1,720,982 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Preliminary studies on potential effect of climate change on stream ecology assessment by using BIOMOD
No full textDissertação de Mestrado, Ecohidrologia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2012Climate change is one of the greatest challenges of the 21st century for biodiversity conservation (www.conservationafrica.org) . Global warming is expected to be associated with diverse changes in freshwater habitats in north-western Europe (Cordellier, 2009). Macroinvertebrates are an important component of biodiversity in stream ecosystems and studies of macroinvertebrates are an estimation of the stream’s response to aquatic biodiversity and it is desirable and valuable to assess the climate change impact (Clarke et al. 2008). A model becomes a useful tool for a better representation of the expected changes. The present study was conducted by using the macroinvertebrate data base from the states Hessen, Nordrhein-Westfalen, Rheinland-Pfalz of Germany. After modelling a current and future distribution (occurrence probability) of 304 macroinvertebrates, the model outputs were collected. The values of probability occurrence of each species in each point from the grid cell was extracted by using ArcGis 10. The single species layer information was achieved, which can be used to predict the climate change impact on their community and individual species. A correlation was made by using model output probability values with abundance (raw sampling data). The range of correlation was -0.08 to 0.94 by using ‘R’ software package 2.14.1. A correlation analysis was made by taking high negative, low and high positive correlated species. According to our single species information from our preliminary study and result comparison with existing literature it was noticed that some species were listed under Red list species and some are going to be threatened in near future due to climate change episode. Another part of the present work was conducted to assess the stream quality by using ASTERICS, an EU developed assessment software for stream quality assessment in Europe by using macroinvertebrate data. With the present abundance record of macroinvertebrates, saprobic index, EPT % (abundance class) and degradation of river morphology metrics were calculated by using this assessment software. In our present investigation the saprobic index mean value was 1.98 and 1.73 for large and small stream type; 9 and 5 respectively. EPT % (abundance class) index had no significant relation in both types of streams and general degradation of river morphology was noticed in both types of streams. Quality class was compared between 9 and 5 stream types and these results are discussed
Ecohydrological assessment of a complex river-floodplain system for the enhancement of its multidimensional potential
No full textRiver floodplain systems are critical for sustaining biodiversity and providing a wide range of ecosystem services. However, climate change and anthropogenic activities increasingly disrupt the hydrological and ecological connectivity of these systems, red ucing their resilience to external pressures. The degradation of floodplains undermines key ecosystem services, including the support of terrestrial and aquatic biodiversity, the regulation of hydrological extremes such as floods and droughts, and the sequ estration of carbon. Given the global challenges of water scarcity and associated ecological consequences, there is an urgent need for
innovative management strategies to enhance the mult idimensional roles of floodplains in water resource management, biodiversity conservation, and climate change adaptation. Therefore, this thesis focused on the study of the river floodplain system that was selected as the demonstration site for the ecohydrological project LIFE Pilica (LIFE19 IPE/PL/000005) in Central Poland. The study addresse d the hydrological connectivity within the river floodplain system during spring and early summer, assessing its effects on water quality. A particular focus was placed on phosphorus dynamics between the water and sediment compartments, aiming to propose management strategies that mitigat e excessive phosphorus release for a sustainable
water retention in the floodplain area. Three primary hydrological connection s were identified between the studied floodplain, Pilica river and an upstream wetland . The connectivity decreased significantly throughout the study (from 0.185 m 3 s 1 in March to 0.002 m 3 s 1 in May )), with the first connection turning into a drainage source in April due to Pilica’s water level decrease . By May, the second source dried up, and the third was projected to cease at a river discharge below 12 m³s⁻¹ (R² = 0.94).
Principal Component Analysis (PCA) revealed a greater difference between water quality from the o xbow l ake with the river ’s inflow (35.4%) than with the wetland’s outflow ( 15.5%). This shift underscores an increased risk of eutrophication in both water bodies, driven by prolonged residence times, nutrient accumulation, and the lack of water exchange from the river.
Sediment analysis revealed significant differences in water content and organic matter between samples ( p < 0.05 at the studied floodplain part . Most sediments were rich in organic phosphorus and bound to Fe, Al, and Mn. Sorption tests showed greater phosphorus adsorption in air dried sediments and a high zero equilibrium phosphorus concentration (EPC₀), indicating a tendency to release phosphoru s when exposed to river water , thus highlighting the need of proper management prior increasing hydrological connectivity . In conclusion, the implementation of a water retention basin in the area will tackle the greatest threat to the studied river floodplain system: the progressive loss of hydrological connectivity.
Furthermore, the potential risk of phosphorus release was ev aluated to refine the management strategy , ensuring it effectively mitigates nutrient loading and supports long term ecosystem health.Os sistemas de rio planície de inundação são essenciais para a sustentação da biodiversidade e fornecem uma vasta gama de serviços ecossistémicos. No entanto, as alterações climáticas e as atividades antropogénicas têm vindo a perturbar cada vez mais a conectividade hidrológica e ecológica destes sistemas, reduzindo a sua resiliência a pressões externas. A degradação das planícies de inundação compromete serviços ecossistémicos fundamentais, incluindo o suporte à biodiversidade terrestre e aquática, a regulação de extremos hidrológicos, como cheias e secas, e a sequestro de carbono. Dada a escassez global de água e as consequências ecológicas associadas, existe uma necessidade urgente de estratégias de gestão inovadoras que reforcem os papéis multidimensionais das planícies de inundação na gestão dos recursos hídricos, conservação da biodiversidade e adaptação às alterações climáticas. Assim, esta dissertação focou se no estudo do sistema rio planície de inundação, que foi selecionado como local de demonstração para o projeto eco hidrológico LIFE Pilica (LIFE19
IPE/PL/000005) na Polónia Central. O estudo abordou a conectividade hidrológica dentro do sistema rio planície de inundação durante a primavera e o início do verão, avaliando os seus efeitos na qualidade da água. Um foco particular foi colocado nas dinâmicas de fósforo entre os compartimentos de água e sedimentos, com o objetivo de propor estratégias de gestão que mitiguem a libertação excessiva de fósforo para uma retenção sustentável de água na área da
planície de inundação. Foram identificadas três conexões hidrológicas principais entre a planície de inundação estudada, o rio Pilica e uma zona húmida a montante. A conectividade diminuiu significativamente ao longo do estudo (de 0,185 m³s⁻¹ em março para 0,002 m³s⁻¹ em maio), sendo que a primeira conexão se transformou numa fonte de drenagem em abril devido à diminuição do nível de água do Pilica. Em maio, a segunda fonte secou, e projetou se que a terceira deixasse de existir a um caudal do rio inferior a 12 m³s⁻¹ (R² = 0,94). A Análise de Componentes Principais (ACP) revelou uma maior diferença na qualidade da água do lago meândrico em comparação com o afluxo do rio (35,4%) do que com o fluxo de saída
da zona húmida (15,5%). Esta alteração destaca um risco acrescido de eutrofiz ação em ambos os corpos de água, causado pelo aumento do tempo de residência, acumulação de nutrientes e falta de troca de água com o rio. A análise de sedimentos revelou diferenças significativas no teor de água e matéria orgânica entre as amostras (p < 0,05) na parte estudada da planície de inundação. A maioria dos sedimentos era rica em fósforo orgânico e ligado a Fe, Al e Mn. Testes de so rção mostraram uma maior adsorção de fósforo em sedimentos secos ao ar e uma alta concentração de fósforo de equilíbrio zero (EPC₀), indicando uma tendência para a libertação de fósforo quando expostos à água do rio, sublinhando a necessidade de uma gestão adequada antes de aumentar a conectividade hidrológica. Em conclusão, a implementação de uma bacia de retenção de água na área abordará a maior ameaça ao sistema rio planície de inundação estudado: a perda progressiva de conectividade hidrológica. Além disso, o risco potencial de libertação de fósforo foi avaliado para refinar a estratégia de gestão, garantindo que esta mitigue eficazmente a carga de nutrientes e apoie a saúde a longo prazo do ecossistema.This work has been conducted under IP LIFE PL Pilica Basin CTRL Nr LIFE19 IPE/PL/000005 in collaboration with the European Regional Centre for Ecohydrology of the Polish Academy of Sciences
The impact of mangrove restoration on mangrove diversity, sedimentation and sediment characteristics in the Rufiji Delta, Tanzania
No full textMangroves are vital for coastal ecosystems but are continuously degraded, requiring restoration. This study examined the effects of mangrove restoration at 4 years on mangrove diversity, sediment characteristics and quality, in the Rufiji Delta, Tanzania from February to April 2023. Plants were sampled using a passive quadrat sampling technique and analyzed for diversity by the Shannon-Wiener Diversity Index. Sediment quality parameters were determined using a HANNA (HI98194) multiparameter probe. Sedimentation rates were examined using aluminium sediment traps. Organic matter, grain size distribution and statistical significance were determined by LOI, sieve granulometry, and ANOVA and Tukey’s HSD test respectively. Mangrove diversity decreased from Natural (1.47), restored (1.22) to degraded (1.08) with 6, 4 and 3 species respectively. Organic matter doubled from degraded to restored sites and tripled to the natural site. Sediments from the natural and restored mangrove had high Dissolved oxygen, low temperature and pH close to neutral (7) while those from degraded mangrove had low Dissolved Oxygen, high temperature and slightly acidic pH of less than 7. Thus, 4 years of restoration demonstrated partial recovery in mangrove diversity and sediment quality. The study recommends the government and conservation stakeholders continue restoration initiatives for mangrove recovery against degradation and harness alternative activities in the local population to reduce mangrove unsustainable harvesting and clearance for agriculture as the drivers for degradation.Os manguezais desempenham um papel vital nos ecossistemas costeiros, mas estão continuamente degradados, necessitando de restauração. Este estudo examinou os efeitos da restauração de manguezais após 4 anos na diversidade dos manguezais, características e qualidade do sedimento, no Delta de Rufiji, Tanzânia, de fevereiro a abril de 2023. As plantas foram amostradas usando uma técnica de amostragem de quadrat passivo e analisadas quanto à diversidade pelo Índice de Diversidade de Shannon-Wiener. Os parâmetros de qualidade do sedimento foram determinados usando uma sonda multiparâmetro HANNA (HI98194). As taxas de sedimentação foram examinadas usando armadilhas de sedimento de alumínio. O teor de matéria orgânica, a distribuição do tamanho dos grãos e a significância estatística foram determinados pelo LOI, granulometria por peneiramento e ANOVA e teste HSD de Tukey, respectivamente. A diversidade dos manguezais diminuiu de Natural (1,47), restaurado (1,22) para degradado (1,08), com 6, 4 e 3 espécies, respectivamente. A matéria orgânica duplicou nos locais degradados em comparação com os restaurados e triplicou em relação ao local natural. Os sedimentos dos manguezais naturais e restaurados tinham alto teor de oxigênio dissolvido, baixa temperatura e pH próximo ao neutro (7), enquanto os dos manguezais degradados tinham baixo teor de oxigênio dissolvido, alta temperatura e pH ligeiramente ácido, inferior a 7. Assim, 4 anos de restauração demonstraram uma recuperação parcial na diversidade dos manguezais e na qualidade do sedimento. O estudo recomenda que o governo e os stakeholders de conservação continuem com iniciativas de restauração para a recuperação dos manguezais contra a degradação e promovam atividades alternativas para a população local, a fim de reduzir a colheita insustentável de manguezais e o desmatamento para a agricultura, que são os principais impulsionadores da degradação.Thanks are also extended to the consortium: the University of Algarve (Universidade do Algarve) in Portugal, University of Lodz (Uniwersytet Łódzki) in Poland, Technical University of Applied Sciences Lübeck (Technische Hochschule Lübeck) in Germany and the University of Antwerp (Universiteit Antwerpen) in Belgium that co-facilitated the Masters in Applied Ecohydrology (MAEH) in advancing knowledge and innovation
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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