Generalized anxiety disorder screening scores are associated with greater treatment need among Veterans with depression.

Comorbid anxiety and depression predict a poorer prognosis than either disorder occurring alone. It is unclear whether self-reported anxiety symptom scores identify patients with depression in need of more intensive mental health services. This study evaluated how anxiety symptoms predicted treatment receipt and outcomes among patients with new depression diagnoses in the Veterans Health Administration (VHA). Electronic medical record data from 128,917 VHA patients (71.6% assessed for anxiety, n = 92,237) with new diagnoses of depression were analyzed to examine how Generalized Anxiety Disorder-7 (GAD-7) scores predicted psychotropic medication prescriptions, psychotherapy receipt, acute care service utilization, and follow-up depression symptoms. Patients who reported severe symptoms of anxiety were significantly more likely to receive adequate acute phase and continuation phase antidepressant treatment, daytime anxiolytics/sedatives, nighttime sedative/hypnotics, and endorse more severe depression symptoms and suicidal ideation at follow-up. Patients who reported severe symptoms of anxiety at baseline were less likely to initiate psychotherapy. The GAD-7 may help identify depressed patients who have more severe disease burden and require additional mental health services.

Does cattle and sheep grazing under best management significantly elevate sediment losses? Evidence from the North Wyke Farm Platform, UK.

PURPOSE: Intensive livestock grazing has been associated with an increased risk of soil erosion and concomitant negative impacts on the ecological status of watercourses. Whilst various mitigation options are promoted for reducing livestock impacts, there is a paucity of data on the relationship between stocking rates and quantified sediment losses. This evidence gap means there is uncertainty regarding the cost-benefit of policy preferred best management. METHODS: Sediment yields from 15 hydrologically isolated field scale catchments on a heavily instrumented ruminant livestock farm in the south west UK were investigated over ~ 26 months spread across 6 years. Sediment yields were compared to cattle and sheep stocking rates on long-term, winter (November-April), and monthly timescales. The impacts of livestock on soil vegetation cover and bulk density were also examined. Cattle were tracked using GPS collars to determine how grazing related to soil damage. RESULTS: No observable impact of livestock stocking rates of 0.15-1.00 UK livestock units (LU) ha-1 for sheep, and 0-0.77 LU ha-1 for cattle on sediment yields was observed at any of the three timescales. Cattle preferentially spent time close to specific fences where soils were visually damaged. However, there was no indication that livestock have a significant effect on soil bulk density on a field scale. Livestock were housed indoors during winters when most rainfall occurs, and best management practices were used which when combined with low erodibility clayey soils likely limited sediment losses. CONCLUSION: A combination of clayey soils and soil trampling in only a small proportion of the field areas lead to little impact from grazing livestock. Within similar landscapes with best practice livestock grazing management, additional targeted measures to reduce erosion are unlikely to yield a significant cost-benefit. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11368-021-02909-y.

Development and calibration of a new mathematical model for the description of an ion-exchange process for ammonia removal in the presence of competing ions.

Ammonia ion removal and recovery via an ion-exchange process using zeolites is a promising alternative to traditional biological treatments. The analysis of its efficiency is not straightforward as it depends on various factors, such as the cation exchange capacity of the zeolite, amount of zeolite available, initial ammonia concentration, contact time, ammonia speciation depending on pH or the presence of competing ions. Mathematical modelling and simulation tools are very useful to analyse the effect of different operational conditions on the efficiency and optimal operation of the process. This paper experimentally analyses the effect that the presence of competing ions has on the efficiency of ammonia removal. This experimental work has shown a reduction of around 21% of ammonia removal efficiency in the presence of competing ions. The main contribution of this paper is the development new mathematical model able to describe the ion-exchange process in the presence of competing ions. The mathematical model developed is able to analyse the performance of the IEX process under different empty bed contact times, influent loads, pH and concentrations of competing ions. The capability of the model to reproduce real data has been proven comparing the experimental and simulation results. Finally, an exploration by simulation has been undertaken to show the potential of the mathematical model developed.

Inclusion of shear rate effects in the kinetics of a discretized population balance model: Application to struvite precipitation.

The effect of mixing in the modelling of processes based on mass transfer phenomena is commonly ignored in wastewater treatment industry. In this contribution, the effect of the average shear rate in the nucleation and growth rates of struvite is analyzed by combining experimental data with simulation results obtained with a previously presented mass-based discretized population balance model. According to the obtained results, the effect of the average shear rate is identifiable for the selected data and mechanisms. Therefore, it should be considered when a detailed modelling of the process is needed. Consequently, in this contribution, the average shear rate has been decoupled from the kinetic constants. In addition, kinetic rates where it is explicitly included as a power law function have been proposed. The exponents in these power law functions for the primary homogeneous nucleation and growth are 1.3 and 0.3, respectively. Considering shear rate effects allowed to see in the simulation outputs experimentally observed effects: a faster pH decay and smaller particle distribution for increasing mixing intensities.

A New Mass-Based Discretized Population Balance Model for Precipitation Processes: Application to Struvite Precipitation.

Mathematical models describing precipitation processes in one step need to be upgraded. Particle size distribution is a crucial variable and its inclusion in the modelling libraries is necessary if the technology wants to be optimized through simulation. With this objective, a mass based population balance model is presented in this contribution. The model has been constructed using a stoichiometric matrix and a kinetic vector and using mass as the internal coordinate, as it is usually done in wastewater treatment modelling. Identifiability of the parameters of the model was evaluated using a sensitivity and a collinearity analysis for six simulation case studies of struvite precipitation. In addition, parameters in the model were calibrated to represent data from two batch tests in the laboratory. The results of the analysis showed that the identifiability of the parameters depends on the available experimental data and explored scenarios. Identifiability of the parameters could be the reason behind the shifting parameter values describing mechanisms of precipitation in the literature. This contribution helps to understand the possibilities and limitations that the population balance model approach offer.

Model-based opti mization of phosphorus management strategies in Sur WWTP, Madrid.

Phosphorus has been considered as a pollutant to be removed from the wastewater. In the last years, however, it has been considered a valuable asset that needs to be recovered due to its shortage in nature. The study of optimum phosphorus management in wastewater treatment plants is not straightforward, due to the complexity of technologies and configurations that may be applied for phosphorus removal and recovery. In this context, plant-wide mathematical modelling and simulation tools are very useful for carrying out these studies. This paper introduces a study carried out at the Sur WWTP (Madrid) to assess optimum phosphorus management strategies based on the PWM. The mathematical model made it possible to describe the phosphorus flux and its characterization throughout the plant. Finally, an exploration by simulation with WEST™ was carried out to analyse different plant configurations and different operational strategies to optimize phosphorus management strategies in the Sur WWTP.

Validation of a multi-phase plant-wide model for the description of the aeration process in a WWTP.

This paper introduces a new mathematical model built under the PC-PWM methodology to describe the aeration process in a full-scale WWTP. This methodology enables a systematic and rigorous incorporation of chemical and physico-chemical transformations into biochemical process models, particularly for the description of liquid-gas transfer to describe the aeration process. The mathematical model constructed is able to reproduce biological COD and nitrogen removal, liquid-gas transfer and chemical reactions. The capability of the model to describe the liquid-gas mass transfer has been tested by comparing simulated and experimental results in a full-scale WWTP. Finally, an exploration by simulation has been undertaken to show the potential of the mathematical model.

Quantitative assessment of energy and resource recovery in wastewater treatment plants based on plant-wide simulations.

The growing development of technologies and processes for resource treatment and recovery is offering endless possibilities for creating new plant-wide configurations or modifying existing ones. However, the configurations' complexity, the interrelation between technologies and the influent characteristics turn decision-making into a complex or unobvious process. In this frame, the Plant-Wide Modelling (PWM) library presented in this paper allows a thorough, comprehensive and refined analysis of different plant configurations that are basic aspects in decision-making from an energy and resource recovery perspective. In order to demonstrate the potential of the library and the need to run simulation analyses, this paper carries out a comparative analysis of WWTPs, from a techno-economic point of view. The selected layouts were (1) a conventional WWTP based on a modified version of the Benchmark Simulation Model No. 2, (2) an upgraded or retrofitted WWTP, and (3) a new Wastewater Resource Recovery Facilities (WRRF) concept denominated as C/N/P decoupling WWTP. The study was based on a preliminary analysis of the organic matter and nutrient energy use and recovery options, a comprehensive mass and energy flux distribution analysis in each configuration in order to compare and identify areas for improvement, and a cost analysis of each plant for different influent COD/TN/TP ratios. Analysing the plants from a standpoint of resources and energy utilization, a low utilization of the energy content of the components could be observed in all configurations. In the conventional plant, the COD used to produce biogas was around 29%, the upgraded plant was around 36%, and 34% in the C/N/P decoupling WWTP. With regard to the self-sufficiency of plants, achieving self-sufficiency was not possible in the conventional plant, in the upgraded plant it depended on the influent C/N ratio, and in the C/N/P decoupling WWTP layout self-sufficiency was feasible for almost all influents, especially at high COD concentrations. The plant layouts proposed in this paper are just a sample of the possibilities offered by current technologies. Even so, the library presented here is generic and can be used to construct any other plant layout, provided that a model is available.

Diagnosis and optimization of WWTPs using the PWM library: full-scale experiences.

Given the shift in perception of wastewater treatment plants as water resource recovery facilities, conventional mathematical models need to be updated. The resource recovery perspective should be applied to new processes, technologies and plant layouts. The number and level of models proposed to date give an overview of the complexity of the new plant configurations and provides a wide range of possibilities and process combinations in order to construct plant layouts. This diversity makes the development of standard, modular and flexible tools and model libraries that allow the incorporation of new processes and components in a straightforward way a necessity. In this regard, the plant-wide modelling (PWM) library is a complete model library that includes conventional and advanced technologies and that allows economic and energetic analyses to be carried out in a holistic way. This paper shows the fundamentals of this PWM library that is built upon the above-mentioned premises and the application of the PWM library in three different full-scale case studies.

A new general methodology for incorporating physico-chemical transformations into multi-phase wastewater treatment process models.

This paper introduces a new general methodology for incorporating physico-chemical and chemical transformations into multi-phase wastewater treatment process models in a systematic and rigorous way under a Plant-Wide modelling (PWM) framework. The methodology presented in this paper requires the selection of the relevant biochemical, chemical and physico-chemical transformations taking place and the definition of the mass transport for the co-existing phases. As an example a mathematical model has been constructed to describe a system for biological COD, nitrogen and phosphorus removal, liquid-gas transfer, precipitation processes, and chemical reactions. The capability of the model has been tested by comparing simulated and experimental results for a nutrient removal system with sludge digestion. Finally, a scenario analysis has been undertaken to show the potential of the obtained mathematical model to study phosphorus recovery.

New systematic methodology for incorporating dynamic heat transfer modelling in multi-phase biochemical reactors.

This paper presents a new modelling methodology for dynamically predicting the heat produced or consumed in the transformations of any biological reactor using Hess's law. Starting from a complete description of model components stoichiometry and formation enthalpies, the proposed modelling methodology has integrated successfully the simultaneous calculation of both the conventional mass balances and the enthalpy change of reaction in an expandable multi-phase matrix structure, which facilitates a detailed prediction of the main heat fluxes in the biochemical reactors. The methodology has been implemented in a plant-wide modelling methodology in order to facilitate the dynamic description of mass and heat throughout the plant. After validation with literature data, as illustrative examples of the capability of the methodology, two case studies have been described. In the first one, a predenitrification-nitrification dynamic process has been analysed, with the aim of demonstrating the easy integration of the methodology in any system. In the second case study, the simulation of a thermal model for an ATAD has shown the potential of the proposed methodology for analysing the effect of ventilation and influent characterization.

Validating the colloid model to optimise the design and operation of both moving-bed biofilm reactor and integrated fixed-film activated sludge systems.

The paper presents a systematic study of simulations, using a previously calibrated Colloid model, from which it was found that: (i) for pure moving-bed biofilm reactor (MBBR) processes with tertiary nitrification conditions (no influent chemical oxygen demand (COD)), dissolved oxygen = 5 mg/L and residual NH4-N > 4 mgN/L, a nitrification rate of 1.2 gN/(m(2)d) was obtained at 10 °C. This rate decreases sharply when residual NH4-N is lower than 2 mgN/L, (ii) for MBBR systems with predenitrification-nitrification zones and COD in the influent (soluble and particulate), the nitrification rate (0.6 gN/(m(2)d)) is half of that in tertiary nitrification due to the effect of influent colloidal XS (particulate slowly biodegradable COD) and (iii) for integrated fixed-film activated sludge (IFAS) processes the nitrification rate in the biofilm (0.72 gN/(m(2)d)) is 20% higher than for the pure MBBR due to the lower effect of influent XS since it is adsorbed onto flocs. However, it is still 40% lower than the tertiary nitrification rate. In the IFAS, the fraction of the nitrification rate in suspension ranges from 10 to 70% when the aerobic solids retention time varies from 1.4 to 6 days.

Add Control: plant virtualization for control solutions in WWTP.

This paper summarizes part of the research work carried out in the Add Control project, which proposes an extension of the wastewater treatment plant (WWTP) models and modelling architectures used in traditional WWTP simulation tools, addressing, in addition to the classical mass transformations (transport, physico-chemical phenomena, biological reactions), all the instrumentation, actuation and automation & control components (sensors, actuators, controllers), considering their real behaviour (signal delays, noise, failures and power consumption of actuators). Its ultimate objective is to allow a rapid transition from the simulation of the control strategy to its implementation at full-scale plants. Thus, this paper presents the application of the Add Control simulation platform for the design and implementation of new control strategies at the WWTP of Mekolalde.

Water network cost optimization in a paper mill based on a new library of mathematical models.

The increasing costs associated with water supply and the disposal of wastewater has stimulated industries to seek more efficient water management systems. Mathematical modelling and simulation can be a very valuable tool for the study of the multiple alternatives available whilst assessing optimum solutions for water management in industry. This study introduces a new steady state model library able to reproduce industrial water circuits. It has been implemented in a novel software framework for the representation, simulation and optimization of industrial water networks. A water circuit representing a paper mill has been modelled and simulated showing the capability to reproduce real case studies. Alternative scenarios for the water network have also been tested to assess the capability of the models to optimize water circuits minimizing total cost.

Automatic characterisation of primary, secondary and mixed sludge inflow in terms of the mathematical generalised sludge digester model.

This paper presents the characterisation procedure of different types of sludge generated in a wastewater treatment plant to be reproduced in a mathematical model of the sludge digestion process. The automatic calibration method used is based on an optimisation problem and uses a set of mathematical equations related to the a priori knowledge of the sludge composition, the experimental measurements applied to the real sludge, and the definition of the model components. In this work, the potential of the characterisation methodology is shown by means of a real example, taking into account that sludge is a very complex matter to characterise and that the models for digestion also have a considerable number of model components. The results obtained suit both the previously reported characteristics of the primary, secondary and mixed sludge, and the experimental measurements specially done for this work. These three types of sludge have been successfully characterised to be used in complex mathematical models.

Chronic hepatitis C treatment in a cystic fibrosis patient in the pulmonary pre-transplant stage.

The standard treatment of chronic hepatitis C, pegylated interferon and ribavirin (pegI/R), has many limitations in both effectiveness and secondary effects, which makes it unsuitable or even contraindicated for some patients. In hepatitis C virus-infected cystic fibrosis patients this treatment could increase respiratory infections with subsequent pulmonary function deterioration. On the contrary, hepatitis C virus (HCV) infection may make lung transplant (LT) unfeasible. We present the case of a cystic fibrosis-young man diagnosed with HCV infection during LT assessment who was treated with pegI/R. In spite of the lung function worsening and respiratory infections, he managed to complete treatment and even sustained virological response (SVR). At present he is on LT waiting list.

Tratamiento de hepatitis crónica C en un paciente con fibrosis quística en situación de pretrasplante pulmonar / Chronic hepatitis C treatment in a cystic fibrosis patient in the pulmonary pre-transplant stage

El tratamiento estándar de la hepatitis crónica C, interferón pegilado (INF-peg) y ribavirina (RBV), puede ser inadecuado o incluso estar contraindicado en algunos pacientes debido a sus limitaciones en cuanto a eficacia y efectos adversos. En pacientes con fibrosis quística infectados por el virus de la hepatitis C (VHC) el tratamiento antiviral podría aumentar las infecciones respiratorias con el consiguiente empeoramiento de la función pulmonar. Por contra, la infección por VHC podría desestimar a estos pacientes para un necesario trasplante pulmonar. Presentamos el caso de un varón con fibrosis quística diagnosticado de infección VHC durante su evaluación previa al trasplante pulmonar. El paciente fue tratado con INF-peg y RBV. A pesar del empeoramiento en la función pulmonar y numerosas infecciones respiratorias intercurrentes, logró completar el tratamiento y obtener respuesta viral sostenida, encontrándose actualmente en lista de espera(AU)

The standard treatment of chronic hepatitis C, pegylated interferon and ribavirin (pegI/R), has many limitations in both effectiveness and secondary effects, which makes it unsuitable or even contraindicated for some patients. In hepatitis C virus-infected cystic fibrosis patients this treatment could increase respiratory infections with subsequent pulmonary function deterioration. On the contrary, hepatitis C virus (HCV) infection may make lung transplant (LT) unfeasible. We present the case of a cystic fibrosisyoung man diagnosed with HCV infection during LT assessment who was treated with pegI/R. In spite of the lung function worsening and respiratory infections, he managed to complete treatment and even sustained virological response (SVR). At present he is on LT waiting list(AU)

New generic mathematical model for WWTP sludge digesters operating under aerobic and anaerobic conditions: Model building and experimental verification.

This paper presents a new mathematical model developed to reproduce the performance of a generic sludge digester working either under aerobic or anaerobic operational conditions. The digester has been modelled as two completely mixed tanks associated with gaseous and liquid volumes. The conversion model has been developed based on a plant wide modelling methodology (PWM) and comprises biochemical transformations, physicochemical reactions and thermodynamic considerations. The model predicts the reactor temperature and the temporary evolution of an extensive vector of model components which are completely defined in terms of elemental mass fractions (C, H, O, N and P) and charge density. Thus, the comprehensive definition of the model components guarantees the continuity of elemental mass and charge in all the model transformations and between any two systems defined by the model. The aim of the generic digester model is to overcome the problems that arise when trying to connect aerobic and anaerobic digestion processes working in series or to connect water and sludge lines in a WWTP. The modelling methodology used has allowed the systematic construction of the biochemical model which acts as an initial illustrative example of an application that has been experimentally verified. The variation of the temperature is also predicted based on a thermal dynamic model. Real data from four different facilities and a straightforward calibration have been used to successfully verify the model predictions in the cases of mesophilic and thermophilic anaerobic digestion as well as autothermal thermophilic aerobic digestion (ATAD). The large amount of data from the full scale ATAD and the anaerobic digestion pilot plants, all of them working under different conditions, has allowed the validation of the model for that case study.

Fotodepilación / Photodepilaton

Los pelos indeseados son un problema frecuente para el cual se han desarrollado diferentes tipos de luz como tratamiento de elección. Desde que en 1996 la Food and Drug Administration (FDA) aprobó el primer láser para depilar, se han hechomuchos avances en la tecnología basada en la luz y los láseres. Los láseres y las fuentes de luz intensa pulsada (IPL) con longitudes de onda en el espectro del rojo o casi el infrarrojo (de 600 a 1.200 nm) son los más utilizados para eliminar el pelo, ya que tienen como diana la melanina de la vaina del pelo, la del epitelio del folículo piloso y la de la matriz. El propósito de esta revisión es describir y comparar los diferentes métodos de fotodepilación disponibles actualmente (AU)

Unwanted hair is a common problem for which different types of light therapy have been developed as the treatment of choice. Since 1996, when the American Food and Drug Administration approved the first laser therapy for depilation, much progress has been made in light-based technology and lasers. Lasers and intense pulsed light sources with red or near infrared wavelengths (600 to 1200 nm) are the most widely used for removing hair as they target the melanin of the hair shaft, hair follicle epithelium, and hair matrix. The aim of this review is to describe and compare the different photodepilation methods currently available (AU)