70 research outputs found
Building the Brazilian Academic Genealogy Tree
Along the history, many researchers provided remarkable contributions to
science, not only advancing knowledge but also in terms of mentoring new
scientists. Currently, identifying and studying the formation of researchers
over the years is a challenging task as current repositories of theses and
dissertations are cataloged in a decentralized way through many local digital
libraries. Following our previous work in which we created and analyzed a large
collection of genealogy trees extracted from NDLTD, in this paper we focus our
attention on building such trees for the Brazilian research community. For
this, we use data from the Lattes Platform, an internationally renowned
initiative from CNPq, the Brazilian National Council for Scientific and
Technological Development, for managing information about individual
researchers and research groups in Brazil
Family stress and satisfaction in college students: does parental divorce matter?
[Resumen] Esta investigación explora si el divorcio de los padres se relaciona con el estrés y la satisfacción familiares de sus hijos universitarios, asà como con la calidad y la frecuencia de las relaciones padres-hijos. Participaron 147 alumnos de primer curso de las titulaciones de Educación Primaria, Educación Social, FilologÃa, SociologÃa y Logopedia de la Universidade da Coruña. Los resultados indicaron que los estudiantes universitarios pertenecientes a familias en las que los padres están divorciados tienen un estrés significativamente mayor, una satisfacción familiar menor y una calidad y frecuencia de las relaciones familiares menor que los estudiantes universitarios pertenecientes a familias de padres no divorciados. Estos resultados podrÃan estar relacionados con los efectos a largo plazo del divorcio y ponen de manifiesto diferencias en las condiciones familiares de los alumnos cuyos padres están divorciados comparados con aquellos cuyos padres continúan casados
Malignant perivascular epithelioid cell tumor of the uterus
Perivascular epithelioid cell tumors (PEComas) are a rare collection of tumors arising in a wide array of anatomic locations and characterized by a myomelanocytic phenotype. PEComas which occur in non-classic anatomic distributions are known as perivascular epithelioid cell tumor-not otherwise specified (PEComa-NOS), and one of the most common primary sites for PEComa-NOS is the uterus. The risk of aggressive behavior of these tumors has been linked to a number of factors evaluable on pathologic review following initial surgical resection. We report a case of PEComa-NOS of the uterus with multiple high-risk features, including frank vascular invasion, with no evidence of recurrent disease 18 months following initial surgical resection
LOBO: Evaluation of Generalization Deficiencies in Twitter Bot Classifiers
Botnets in online social networks are increasingly often affecting
the regular flow of discussion, attacking regular users and
their posts, spamming them with irrelevant or offensive content,
and even manipulating the popularity of messages and
accounts. Researchers and cybercriminals are involved in an
arms race, and new and updated botnets designed to defeat
current detection systems are constantly developed, rendering
such detection systems obsolete.
In this paper, we motivate the need for a generalized evaluation
in Twitter bot detection and propose a methodology to
evaluate bot classifiers by testing them on unseen bot classes.
We show that this methodology is empirically robust, using bot
classes of varying sizes and characteristics and reaching similar
results, and argue that methods trained and tested on single
bot classes or datasets might not able to generalize to new
bot classes. We train one such classifier on over 200,000 data
points and show that it achieves over 97% accuracy. The data
used to train and test this classifier includes some of the largest
and most varied collections of bots used in literature. We
then test this theoretically sound classifier using our methodology,
highlighting that it does not generalize well to unseen bot
classes. Finally, we discuss the implications of our results, and
reasons why some bot classes are easier and faster to detect
than others
Can Social News Websites Pay for Content and Curation? The SteemIt Cryptocurrency Model
This is an accepted manuscript of an article published by SAGE Publishing in Journal of Information Science on 15/12/2017, available online: https://doi.org/10.1177/0165551517748290
The accepted version of the publication may differ from the final published version.SteemIt is a Reddit-like social news site that pays members for posting and curating content. It uses micropayments backed by a tradeable currency, exploiting the Bitcoin cryptocurrency generation model to finance content provision in conjunction with advertising. If successful, this paradigm might change the way in which volunteer-based sites operate. This paper investigates 925,092 new members’ first posts for insights into what drives financial success in the site. Initial blog posts on average received 20,680.83. Longer, more sentiment-rich or more positive comments with personal information received the greatest financial reward in contrast to more informational or topical content. Thus, there is a clear financial value in starting with a friendly introduction rather than immediately attempting to provide useful content, despite the latter being the ultimate site goal. Follow-up posts also tended to be more successful when more personal, suggesting that interpersonal communication rather than quality content provision has driven the site so far. It remains to be seen whether the model of small typical rewards and the possibility that a post might generate substantially more are enough to incentivise long term participation or a greater focus on informational posts in the long term
Polymorphisms in the leptin gene in divergent swine breeds
Investigou-se a exist?ncia de polimorfismo no gene da leptina (gene da obesidade) entre varr?es da ra?a nativa Piau (porco tipo banha) e matrizes mesti?as de ra?as comerciais (Landrace/Large White e Landrace/Large White com Pietrain), selecionadas para peso e precocidade. Oito pares de primers foram desenhados a partir da seq??ncia dispon?vel no GenBank (U66254), usada, neste trabalho, como seq??ncia de refer?ncia. Amostras de DNA foram extra?das de c?lulas sang??neas brancas utilizando-se solu??o de fenol:clorof?rmio, ap?s tratamento com proteinase K. Os fragmentos gerados por amplifica??o da rea??o em cadeia da polimerase foram purificados e seq?enciados em seq?enciador autom?tico. As seq??ncias de nucleot?deos, obtidas a partir do DNA das ra?as comerciais de su?no, apresentaram maior similaridade com a seq??ncia de refer?ncia, e as seq??ncias geradas a partir do DNA dos animais nativos divergiram de ambas em algumas posi??es. Dos 28 polimorfismos encontrados, oito foram observados em apenas uma das tr?s seq??ncias geradas a partir do DNA das ra?as nativas. Doze estavam presentes em duas seq??ncias, e os oito polimorfismos restantes foram encontrados nos tr?s animais nativos.Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)Leptin gene (obese gene) polymorphism was investigated in Piau boars (a fat, native breed) and sows from commercial strains (Landrace/Large White and Landrace/Large White by Pietrain) chosen for rapid growth and early sexual maturity. Eight pairs of primers designed using the sequence available from GenBank (access n? U66254) were identified as the reference sequence in this project. DNA samples were extracted from white blood cells using phenol:chloroform solution, after treatment with proteinase K. Fragments generated by amplification of the Polymerase Chain Reaction were purified and sequenced in an automatic sequencer. Nucleotide sequences obtained from DNA of commercial swine breeds were similar to the reference sequence; whereas sequences generated from native breed DNA diverged from the reference sequence and from domestic breed DNA. Of the 28 polymorphisms found, eight were observed in only one of the three sequences generated from DNA of native breeds. Twelve polymorphisms were present in two sequences and the eight remaining polymorphisms were found in all three categories of DNA
There and back again: historical perspective and future directions for Vaccinium breeding and research studies
The genus Vaccinium L. (Ericaceae) contains a wide diversity of culturally and economically important berry crop species. Consumer demand and scientific research in blueberry (Vaccinium spp.) and cranberry (Vaccinium macrocarpon) have increased worldwide over the crops' relatively short domestication history (~100 years). Other species, including bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), and ohelo berry (Vaccinium reticulatum) are largely still harvested from the wild but with crop improvement efforts underway. Here, we present a review article on these Vaccinium berry crops on topics that span taxonomy to genetics and genomics to breeding. We highlight the accomplishments made thus far for each of these crops, along their journey from the wild, and propose research areas and questions that will require investments by the community over the coming decades to guide future crop improvement efforts. New tools and resources are needed to underpin the development of superior cultivars that are not only more resilient to various environmental stresses and higher yielding, but also produce fruit that continue to meet a variety of consumer preferences, including fruit quality and health related trait
- …