, they ate contaminated and uncontaminated foods indiscriminately. What was surprising was a lack of correlation between burden and consumption of contaminated foods and all of the behaviors we monitored (i.e., aggression, activity, feeding rates and defecation frequency). Overall, these data suggest that house sparrows do not benefit from typical parasite-avoidance behaviors. In sum, this dissertation research implies that house sparrows respond to parasite infection differently than many other known vertebrates, most likely in an effort to maximize efficient use of resources and, in so doing, augment competitive ability and invasion success.

Alfalfa is a major cash crop in the western United States, where fields that are infested with the alfalfa stem nematode (Ditylenchus dipsaci) can be found. With no nematicides available to control alfalfa stem nematode spread, growers can use nematode resistant varieties of alfalfa to manage nematode populations in a field. A deterministic, discrete-time, host-parasite model is presented that describes the spread of alfalfa stem nematodes on resistant hosts that was fit to experimental data obtained in Weber County, Utah. Numerical results obtained from simulations with the model are used to compare how varying levels of resistance can affect harvest yield. Resistant varieties can also affect the invasion speeds of epidemics in crops. A continuous time, spatial model is presented that describes how these resistant varieties affect invasion speeds in general crop systems. Speeds of traveling wave fronts are determined for simple epidemics in crops that contain a mixture of resistant and non-resistant hosts. For the model, it was found that the wave speeds will slow down as highly nematode resistant varieties of alfalfa are used. The speed of invasion for the alfalfa stem nematode can be determined by using a mathematical relationship that is know as the contact distribution. We present a spatial model for the spread of alfalfa stem nematodes that uses a Gaussian distribution as the contact distribution of the alfalfa stem nematodes, which was determined by experimental data. Using this contact distribution we are able to approximate the speed of nematode invasive fronts in absence of advection, i.e. without nematode trans-port through flood irrigation. The contact distribution is then used to calculate front speeds when resistant varieties of alfalfa are introduced. We found that, unsurprisingly, invasive speeds are relatively low and cannot support the rapid dispersal of the disease among fields as seen in practice. However, this result leads to conjecture that changing current irrigation practices, from flood to sprinkle irrigation, could effectively contribute to control the spread of alfalfa stem nematodes. Resistant varieties of alfalfa can be used to effectively control the spread of the alfalfa stem nematode. In this work we have shown that using resistant varieties of alfalfa can increase yield up to 83%, they can slow down invasion speeds of nematodes, and switching from flood to sprinkler irrigation could effectively contribute to the control of the alfalfa stem nematode.

Glioblastoma multiforme (GBM) is the most lethal primary central nervous system tumor, with median survival after diagnosis of less than 12 months because dissemination into the brain parenchyma limits the long-term effectiveness of surgical resection, and because GBM cells are resistant to radiation and chemotherapy. This sad dismal prognosis for patients with GBM emphasizes the need for greater understand of the fundamental biology of the disease. Invasion is one of the major causes of treatment failure and death from glioma, because disseminated tumor cells provide the seeds for tumor recurrence. Inflammation is increasingly recognized as an important component of invasion. In the brain, inflammation can occur by activation of microglia, the resident macrophages of the brain, or by tumor-associated blood macrophages. Therefore, we hypothesize that activity of the innate immune system in the brain can influence tumor progression by secreting cytokines such as Tumor Necrosis Factor alpha (TNF-α). In this study, we show that patient-derived glioma spheres undergo morphological changes in response to TNF‑α that are associated with changes in migration behavior in vitro. These morphological changes include appearance of tumor islands in site different from where the primary tumor cells were seeded. We further showed that TNF‑α treated cells significantly increased expression of cell adhesion molecules such as CD44 and VCAM-1. Furthermore, we demonstrate increased cell density also caused increased in expression of cell adhesion molecules. The extent to which these are recapitulated in vivo will be investigated.

Understanding what promotes invasiveness of species outside their native range and predicting which ecosystems and under which conditions will be invaded is an ultimate goal of the field of invasion ecology. Obtaining general answers to these questions requires synthesis of extensive yet heterogeneous empirical evidence, coupled with a solid theoretical background. In this dissertation, I sought to provide insight into the drivers of non-native plant invasions through combining and synthesizing ecological data from various sources using advanced statistical techniques. The results of this work are presented as three independent research studies. In the first study, I aimed to understand what determines competitive advantage of non-native over native plants: the ability to suppress other plants, tolerate them, or both. For this, I collected data from 192 studies on plant competition and analyzed them within a Bayesian multilevel meta-analytic framework. I showed that non-native plants outperform their native counterparts due to the high tolerance of competition, as opposed to strong suppressive ability. Competitive tolerance ability of non-native plants was driven by neighbor’s origin and was expressed in response to native species and not to other non-native species. This synthesis demonstrates that non-native plants are competitively distinct from native plants and challenges the common notion that neighbor suppression is the primary strategy for plant invasion success. In the second study, I quantified the extent to which regional, landscape and local environmental factors individually and jointly affect understory non-native invasive plants across northern US forests. I used boosted regression trees and Bayesian nonlinear regressions to analyze forest inventory data spanning 14 northern US states in combination with data on climate, land use, and disturbance. Regionally, the highest level of plant invasion was observed in hotter regions with lower annual precipitation and climate seasonality and higher summer precipitation. Locally, young forests with moist to wet soils and relatively flat topography in open, human-altered landscapes at low elevation were most susceptible to invasion. Climate and land use strongly interacted in their effect on plant invasions. This study refines the understanding of the non-native plant invasion process in northern US forests and the obtained models can be used to generate predictions under current and future environmental regimes to inform management. In the third study, I tested the relationship between the long-term history of recurrent canopy disturbance by a non-native invasive defoliator, the gypsy moth (Lymantria dispar), and the level of non-native plant invasion in northeastern US forests. I reconstructed 46 years (1970–2015) of gypsy-moth defoliation history and quantified the cumulative effect of defoliation on understory non-native invasive plant species using multivariate techniques and Bayesian nonlinear regressions. Contrary to what is commonly expected, the cumulative severity of gypsy moth defoliation tended to be negatively associated with the presence and richness of invasive plant species, although this association was weak. This study suggests that the effect of biotic disturbance on forest plant invasions may vary in both the magnitude and direction depending on characteristics of disturbance regime and its effect on resident biota, and this needs to be explicitly taken into account when predicting future plant invasions.

Thesis (M. Phil. (Environmental Law and Management) -- University of Limpopo, 2010 / According to the Ramsar Convention of 1971, Wetlands are areas of marshes, firm, peatlands or waterlogged. They are either natural or artificial. They have water that is static or flowing, fresh, brackish or salty and include areas of marine water with the depth, which at low tides does not exceed six meters. Wetlands are regarded as important ecological components of the natural environment because of their richness and ability to support life. Wetlands essentially catch, clean and preserve any water. They are able to reduce the severity of drought and floods by regulating a stream flow. They also control erosion and provide habitat for many different plant and animal species. Wetlands also serve as valuable source of water, fish and grazing for livestock. They are important nesting grounds for birds. Wetland resources are also known to be of socio-economic importance because they provide materials for furniture and craft’s work Ga-Riba wetlands are very important for the community of Ga –Riba because they provide them with food such as fish and birds. Some of the community members make baskets, hats and mats using wetlands grass. They also make pottery using clay from the wetlands. During winter the wetlands are used as areas where traditional initiation for Ga-Riba girls is perfomed. Some people own fields within the wetlands on which they cultivate vegetables, maize and other crops. They also use wetland as grazing areas for their domestic animals such as cattle and goats. The Ga-Riba wetlands are being invaded by one of the alien plant called Populus alba L (Poplar). This type of alien plant, like other alien plants disturbs the ecological stability of the wetlands. Findings of the tests conducted on soil and water indicated that Poplars are changing the nature of the soil and the water of the wetlands. Vegetation survey showed that, wetlands had less vegetation than they were supposed to. With regard to legal instruments to control the invasion of wetlands by alien plants, findings showed that there are insuffient legal instruments which can be utilized.