Robust explicit MPC design under finite precision arithmetic

We propose a design methodology for explicit Model Predictive Control (MPC) that guarantees hard constraint satisfaction in the presence of finite precision arithmetic errors. The implementation of complex digital control techniques, like MPC, is becoming increasingly adopted in embedded systems, where reduced precision computation techniques are embraced to achieve fast execution and low power consumption. However, in a low precision implementation, constraint satisfaction is not guaranteed if infinite precision is assumed during the algorithm design. To enforce constraint satisfaction under numerical errors, we use forward error analysis to compute an error bound on the output of the embedded controller. We treat this error as a state disturbance and use this to inform the design of a constraint-tightening robust controller. Benchmarks with a classical control problem, namely an inverted pendulum, show how it is possible to guarantee, by design, constraint satisfaction for embedded systems featuring low precision, fixed-point computations

Energy-aware MPC co-design for DC-DC converters

In this paper, we propose an integrated controller design methodology for the implementation of an energy-aware explicit model predictive control (MPC) algorithms, illustrat- ing the method on a DC-DC converter model. The power consumption of control algorithms is becoming increasingly important for low-power embedded systems, especially where complex digital control techniques, like MPC, are used. For DC-DC converters, digital control provides better regulation, but also higher energy consumption compared to standard analog methods. To overcome the limitation in energy efficiency, instead of addressing the problem by implementing sub-optimal MPC schemes, the closed-loop performance and the control algorithm power consumption are minimized in a joint cost function, allowing us to keep the controller power efficiency closer to an analog approach while maintaining closed-loop op- timality. A case study for an implementation in reconfigurable hardware shows how a designer can optimally trade closed-loop performance with hardware implementation performance

La elección de política contable en el marco de la NIC 16: “propiedad, planta y equipo”

La NIC 16 permite optar por el modelo de costo o el de revaluación para la medición periódica de cada grupo o clases de bienes integrantes de propiedad, planta y equipo. El modelo de costo se presenta como la opción más sencilla y menos costosa. No obstante, es indudable que la utilización de valores razonables permite brindar información más relevante a los usuarios de los estados financieros. El debate sobre el valor razonable se centra fundamentalmente en la compensación entre la relevancia y la confiabilidad. En concordancia con estudios previos, el relevamiento realizado muestra un uso muy limitado del modelo de revaluación por parte de las empresas cotizantes en Argentina, lo que sugiere que los directivos, en general, no consideran que la adopción del modelo de revaluación redunde en mayores beneficios económicos netos que el empleo del modelo de costo. Las empresas que optaron por el modelo de revaluación, en su mayoría lo hicieron para la clase de bienes inmuebles. Es probable que esta situación obedezca a que para estos bienes existe en general un mercado activo que facilita la determinación de valores razonables.IAS 16 provides a free choice between the cost model and the revaluation model for each asset class comprising property, plant and equipment. The cost model is presented as the simplest and least expensive option. However, there is no doubt that the use of fair value provides more relevant financial information to stakeholders. The debate over the fair value is primarily focused on the compensation between relevance and reliability. Consistent with previous studies, this research shows a very limited use of the revaluation model by the listed companies in Argentina, suggesting that, in general, managers do not consider that adopting the revaluation model brings greater economic benefits than the use of the cost model. Most of the companies that have chosen the revaluation model did it for the property asset class. This situation is probably explained by the fact that, normally, there is an active market for these assets that facilitates fair value measurements.Suardi, Diana; Facultad de Ciencias Económicas y Estadística; Universidad Nacional de Rosario; Argentin

Los informes contables de las pymes. Un trabajo exploratorio

n.d.Bertolino, Gisela; Facultad de Ciencias Económicas y Estadística; Universidad Nacional de Rosario; Argentin

Tumour architecture is an independent predictor of outcomes after nephroureterectomy: a multi-institutional analysis of 1363 patients

To assess whether tumour architecture can help to refine the prognosis of patients treated with nephroureterectomy (NU) for urothelial carcinoma (UC) of the upper urinary tract (UT), as the prognostic value of tumour architecture (papillary vs sessile) in UTUC remains elusive. PATIENTS AND METHODS The study included 1363 patients with UTUC and treated with radical NU at 12 centres worldwide. All slides were re-reviewed according to strict criteria by genitourinary pathologists who were unaware of the findings of the original pathology slides and clinical outcomes. Gross tumour architecture was categorized as sessile vs papillary. RESULTS Papillary growth was identified in 983 patients (72.2%) and sessile growth in 380 (27.8%). The sessile growth pattern was associated with higher tumour grade, more advanced stage, lymphovascular invasion, and metastasis to lymph nodes (all P  < 0.001). In multivariable Cox regression analyses that adjusted for the effects of pathological stage, grade and lymph node status, tumour architecture (sessile or papillary) was an independent predictor of cancer recurrence (hazard ratio 1.5, P  = 0.002) and cancer-specific mortality (1.6, P  = 0.001). Adding tumour architecture increased the predictive accuracy of a model that comprised pathological stage, grade and lymph node status for predicting cancer recurrence and cancer-specific death by a minimal but statistically significant margin (gain in predictive accuracy 1% and 0.5%, both P  < 0.001). CONCLUSION The tumour architecture of UTUC is associated with established features of biologically aggressive disease, and more importantly, with prognosis after radical NU. Including tumour architecture in predictive models for disease progression should be considered, aiming to identify patients who might benefit from early systemic therapeutic intervention.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72257/1/j.1464-410X.2008.08003.x.pd

Impact of social determinants on antiretroviral therapy access and outcomes entering the era of universal treatment for people living with HIV in Italy

Background: Social determinants are known to be a driving force of health inequalities, even in high income countries. Aim of our study was to determine if these factors can limit antiretroviral therapy (ART) access, outcome and retention in care of people living with HIV (PLHIV) in Italy. Methods: All ART naïve HIV+ patients (pts) of Italian nationality enrolled in the ICONA Cohort from 2002 to 2016 were included. The association of socio-demographic characteristics (age, sex, risk factor for HIV infection, educational level, occupational status and residency area) with time to: ART initiation (from the first positive anti-HIV test), ART regimen discontinuation, and first HIV-RNA &lt; 50 cp/mL, were evaluated by Cox regression analysis, Kaplan Meier method and log-rank test. Results: A total of 8023 HIV+ pts (82% males, median age at first pos anti-HIV test 36 years, IQR: 29-44) were included: 6214 (77.5%) started ART during the study period. Women, people who inject drugs (PWID) and residents in Southern Italy presented the lowest levels of education and the highest rate of unemployment compared to other groups. Females, pts aged &gt; 50 yrs., unemployed vs employed, and people with lower educational levels presented the lowest CD4 count at ART initiation compared to other groups. The overall median time to ART initiation was 0.6 years (yrs) (IQR 0.1-3.7), with a significant decrease over time [2002-2006 = 3.3 yrs. (0.2-9.4); 2007-2011 = 1.0 yrs. (0.1-3.9); 2012-2016 = 0.2 yrs. (0.1-2.1), p &lt; 0.001]. By multivariate analysis, females (p &lt; 0.01) and PWID (p &lt; 0.001), presented a longer time to ART initiation, while older people (p &lt; 0.001), people with higher educational levels (p &lt; 0.001), unemployed (p = 0.02) and students (p &lt; 0.001) were more likely to initiate ART. Moreover, PWID, unemployed vs stable employed, and pts. with lower educational levels showed a lower 1-year probability of achieving HIV-RNA suppression, while females, older patients, men who have sex with men (MSM), unemployed had higher 1-year risk of first-line ART discontinuation. Conclusions: Despite median time to ART start decreased from 2002 to 2016, socio-demographic factors still contribute to disparities in ART initiation, outcome and durability

Normas contables específicas para pymes: antecedentes y principales aspectos a considerar para su elaboración

n.d.Fil: Suardi, Diana - Facultad Ciencias Economicas y Estadística -Universidad Nacional de Rosario - Argentin

Fully Immunocompetent CD8+ T Lymphocytes Are Present in Autologous Haematopoietic Stem Cell Transplantation Recipients Despite an Ineffectual T-Helper Response

BACKGROUND: Reduced CD4 T lymphocytes counts can be observed in HIV infection and in patients undergoing autologous haematopoietic stem cell transplantation (ASCT). Nevertheless, whereas opportunistic infections (OI) are frequent in HIV-infected individuals with low cell counts, OI are uncommon in ASCT patients. METHODOLOGY/PRINCIPAL FINDINGS: To verify whether this observation could be secondary to intrinsic HIV-correlated T cell defects, we performed in-depth immunologic analyses in 10 patients with comparable CD4 counts in whom lymphopenia was secondary either to HIV-infection or ASCT-associated immunosuppressive therapy and compared them to age-matched healthy subjects. Results showed the presence of profound alterations in CD4+ T lymphocytes in both groups of patients with respect to healthy controls. Thus, a low percentage of CCR7+ CD4+ T cells and a compensative expansion of CD45RA-CCR7- CD4+ T cells, a reduced IL-2/IFN-gamma cytokine production and impaired recall antigens-specific proliferative responses were detected both in ASCT and HIV patients. In stark contrast, profound differences were detected in CD8+ T-cells between the two groups of patients. Thus, mature CD8+ T cell prevailed in ASCT patients in whom significantly lower CD45RA-CCR7- cells, higher CD45RA+CCR7- CD8+ cells, and an expansion of CCR7+CD8+ cells was detected; this resulted in higher IFN-gamma +/TNFalpha production and granzyme CD8+ expression. The presence of strong CD8 T cells mediated immune responses justifies the more favorable clinical outcome of ASCT compared to HIV patients. CONCLUSION/SIGNIFICANCE: These results indicate that CD8 T cells maturation and functions can be observed even in the face of a profound impairment of CD4+ T lymphocytes in ASCT but not in HIV patients. Primary HIV-associated CD8 defects or an imprinting by an intact CD4 T cell system in ASCT could justify these results