The effect of sodium valproate in Cushing's disease, Nelson's syndrome and Addison's disease

We investigated the effect of sodium valproate on plasma ACTH and serum cortisol concentrations in different pathological states of ACTH hypersecretion. Five patients with pituitary dependent Cushing's syndrome, two patients with Nelson's syndrome and five patients with Addison's disease were studied. Neither a single dose nor long term administration of sodium valproate resulted in a significant decrease of plasma ACTH levels in patients with Cushing's disease and Nelson's syndrome. Furthermore, the response of ACTH and cortisol to stimulation with lysine-vasopressin was unaffected during acute and chronic treatment. Patients with Addison's disease showed a slight attenuation of the ACTH response to lysine-vasopressin as compared to placebo but the difference was not statistically significant. In conclusion: sodium valproate does not appear to be effective in controlling ACTH hypersecretion in pituitary dependent Cushing's syndrome

Nonhypnotic low-dose etomidate for rapid correction of hypercortisolaemia in cushing's syndrome

We determined the adrenostatic potential of low-dose nonhypnotic etomidate in six patients with Cushing's syndrome (ectopic Cushing's syndrome,n=2; Cushing's disease,n=3; bilateral adrenal adenoma,n=1). Etomidate was given as a continuous infusion for 32 h in a dose of 2.5 mg/h (n=5) or 0.3 mg/kg/h (n=3), respectively. Saline was given during a control period. The responsiveness to exogenous ACTH was studied during placebo and 7 and 31 h after commencing etomidate by administration of 250 µg 1–24 ACTH i.v. Etomidate (2.5 mg/h) led to a consistent decrease in serum cortisol in all patients from a mean of 39.4±13.3 to 21.1±5.7 µg/dl after 7 h (P<0.05 compared with placebo). After 24 h cortisol was reduced further to a mean steady state concentration of 12.3±5.7 µg/dl (P<0.05). At the end of the infusion period the cortisol increase in response to ACTH was reduced but not abolished. In contrast, a dose of 0.3 mg/kg/h etomidate induced unresponsiveness of serum cortisol to exogenous ACTH within 7 h. However, sedation was observed in two out of three patients at this dose, while during etomidate in a dose of 2.5 mg/h no side effects were seen. We conclude that low-dose non-hypnotic etomidate reduces serum cortisol to within the normal range in patients with Cushing's syndrome. The possibility to dissociate the adrenostatic effect of etomidate from its hypnotic action, the absence of side effects, and the i.v. route suggest that etomidate in a dose of 0.04–0.05 mg/kg/h may become the drug of choice for rapid initial control of hypercortisolism

Endoparasite community of Rattus norvegicus captured in a shantytown of Buenos Aires City, Argentina

Summary: The aim of this study was to evaluate the role of the brown rat (Rattus norvegicus) as a potential reservoir of zoonotic parasites in an urban area of Argentina. A parasitological survey in 40 brown rats trapped in a shantytown of Buenos Aires City was carried out. 97. 5 % of the analyzed rats were parasitized with at least one of the 12 species of helminth or protozoan species recorded. Among the species identified, Hymenolepis nana is recognized as one of the most common human helminthes parasites. The average number of parasite species was higher in males than females rats, and in the last case, a direct relationship between parasite species richness and host's body size was recorded. Variations in endoparasite community throughout the year seasons were recorded, probably related to environmental factors, which limits the performance of the life cycle of different parasite species. The presence of zoonotic endoparasites confirms R. norvegicus as a reservoir for different types of pathologies, which, therefore, represents a risk to the public health in an overcrowded urban area.Centro de Estudios Parasitológicos y de Vectore

Endoparasite community of Rattus norvegicus captured in a shantytown of Buenos Aires City, Argentina

Summary: The aim of this study was to evaluate the role of the brown rat (Rattus norvegicus) as a potential reservoir of zoonotic parasites in an urban area of Argentina. A parasitological survey in 40 brown rats trapped in a shantytown of Buenos Aires City was carried out. 97. 5 % of the analyzed rats were parasitized with at least one of the 12 species of helminth or protozoan species recorded. Among the species identified, Hymenolepis nana is recognized as one of the most common human helminthes parasites. The average number of parasite species was higher in males than females rats, and in the last case, a direct relationship between parasite species richness and host's body size was recorded. Variations in endoparasite community throughout the year seasons were recorded, probably related to environmental factors, which limits the performance of the life cycle of different parasite species. The presence of zoonotic endoparasites confirms R. norvegicus as a reservoir for different types of pathologies, which, therefore, represents a risk to the public health in an overcrowded urban area.Centro de Estudios Parasitológicos y de Vectore

Aquatic Eddy Correlation: Quantifying the Artificial Flux Caused by Stirring-Sensitive O2 Sensors

In the last decade, the aquatic eddy correlation (EC) technique has proven to be a powerful approach for non-invasive measurements of oxygen fluxes across the sediment water interface. Fundamental to the EC approach is the correlation of turbulent velocity and oxygen concentration fluctuations measured with high frequencies in the same sampling volume. Oxygen concentrations are commonly measured with fast responding electrochemical microsensors. However, due to their own oxygen consumption, electrochemical microsensors are sensitive to changes of the diffusive boundary layer surrounding the probe and thus to changes in the ambient flow velocity. The so-called stirring sensitivity of microsensors constitutes an inherent correlation of flow velocity and oxygen sensing and thus an artificial flux which can confound the benthic flux determination. To assess the artificial flux we measured the correlation between the turbulent flow velocity and the signal of oxygen microsensors in a sealed annular flume without any oxygen sinks and sources. Experiments revealed significant correlations, even for sensors designed to have low stirring sensitivities of ~0.7%. The artificial fluxes depended on ambient flow conditions and, counter intuitively, increased at higher velocities because of the nonlinear contribution of turbulent velocity fluctuations. The measured artificial fluxes ranged from 2-70 mmol m(-2) d(-1) for weak and very strong turbulent flow, respectively. Further, the stirring sensitivity depended on the sensor orientation towards the flow. For a sensor orientation typically used in field studies, the artificial flux could be predicted using a simplified mathematical model. Optical microsensors (optodes) that should not exhibit a stirring sensitivity were tested in parallel and did not show any significant correlation between O2 signals and turbulent flow. In conclusion, EC data obtained with electrochemical sensors can be affected by artificial flux and we recommend using optical microsensors in future EC-studies

Energy-aware hybrid MAC protocol for IoT enabled WBAN systems

Energy efficiency is an important quality-of-service requirement that needs to be considered when designing an efficient MAC protocol for a WBAN system due to the limited power resources of biomedical sensor devices. To address this, an energy-aware multi-group hybrid MAC (MG-HYMAC) protocol is proposed in this work to improve energy efficiency as well as the lifetime of the biomedical sensor devices in a personalized healthcare system. The proposed protocol combines both the advantages of the CSMA/CA and the TDMA schemes to enable the biomedical sensors to efficiently contend for transmission opportunities and to allow them to efficiently transmit health data. The MG-HYMAC protocol is combined with a transmission scheduling technique to duty cycle the operations of the biomedical devices with less critical data to determine when and how the biomedical sensor devices will transmit their health data packets in order to reduce collisions to save energy and prolong the battery lifetime of the biomedical sensor devices so as to improve the overall network lifetime. Also, a stochastic probability model and a heuristic-based power control scheme are developed to solve time allocation and power control problems to improve energy efficiency and the biomedical sensor devices lifetime. To validate the MG-HYMAC protocol, it was compared with other related protocols (including HyMAC and CPMAC) and simulated in MATLAB. The simulation results proved that the proposed MG-HYMAC protocol outperformed the existing MAC protocols using standard metrics like energy efficiency, biomedical sensor devices lifetime, and convergence speed.https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=7361hj2023Electrical, Electronic and Computer Engineerin

Two-Step Wind Power Prediction Approach With Improved Complementary Ensemble Empirical Mode Decomposition and Reinforcement Learning

The strong stochastic nature of wind power generation makes it extremely challenging to accurately predict and support the planning and operation of modern power systems with significant penetration of renewable energy. This article proposes a two-step wind power prediction method, which consists of two phases: long time-scale coarse prediction and short time-scale fine correction. In the long time-scale phase, a complementary ensemble empirical mode decomposition-based sigma point Kalman filter approach is proposed to coarsely predict wind power merely with historical data. In the short time-scale phase, a deep deterministic policy gradient approach learns from real-time weather information to correct the coarse prediction result, which results in an improved prediction accuracy. A real-life case study confirms that the proposed method can properly predict wind power generation and have a better prediction accuracy than existing techniques, thus offering a viable and promising alternative for predicting wind power generation

A hybrid multi-class MAC protocol for IoT-enabled WBAN systems

This study proposes a hybrid MAC protocol that can efficiently and effectively optimize the communication channel access of a WBAN multi-class system. The proposed protocol consists of two major processes that include the contention phase (CP) and the transmission phase (TP). In the CP, only the biomedical devices that have health packets to transmit randomly contend with equal probabilities using a slotted ALOHA scheme for transmission opportunities and the successful biomedical devices are allocated a transmission time-slot by employing a reservation-based time division multiple access (TDMA) scheme in the transmission phase. A multi-objective optimization problem was formulated to maximize the system sum-throughput, packet success-access-ratio, as well as the reservation ratio, and solved by the controller (i.e., access point) to determine the optimal length of the CP and the number of biomedical devices that can transmit in the TP. Monte Carlo simulation was performed and the optimization solution improved the proposed protocol's performances. For validation purposes, the simulated results in MATLAB revealed that the proposed protocol performs better than the contemporary system in the context of the system sum-throughput, reservation ratio, and the average health packet delay with performance gains of about 9.2%, 9.5%, and 9.6% respectively.This work was supported in part by the Council for Scientific and Industrial Research, Pretoria, South Africa, through the Smart Networks collaboration initiative and IoT-Factory Program (funded by the Department of Science and Innovation).https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=7361hj2021Electrical, Electronic and Computer Engineerin

An assessment of the precision and confidence of aquatic eddy correlation measurements

The quantification of benthic fluxes with the aquatic eddy correlation (EC) technique is based on simultaneous measurement of the current velocity and a targeted bottom water parameter (e. g., O-2, temperature). High-frequency measurements (64Hz) are performed at a single point above the seafloor using an acoustic Doppler velocimeter (ADV) and a fast-responding sensor. The advantages of aquatic EC technique are that 1) it is noninvasive, 2) it integrates fluxes over a large area, and 3) it accounts for in situ hydrodynamics. The aquatic EC has gained acceptance as a powerful technique; however, an accurate assessment of the errors introduced by the spatial alignment of velocity and water constituent measurements and by their different response times is still needed. Here, this paper discusses uncertainties and biases in the data treatment based on oxygen EC flux measurements in a large-scale flume facility with well-constrained hydrodynamics. These observations are used to review data processing procedures and to recommend improved deployment methods, thus improving the precision, reliability, and confidence of EC measurements. Specifically, this study demonstrates that 1) the alignment of the time series based on maximum cross correlation improved the precision of EC flux estimations; 2) an oxygen sensor with a response time of <0.4 s facilitates accurate EC fluxes estimates in turbulence regimes corresponding to horizontal velocities <11 cm s(-1); and 3) the smallest possible distance (<1 cm) between the oxygen sensor and the ADV's sampling volume is important for accurate EC flux estimates, especially when the flow direction is perpendicular to the sensor's orientation