26 research outputs found

    17 ways to say yes:Toward nuanced tone of voice in AAC and speech technology

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    People with complex communication needs who use speech-generating devices have very little expressive control over their tone of voice. Despite its importance in human interaction, the issue of tone of voice remains all but absent from AAC research and development however. In this paper, we describe three interdisciplinary projects, past, present and future: The critical design collection Six Speaking Chairs has provoked deeper discussion and inspired a social model of tone of voice; the speculative concept Speech Hedge illustrates challenges and opportunities in designing more expressive user interfaces; the pilot project Tonetable could enable participatory research and seed a research network around tone of voice. We speculate that more radical interactions might expand frontiers of AAC and disrupt speech technology as a whole

    Diagnostic Performance of PET or PET/CT Using <sup>18</sup>F-FDG Labeled White Blood Cells in Infectious Diseases: A Systematic Review and a Bivariate Meta-Analysis.

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    Diagnostic performance of positron emission tomography using white blood cells labeled with fluorine-18-fluorodeoxyglucose ( &lt;sup&gt;18&lt;/sup&gt; F-FDG-WBC PET or PET/CT) in patients with suspicious infectious diseases has been evaluated in several studies; however, there is no consensus about the diagnostic accuracy of this method. Therefore, a systematic review and meta-analysis was carried out on this topic. A comprehensive computer literature search screening PubMed/MEDLINE, Embase and Cochrane library databases through March 2019 was performed. Pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-), and diagnostic odds ratio (DOR) of &lt;sup&gt;18&lt;/sup&gt; F-FDG-WBC PET or PET/CT in patients with infectious diseases were calculated. Eight studies on the use of &lt;sup&gt;18&lt;/sup&gt; F-FDG-WBC PET or PET/CT in suspicious infectious diseases were discussed in the systematic review. The meta-analysis of seven studies (236 patients) provided these pooled results on a per patient-based analysis: sensitivity was 86.3% [95% confidence interval (95%CI) 75-92.9%], specificity 92% (95%CI 79.8-97.1%), LR+ 6.6 (95%CI: 3.1-14.1), LR- 0.2 (95%CI: 0.12-0.33), DOR 43.5 (95%CI: 12.2-155). A statistically significant heterogeneity was not detected. Despite limited literature data, &lt;sup&gt;18&lt;/sup&gt; F-FDG-WBC PET or PET/CT demonstrated a good diagnostic accuracy for the diagnosis of infectious diseases; nevertheless, larger studies are needed

    The Term Structure of Interest Rates and its Impact on the Liability Adequacy Test for Insurance Companies in Brazil

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    The Brazilian regulation for applying the Liability Adequacy Test (LAT) to technical provisions in insurance companies requires that the current estimate is discounted by a term structure of interest rates (hereafter TSIR). This article aims to analyze the LAT results, derived from the use of various models to build the TSIR: the cubic spline interpolation technique, Svensson's model (adopted by the regulator) and Vasicek's model. In order to achieve the objective proposed, the exchange rates of BM&FBOVESPA trading days were used to model the ETTJ and, consequently, to discount the cash flow of the insurance company. The results indicate that: (i) LAT is sensitive to the choice of the model used to build the TSIR; (ii) this sensitivity increases with cash flow longevity; (iii) the adoption of an ultimate forward rate (UFR) for the Brazilian insurance market should be evaluated by the regulator, in order to stabilize the trajectory of the yield curve at longer maturities. The technical provision is among the main solvency items of insurance companies and the LAT result is a significant indicator of the quality of this provision, as this evaluates its sufficiency or insufficiency. Thus, this article bridges a gap in the Brazilian actuarial literature, introducing the main methodologies available for modeling the yield curve and a practical application to analyze the impact of its choice on LAT.</p

    Social disclosure and cost of equity in public companies in Brazil

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    Esta pesquisa tem por objetivo analisar a relação entre o nível de social disclosure e o custo de capital próprio em companhias abertas no Brasil. Assume-se a hipótese de que os programas sociais externos promovidos ou apoiados pelas empresas contribuem para a construção da imagem reputacional das organizações, compensando as externalidades, trazendo benefícios sob o ponto de vista econômico, pela relação negativa com o custo do capital. Para testar essa hipótese, foram coletados e analisados os relatórios de responsabilidade social de 83 empresas listadas na Bolsa de Valores, Mercadorias e Futuros de São Paulo (BM&FBovespa), no período de 2005 a 2009. Para avaliação do nível de social disclosure das empresas analisadas, foi utilizado um índice composto de 13 indicadores. O custo de capital próprio foi ajustado ao risco mediante o Capital Asset Pricing Model (CAPM) e testado por meio de regressão com dados em painel com efeitos fixos seccionais. Os resultados evidenciam que há relação negativa entre custo de capital próprio e nível de social disclosure, indicando, para o mercado acionário brasileiro, uma forma semiforte de eficiência de mercado. _________________________________________________________________________________ ABSTRACTThis study aims to analyze the relationship between the level of social disclosure and the cost of equity in public companies in Brazil. The hypothesis is that external social programs promoted or supported by a company increase the organization's reputation, compensate for externalities and bring economic benefits through the negative relationship with the cost of equity. To test this hypothesis, social responsibility reports of 83 companies listed on the São Paulo Stock, Mercantile and Futures Exchanges (Bolsa de Valores, Mercadorias e Futuros de São Paulo - BM&FBovespa) from the period 2005-2009 were collected and analyzed. A composite index of 13 indicators was used to evaluate the social disclosure level of the companies analyzed. The cost of equity was risk-adjusted using the capital asset-pricing model (CAPM) and regression tested using panel data with cross-sectional fixed effects. The results show a negative relationship between the cost of equity and level of social disclosure, indicating that the Brazilian stock market has a semi-strong form of market efficiency

    Pulmonary Lymphangitic Carcinomatosis: Diagnostic Performance of High-Resolution CT and <sup>18</sup>F-FDG PET/CT in Correlation with Clinical Pathologic Outcome.

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    The rationale of this study was to investigate the performance of high-resolution CT (HRCT) versus &lt;sup&gt;18&lt;/sup&gt; F-FDG PET/CT for the diagnosis of pulmonary lymphangitic carcinomatosis (PLC). Methods: In this retrospective institution-approved study, 94 patients addressed for initial staging of lung cancer with suspicion of PLC were included. Using double-blind analysis, we assessed the presence of signs favoring PLC on HRCT (smooth or nodular septal lines, subpleural nodularity, peribronchovascular thickening, satellite nodules, lymph node enlargement, and pleural effusion). &lt;sup&gt;18&lt;/sup&gt; F-FDG PET/CT images were reviewed to qualitatively evaluate peritumoral uptake and to quantify tracer uptake in the tumoral and peritumoral areas. Histology performed on surgical specimens served as the gold standard for all patients. Results: Among 94 included patients, 73% (69/94) had histologically confirmed PLC. Peribronchovascular thickening, lymph node involvement, and increased peritumoral uptake were more often present in patients with PLC (P &lt; 0.009). Metabolic variables, including tumor SUV &lt;sub&gt;max&lt;/sub&gt; , SUV &lt;sub&gt;mean&lt;/sub&gt; , metabolic tumor volume, and total lesion glycolysis, as well as peritumoral SUV &lt;sub&gt;max&lt;/sub&gt; , SUV &lt;sub&gt;mean&lt;/sub&gt; , and their respective ratios to background, were significantly higher in the PLC group than in the non-PLC group (P ≤ 0.0039). Sensitivity, specificity, and area under the receiver-operating-characteristic curve for peribronchovascular thickening (69%, 83%, and 0.76, respectively; 95% confidence interval [95%CI], 0.67-0.85) and increased peritumoral uptake (94%, 84%, and 0.89, respectively; 95%CI, 0.81-0.97) were similar (P = 0.054). For detecting PLC, sensitivity, specificity, and area under the receiver-operating-characteristic curve were significantly higher, at 97%, 92%, and 0.98, respectively (95%CI, 0.96-1.00), for peritumoral SUV &lt;sub&gt;max&lt;/sub&gt; and 94%, 88%, and 0.96, respectively (95%CI, 0.92-1.00), for peritumoral SUV &lt;sub&gt;mean&lt;/sub&gt; (all P ≤ 0.025). Conclusion: Qualitative evaluation of &lt;sup&gt;18&lt;/sup&gt; F-FDG PET/CT and HRCT perform similarly for the diagnosis of PLC, with both being outperformed by &lt;sup&gt;18&lt;/sup&gt; F-FDG PET/CT quantitative parameters

    Prospective evaluation of MR-TRG (Tumor Regression Grade) in esophageal cancer after neo-adjuvant therapy: Preliminary results.

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    To develop MRI-based criteria to assess tumor response to neoadjuvant therapies (NAT) of esophageal cancers (EC) and to evaluate its diagnostic performance in predicting the pathological Tumor Regression Grade (pTRG). From 2018 to 2022, patients with newly diagnosed locally advanced EC underwent MRI examinations for initial staging and restaging after NAT. Magnetic Resonance TRG (MR-TRG), equivalent to the Mandard and Becker classifications, were developed and independently assessed by two radiologists, blinded to pTRG, using T2W and DW-MR Images. All patients underwent surgery and benefited from a blinded pTRG evaluation by two pathologists. The agreement between readers and between MR-TRG and pTRG were assessed with Cohen's Kappa. The correlation of MR-TRG and pTRG was determined using Spearman's correlation. 28 patients were included. Interrater agreement was substantial between radiologists, improved when grouping grade 1 and 2 (κ = 0.78 rose to 0,84 for Mandard and 0.68 to 0,78 for Becker score). Agreement between pTRG and MR-TRG was moderate with a percentaged agreement (p) = 87.5 %, kappa (κ) = 0.54 and p = 83.3 %, κ = 0.49 for Mandard and Becker, respectively. Agreement was improved to substantial when grouping grades 1-2 for Mandard and 1a-1b for Becker with p = 89.3 %, κ = 0.65 and p = 85.2 %, κ = 0.65 respectively. Sensitivity and specificity of MR-TRG in predicting pTRG were 88.2 % and 72.7 % for Mandard system (scores 1-2 versus 3-5), and 83.3 % and 80 % for Becker system (scores 1a-1b versus 2-3). A substantial agreement between MR-TRG and pTRG was achieved when grouping grade 1-2. Hence, MR-TRG could be used as a surrogate of complete and near-complete pTRG

    The combination of non-contrast abbreviated MRI and alpha foetoprotein has high performance for hepatocellular carcinoma screening.

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    This study aimed to compare two abbreviated MRI (AMRI) protocols to complete MRI for HCC detection: non-contrast (NC)-AMRI without/with alpha foetoprotein (AFP) and dynamic contrast-enhanced (Dyn)-AMRI. This retrospective single-center study included 351 patients (M/F: 264/87, mean age: 57y) with chronic liver disease, who underwent MRI for HCC surveillance between 2014 and 2020. Two reconstructed AMRI sets were obtained based on complete MRI: NC-AMRI (T2-weighted imaging (WI) + diffusion-WI) and Dyn-AMRI (T2-WI + dynamic T1-WI) and were assessed by 2 radiologists who reported all suspicious lesions, using LI-RADS/adapted LI-RADS classification. The reference standard was based on all available patient data. Inter-reader agreement was assessed and MRI diagnostic performance was compared to the reference standard. The reference standard demonstrated 83/351 HCC-positive patients (prevalence: 23.6%, median size: 22 mm, and positive MRIs: 83/631). Inter-reader agreement was substantial for all sets. Sensitivities of Dyn-AMRI and complete MRI (both 92.8%) were similar, higher than NC-AMRI (72.3%, p &lt; 0.001). Specificities were not different between sets. NC-AMRI + AFP (92.8%) had similar sensitivity to Dyn-AMRI and complete MRI. In patients with small size HCCs (≤ 2 cm), sensitivities of Dyn-AMRI (85.3%) and complete MRI (88.2%) remained similar (p = 0.564), also outperforming NC-AMRI (52.9%, p &lt; 0.05). NC-AMRI + AFP had similar sensitivity (88.2%) to Dyn-AMRI and complete MRI (p = 0.706 and p = 1, respectively). Dyn-AMRI has similar diagnostic performance to complete MRI for HCC detection, while both outperform NC-AMRI, especially for small size HCCs. NC-AMRI + AFP demonstrates similar sensitivity to Dyn-AMRI and complete MRI. Due to the low sensitivity of ultrasound for hepatocellular screening, new screening methods are needed. Abbreviated MRI (AMRI) is a candidate, especially non-contrast AMRI with serum alpha foetoprotein as the acquisition time is low, without the need for contrast medium injection. • Dynamic contrast-enhanced abbreviated MRI using extracellular gadolinium-based contrast agent and complete MRI have similar diagnostic performance for hepatocellular carcinoma detection in an at-risk population. • Non-contrast abbreviated MRI with alpha foetoprotein has similar diagnostic performance to dynamic contrast-enhanced abbreviated MRI and complete MRI, including when considering small size hepatocellular carcinoma ≤ 2 cm. • Non-contrast abbreviated MRI and dynamic contrast-enhanced abbreviated MRI can be performed in 7 and 10 min, excluding patient setup time

    Detection Rate of Culprit Tumors Causing Osteomalacia Using Somatostatin Receptor PET/CT: Systematic Review and Meta-Analysis.

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    Tumor-induced or oncogenic osteomalacia (TIO) is a rare paraneoplastic syndrome in which osteomalacia is a consequence of fibroblast growth factor 23 (FGF23) secretion by a mesenchymal tumor. The localization of the culprit lesion in patients with TIO is often challenging. Several studies have evaluated the detection rate (DR) of these tumors using somatostatin receptor positron emission tomography (SSTR-PET/CT). We aimed to summarize literature findings on this topic providing pooled estimates of DR. A comprehensive literature search by screening PubMed, Embase and Cochrane library electronic databases through August 2019 was performed. The pooled DR of culprit tumors using SSTR-PET/CT in patients with TIO was calculated using a random-effects statistical model. Fourteen studies on the use of SSTR-PET/CT in detecting the culprit tumor in patients with TIO were included in the qualitative analysis. The pooled DR of SSTR-PET/CT on a per-patient-based analysis calculated using eleven studies (166 patients) was 87.6% (95% confidence interval (95% CI) 80.2-95.1%). Statistical heterogeneity among studies was detected (I-square = 63%), likely due to the use of different radiolabeled somatostatin analogues, as demonstrated by a subgroup analysis. Despite limited literature data due to the rarity of the disease, SSTR-PET/CT demonstrated a very high DR of culprit tumors in patients with TIO and it could be used as first-line imaging method for this indication

    Comparison Between Magnetic Resonance Imaging and Computed Tomography in the Detection and Volumetric Assessment of Lung Nodules: A Prospective Study.

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    Computed tomography (CT) lung nodule assessment is routinely performed and appears very promising for lung cancer screening. However, the radiation exposure through time remains a concern. With the overall goal of an optimal management of indeterminate lung nodules, the objective of this prospective study was therefore to evaluate the potential of optimized ultra-short echo time (UTE) MRI for lung nodule detection and volumetric assessment. Eight (54.9 ± 13.2 years) patients with at least 1 non-calcified nodule ≥4 mm were included. UTE under high-frequency non-invasive ventilation (UTE-HF-NIV) and in free-breathing at tidal volume (UTE-FB) were investigated along with volumetric interpolated breath-hold examination at full inspiration (VIBE-BH). Three experienced readers assessed the detection rate of nodules ≥4 mm and ≥6 mm, and reported their location, 2D-measurements and solid/subsolid nature. Volumes were measured by two experienced readers. Subsequently, two readers assessed the detection and volume measurements of lung nodules ≥4mm in gold-standard CT images with soft and lung kernel reconstructions. Volumetry was performed with lesion management software (Carestream, Rochester, New York, USA). UTE-HF-NIV provided the highest detection rate for nodules ≥4 mm (n = 66) and ≥6 mm (n = 32) (35 and 50%, respectively). No dependencies were found between nodule detection and their location in the lung with UTE-HF-NIV (p &gt; 0.4), such a dependency was observed for two readers with VIBE-BH (p = 0.002 and 0.03). Dependencies between the nodule's detection and their size were noticed among readers and techniques (p &lt; 0.02). When comparing nodule volume measurements, an excellent concordance was observed between CT and UTE-HF-NIV, with an overestimation of 13.2% by UTE-HF-NIV, &lt;25%-threshold used for nodule's growth, conversely to VIBE-BH that overestimated the nodule volume by 28.8%. UTE-HF-NIV is not ready to replace low-dose CT for lung nodule detection, but could be used for follow-up studies, alternating with CT, based on its volumetric accuracy
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