1,198 research outputs found
A requirements engineering and management training course for software development professionals
Devising a course for software professionals working in industry depends on several factors. In order to create a course that fulfils professionalsâ expectations, it is important to take account of the skills of the participants, the time available, and the specific topics to be covered. This paper presents the curriculum of a course in requirements engineering and management intended for software developers with a first-level academic degree in computing and experience in developing real software solutions. This context requires the course to concentrate on topics that were not taught in the participantsâ previous education and that can have a positive impact on their daily practices
Positive Selection Linked with Generation of Novel Mammalian Dentition Patterns
A diverse group of genes are involved in the tooth development of mammals. Several studies, focused mainly on mice and rats, have provided a detailed depiction of the processes coordinating tooth formation and shape. Here we surveyed 236 tooth-associated genes in 39 mammalian genomes and tested for signatures of selection to assess patterns of molecular adaptation in genes regulating mammalian dentition. Of the 236 genes, 31 (âŒ13.1%) showed strong signatures of positive selection that may be responsible for the phenotypic diversity observed in mammalian dentition. Mammalian-specific tooth-associated genes had accelerated mutation rates compared with older genes found across all vertebrates. More recently evolved genes had fewer interactions (either genetic or physical), were associated with fewer Gene Ontology terms and had faster evolutionary rates compared with older genes. The introns of these positively selected genes also exhibited accelerated evolutionary rates, which may reflect additional adaptive pressure in the intronic regions that are associated with regulatory processes that influence tooth-gene networks. The positively selected genes were mainly involved in processes like mineralization and structural organization of tooth specific tissues such as enamel and dentin. Of the 236 analyzed genes, 12 mammalian-specific genes (younger genes) provided insights on diversification of mammalian teeth as they have higher evolutionary rates and exhibit different expression profiles compared with older genes. Our results suggest that the evolution and development of mammalian dentition occurred in part through positive selection acting on genes that previously had other functions
Recommended from our members
Maternal Immune Activation in Nonhuman Primates Alters Social Attention in Juvenile Offspring
BACKGROUND: Sickness during pregnancy is associated with an increased risk of offspring neurodevelopmental disorders. Rodent models have played a critical role in establishing causal relationships and identifying mechanisms of altered brain and behavior development in pups prenatally exposed to maternal immune activation (MIA). We recently developed a novel nonhuman primate model to bridge the gap between human epidemiological studies and rodent models of prenatal immune challenge. Our initial results demonstrated that rhesus monkeys given the viral mimic synthetic double-stranded RNA (polyinosinic:polycytidylic acid stabilized with poly-l-lysine) during pregnancy produce offspring with abnormal repetitive behaviors, altered communication, and atypical social interactions.
METHODS: We utilized noninvasive infrared eye tracking to further evaluate social processing capabilities in a
subset of the first trimester MIA-exposed offspring (n = 4) and control animals (n = 4) from our previous study.
RESULTS: As juveniles, the MIA offspring differed from control animals on several measures of social attention,
particularly when viewing macaque faces depicting the fear grimace facial expression. Compared with control animals, MIA offspring had a longer latency before fixating on the eyes, had fewer fixations directed at the eyes, and spent less total time fixating on the eyes of the fear grimace images.
CONCLUSIONS: In the rhesus monkey model, exposure to MIA at the end of the first trimester results in abnormal gaze patterns to salient social information. The use of noninvasive eye tracking extends the findings from rodent MIA models to more human-like behaviors resembling those in both autism spectrum disorder and schizophrenia
Recommended from our members
Highly proteolytic bacteria from semi-ripened Chiapas cheese elicit angiotensin-I converting enzyme inhibition and antioxidant activity
Chiapas cream cheese (CCH) manufacturing process involves a long acid-enzymatic coagulation period of full-fat cow raw milk to achieve an acid and crumbly cheese. These sensorial aspects are related to lactic acid bacteria activity during ripening. Our main objective was to test the hypothesis that CCH contained highly proteolytic strains able to release bioactive compounds upon milk-protein hydrolysis. First, the proteolysis of CCH was evaluated considering the peptide and amino acid profiles of cheese samples collected from Veracruz (AVCH) and Tabasco (HTCH). The angiotensin-converting-enzyme (ACE) inhibitory activity in cheese water-soluble fractions was evaluated. Thereafter, strains from both CCH samples were isolated and selected based on their proteolytic capability, genetic fingerprint differentiation and growth conditions. Finally, a range of activities in vitro were tested in milk fractions fermented with selected strains. CCH showed ACE inhibitory activity: IC50=1.75-2.75 mg/mL. Interestingly, AVCH contains 0.78 g/kg of the antihypertensive Îł-aminobutyric acid. Three highly proteolytic strains showed ACE and high antioxidant activities upon milk fermentation. In conclusion, CCH contain proteolytic strains able to release bioactive compounds from milk proteins and potentially useful to produce functional ingredients and foods
Multipolar mitosis and aneuploidy after chrysotile treatment: a consequence of abscission failure and cytokinesis regression
Chrysotile, like other types of asbestos, has been associated with mesothelioma, lung cancer and asbestosis. However, the cellular abnormalities induced by these fibers involved in cancer development have not been elucidated yet. Previous works show that chrysotile fibers induce features of cancer cells, such as aneuploidy, multinucleation and multipolar mitosis. In the present study, normal and cancer derived human cell lines were treated with chrysotile and the cellular and molecular mechanisms related to generation of aneuploid cells was elucidated. The first alteration observed was cytokinesis regression, the main cause of multinucleated cells formation and centrosome amplification. The multinucleated cells formed after cytokinesis regression were able to progress through cell cycle and generated aneuploid cells after abnormal mitosis. To understand the process of cytokinesis regression, localization of cytokinetic proteins was investigated. It was observed mislocalization of Anillin, Aurora B, Septin 9 and Alix in the intercellular bridge, and no determination of secondary constriction and abscission sites. Fiber treatment also led to overexpression of genes related to cancer, cytokinesis and cell cycle. The results show that chrysotile fibers induce cellular and molecular alterations in normal and tumor cells that have been related to cancer initiation and progression, and that tetraploidization and aneuploid cell formation are striking events after fiber internalization, which could generate a favorable context to cancer development
Recommended from our members
Long-Term Crop Residue and Nitrogen Management Effects on Soil Profile Carbon and Nitrogen in WheatâFallow Systems
Intensive cultivation of native grassland for dryland agriculture continuously depleted soil organic carbon (SOC) and nutrients. In 2010, we evaluated the influence of 80 yr of crop residue and nutrient management practices on SOC and N in 0- to 60-cm soil depth profiles in conventionally tilled winter wheat (Triticum aestivum L.)âsummer fallow (WWâSF) system. Residue and N treatments, no N addition with fall burning (FB0), spring burning (SB0), and no burning (NB0), 45 kg N haâ»Âč with SB (SB45) and NB (NB45), 90 kg N haâ»Âč with SB (SB90) and NB (NB90), manure (MN, 5.32 Mg dry mass haâ»Âč yrâ»Âč), and pea vines (PV, 0.99 Mg dry mass haâ»Âč yrâ»Âč), were in ordered arrangement, and an undisturbed grassland (GP) was used as a reference. All WWâSF treatments had less SOC and N stocks than GP. The SOC stocks were lowest under FB0 with 50% less SOC than GP. The WWâSF treatments have depleted up to 63 and 26% of SOC and N from surface soil since 1931. Fall burning and MN treatments depleted SOC at rates of 0.64 and 0.17 Mg haâ»Âč yrâ»Âč. Nitrogen stocks decreased at a rate of 0.02 Mg haâ»Âč yrâ»Âč in FB, SB, and NB treatments, and 0.01 Mg haâ»Âč yrâ»Âč in PV treatment. Reduction in tillage, application of low C/N ratio residues, and elimination of burning can improve sustainability of winter wheat production in the summer fallow region of the Pacific Northwest (PNW)
Recommended from our members
No-Tillage Cropping Systems Can Replace Traditional Summer Fallow in North-Central Oregon
The traditional winter wheat (Triticum aestivum L.)âsummer fallow (WWâSF) using conventional tillage (CT), the predominant cropping system in eastern Oregon, has increased soil erosion and depleted soil organic carbon (SOC). This research evaluates no-tillage (NT) systems designed to reduce these negative impacts on soil. In this long-term experiment (2004â2010), WWâSF using CT was compared with annual winter wheat (WWâWW), annual spring wheat (SWâSW), annual spring barley (Hordeum vulgare L.) (SBâSB), winter wheatâchemical fallow (WWâCF), winter wheatâwinter pea (Pisum sativum L.) (WWâWP), and winter wheatâspring barleyâchemical fallow rotation (WWâSBâCF), using NT. Measurements included, phenology, plant population, grain yield and yield components, residues, SOC, soil moisture, and precipitation. Water-use efficiency (WUE) was derived from precipitation and yield data. Under annual cropping, WWâWP and SBâSB produced higher yields than WWâWW and SWâSW. Grain yields in rotations with fallow (WWâSF, WWâCF, and WWâSBâCF) were not significantly different. On an annual basis, SBâSB and WW-WP produced the highest and lowest yields, respectively. The WUEs of fallow rotations, SBâSB, and SWâSW, were not different but were higher than WUEs of WWâWP and WWâWW. Residue cover and SOC were highest under annual cropping systems and lowest following peas in WWâWP and SF in WWâSF. We conclude that rotations with fallow using NT (WWâCF and WWâSBâCF) can replace the traditional WWâSF system without yield penalty
- âŠ