430 research outputs found
On the Numerical Accuracy of Spreadsheets
This paper discusses the numerical precision of five spreadsheets (Calc, Excel, Gnumeric, NeoOffice and Oleo) running on two hardware platforms (i386 and amd64) and on three operating systems (Windows Vista, Ubuntu Intrepid and Mac OS Leopard). The methodology consists of checking the number of correct significant digits returned by each spreadsheet when computing the sample mean, standard deviation, first-order autocorrelation, F statistic in ANOVA tests, linear and nonlinear regression and distribution functions. A discussion about the algorithms for pseudorandom number generation provided by these platforms is also conducted. We conclude that there is no safe choice among the spreadsheets here assessed: they all fail in nonlinear regression and they are not suited for Monte Carlo experiments.
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Optimizing survival outcomes with post-remission therapy in acute myeloid leukemia.
Optimization of post-remission therapies to maintain complete remission and prevent relapse is a major challenge in treating patients with acute myeloid leukemia (AML). Monitoring patients for measurable residual disease (MRD) is helpful to identify those at risk for relapse. Hypomethylating agents are being investigated as post-remission therapy. Identification of recurrent genetic alterations that drive disease progression has enabled the design of new, personalized approaches to therapy for patients with AML. Emerging data suggest that targeted post-remission therapy, alone or in combination with chemotherapy, may improve outcomes. Results of ongoing clinical trials will further define potential clinical benefits
Complete remission of primary plasma cell leukemia with bortezomib, doxorubicin, and dexamethasone: a case report
Disparities in early death and survival in children, adolescents, and young adults with acute promyelocytic leukemia in California.
BACKGROUND: Findings from clinical trials and population-based studies have differed with regard to whether mortality within 30 days of diagnosis (early death) of acute promyelocytic leukemia (APL) has decreased in the era of all-trans retinoic acid and anthracycline-based chemotherapy. METHODS: Using data from the California Cancer Registry, the authors investigated 7-day and 30-day mortality and survival in 772 patients who were aged birth to 39 years when they were diagnosed with APL during 1988 to 2011. Logistic regression and Cox proportional models were used to examine the association of early death and survival, respectively, with sociodemographic and clinical factors. RESULTS: The overall 30-day mortality decreased significantly over time, from 26% (1988-1995) to 14% (2004-2011) (P =.004). On multivariable analysis, the odds of 30-day mortality were 3 times as high during 1988 through 1995 than 2004 through 2011 (P =.001). However, 7-day mortality did not improve over time (P =.229). When patients who died within 7 days of diagnosis were excluded, the 30-day mortality during 1996 to 2011 was 3% to 8%, which is similar to levels reported in clinical trials. Higher early death and lower survival were associated with a lack of health insurance (1996-2011) (early death odds ratio, 2.67; P =.031) and Hispanic race/ethnicity (early death odds ratio, 2.13; P =.014). Early death was not found to be associated with age, sex, socioeconomic status, or hospital type. Black patients also experienced worse survival. CONCLUSIONS: The findings of the current study revealed a decreased 30-day mortality during the all-trans retinoic acid era, but 7-day mortality remained high. Efforts to achieve equal outcomes in young patients with APL should focus on improving access to effective treatment, mainly among uninsured patients and those of Hispanic and black race/ethnicity
On the Numerical Accuracy of Spreadsheets
This paper discusses the numerical precision of five spreadsheets (Calc, Excel, Gnumeric, NeoOffice and Oleo) running on two hardware platforms (i386 and amd64) and on three operating systems (Windows Vista, Ubuntu Intrepid and Mac OS Leopard). The methodology consists of checking the number of correct significant digits returned by each spreadsheet when computing the sample mean, standard deviation, first-order autocorrelation, F statistic in ANOVA tests, linear and nonlinear regression and distribution functions. A discussion about the algorithms for pseudorandom number generation provided by these platforms is also conducted. We conclude that there is no safe choice among the spreadsheets here assessed: they all fail in nonlinear regression and they are not suited for Monte Carlo experiments
Screening protocol for dysphagia in adults: comparison with videofluoroscopic findings
OBJECTIVES: To compare the videofluoroscopic findings of patients with suspected oropharyngeal dysphagia with the results of a clinical screening protocol. METHODS: A retrospective observational cohort study was conducted on all consecutive patients with suspected oropharyngeal dysphagia between March 2015 and February 2016 who were assigned to receive a videofluoroscopic assessment of swallowing. All patients were first submitted to videofluoroscopy and then to the clinical assessment of swallowing. The clinical assessment was performed within the first 24 hours after videofluoroscopy. The videofluoroscopy results were analyzed regarding penetration/aspiration using an 8-point multidimensional perceptual scale. The accuracy of the clinical protocol was analyzed using the sensitivity, specificity, likelihood ratios and predictive values. RESULTS: The selected sample consisted of 50 patients. The clinical protocol presented a sensitivity of 50% and specificity of 95%, with an accuracy of 88%. “Cough” and “wet-hoarse” vocal quality after/during swallowing were clinical indicators that appeared to correctly identify the presence of penetration/aspiration risk. CONCLUSION: The clinical protocol used in the present study is a simple, rapid and reliable clinical assessment. Despite the absence of a completely satisfactory result, especially in terms of the sensitivity and positive predictive values, we suggest that lower rates of pneumonia can be achieved using a formal dysphagia screening method
Real-World Treatment Patterns and Outcomes among Elderly Acute Myeloid Leukemia Patients in the United States
Over half of patients diagnosed with acute myeloid leukemia (AML) are 65 years or older. Using the linked SEER-Medicare database, we conducted a retrospective cohort analysis to examine patient characteristics, treatment patterns, and survival among the elderly AML patients in routine clinical practice. Out of 29,857 patients with AML in the database, 8336 were eligible for inclusion in the study. The inclusion criteria included a diagnosis with first primary AML between January 1, 2000 and December 31, 2009, >66 years of age, and continuous enrollment in Medicare Parts A and B in the year before diagnosis. Forty percent (N = 3327) of the cohort received chemotherapy within 3 months after diagnosis. The multivariable overall survival analyses showed a lower risk of death among those receiving intensive and hypomethylating agent therapies compared with no therapy. Among the younger cohort, a significant lower mortality was also noted with receipt of allogeneic hematopoietic stem cell transplantation. Over the past decade, about 60% of the elderly AML patients remain untreated in routine clinical practice. Use of antileukemic therapy was associated with a significant survival benefit and provides further support that age alone should not deter the use of guideline-recommended therapies particularly because of the high disparities in outcomes between treatment receipt and palliative care in this elderly cohort
Hyperglycemia can delay left ventricular dysfunction but not autonomic damage after myocardial infarction in rodents
<p>Abstract</p> <p>Background</p> <p>Although clinical diabetes mellitus is obviously a high risk factor for myocardial infarction (MI), in experimental studies disagreement exists about the sensitivity to ischemic injury of an infarcted myocardium. Recently, our group demonstrated that diabetic animals presented better cardiac function recovery and cellular resistance to ischemic injury than nondiabetics. In the present study, we evaluated the chronic effects of MI on left ventricular (LV) and autonomic functions in streptozotocin (STZ) diabetic rats.</p> <p>Methods</p> <p>Male Wistar rats were divided into 4 groups: control (C, n = 15), diabetes (D, n = 16), MI (I, n = 21), and diabetes + MI (DI, n = 30). MI was induced 15 days after diabetes (STZ) induction. Ninety days after MI, LV and autonomic functions were evaluated (8 animals each group). Left ventricular homogenates were analyzed by Western blotting to evaluate the expression of calcium handling proteins.</p> <p>Results</p> <p>MI area was similar in infarcted groups (~43%). Ejection fraction and +dP/dt were reduced in I compared with DI. End-diastolic pressure was additionally increased in I compared with DI. Compared with DI, I had increased Na<sup>+</sup>-Ca<sup>2+ </sup>exchange and phospholamban expression (164%) and decreased phosphorylated phospholamban at serine<sup>16 </sup>(65%) and threonine<sup>17 </sup>(70%) expression. Nevertheless, diabetic groups had greater autonomic dysfunction, observed by baroreflex sensitivity and pulse interval variability reductions. Consequently, the mortality rate was increased in DI compared with I, D, and C groups.</p> <p>Conclusions</p> <p>LV dysfunction in diabetic animals was attenuated after 90 days of myocardial infarction and was associated with a better profile of calcium handling proteins. However, this positive adaptation was not able to reduce the mortality rate of DI animals, suggesting that autonomic dysfunction is associated with increased mortality in this group. Therefore, it is possible that the better cardiac function has been transitory, and the autonomic dysfunction, more prominent in diabetic group, may lead, in the future, to the cardiovascular damage.</p
Garbage In, Garbage Out? Do Machine Learning Application Papers in Social Computing Report Where Human-Labeled Training Data Comes From?
Many machine learning projects for new application areas involve teams of
humans who label data for a particular purpose, from hiring crowdworkers to the
paper's authors labeling the data themselves. Such a task is quite similar to
(or a form of) structured content analysis, which is a longstanding methodology
in the social sciences and humanities, with many established best practices. In
this paper, we investigate to what extent a sample of machine learning
application papers in social computing --- specifically papers from ArXiv and
traditional publications performing an ML classification task on Twitter data
--- give specific details about whether such best practices were followed. Our
team conducted multiple rounds of structured content analysis of each paper,
making determinations such as: Does the paper report who the labelers were,
what their qualifications were, whether they independently labeled the same
items, whether inter-rater reliability metrics were disclosed, what level of
training and/or instructions were given to labelers, whether compensation for
crowdworkers is disclosed, and if the training data is publicly available. We
find a wide divergence in whether such practices were followed and documented.
Much of machine learning research and education focuses on what is done once a
"gold standard" of training data is available, but we discuss issues around the
equally-important aspect of whether such data is reliable in the first place.Comment: 18 pages, includes appendi
World Press Photo 2012: the discursive construction of the Arab Spring
O presente artigo pretende analisar a forma como o fenómeno da Primavera Árabe foi retratado nas fotografias vencedoras do concurso World Press Photo em 2012.
As fotografias jornalísticas, embora se apresentem como índices do real, condicionam frequentemente a percepção dos indivíduos e influenciam as suas práticas sociais.
Também as fotografias vencedoras do World Press Photo, um dos concursos mais prestigiados de fotojornalismo, em 2012 não fogem ao construtivismo discursivo que molda a representação e a percepção dos acontecimentos.
A partir da análise crítica do discurso, nomeadamente dos instrumentos teóricos da semiótica barthesiana e da semiótica social de Gunther Kress e Theo van Leeuwen, procurámos interpretar as 38 fotografias vencedoras do World Press Photo 2012, a fim de reflectirmos sobre o modo como contribuíram para a compreensão da Revolta Árabe e como despertaram o nosso interesse e a nossa imaginação para o desenrolar do conflito.ABSTRACT:This article aims to analyze how the Arab Spring phenomenon was represented in the award-winning photographs of the World Press Photo contest in 2012.
Although news photographs are usually seen as indexes of the real, they often limit the perception of individuals and influence their social practices.
Also the winning photographs in 2012 of the World Press Photo, one of the most prestigious photojournalism contests, do not escape the discursive constructivism that shapes the representation and perception of events.
Drawing from critical discourse analysis, namely from the theoretical tools of barthesian semiotics and Gunther Kress’s and Theo van Leeuwen’s social semiotics, we sought to interpret the 38 award-winning photographs of the World Press Photo contest in 2012, in order to reflect on the way they have contributed to our understanding of the Arab Revolt and aroused our interest and imagination to the unfolding of the conflict.info:eu-repo/semantics/publishedVersio
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