4,798 research outputs found
Investigating Problem Definition and End-User Involvement in Agile Projects that Use Lean Inceptions
No full textArtefatos utilizados para coleta e análise de dados do artigo:
Bruna Ferreira,, Marcos Kalinowski, Marcos V. C. Gomes,, Marcelo C. Marques, and Hélio Lopes,, Simone D. J. Barbosa. 2021. Investigating ProblemDefinition and End-User Involvement in Agile Projects that Use Lean In-ceptions. InSBQS ’21: 35th Brazilian Symposium on Software Quality AC
Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (p) ppGpp synthase
Full text linkBrockmann-Gretza O, Kalinowski J. Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (p) ppGpp synthase. BMC Genomics. 2006;7(1):230.Background: The stringent response is the initial reaction of microorganisms to nutritional stress. During stringent response the small nucleotides ( p) ppGpp act as global regulators and reprogram bacterial transcription. In this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing Corynebacterium glutamicum. Results: The transcriptome of a C. glutamicum rel gene deletion mutant, unable to synthesize ( p) ppGpp and to induce the stringent response, was compared with that of its rel-proficient parent strain by microarray analysis. A total of 357 genes were found to be transcribed differentially in the rel-deficient mutant strain. In a second experiment, the stringent response was induced by addition of DL-serine hydroxamate (SHX) in early exponential growth phase. The time point of the maximal effect on transcription was determined by real-time RT-PCR using the histidine and serine biosynthetic genes. Transcription of all of these genes reached a maximum at 10 minutes after SHX addition. Microarray experiments were performed comparing the transcriptomes of SHX-induced cultures of the rel-proficient strain and the rel mutant. The differentially expressed genes were grouped into three classes. Class A comprises genes which are differentially regulated only in the presence of an intact rel gene. This class includes the non-essential sigma factor gene sigB which was upregulated and a large number of genes involved in nitrogen metabolism which were downregulated. Class B comprises genes which were differentially regulated in response to SHX in both strains, independent of the rel gene. A large number of genes encoding ribosomal proteins fall into this class, all being downregulated. Class C comprises genes which were differentially regulated in response to SHX only in the rel mutant. This class includes genes encoding putative stress proteins and global transcriptional regulators that might be responsible for the complex transcriptional patterns detected in the rel mutant when compared directly with its rel-proficient parent strain. Conclusion: In C. glutamicum the stringent response enfolds a fast answer to an induced amino acid starvation on the transcriptome level. It also showed some significant differences to the transcriptional reactions occuring in Escherichia coli and Bacillus subtilis. Notable are the rel-dependent regulation of the nitrogen metabolism genes and the rel-independent regulation of the genes encoding ribosomal proteins
A multivocal literature review on the benefits and limitations of industry-leading AutoML tools
Full text linkContext:
Rapid advancements in Artificial Intelligence (AI) and Machine Learning (ML) are revolutionizing software engineering in every application domain, driving unprecedented transformations and fostering innovation. However, despite these advances, several organizations are experiencing friction in the adoption of ML-based technologies, mainly due to the current shortage of ML professionals. In this context, Automated Machine Learning (AutoML) techniques have been presented as a promising solution to democratize ML adoption, even in the absence of specialized people.
Objective:
Our research aims to provide an overview of the evidence on the benefits and limitations of AutoML tools being adopted in industry.
Methods:
We conducted a Multivocal Literature Review, which allowed us to identify 54 sources from the academic literature and 108 sources from the grey literature reporting on AutoML benefits and limitations. We extracted explicitly reported benefits and limitations from the papers and applied the thematic analysis method for synthesis.
Results:
In general, we identified 18 reported benefits and 25 limitations. Concerning the benefits, we highlight that AutoML tools can help streamline the core steps of ML workflows, namely data preparation, feature engineering, model construction, and hyperparameter tuning—with concrete benefits on model performance, efficiency, and scalability. In addition, AutoML empowers both novice and experienced data scientists, promoting ML accessibility. However, we highlight several limitations that may represent obstacles to the widespread adoption of AutoML. For instance, AutoML tools may introduce barriers to transparency and interoperability, exhibit limited flexibility for complex scenarios, and offer inconsistent coverage of the ML workflow.
Conclusion:
The effectiveness of AutoML in facilitating the adoption of machine learning by users may vary depending on the specific tool and the context in which it is used. Today, AutoML tools are used to increase human expertise rather than replace it and, as such, require skilled users
Transcripts for dissertation, "Iron fellows : commitment and activism in a poor people's movement"
No full textThis set contains transcripts from Marcos Perez's dissertation project. Data is available by request to interested scholars and students. Visitors may not download the files without express permission from the author. Visitors may not make copies of the transcripts, nor distribute any part of them separately. To request access, please contact [email protected]
The alternative sigma factor SigB of Corynebacterium glutamicum modulates global gene expression during transition from exponential growth to stationary phase
Full text linkLarisch C, Nakunst D, Hueser AT, Tauch A, Kalinowski J. The alternative sigma factor SigB of Corynebacterium glutamicum modulates global gene expression during transition from exponential growth to stationary phase. BMC Genomics. 2007;8(1): 4.Background: Corynebacterium glutamicum is a gram-positive soil bacterium widely used for the industrial production of amino acids. There is great interest in the examination of the molecular mechanism of transcription control. One of these control mechanisms are sigma factors. C. glutamicum ATCC 13032 has seven putative sigma factor-encoding genes, including sigA and sigB. The sigA gene encodes the essential primary sigma factor of C. glutamicum and is responsible for promoter recognition of house-keeping genes. The sigB gene codes for the non-essential sigma factor SigB that has a proposed role in stress reponse. Results: The sigB gene expression was highest at transition between exponential growth and stationary phase, when the amount of sigA mRNA was already decreasing. Genome-wide transcription profiles of the wild-type and the sigB mutant were recorded by comparative DNA microarray hybridizations. The data indicated that the mRNA levels of 111 genes are significantly changed in the sigB-proficient strain during the transition phase, whereas the expression profile of the sigB-deficient strain showed only minor changes ( 26 genes). The genes that are higher expressed during transition phase only in the sigB-proficient strain mainly belong to the functional categories amino acid metabolism, carbon metabolism, stress defense, membrane processes, and phosphorus metabolism. The transcription start points of six of these genes were determined and the deduced promoter sequences turned out to be indistinguishable from that of the consensus promoter recognized by SigA. Real-time reverse transcription PCR assays revealed that the expression profiles of these genes during growth were similar to that of the sigB gene itself. In the sigB mutant, however, the transcription profiles resembled that of the sigA gene encoding the house-keeping sigma factor. Conclusion: During transition phase, the sigB gene showed an enhanced expression, while simultaneously the sigA mRNA decreased in abundance. This might cause a replacement of SigA by SigB at the RNA polymerase core enzyme and in turn results in increased expression of genes relevant for the transition and the stationary phase, either to cope with nutrient limitation or with the accompanying oxidative stress. The increased expression of genes encoding anti-oxidative or protection functions also prepares the cell for upcoming limitations and environmental stresses
Courageous women in media: Marcos and censorship in the Philippines
Full text linkWhen Philippine President Ferdinand Marcos declared Martial Law in 1972, press freedom became the first casualty in the country that once boasted of being the 'freest in Asia'. Printing presses, newspaper offices, television and radio stations were raided and padlocked. Marcos was especially fearful of the press and ordered the arrest of journalists whom he charged with conspiring with the 'Left'. Pressured into lifting martial law after nearly 10 years, Marcos continued to censor the media, often demanding publishers to sack journalists whose writing he disapproved of. Ironically, he used the same 'subversive writings' as proof to Western observers that freedom of the press was alive and well under his dictatorship. This article looks at the writings of three female journalists from the Bulletin Today. The author examines the work of Arlene Babst, Ninez Cacho-Olivares, and Melinda de Jesus and how they traversed the dictator's fickle, sometimes volatile, reception of their writing. Interviewed is Ninez Cacho-Olivare, who used humour and fairy tales in her popular column to criticise Marcos, his wife, Imelda, and even the military that would occasionally 'invite' her for questioning. She explains an unwritten code of conduct between Marcos and female journalists that served to shield them from total political repression
The DtxR protein acting as dual transcriptional regulator directs a global regulatory network involved in iron metabolism of Corynebacterium glutamicum
Full text linkBrune I, Werner H, Hüser AT, Kalinowski J, Pühler A, Tauch A. The DtxR protein acting as dual transcriptional regulator directs a global regulatory network involved in iron metabolism of Corynebacterium glutamicum. BMC Genomics. 2006;7(1): 21.Background: The knowledge about complete bacterial genome sequences opens the way to reconstruct the qualitative topology and global connectivity of transcriptional regulatory networks. Since iron is essential for a variety of cellular processes but also poses problems in biological systems due to its high toxicity, bacteria have evolved complex transcriptional regulatory networks to achieve an effective iron homeostasis. Here, we apply a combination of transcriptomics, bioinformatics, in vitro assays, and comparative genomics to decipher the regulatory network of the iron-dependent transcriptional regulator DtxR of Corynebacterium glutamicum. Results: A deletion of the dtxR gene of C. glutamicum ATCC 13032 led to the mutant strain C. glutamicum IB2103 that was able to grow in minimal medium only under low-iron conditions. By performing genome-wide DNA microarray hybridizations, differentially expressed genes involved in iron metabolism of C. glutamicum were detected in the dtxR mutant. Bioinformatics analysis of the genome sequence identified a common 19-bp motif within the upstream region of 31 genes, whose differential expression in C. glutamicum IB2103 was verified by real-time reverse transcription PCR. Binding of a His-tagged DtxR protein to oligonucleotides containing the 19-bp motifs was demonstrated in vitro by DNA band shift assays. At least 64 genes encoding a variety of physiological functions in iron transport and utilization, in central carbohydrate metabolism and in transcriptional regulation are controlled directly by the DtxR protein. A comparison with the bioinformatically predicted networks of C. efficiens, C. diphtheriae and C. jeikeium identified evolutionary conserved elements of the DtxR network. Conclusion: This work adds considerably to our currrent understanding of the transcriptional regulatory network of C. glutamicum genes that are controlled by DtxR. The DtxR protein has a major role in controlling the expression of genes involved in iron metabolism and exerts a dual regulatory function as repressor of genes participating in iron uptake and utilization and as activator of genes responsible for iron storage and DNA protection. The data suggest that the DtxR protein acts as global regulator by controlling the expression of other regulatory proteins that might take care of an iron-dependent regulation of a broader transcriptional network of C. glutamicum genes
Cross- vs. within-company cost estimation studies revisited: an extended systematic review
No full text[Objective] The objective of this paper is to extend a previously conducted systematic literature review (SLR) that investigated under what circumstances individual organizations would be able to rely on cross-company based estimation models. [Method] We applied the same methodology used in the SLR we are extending herein (covering the period 2006-2013) based on primary studies that compared predictions from cross-company models with predictions from within-company models constructed from analysis of project data. [Results] We identified 11 additional papers; however two of these did not present independent results and one had inconclusive findings. Two of the remaining eight papers presented both, trials where cross-company predictions were not significantly different from within-company predictions and others where they were significantly different. Four found that cross-company models gave prediction accuracy significantly different from within-company models (one of them in favor of cross-company models), while two found no significant difference. The main pattern when examining the study related factors was that studies where cross-company predictions were significantly different from within-company predictions employed larger within-company data sets. [Conclusions] Overall, half of the analyzed evidence indicated that cross-company estimation models are not significantly worse than within-company estimation models. Moreover, there is some evidence that sample size does not imply in higher estimation accuracy, and that samples for building estimation models should be carefully selected/filtered based on quality control and project similarity aspects. The results need to be combined with the findings from the SLR we are extending to allow further investigating this topic
Producing Ferdinand E. Marcos, the Scholarly Author
Full text linkThisarticle discusses the compelling evidence—found in various primaryand secondary sources and analyzed through methods drawn from bookhistory and plagiarism detection—that not one of the books authored byPres. Ferdinand E. Marcos was actually written by him. Thearticle alsoshows how many of “Marcos’s” books had either plagiarized content(e.g., republishing contents from previous works) or were “padded” withlengthy appendices. It also explains the seemingly far-reaching distributionnetwork of these books. Lastly, thearticle looks into how these books,although they have not been republished for decades, continue to servetheir intended functions.KEYWORDS: FERDINAND E. MARCOS • BOOK HISTORY • GHOSTWRITING • PLAGIARISM• ADRIAN CRISTOBA
ESEM '21: Proceedings of the 15th ACM / IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM)
No full textESEM '21 Paper Acceptance Rate 24 of 124 submissions, 19
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