1,720,983 research outputs found
Dissection of the key intestinal microbiota in residents of Pemba Island in Tanzania and use of Bifidobacterium breve in prevention against colitis in mice
Full text linkPemba Island is located on the eastern coast of Tanzania and is one part of the
Zanzibar Islands. The climate on the island is mild, and the temperature is kept between
24°C and 28°C throughout the year. Therefore, the residents on the island plant plenty
bananas and feed on them. In addition, the residents of the island consume large
amounts of vegetables and fruits, mainly cassava, rice and corn as their staple food, and
fish as the main source of animal food. The parasitic diseases in Africa are highly
prevalent, which seriously endangers the quality of life of the African people. The
prevalence of soil-borne helminthiasis on Pemba Island is relatively high. The research
center Public Health Laboratory Ivo de Carneri (PHL-IdC) hosts researchers from many
countries on Pemba Island to carry out scientific research. The field part of the
investigation reported in this thesis was conducted with the support of the PHL-IdC.
At present, there are very few studies on the dietary structure of African island
residents. Most of the research are carried out on the dietary structure of Western
countries, such as the Mediterranean diet and the typical Western diet. In this study, a
total of 32 pairs (64) of mother and child volunteers on Pemba Island with similar diets
were recruited in three different villages on the Island. First, we used the Food
Frequency Questionnaire (FFQ) to analyze the dietary structure and food composition
of women and their children. At the same time, we used 16S rDNA high-throughput
sequencing technology to study the intestinal flora of the volunteers. Heat maps were
utilized to show the correlation between gut microbiota and diet structure, gut
microbiota and nutrient intake. We found that Pemba women and children’s diets were
characterized by high carbohydrate and high dietary fiber intake, low protein and low fat intake. Supply ratios of carbohydrate, fat and protein were out of balance; The
percentage of carbohydrates supply was too high, the percentage of fat supply was too
low. There was a significant positive correlation between the abundance of
Faecalibacterium and the intake of Cu, and a negative correlation between
Faecalibacterium and the intake of fat in the intestine of healthy Pemba women. There
was a significant positive correlation between Bacteroides and Se, and a significant
negative correlation between Bacteroides and Cu in the intestine of healthy Pemba
children (Chapter 2).
Secondly, we used the gut microbiota of healthy Spanish women and Australian
children as reference to analyze the similarities and differences in the structure and
function of the core intestinal microbiota of healthy women and children from Pemba
Island. We found that Firmicutes and Bacteroidetes were the dominant phyla in the gut
microbiota of Pemba women and children, moreover, Prevotella was the dominant
genus. The structure of the gut microbiota in healthy Pemba women was significantly
different from that of Spanish women, and the structure of the gut microbiota of Pemba
children was also significantly different from the Australian children; PICRUST
prediction analysis revealed that the metabolic pathways "Lipid metabolism" and
"Nucleotide metabolism" showed significantly higher abundance in women and
children from Pemba Island, compared with Spanish women and Australian children
respectively (Chapter 3).
Then, based on the results of the Mini-Flotac parasitological examination, we
divided all volunteers of Pemba Island into four groups, healthy women group,
whipworm-infected women group, healthy children group, whipworm-infected
children group, and used bioinformatics technology to analyze the association between
the intestinal microbiota and whipworm infection. We found that, compared with
healthy women and children, the diversity of the gut microbiota of whipworm-infected
women and children were higher, especially in the microbiota of the infected women,
the alpha diversity and beta diversity of infected women were significantly increased.
Short-chain fatty acid-producing bacteria such as Blautia and Bacteroides showed decreased level in whipworm-infected children, and short-chain fatty acid-producing
bacteria such as Prevotella 2, Prevotella 9 and Ruminococcaceae UCG-005 showed
decreased level in whipworm-infected women volunteers. Opportunistic pathogens
such as Enterococcus showed increased level in whipworm-infected children, and
Campylobacter showed elevated level in whipworm-infected women; the abundance of
Bifidobacterium exerted decreased amount in the gut of healthy women and children
with respect to the infected counterpart. Notably, in the healthy women’s gut, the
abundance of Bifidobacterium presented a significantly reduced level (Chapter 4).
Finally, we speculated that Bifidobacterium may have the potential to regulate IBD.
Therefore, in the last chapter, we used Bifidobacterium breve to intervene in the mouse
IBD model to explore the potential immune regulation of B. breve. We found that low
concentration of B. breve could reduce the DAI index of DSS-induced mouse colitis,
reduce colon shortening and slice pathological damage, and exert preventive roles. B.
breve could promote the secretion of anti-inflammatory cytokines and inhibit the
expression of pro-inflammatory cytokines in serum, at the same time, it could increase
the number of CD4+CD25+Foxp3+ Treg cells, and inhibit the number of CD3+CD4+
IL-
17+Tcells in mesenteric lymph nodes, to reduce intestinal injury. Low-concentration B.
breve intervention could also improve the composition of the gut microbiota, reduce
the loss of short-chain fatty acid-producing bacteria, reduce the production of pro-
inflammatory bacteria, reshape the intestinal microecology and reduce intestinal
inflammation (Chapter 5)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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
Dissection of the gut microbiota in mothers and children with chronic Trichuris trichiura infection in Pemba Island, Tanzania
Full text linkBackground: Soil-transmitted helminthiases are important neglected tropical diseases that result in a notably high number of disability-adjusted life years worldwide. Characterizing the interactions between the human intestinal microbiome and helminths is of interest in the development of alternative treatments that do not rely on chemotherapeutics and do not lead to drug resistance.MethodsWe recruited and obtained fecal samples from 32 pairs of mothers and children on Pemba Island and monitored their intestinal microbiota using 16S rRNA gene sequencing.ResultsWe observed that microbial changes occur in the gut microbiota of infected mothers and children. Some short-chain fatty acid (SCFA)-producing bacteria and carbohydrate-degrading bacteria exhibited lower abundance in the infected individuals. Potentially pathogenic Campylobacter and proinflammatory Methanobrevibacter in infected mothers and opportunistic Enterococcus in infected children exhibited greater abundance.ConclusionsOur findings could reveal the microbiota profiling in T. trichiura-infected individuals, indicate the potential roles of key microbiota in the host and aid to the development of novel strategies to control T. trichiura infection
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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