Knowledge-Based Sensors for Controlling A High-Concentration Photovoltaic Tracker.

To reduce the cost of generated electrical energy, high-concentration photovoltaic systems have been proposed to reduce the amount of semiconductor material needed by concentrating sunlight using lenses and mirrors. Due to the concentration of energy, the use of tracker or pointing systems is necessary in order to obtain the desired amount of electrical energy. However, a high degree of inaccuracy and imprecision is observed in the real installation of concentration photovoltaic systems. The main objective of this work is to design a knowledge-based controller for a high-concentration photovoltaic system (HCPV) tracker. The methodology proposed consists of using fuzzy rule-based systems (FRBS) and to implement the controller in a real system by means of Internet of Things (IoT) technologies. FRBS have demonstrated correct adaptation to problems having a high degree of inaccuracy and uncertainty, and IoT technology allows use of constrained resource devices, cloud computer architecture, and a platform to store and monitor the data obtained. As a result, two knowledge-based controllers are presented in this paper: the first based on a pointing device and the second based on the measure of the electrical current generated, which showed the best performance in the experiments carried out. New factors that increase imprecision and uncertainty in HCPV solar tracker installations are presented in the experiments carried out in the real installation.

A Systematic Analysis of Narrowband IoT Quality of Service.

Narrowband-IoT (NB-IoT) is part of a novel group of access technologies referred to as Low-Power Wide Area Networks (LPWANs), which provide energy-efficient and long-range network access to IoT devices. Although NB-IoT Release 13 has been deployed by Mobile Network Operators (MNO), detailed Quality of Service (QoS) evaluations in public networks are still rare. In this paper, systematic physical layer measurements are conducted, and the application layer performance is verified. Special consideration is given to the influence of the radio parameters on the application layer QoS. Additionally, NB-IoT is discussed in the context of typical smart metering use cases. The results indicate that NB-IoT meets most theoretical Third Generation Partnership Project (3GPP) design goals in a commercial deployment. NB-IoT provides a wide coverage by using signal repetitions, which improve the receiver sensitivity, but simultaneously increase the system latency. The maximum data rates are consistent over a wide range of coverage situations. Overall, NB-IoT is a reliable and flexible LPWAN technology for sensor applications even under challenging radio conditions. Four smart metering transmission categories are analyzed, and NB-IoT is verified to be appropriate for applications that are not latency sensitive.

Wireless Acoustic Sensor Nodes for Noise Monitoring in the City of Linares (Jaén).

Noise pollution is a problem that affects millions of people worldwide. Over the last few years, many researchers have devoted their attention to the design of wireless acoustic sensor networks (WASNs) to monitor the real data of continuous and precise noise levels and to create noise maps in real time and space. Although WASNs are becoming a reality in smart cities, some research studies argue that very few projects have been deployed around the world, with most of them deployed as pilots for only days or weeks, with a small number of nodes. In this paper, we describe the design and implementation of a complete system for a WASN deployed in the city of Linares (Jaén), Spain, which has been running continuously for ten months. The complete system covers the network topology design, hardware and software of the sensor nodes, protocols, and a private cloud web server platform. As a result, the information provided by the system for each location where the sensor nodes are deployed is as follows: LAeq for a given period of time; noise indicators Lden, Lday, Levening, and Lnight; percentile noise levels (LA01T, LA10T, LA50T, LA90T, and LA99T); a temporal evolution representation of noise levels; and the predominant frequency of the noise. Some comparisons have been made between the noise indicators calculated by the sensor nodes and those from a commercial sound level meter. The results suggest that the proposed system is perfectly suitable for use as a starting point to obtain accurate maps of the noise levels in smart cities.

Towards new recommendations to reduce the burden of alcohol-induced hypertension in the European Union.

BACKGROUND: Hazardous and harmful alcohol use and high blood pressure are central risk factors related to premature non-communicable disease (NCD) mortality worldwide. A reduction in the prevalence of both risk factors has been suggested as a route to reach the global NCD targets. This study aims to highlight that screening and interventions for hypertension and hazardous and harmful alcohol use in primary healthcare can contribute substantially to achieving the NCD targets. METHODS: A consensus conference based on systematic reviews, meta-analyses, clinical guidelines, experimental studies, and statistical modelling which had been presented and discussed in five preparatory meetings, was undertaken. Specifically, we modelled changes in blood pressure distributions and potential lives saved for the five largest European countries if screening and appropriate intervention rates in primary healthcare settings were increased. Recommendations to handle alcohol-induced hypertension in primary healthcare settings were derived at the conference, and their degree of evidence was graded. RESULTS: Screening and appropriate interventions for hazardous alcohol use and use disorders could lower blood pressure levels, but there is a lack in implementing these measures in European primary healthcare. Recommendations included (1) an increase in screening for hypertension (evidence grade: high), (2) an increase in screening and brief advice on hazardous and harmful drinking for people with newly detected hypertension by physicians, nurses, and other healthcare professionals (evidence grade: high), (3) the conduct of clinical management of less severe alcohol use disorders for incident people with hypertension in primary healthcare (evidence grade: moderate), and (4) screening for alcohol use in hypertension that is not well controlled (evidence grade: moderate). The first three measures were estimated to result in a decreased hypertension prevalence and hundreds of saved lives annually in the examined countries. CONCLUSIONS: The implementation of the outlined recommendations could contribute to reducing the burden associated with hypertension and hazardous and harmful alcohol use and thus to achievement of the NCD targets. Implementation should be conducted in controlled settings with evaluation, including, but not limited to, economic evaluation.

The role of alcohol in the management of hypertension in patients in European primary health care practices - a survey in the largest European Union countries.

BACKGROUND: Even though addressing lifestyle problems is a major recommendation in most guidelines for the treatment of hypertension (HTN), alcohol problems are not routinely addressed in the management of hypertension in primary health care. METHODS: Internet based survey of 3081 primary care physicians, recruited via the mailing lists of associations for general practitioners (GPs) in France, Germany, Italy, Spain and the UK. Clinical practice, attitudes, knowledge, education and training were assessed. Logistic regression to predict screening, brief intervention and treatment for alcohol dependence in the management of hypertension were assessed. RESULTS: Overall, about one third of the interviewed GPs reported sufficient screening in cases with HTN (34.0 %, 95 % confidence interval (CI):32.1-35.8 %). One out of five GPs screened and delivered brief interventions in HTN patients with hazardous consumption (22.2 %, 95 % CI: 20.6-23.8 %) and about one in 13 GPs provided treatment for HTN patients with alcohol dependence other than advice or brief intervention (7.8 %, 95 % CI: 6.8-8.9 %). Post-graduate training and belief in their effectiveness predicted interventions. There were marked differences between countries. CONCLUSIONS: While current interventions were overall low, marked differences between countries indicate that current practices could be improved. Education and post-graduate training seems to be key in improving clinical practice of including interventions for problematic alcohol consumption and alcohol dependence in primary health care.

Arginine-guanidinoacetate-creatine pathway in preterm newborns: creatine biosynthesis in newborns.

The phosphocreatine/creatine system is fundamental for the proper development of the embryonic brain. Being born prematurely might alter the creatine biosynthesis pathway, in turn affecting creatine supply to the developing brain. We enrolled 53 preterm and very preterm infants and 55 full-term newborns. The levels of urinary guanidinoacetate, creatine, creatinine and amino acids were measured in the preterm and very preterm groups, 48 h and 9 days after birth and at discharge, and 48 h after birth in the full-term group. Guanidinoacetate concentrations of both preterm and very preterm newborns were significantly higher at discharge than the values for the full-term group at 48 h, while very preterm infants showed urinary creatine values significantly lower than those measured in the full-term group. Our results suggest an impairment of the creatine biosynthesis pathway in preterm and very preterm newborns, which could lead to creatine depletion affecting the neurological outcome in prematurely born infants.

Expression of proinflammatory factors in renal cortex induced by methylmalonic acid.

BACKGROUND: Methylmalonic aciduria is an inborn error of metabolism that causes renal failure and tubulointerstitial (TI) nephritis as complications. This study aimed to examine the levels of expression of several genes related to inflammation, oxidative stress, and mitochondrial function in the renal cortex of rats receiving methylmalonic acid (MMA). METHODS: Rats received MMA subcutaneously for a month. Tumor necrosis factor alpha (TNFα), nuclear factor-kappa B, interleukin 1 beta (IL-1ß), and cyclooxygenase 2 (COX-2) genes were examined by real-time polymerase chain reaction. We also examined transforming growth factor beta (TGF-ß) related to TI fibrosis, c-FOS, belonging to the immediate early gene family of transcription factors, and expression of SIRT1, related to energy production. RESULTS: There was significantly higher expression of TNFα and a trend toward a higher level of TGF-ß transcripts in the methylmalonic model group compared with the controls. However, SIRT1 expression was not different among the groups. Urinary MMA excretion correlated positively with mRNA level of TGF-ß. The expression of COX-2 was positively associated with the expression of c-FOS and inversely related to the expression of IL-1ß. CONCLUSIONS: The higher levels of TNFα and TGF-ß transcripts suggest inflammation and differentiation processes in the renal cortex in rats because of MMA. After 1 month of MMA injections, expression levels of SIRT1 were not affected, suggesting mitochondrial preservation in early stages of the disease.

An architecture for performance optimization in a collaborative knowledge-based approach for wireless sensor networks.

Over the past few years, Intelligent Spaces (ISs) have received the attention of many Wireless Sensor Network researchers. Recently, several studies have been devoted to identify their common capacities and to set up ISs over these networks. However, little attention has been paid to integrating Fuzzy Rule-Based Systems into collaborative Wireless Sensor Networks for the purpose of implementing ISs. This work presents a distributed architecture proposal for collaborative Fuzzy Rule-Based Systems embedded in Wireless Sensor Networks, which has been designed to optimize the implementation of ISs. This architecture includes the following: (a) an optimized design for the inference engine; (b) a visual interface; (c) a module to reduce the redundancy and complexity of the knowledge bases; (d) a module to evaluate the accuracy of the new knowledge base; (e) a module to adapt the format of the rules to the structure used by the inference engine; and (f) a communications protocol. As a real-world application of this architecture and the proposed methodologies, we show an application to the problem of modeling two plagues of the olive tree: prays (olive moth, Prays oleae Bern.) and repilo (caused by the fungus Spilocaea oleagina). The results show that the architecture presented in this paper significantly decreases the consumption of resources (memory, CPU and battery) without a substantial decrease in the accuracy of the inferred values.

Methylation cycle, arginine-creatine pathway and asymmetric dimethylarginine in paediatric renal transplant.

BACKGROUND: Hyperhomocysteinaemia represents an important cause of morbidity in recipients of renal transplants, but few investigations have been carried out to evaluate the status of the methylation cycle and its relation with levels of new cardiovascular biomarkers, such as asymmetric dimethylarginine (ADMA). METHODS: Twenty-six children and adolescents aged 7-18 years (17 male, 9 female) with stable renal transplants were recruited for the study. None had received treatment with folate, vitamin B(12) or statins. Levels of ADMA in plasma and of components of the methylation cycle and arginine (Arg)-creatine pathway in plasma and urine were analysed by specific analytical methods. Results were compared to those obtained by us with identical methods in healthy children of similar age. RESULTS: Concentrations of homocysteine (Hcys), S-adenosylhomocysteine (SAH) and ADMA were significantly higher, while S-adenosylmethionine (SAM)/SAH and Arg/ADMA ratios were significantly lower than controls. Arg/ADMA ratio correlated with plasma guanidinoacetate. The components of the methylation cycle, Hcys and SAH correlated with renal function. CONCLUSIONS: Children with renal transplant showed low methylation power (SAM/SAH) mainly due to increased levels of SAH which acts as a cardiovascular biomarker. Elevated values of ADMA and low Arg/ADMA coefficients also represent a novel finding because it inhibits nitric oxide synthesis contributing to endothelial dysfunction and cardiovascular risk in such patients.

Fatty acid profile in patients with phenylketonuria and its relationship with bone mineral density.

BACKGROUND: Patients with phenylketonuria (PKU) undergo a restrictive vegan-like diet, with almost total absence of n-3 fatty acids, which have been proposed as potential contributors to bone formation in the healthy population. The PKU diet might lead these patients to bone mass loss and, consequently, to the development of osteopenia/osteoporosis. Therefore, we proposed to analyze their plasma fatty acid profile status and its relationship with bone health. METHODS: We recruited 47 PKU patients for this cross-sectional study and divided the cohort into three age groups (6-10 years, 11-18 years, 19-42 years). We measured their plasma fatty acid profile and bone mineral density (BMD) (both at the femoral neck and the lumbar spine). Seventy-seven healthy controls also participated as reference values of plasma fatty acids. RESULTS: Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and total n-3 fatty acids were significantly diminished in PKU patients compared with healthy controls. DHA, EPA, and total n-3 fatty acids were also positively associated with bone mineral density (r = 0.83, p = 0.010; r = 0.57, p = 0.006; r = 0.73, p = 0.040, respectively). There was no association between phenylalanine (Phe), Index of Dietary Control (IDC), calcium, 25-hydroxivitamin D concentrations, daily calcium intake, and BMD. CONCLUSION: Our results suggest a possible influence of essential fatty acids over BMD in PKU patients. The lack of essential n-3 fatty acids intake in the PKU diet might affect bone mineralization. Further clinical trials are needed to confirm the effect of the n-3 essential fatty acids on bone accrual in a cohort of PKU patients.

Wireless Intelligent Sensors Management Application Protocol-WISMAP.

Although many recent studies have focused on the development of new applications for wireless sensor networks, less attention has been paid to knowledge-based sensor nodes. The objective of this work is the development in a real network of a new distributed system in which every sensor node can execute a set of applications, such as fuzzy ruled-base systems, measures, and actions. The sensor software is based on a multi-agent structure that is composed of three components: management, application control, and communication agents; a service interface, which provides applications the abstraction of sensor hardware and other components; and an application layer protocol. The results show the effectiveness of the communication protocol and that the proposed system is suitable for a wide range of applications. As real world applications, this work presents an example of a fuzzy rule-based system and a noise pollution monitoring application that obtains a fuzzy noise indicator.

A new collaborative knowledge-based approach for wireless sensor networks.

This work presents a new approach for collaboration among sensors in Wireless Sensor Networks. These networks are composed of a large number of sensor nodes with constrained resources: limited computational capability, memory, power sources, etc. Nowadays, there is a growing interest in the integration of Soft Computing technologies into Wireless Sensor Networks. However, little attention has been paid to integrating Fuzzy Rule-Based Systems into collaborative Wireless Sensor Networks. The objective of this work is to design a collaborative knowledge-based network, in which each sensor executes an adapted Fuzzy Rule-Based System, which presents significant advantages such as: experts can define interpretable knowledge with uncertainty and imprecision, collaborative knowledge can be separated from control or modeling knowledge and the collaborative approach may support neighbor sensor failures and communication errors. As a real-world application of this approach, we demonstrate a collaborative modeling system for pests, in which an alarm about the development of olive tree fly is inferred. The results show that knowledge-based sensors are suitable for a wide range of applications and that the behavior of a knowledge-based sensor may be modified by inferences and knowledge of neighbor sensors in order to obtain a more accurate and reliable output.

Persistence of essential fatty acid deficiency in cystic fibrosis despite nutritional therapy.

To study the evolution of plasma fatty acid composition of patients with cystic fibrosis (CF) in relation to nutritional status, pancreatic function, and development of CF-related liver disease (CFRLD) and diabetes mellitus, 24 CF pediatric patients with stable pulmonary disease were studied before and after an approximate period of 8 y. Nutritional status, pulmonary function, pancreatic function, and presence of CFRLD or diabetes mellitus were recorded. Results were compared with data obtained in 83 healthy children. Patients with CF have significantly lower linoleic acid (LA), docosahexaenoic acid (DHA), lignoceric acid, and LA x DHA product and higher oleic acid, mead acid, dihomo-gamma-linoleic acid, and docosapentaenoic acid (DPA). Comparison of samples taken at first and second studies revealed a significant decrease in LA levels and lignoceric acid associated with a significant increase in dihomo-gamma-linoleic acid levels. Patients with CFRLD showed significantly higher mead acid/arachidonic acid ratio and lower total omega6 polyunsaturated fatty acids content. There was no relation of plasma fatty acids composition with pancreatic function, pulmonary function, or diabetes mellitus. Follow-up of patients with CF shows that essential fatty acids deficiency, particularly in LA and DHA content, persisted unmodified along time despite an adequate nutritional therapy. Future studies after supplementation with omega3 polyunsaturated fatty acids should be undertaken.

Determination of creatine and guanidinoacetate by GC-MS: study of their stability in urine at different temperatures.

OBJECTIVES: Evaluation of a GC-MS method using N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA) as the silylating agent for GC-MS. Study of the stability of creatine and guanidinoacetate in urine. DESIGN AND METHODS: 22 urines were kept at RT, 4 degrees C and -30 degrees C for 15 days. RESULTS: MTBSTFA produces a single chromatographic peak in contrast with other derivatizing agents. Creatine concentration increases at room temperature (326% on average), and at 4 degrees C (75%). However, detection decreases after freezing (-37%). Guanidinoacetate is stable, but decreases after freezing (-37%). Sonication before analysis is crucial to obtain repetitive results. CONCLUSIONS: A modified GC-MS method has been validated and the conditions for preservation of the urine have been established.

Fatty acid deficiency profile in children with food allergy managed with elimination diets.

AIM: To evaluate plasma fatty acid (FA) composition of children with food allergy undergoing elimination diets that avoided the offending antigens. METHODS: Twenty-five children (14 male, 11 female) aged 3.8 +/- 1.6 years (range 2-7 years) affected of multiple food allergy and managed with elimination diets participated in a cross-sectional study. Results of plasma fatty acids were compared with data obtained in 61 healthy children. RESULTS: The patients had significantly lower values for plasma content in total polyunsaturated fatty acids, omega3 polyunsaturated fatty acids and long-chain omega3 polyunsaturated fatty acids (p < 0.001) and particularly, in eicosapentaenoic acid (EPA) (20:5omega3) and docosahexaenoic acid (DHA) (22:6omega3) (p < 0.001). Moreover, all established indices (essential fatty acid [EFA] index ((omega3 +omega6)/(omega7 +omega9)) (p < 0.001) and sufficiency of docosahexaenoic acid index (C22:6omega3/C22:5omega6) (p < 0.001)) confirmed the presence of EFA deficiency. CONCLUSION: Children with food allergy managed with restricted intake of foods such as milk, egg, fish and vegetables are at risk of developing a deficiency in EFA and particularly in omega3 long-chain polyunsaturated fatty acids, which are especially necessary for adequate growth, neurological development and cardiovascular health.

The arginine-creatine pathway is disturbed in children and adolescents with renal transplants.

Cardiovascular disease is an important cause of morbidity in recipients of renal transplants. The aim of the present study was to analyze the status of the arginine-creatine pathway in such patients, given the relationship between the arginine metabolism and both renal function and the methionine-homocysteine cycle. Twenty-nine children and adolescents (median age 13, range 6-18 years), who had received a renal allograft 14.5-82.0 months before, were recruited for the study. On immunosuppressive therapy, all patients evidenced an adequate level of renal function. Plasma concentrations of homocysteine and glycine were significantly higher, whereas urinary excretions of guanidinoacetate and creatine were significantly lower than controls. Urinary excretions of guanidinoacetate and creatine correlated positively with creatinine clearance. Urinary excretion of creatine was negatively correlated with plasma concentration of homocysteine. The demonstration of disturbances in the arginine-creatine pathway in patients with well-functioning renal transplants and in absence of chronic renal failure represents a novel finding. We speculate that the low urinary excretion of guanidinoacetate and creatine is probably related to the nephrotoxic effect of immunosuppressive therapy and to defective methylation associated with the presence of hyperhomocysteinemia.

Stability of urinary glycosaminoglycans in patients with mucopolysaccharidoses.

OBJECTIVE: The aim of this work is to investigate the degradation of urinary glycosaminoglycans (GAGs) at different storage temperatures, in order to identify whether frozen transportation to reference laboratories is necessary. An improved method for the determination of total GAGs with 1,9-dimethylmethylene blue (DMB) is presented. DESIGN AND METHODS: Urine samples of 37 patients suffering from mucopolysaccharidoses (MPS) were analyzed in this study (13 Hunter, 6 Maroteaux-Lamy, 6 Morquio, 6 Sanfilippo, 5 Hurler-Scheie, and 1 Sly). Stability was assayed at room temperature, 5 degrees C and -30 degrees C, and analyses were repeated for at least 15 days. Spectrophotometric quantitation of GAGs with DMB was used for all determinations, using a variable wavelength for quantitation. RESULTS: The concentration of urinary GAGs was stable for 10 days at room temperature, but it was found to be stable for more than 15 days at 5 degrees C and -30 degrees C. CONCLUSIONS: The stability of GAGs allows urine samples to be sent for quantitation at a clinical laboratory without the need to freeze samples, as this would not affect results. This issue is important for the rapid detection of MPS at hospitals or primary health care centres, where GAGs determination is not performed.

[Prevention of sepsis in asplenic patients]. / Prevención de la sepsis en pacientes esplenectomizados.

Although the high mortality rate from infectious causes in asplenic patients has been well known since the beginning of the twentieth century, rates of antibiotic prophylaxis in these patients continue to be worryingly low. Consequently, we reviewed the causes of these high mortality rates with a view to recommending preventive measures. The attitude to prophylaxis in these patients depends on age and the cause of splenectomy both in vaccination and antibiotic prophylaxis. The immune status of these patients is decisive in antibiotic prophylaxis, as this treatment will differ in patients splenectomized after a traffic accident and in those splenectomized for lymphoma.

Prevención de la sepsis en pacientes esplenectomizados / Prevention of sepsis in asplenic patients

A pesar de que desde principios del siglo xx se conoce la alta mortalidad por infección entre los pacientes esplenectomizados, aún hoy las tasas de profilaxis antibacteriana en estos pacientes siguen siendo preocupantemente bajas. Por ello se planteó una búsqueda sobre la situación actual de la cuestión para elaborar unas recomendaciones aplicables a los pacientes esplenectomizados. Se expone la actitud profiláctica ante este tipo de pacientes dependiendo de su edad y el motivo de la esplenectomía, tanto de vacunación como de antibioterapia. El estado inmunitario del paciente es muy importante en la necesidad de profilaxis antibiótica, pues no seguirán la misma pauta un paciente sometido a esplenectomía tras un accidente de tráfico y un paciente hematológico (AU)

Although the high mortality rate from infectious causes in asplenic patients has been well known since the beginning of the twentieth century, rates of antibiotic prophylaxis in these patients continue to be worryingly low. Consequently, we reviewed the causes of these high mortality rates with a view to recommending preventive measures. The attitude to prophylaxis in these patients depends on age and the cause of splenectomy both in vaccination and antibiotic prophylaxis. The immune status of these patients is decisive in antibiotic prophylaxis, as this treatment will differ in patients splenectomized after a traffic accident and in those splenectomized for lymphoma (AU)

Essential fatty acid deficiency profile in patients with nephrotic-range proteinuria.

Plasma free fatty acids are bound to albumin, filtered through the glomeruli, and reabsorbed at the proximal nephron. The aim of the present investigation was to determine if urinary loss of fatty acids results in essential fatty acid (EFA) deficiency in patients with nephrotic-range proteinuria. We studied 12 patients aged 9 months to 23 years (eight male, four female) four suffering from congenital nephrotic syndrome (NS) and eight from different renal diseases. Six patients were studied postrenal transplantation. Proteinuria ranged between 41 and 829 mg/m2/h. Results were compared with data obtained in 83 healthy children. The patients had significantly lower values for plasma arachidonic acid content and EFA index (omega3 + omega6/omega7 + omega9). Deficiency in polyunsaturated fatty acids (PUFA) was especially manifest in infants with congenital NS. Plasma content of arachidonic and docosahexaenoic acids related negatively with the degree of proteinuria. In the lineal regression model, the degree of proteinuria explained 60% of the variability of plasma values of those fatty acids. We conclude that plasma fatty acid status should be regularly monitored in patients with nephrotic-range proteinuria, especially in young infants with congenital NS, who represent a population at special risk with regard to neurological development.