Continuous Positive Airway Pressure Treatment in Patients with Alzheimer's Disease: A Systematic Review

Background: Epidemiological studies have suggested a pathophysiological relationship between obstructive sleep apnea syndrome (OSAS) and Alzheimer's disease (AD). The aim of this study is to evaluate the treatment of obstructive sleep apnea with continuous positive airway pressure (CPAP) in AD and its relationship with neurocognitive function improvement. Methods: Systematic review conducted following PRISMA's statements. Relevant studies were searched in MEDLINE, PEDro, SCOPUS, PsycINFO, Web of Science, CINAHL and SportDicus. Original studies in which CPAP treatment was developel in AD patients have been included. Results: 5 studies, 3 RCTs (Randomized controlled trials) and 2 pilot studies. In all RCTs the CPAP intervention was six weeks; 3 weeks of therapeutic CPAP vs. 3 weeks placebo CPAP (pCPAP) followed by 3 weeks tCPAP in patients with AD and OSA. The two pilot studies conducted a follow-up in which the impact on cognitive impairment was measured. Conclusions: CPAP treatment in AD patients decreases excessive daytime sleepiness and improves sleep quality. There are indications that cognitive deterioration function measured with the Mini Mental Scale decreases or evolves to a lesser extent in Alzheimer's patients treated with CPAP. Caregivers observe stabilization in disease progression with integration of CPAP. More research is needed on the topic presented

Fractional transformation-based decentralized robust control of a coupled-tank system for industrial applications

Petrochemical and dairy industries, waste management, and paper manufacturing fall under the category of process industries where flow and liquid control are essential. Even when liquids are mixed or chemically treated in interconnected tanks, the fluid and flow should constantly be observed and controlled, especially when dealing with nonlinearity and imperfect plant models. In this study, we propose a nonlinear dynamic multiple-input multiple-output (MIMO) plant model. This model is then transformed through linearization, a technique frequently utilized in the analysis and modeling of fractional processes, and decoupling for decentralized fixed-structure H-infinity robust control design. Simulation tests based on MATLAB and SIMULINK are subsequently executed. Numerous assessments are conducted to evaluate tracking performance, external disturbance re jection, and plant parameter fluctuations to gauge the effectiveness of the proposed model. The objective of this work is to provide a framework that anticipates potential outcomes, paving the way for implementing a reliable controller synthesis for MIMO-connected tanks in real-world scenarios.This research was partially funded by FONDECYT grant number 1200525 (V.L.) from the National Agency for Research and Development (ANID) of the Chilean government under the Ministry of Science, Technology, Knowledge, and Innovation; and by Portuguese funds through the CMAT—Research Centre of Mathematics of University of Minho—within projects UIDB/00013/2020 and UIDP/00013/2020 (C.C.)

Interactions between surrounding landscape biodiversity and intermittent rivers in mediterranean environments – case study of the Caia River

Landscape is a dynamic mosaic of various structures interacting together. Neglecting or overusing one part of this mosaic may boost up or damage the development of others. For instance, overgrazing may increase soil erosion process which may clog a river/stream. In this regard land use changes, climate change and landscape management may lead to increase the intermittency of the surface watercourses, as well as in the ecosystem services provided by riverscapes for humans. Therefore, the present research focus on the existing interactions between the Caia River, an intermittent river located in the Mediterranean region, and its surrounding agricultural and natural landscapes. The performed analyses considered the identification of the existing interaction between natural and agricultural landscapes with the Caia River defining the predictable ecosystem services provided by each element of the landscape and assessing the potential decrease of the ecosystem services provided in case of landscape changes, which according to the performed research might enclose significant impacts both in ecologic and socioeconomic terms

Interactions between surrounding landscape biodiversity and intermittent rivers in mediterranean environments – case study of the Caia River

Landscape is a dynamic mosaic of various structures interacting together. Neglecting or overusing one part of this mosaic may boost up or damage the development of others. For instance, overgrazing may increase soil erosion process which may clog a river/stream. In this regard land use changes, climate change and landscape management may lead to increase the intermittency of the surface watercourses, as well as in the ecosystem services provided by riverscapes for humans. Therefore, the present research focus on the existing interactions between the Caia River, an intermittent river located in the Mediterranean region, and its surrounding agricultural and natural landscapes. The performed analyses considered the identification of the existing interaction between natural and agricultural landscapes with the Caia River defining the predictable ecosystem services provided by each element of the landscape and assessing the potential decrease of the ecosystem services provided in case of landscape changes, which according to the performed research might enclose significant impacts both in ecologic and socioeconomic terms.info:eu-repo/semantics/publishedVersio

Buenas prácticas en la gestión del capital de trabajo y su relación con el EVA en el periodo 2015 al 2019 caso de las empresas: Unión de Cervecerías Peruanas Backus y Johnston S.A.A., Cementos Pacasmayo S.A.A. y Compañía Minera Poderosa S.A.

El presente estudio tiene como propósito identificar las buenas prácticas en la gestión del capital de trabajo que han tenido relación en el desempeño de las empresas Unión de Cervecerías Peruanas Backus y Johnston S.A., Cementos Pacasmayo S.A.A. y Compañía Minera Poderosa S.A., entre el periodo 2015 a 2019. De esta manera brindar un aporte académico a los estudios previos que existen sobre este tema en la comunidad académica del país. A propósito de lo señalado anteriormente, se presenta la situación actual del capital de trabajo, analizando la gestión del efectivo, cuentas por cobrar, inventarios y cuentas por pagar, de cada empresa utilizando el ciclo de conversión de efectivo para cada participante del estudio. El indicador EVA ha sido calculado y presentado para cada empresa y se relaciona con la gestión del capital de trabajo, al simular el comportamiento de los principales indicadores de capital de trabajo en cada una de las empresas estudiadas, observamos la siguiente relación con el EVA: relación negativa entre el EVA y el ciclo de conversión de efectivo, las cuentas por cobrar e inventario, y relación positiva entre el EVA y las cuentas por pagar. Se identificaron buenas prácticas en la gestión del capital de trabajo con respecto a la empresa Unión de Cervecerías Peruanas Backus y Johnston S.A. las cuales son: En la gestión del efectivo son la proyección de fondos de ocho semanas para pagos de obligaciones e inversión de efectivo disponible en el mercado de capitales. En la gestión de cuentas por cobrar son la revisión mensual de la cartera de créditos considerando la exposición al riesgo, recorte de créditos de acuerdo con el cumplimiento de metas, negociación con clientes por pronto pago, uso de factoring con clientes seleccionados siempre que la tasa sea menor al WACC, evaluación mensual del nivel de cuentas por cobrar comparándolo con el nivel de pasivos generados para mantenerlos en línea con los objetivos, uso de indicadores diferenciados según el canal de ventas tales como cuentas por cobrar entre el net revenue el cual debe ser alrededor del 5%, el crédito vencido no debe ser mayor al 3% de la cartera de créditos, el porcentaje de apalancamiento ventas al crédito entre ventas totales debe estar alrededor de 35%. En la gestión del inventario son el control de inventarios de máximos y mínimos insumos para cubrir la producción y demanda según el lead time para la venta, el uso del indicador inventario entre el net revenue el cual debe ser alrededor del 6.5%. En la gestión de cuentas por pagar tenemos la negociación directa con proveedores, el uso de factoring con proveedores cuyo costo es asumido por los proveedores mediante tasas competitivas, uso de tarjetas de crédito para pagos relevantes a través de los pagos en los días establecidos para evitar intereses, uso del indicador cuentas por pagar entre el net revenue el cual debe ser alrededor del 6.5%. Con respecto a la empresa Cementos Pacasmayo S.A.A las buenas prácticas identificadas son: En la gestión del efectivo el manejo del flujo de caja operativo y el flujo de caja proyectado. En la gestión de cuentas por cobrar son las políticas de ventas respaldadas con garantías, evaluación constante del comportamiento de pagos del cliente para el otorgamiento de créditos. En la gestión de inventarios son el control de inventarios por planta y por producto. En la gestión de cuentas por pagar son la negociación directa con los proveedores para cumplir con los objetivos de la empresa. Con respecto a la empresa Compañía Minera Poderosa S.A. las buenas prácticas identificadas son: En la gestión de efectivo son el uso del flujo de caja para garantizar la liquidez en el cumplimiento de sus obligaciones, no realizar inversiones que no estén dirigidas a la operación de la empresa. En la gestión de las cuentas por cobrar son el uso de acuerdos previos para asegurar la cobranza inmediata. En la gestión de inventarios son el uso de un sistema in house para el manejo del inventario, control de inventarios por procesos y el uso de la metodología ABC; el uso de ratios de inventarios como el reporte de devoluciones, stock out, nivel de atención oportuna, nivel de materiales obsoletos. En la gestión de cuentas por pagar son los descuentos por pronto pago, negociación de plazos de pago con los proveedores asegurando que no se rompa la cadena de pagos.The purpose of this study is to identify good practices in the management of working capital that have been related to the performance of the companies Unión de Cervecerías Peruanas Backus y Johnston S.A., Cementos Pacasmayo S.A.A. and Compañía Minera Poderosa S.A., between the period 2015 to 2019. In this way, provide an academic contribution to the previous studies that exist on this subject in the academic community of the country. Regarding the aforementioned, the current situation of working capital is presented, analyzing the management of cash, accounts receivable, inventories and accounts payable, of each company using the cash conversion cycle for each participant in the study. The EVA indicator has been calculated a presented for each company and is related to the management of working capital, by simulating the behavior of the main working capital indicators in each of the companies studied, we observe the following relationship with the EVA: negative relationship between EVA and cash conversion cycle, accounts receivable and inventory, and positive relationship between EVA and accounts payable. Good practices were identified in the management of working capital with respect to the company Unión de Cervecerías Peruanas Backus y Johnston S.A. which are: In cash Management are the projection of funds of eight weeks for payments of obligations and investment of cash available in the capital market. In the management of accounts receivable, they are the monthly review of the loan portfolio considering risk exposure, credit cut in accordance with the fulfillment of goals, negotiation with clients promp payment, use of factoring with selected clients as long as the rate is lower than the WACC, monthly evaluation of the level of accounts receivable comparing it with the level of liabilities generated to keep them in line with the objectives, use of differentiated indicators according to the sales channel such as accounts receivable between net revenue which should be around 5%, overdue credit should not be greater than 3% of the loan portfolio, the percentage of leverage sales on credit between total sales it should be around 35%. In inventory management, the inventory control of maximum and minimum inputs to cover production and demand according to the lead time for sale is the use of the inventory indicator between the net revenue, which should be around 6.5%. In the management of accounts payable we have direct negotiation with suppliers, the use of factoring with suppliers whose cost is assumed by the suppliers through competitive rates, use of credit cards for relevant payments through payments on the established days to avoid interest, use of the accounts payable indicator between the net revenue which should be around 6.5%. Regarding the company Cementos Pacasmayo S.A. A, the good practices identified are: In cash management, they are the management of the operating cash flow and the projected cash flow. In the management of accounts receivable, sales policies are backed by guarantees, constant evaluation of the customer's payment behavior for the granting of credits. In inventory management are inventory control by plant and by product. In the management of accounts payable they are direct negotiation with suppliers to meet the objectives of the company. With respect to the company Compañía Minera Poderosa S.A. the good practices identified are: In cash management, they are the use of cash flow to guarantee liquidity in the fulfillment of its obligations, not to make investments that are not directed to the operation of the company. In the management of accounts receivable are the use of prior agreements to ensure immediate collection. In inventory management they are the use of an in-house system for inventory management, inventory control by processes and the use of the ABC methodology; the use of inventory ratios such as the report of returns, stock out, level of timely attention, level of obsolete materials. In the management of accounts payable are discounts for prompt payment, negotiation of payment terms with suppliers ensuring that the chain of payments is not broken

Expression of chemokines and their receptors by human brain endothelium: Implications for multiple sclerosis

Leukocyte migration into the CNS is mediated by chemokines, expressed on the surface of brain endothelium. This study investigated the production of chemokines and expression of chemokine receptors by human brain endothelial cells (HBEC), in vitro and in situ in multiple sclerosis tissue. Four chemokines (CCL2, CCL5, CXCL8 and CXCL10), were demonstrated in endothelial cells in situ, which was reflected in the chemokine production by primary HBEC and a brain endothelial cell line, hCEMC/D3. CXCL8 and CCL2 were constitutively released and increased in response to TNF and/or IFN . CXCL10 and CCL5 were undetectable in resting cells but were secreted in response to these cytokines. TNF strongly increased the production of CCL2, CCL5 and CXCL8, while IFN up-regulated CXCL10 exclusively. CCL3 was not secreted by HBECs and appeared to be confined to astrocytes in situ. The chemokine receptors CXCR1 and CXCR3 were expressed by HBEC both in vitro and in situ, and CXCR3 was up-regulated in response to cytokine stimulation in vitro. By contrast, CXCR3 expression was reduced in silent MS lesions. Brain endothelium expresses particularly high levels of CXCL10 and CXCL8, which may account for the predominant TH1-type inflammatory reaction seen in chronic conditions such as multiple sclerosis

Contribution of Type 2 Diabetes Mellitus to Subclinical Atherosclerosis in Subjects with Morbid Obesity

Introduction: Type 2 diabetes mellitus (T2DM) and obesity are both related to increased risk of cardiovascular disease and mortality. Early atherosclerotic vascular changes can be detected by non-invasive tests like carotid artery intima-media thickness (cIMT) and pulse wave velocity (PWV). Both cIMT and PWV are significantly impaired in T2DM patients and in obese patients, but the additional effect of T2DM on these vascular measurements in obese subjects has not been evaluated. Methods: Two hundred morbidly obese patients with or without T2DM were enrolled in a prospective cohort study and underwent extensive laboratory testing, including cIMT and PWV measurements. The cohort was divided into a group with and a group without T2DM. Results: Within this cohort, 43 patients (21.5%) were diagnosed with T2DM. These patients were older and had more often (a history of) hypertension as compared to patients without T2DM. HbA1c levels were significantly increased, while LDL cholesterol was significantly lower and the use of statins higher than in non-diabetic participants. cIMT and PWV were significantly increased in subjects suffering from T2DM. The variability in cIMT and PWV was related to differences in age and systolic blood pressure, but not to the presence of T2DM. Conclusion: While T2DM negatively affects the vasculature in morbid obesity, hypertension and age seem to be the major risk factors, independent from the presence of T2DM. Clinical Trial Registration: Dutch Trial Register NTR5172

Statistical characterization of vaccinated cases and deaths due to COVID-19: methodology and case study in South America

Many studies have been performed in different regions of the world as a result of the COVID-19 pandemic. In this work, we perform a statistical study related to the number of vaccinated cases and the number of deaths due to COVID-19 in ten South American countries. Our objective is to group countries according to the aforementioned variables. Once the groups of countries are built, they are characterized based on common properties of countries in the same group and differences between countries that are in different groups. Countries are grouped using principal component analysis and K-means analysis. These methods are combined in a single procedure that we propose for the classification of the countries. Regarding both variables, the countries were classified into three groups. Political decisions, availability of resources, bargaining power with suppliers and health infrastructure among others are some of the factors that can affect both the vaccination process and the timely care of infected people to avoid death. In general, the countries acted in a timely manner in relation to the vaccination of their citizens with the exception of two countries. Regarding the number of deaths, all countries reached peaks at some point in the study period

Spectral signatures of reorganised brain networks in disorders of consciousness.

Theoretical advances in the science of consciousness have proposed that it is concomitant with balanced cortical integration and differentiation, enabled by efficient networks of information transfer across multiple scales. Here, we apply graph theory to compare key signatures of such networks in high-density electroencephalographic data from 32 patients with chronic disorders of consciousness, against normative data from healthy controls. Based on connectivity within canonical frequency bands, we found that patient networks had reduced local and global efficiency, and fewer hubs in the alpha band. We devised a novel topographical metric, termed modular span, which showed that the alpha network modules in patients were also spatially circumscribed, lacking the structured long-distance interactions commonly observed in the healthy controls. Importantly however, these differences between graph-theoretic metrics were partially reversed in delta and theta band networks, which were also significantly more similar to each other in patients than controls. Going further, we found that metrics of alpha network efficiency also correlated with the degree of behavioural awareness. Intriguingly, some patients in behaviourally unresponsive vegetative states who demonstrated evidence of covert awareness with functional neuroimaging stood out from this trend: they had alpha networks that were remarkably well preserved and similar to those observed in the controls. Taken together, our findings inform current understanding of disorders of consciousness by highlighting the distinctive brain networks that characterise them. In the significant minority of vegetative patients who follow commands in neuroimaging tests, they point to putative network mechanisms that could support cognitive function and consciousness despite profound behavioural impairment.This work was supported by grants from the Wellcome Trust [WT093811MA to T.B.]; the James S. McDonnell Foundation [to A.M.O. and J.D.P.]; the UK Medical Research Council [U.1055.01.002.00001.01 to A.M.O. and J.D.P.]; the Canada Excellence Research Chairs program [to A.M.O.]; the National Institute for Health Research Cambridge Biomedical Research Centre [to J.D.P.]; and the National Institute for Health Research Senior Investigator and Healthcare Technology Cooperative awards [to J.D.P.].This is the final version of the article. It first appeared from PLOS via http://dx.doi.org