Control of mass balance error in a detailed model of surface-subsurface flow interaction

Several process-based catchment-scale hydrologic models have been developed in recent years to describe the interactions and feedbacks between different components of the water cycle, but few studies have considered the sources of coupling error in these models. In this work we analyze the sequential iterative coupling scheme of the distributed model CATHY (CATchment HYdrology) in order to identify the different sources of mass balance error and to examine how these are influenced by topography, hydraulic properties, and atmospheric forcing. A pair of adimensional indices that quantify the degree of coupling and of flux partitioning is presented. Our analysis shows that mass balance errors increase during the flood recession limb because of the exchange of information between surface and subsurface water flow. Surface water propagation is cell centered, while the subsurface flow equation is solved on the vertices of surface cells. Evaluation of surface pressure heads and exchange fluxes is critical on this staggered surface-subsurface mesh, especially during transitions from unsaturated to saturated conditions and vice versa. A modified version of the flux exchange algorithm is introduced that considers the effective availability of water on surface cells. The performance of the model is also improved by introducing a heuristic procedure to control and adapt the time step interval. Starting from numerical stability and convergence constraints, this procedure varies the computational interval as a function of the rate of change of surface saturation via the coupling degree index. A final improvement made to the sequential coupling scheme in CATHY is to solve the surface routing equation after rather than before the subsurface module. We find that the modified version improves the water balance by more than 50% in most of the tests considered for a simple v-shaped catchment. The results so far obtained for the synthetic v-catchment indicate the need for a more comprehensive analysis including real catchments

CONTROL OF COUPLING MASS BALANCE ERROR IN A PROCESS- BASED NUMERICAL MODEL OF SURFACE-SUBSURFACE FLOW INTERACTION

KEY POINTS • Sources of mass balance error in a process-based hydrological model of surface-subsurface flow interaction are investigated to improve the model’s coupling scheme • These sources of mass balance error are identified by using a set of dimensionless indices and the analysis of temporal and spatial patterns of error • A time step control based on a degree of coupling index is proposed and the interpolation algorithm used to pass exchange variables of surface-subsurface flow interaction is improve

Evaluation of soil management effect on crop productivity and vegetation indices accuracy in mediterranean cereal-based cropping systems

none3noMostly, precision agriculture applications include the acquisition and elaboration of images, and it is fundamental to understand how farmers’ practices, such as soil management, affect those images and relate to the vegetation index. We investigated how long-term conservation agriculture practices, in comparison with conventional practices, can affect the yield components and the accuracy of five vegetation indexes. The experimental site is a part of a long-term experiment established in 1994 and is still ongoing that consists of a rainfed 2-year rotation with durum wheat and maize, where two unfertilized soil managements were repeated in the same plots every year. This study shows the superiority of no tillage over conventional tillage for both nutritional and productive aspects on durum wheat. The soil management affects the vegetation indexes’ accuracy, which is related to the nitrogen nutrition status. No-tillage management, which is characterized by a higher content of soil organic matter and nitrogen availability into the soil, allows obtaining a higher accuracy than the conventional tillage. So, the users of multispectral cameras for precision agriculture applications must take into account the soil management, organic matter, and nitrogen content.openOrsini R.; Fiorentini M.; Zenobi S.Orsini, R.; Fiorentini, M.; Zenobi, S

Influence of wall thickness and diameter on arterial shear wave elastography: a phantom and finite element study

Quantitative, non-invasive and local measurements of arterial mechanical properties could be highly beneficial for early diagnosis of cardiovascular disease and follow up of treatment. Arterial shear wave elastography (SWE) and wave velocity dispersion analysis have previously been applied to measure arterial stiffness. Arterial wall thickness (h) and inner diameter (D) vary with age and pathology and may influence the shear wave propagation. Nevertheless, the effect of arterial geometry in SWE has not yet been systematically investigated. In this study the influence of geometry on the estimated mechanical properties of plates (h = 0.5–3 mm) and hollow cylinders (h = 1, 2 and 3 mm, D = 6 mm) was assessed by experiments in phantoms and by finite element method simulations. In addition, simulations in hollow cylinders with wall thickness difficult to achieve in phantoms were performed (h = 0.5–1.3 mm, D = 5–8 mm). The phase velocity curves obtained from experiments and simulations were compared in the frequency range 200–1000 Hz and showed good agreement (R2 = 0.80 ± 0.07 for plates and R2 = 0.82 ± 0.04 for hollow cylinders). Wall thickness had a larger effect than diameter on the dispersion curves, which did not have major effects above 400 Hz. An underestimation of 0.1–0.2 mm in wall thickness introduces an error 4–9 kPa in hollow cylinders with shear modulus of 21–26 kPa. Therefore, wall thickness should correctly be measured in arterial SWE applications for accurate mechanical properties estimation

Myocardial infarction in major noncardiac surgery: Epidemiology, pathophysiology and prevention

The number of subjects undergoing major noncardiac surgery who are at risk for perioperative myocardial infarction (MI) is growing worldwide. It has been estimated that 500,000 to 900,000 patients suffer major perioperative cardiovascular complications every year, with consequent heavy, long-term prognostic implications and costs. It is well known that perioperative MIs don't share the same pathophysiology as nonsurgical MIs but the relative role of the different, potential triggers has not been completely clarified. Many aspects of the perioperative management, including risk-stratification and prophylactic or postoperative interventions have also not been completely defined. Throughout recent years many resources have been invested to clarify these aspects and experts have developed indices and algorithm-based strategies to better assess the cardiac risk and to guide the perioperative management. The scope of the present review is to discuss the main aspects of perioperative MI in noncardiac surgery, with particular regard to epidemiology, pathophysiology, preoperative risk stratification, prophylaxis and therapy

Visita pré-operatória: um desafio para a melhoria dos cuidados de enfermagem

Relatório de Estágio de Mestrado em Enfermagem Perioperatória apresentado para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Enfermagem PerioperatóriaNo âmbito do 1º Mestrado em Enfermagem Perioperatória (MEPO) da Escola Superior de Saúde – Instituto Politécnico de Setúbal, sistematiza-se no presente relatório o processo desenvolvido para a aquisição das competências do Enfermeiro Mestre em Enfermagem Perioperatória. O Estágio realizado em ambiente perioperatório contemplou a realização de um projeto sobre a área que constatámos ser a mais carente de intervenção. Recorremos à Metodologia de Projeto e através do método de análise do tipo e efeito da falha (FMEA), aferimos que o problema que veio motivar o desenvolvimento desde projeto foi o comprometimento da qualidade dos cuidados de enfermagem prestados no Bloco Operatório, devido à inexistência de visita pré-operatória (VPO). A VPO é o alicerce de todo o processo de cuidados perioperatórios e a sua importância reflete-se em termos de melhoria da qualidade de vida da pessoa submetida a cirurgia e diminuição da ansiedade. Esta permite ainda conhecer a pessoa, identificar os seus problemas e elaborar o plano de cuidados de acordo com os dados colhidos. Nesse sentido foi definido o seguinte objetivo geral: contribuir para a melhoria da qualidade dos cuidados prestados no Bloco Operatório através da proposta de uma Norma de Orientação Clinica da VPO. Através da elaboração de uma Revisão Sistemática sobre a importância da VPO, da realização de Visitas Pré-operatórias exploratórias e do Método de Delphi, foi possível obter como resultado, a validação de uma Norma de Orientação Clinica da VPO. O trabalho desenvolvido ao longo do MEPO e concretamente durante a realização do Projeto foi um importante contributo para construir conhecimento e evidência científica na área das Normas de Orientação Clinica da VPO. A nível individual, o MEPO facultou-nos momentos de reflexão, análise e prática clínica que conduziram ao desenvolvimento das competências de Mestre em Enfermagem Perioperatória.Abstract: 8 ABSTRACT Within the 1st Master in Perioperative Nursing of Escola Superior de Saúde – Instituto Politécnico de Setúbal, the present report systematizes the whole process developed in order to acquire the skills required to nurses Master in Perioperative Nursing. The internship conducted in the Operating Room included the realization of a project on the area that we found to be the most needed of intervention. We resorted to the project´s methodology and by the method of Failure Mode and Effect Analysis (FMEA), we verified that the problem that motivates the development of this project was the quality commitment of nursing care provided in the Operating Room, due to the inexistence of the preoperative visit. The preoperative visit is the foundation of the entire perioperative care process and its importance is reflected in terms of improvement of quality of life of the person undergoing surgery, decreased fear and anxiety. It allows knowing the person, identifying its problems and developing a care plan according to the data collected. Therefore we defined the following objective: contribute to the improvement of the quality of care provided in the operating room through the proposal of the preoperative visit’s guideline. Developing a Systematic Review on the importance of Preoperative Visit, conducting exploratory Preoperative Visits and Using the Delphi Method was possible to obtain as a result, the validation of the preoperative visit’s guideline. The work developed along this Master in Perioperative Nursing and specifically during the development of the Project was an important contribution to acquire knowledge and scientific evidence in the area of pre-operative visit’s guidlines. At the individual level, it has provided us moments of reflection, analysis and clinical practice that led to the development of the skills of Master in Perioperative Nursing

Palliation with a multimodality treatment including hypoxic pelvic perfusion for unresectable recurrent rectal cancer: outcomes based on a retrospective study

Patients with unresectable recurrent rectal cancer that progresses after systemic chemotherapy and radiotherapy are candidates for palliation with hypoxic pelvic perfusion (HPP). The aim of this observational retrospective study was to evaluate if a multimodality treatment including HPP and targeted-therapy may be useful to prolong clinical responses and survival of these patients. From a cohort of 77 patients with unresectable recurrent rectal cancer in progression after standard treatments and submitted to HPP, 21 patients underwent repeat HPP using mitomycin C (MMC) at the dose of 25 mg/m2. After the last HPP, 7 patients received a targeted-therapy with cetuximab according to overexpression of epidermal growth factor receptor in recurrence cancer cells. The median overall survival of these 21 patients from the diagnosis of unresectable recurrent rectal cancer was 23 months (iqr 18-24). After the first HPP, the median survival of the 21 patients until death or end of follow-up was 10 months (iqr 9-13). The 1-year and 2-year survival rates were 71.4%, and 4.8%, respectively. From the first HPP, age\u2009>\u200960 years, a recurrence shrinkage of at least 30% (partial response), and the addition of a post-HPP targeted-therapy with cetuximab significantly affected survival (P\u2009<\u20090.04). In conclusion, repeated MMC-HPP followed by targeted-therapy seems to be an effective palliative treatment for patients with unresectable recurrent rectal cancer in progression after systemic chemotherapy and radiation but the results of this study have to be confirmed by a larger phase III trial

Ocular tolerance and efficacy of short-term tamponade with double filling of polydimethyloxane and perfluoro-n-octane

Stefano Zenoni1, Mario R Romano2, Sonia Palmieri1, Natalia Comi1, Edoardo Fiorentini1, Piero Fontana11Ospedali Riuniti di Bergamo, Bergamo, Italy; 2Istituto Clinico Humanitas IRCSS, Rozzano, Milan, ItalyObjective: The aim of the study was to evaluate the ocular tolerance and efficacy of double filling with perfluoro-n-octane (n-C8F18) (PFO) and polydimethyloxane (PDMS) as a temporary vitreous substitute in patients with retinal detachment complicated by proliferative vitreoretinopathy (PVR).Material and methods: Tamponade was performed in 30 eyes of 30 patients by double filling with 30% PFO and 70% PDMS for an average of 23 (standard deviation 2.2) days. The follow-up visits were scheduled 1 week, 1 month, and 3 months after surgery. The main outcome measures were visual acuity, intraocular pressure (IOP), PVR reproliferation, and electrophysiological parameters.Results: The primary success rate was 80% (24/30). Fourteen patients (46.7%) had a postoperative improvement in visual acuity, 12 patients (40.0%) maintained their preoperative visual acuity, and four patients (13.3%) experienced a reduction in visual acuity. The mean postoperative IOP was 19.7 mm Hg (11–32 mm Hg); nine cases (30.0%) developed an IOP increase that was treated with topical drops and/or systemic carbonic anhydrase inhibitors. The electroretinogram (ERG) and the bright flash electroretinogram (bf ERG) parameters showed a statistically significant difference of means between 4- and 8-week follow-up visits.Conclusion: Our experience with double filling in selected cases of retinal detachment has been positive. No electroretinographic signs of retinal toxicity and a low incidence of PVR reproliferation were observed.Keywords: double filling, proliferative vitreo-retinopathy, perfluoro-n-octane, polydimethyloxane, retinal detachment, retinal detachment electrophysiolog

Nitrogen and chlorophyll status determination in durum wheat as influenced by fertilization and soil management: Preliminary results.

Handheld chlorophyll meters as Soil Plant Analysis Development (SPAD) have proven to be useful tools for rapid, no-destructive assessment of chlorophyll and nitrogen status in various crops. This method is used to diagnose the need of nitrogen fertilization to improve the efficiency of the agricultural system and to minimize nitrogen losses and deficiency. The objective of this study is to evaluate the effect of repeated conservative agriculture practices on the SPAD readings, leaves chlorophyll concentration and Nitrogen Nutrition Index (NNI) relationships in durum wheat under Mediterranean conditions. The experimental site is a part of a long-term-experiment established in 1994 and is still on-going where three tillage managements and three nitrogen fertilizer treatments were repeated in the same plots every year. We observed a linear relationship between the SPAD readings performed in the central and distal portion of the leaf (R2 = 0.96). In fertilized durum wheat, we found all positive exponential relationships between SPAD readings, chlorophyll leaves concentration (R2 = 0.85) and NNI (R2 = 0.89). In the unfertilized treatment, the SPAD has a good attitude to estimate leaves chlorophyll concentration (R2 = 0.74) and NNI (R2 = 0.77) only in crop grow a soil with relative high content of soil organic matter and nitrogen availability, as observed in the no tilled plots. The results show that the SPAD can be used for a correct assessment of chlorophyll and nitrogen status in durum wheat but also to evaluate indirectly the content of soil organic matter and nitrogen availability during different growth stages of the crop cycle