An Improved System to Measure Leaf Gas Exchange on Adaxial and Abaxial Surfaces.

Measurement of leaf carbon gain and water loss (gas exchange) in planta is a standard procedure in plant science research for attempting to understand physiological traits related to water use and photosynthesis. Leaves carry out gas exchange through the upper (adaxial) and lower (abaxial) surfaces at different magnitudes, depending on the stomatal density, stomatal aperture, cuticular permeability, etc., of each surface, which we account for in gas exchange parameters such as stomatal conductance. Most commercial devices measure leaf gas exchange by combining the adaxial and abaxial fluxes and calculating bulk gas exchange parameters, missing details of the plant's physiological response on each side. Additionally, the widely used equations to estimate gas exchange parameters neglect the contribution of small fluxes such as cuticular conductance, adding extra uncertainties to measurements performed in water-stress or low-light conditions. Accounting for the gas exchange fluxes from each side of the leaf allows us to better describe plants' physiological traits under different environmental conditions and account for genetic variability. Here, apparatus and materials are presented for adapting two LI-6800 Portable Photosynthesis Systems to work as one gas exchange system to measure adaxial and abaxial gas exchange simultaneously. The modification includes a template script with the equations to account for small fluxes. Instructions are provided for incorporating the add-on script into the device's computational sequence, display, variables, and spreadsheet results. We explain the method to obtain an equation to estimate boundary layer conductance to water for the new setup and how to embed this equation in the devices' calculations using the provided add-on script. The apparatus, methods, and protocols presented here provide a simple adaptation combining two LI-6800s to obtain an improved system to measure leaf gas exchange on adaxial and abaxial surfaces. Graphical overview Figure 1.Diagram of the connection of two LI-6800s.Figure adapted from Márquez et al. (2021).

Registro Argentino de Medición de la Presión Arterial en Consultorio. Estudio RAMPAC / Argentine registry of office blood pressure monitoring. RAMPAC study

Introducción: La hipertensión es el factor de riesgo más importante para la muerte cardiovascular a nivel mundial. En Argentina cerca del 44% de las personas desconocen ser hipertensos, y posiblemente sea debido a que no se les mide de la presión arterial (PA) en la consulta médica. Nuestra hipótesis es que la medición y el registro de la PA (MRPA) es omitida durante la consulta médica en Argentina. Objetivo: Determinar la frecuencia de MRPA en la consulta médica en Argentina. Métodos: Estudio multicéntrico, retrospectivo de punto de prevalencia. Se analizaron todas las consultas externas realizadas el 19/09/2019 en mayores de 18 años, en 9 instituciones sanitarias de Argentina y se evaluó la MRPA. Resultados: Se analizaron 2.982 consultas. La edad promedio fue de 52,1 años (18-103), 1.780 (59,7%) eran mujeres y 702 (36,1%) tenían antecedentes de hipertensión arterial (HTA). La PA se midió y registró en 420 consultas (14,1%; IC 95%: 12,8-15,4). En un modelo de regresión logística multivariado el antecedente de HTA (OR: 1,91; p<0,001) y de enfermedad cardiovascular (OR: 1,76; p<0,001) fueron las variables que más se asociaron a la MRPA. La presencia de cáncer se asoció un descenso de MRPA (OR: 0,51; p<0,01). Cardiología fue la especialidad que más midió la PA 49,5% (144/291 consultas), seguida por clínica médica 30% (152/507 consultas). Conclusión: La MRPA en la consulta médica ambulatoria es deficitaria y constituye una oportunidad perdida en salud. Se necesitan estrategias que mejoren la detección y el control de la HTA.

Introduction: Hypertension (HTN) is the leading cause of mortality and disability in the world. In Argentina, almost 44% of hypertensives do not know about their condition and this may be due to the low rate of blood pressure (BP) measurements during the office visit. Our hypothesis is that the measurement and electronic recording of BP (BPMR) is not a routine practice in Argentina. Objective: To describe the rate of office BP measurement in Argentina. Methods: This is a retrospective, multicentre, point prevalence study. We analysed all office visits on 9/19/2019 at 9 medical institutions in 6 provinces of Argentina. Results: Two thousand and eighty-two office visits were analysed. The patients’ mean age was 52.1 years (18-103), 1790 (59.7%) were female, and 702 (36.1%) were hypertensives. BP was measured in 420 visits (14.1%; 95% CI 12.8-15.4). In a multivariate logistic regression model, history of HTN (OR 1.91, P<.001) and previous cardiovascular event (OR 1.76, P<.001) were associated with more odds of BPMR. The presence of cancer was associated with fewer odds of BPMR (OR .51, P<.01). Cardiology measured BP up to 49.5% (144/291 visits), followed by internal medicine 30% (152/507 visits). Conclusion: BPMR during office visits is deficient in Argentina and represents a missed healthcare opportunity. Different strategies are needed to detect hypertensive patients and reduce cardiovascular events.

[Argentine registry of office blood pressure monitoring. RAMPAC study]. / Registro Argentino de Medición de la Presión Arterial en Consultorio. Estudio RAMPAC.

INTRODUCTION: Hypertension (HTN) is the leading cause of mortality and disability in the world. In Argentina, almost 44% of hypertensives do not know about their condition and this may be due to the low rate of blood pressure (BP) measurements during the office visit. Our hypothesis is that the measurement and electronic recording of BP (BPMR) is not a routine practice in Argentina. OBJECTIVE: To describe the rate of office BP measurement in Argentina. METHODS: This is a retrospective, multicentre, point prevalence study. We analysed all office visits on 9/19/2019 at 9 medical institutions in 6 provinces of Argentina. RESULTS: Two thousand and eighty-two office visits were analysed. The patients' mean age was 52.1 years (18-103), 1790 (59.7%) were female, and 702 (36.1%) were hypertensives. BP was measured in 420 visits (14.1%; 95% CI 12.8-15.4). In a multivariate logistic regression model, history of HTN (OR 1.91, P<.001) and previous cardiovascular event (OR 1.76, P<.001) were associated with more odds of BPMR. The presence of cancer was associated with fewer odds of BPMR (OR .51, P<.01). Cardiology measured BP up to 49.5% (144/291 visits), followed by internal medicine 30% (152/507 visits). CONCLUSION: BPMR during office visits is deficient in Argentina and represents a missed healthcare opportunity. Different strategies are needed to detect hypertensive patients and reduce cardiovascular events.

Identifying Barriers to Physical Activity Among African American Women with Asthma.

OBJECTIVE: African American Women (AAW) are disproportionately impacted by both physical inactivity and asthma. The aims of this study were to: 1) understand barriers to physical activity among AAW with asthma; 2) obtain feedback from AAW on an evidence-based walking intervention; and 3) modify the intervention using input from AAW with asthma. METHODS: Focus groups and interviews were conducted with sedentary AAW with uncontrolled asthma to identify barriers to walking. Women also suggestions for tailoring an existing walking intervention. Qualitative data were coded using domains from the Behavior Change Wheel and guided modifications of the existing walking intervention to tailor the content for sedentary AAW with asthma. RESULTS: Six focus groups (2-4 /group) and five interviews were completed. Women (n=20) represented an obese (37 kg/m2 ± 11), middle-aged (46 years ± 15) and low-income population. Barriers to physical activity were mapped to 8 theoretical domains: 1) Limited physical capability; 2) Lack of knowledge; 3) Lack of self-monitoring skills; 4) Complex decision making processes; 5) Lack of areas to walk; 6) Lack of social support; 7) Beliefs about consequences; 8) Beliefs about capability. To target these barriers, the existing walking intervention was modified to include an asthma education session, text messages, monthly group meetings, a walking session and informational materials. CONCLUSION: AAW with asthma reported unique barriers to engaging in physical activity. An assessment of the feasibility, acceptability and efficacy of a modified intervention that addresses these barriers is warranted to address physical inactivity and poor asthma outcomes among AAW with asthma.

The cytotoxicity and genotoxicity of particulate and soluble hexavalent chromium in leatherback sea turtle lung cells.

Hexavalent chromium [Cr(VI)] is a marine pollution of concern as recent studies show it has a global distribution, with some regions showing high Cr concentrations in marine animal tissue, and it is extensively used. Leatherback sea turtles (Dermochelys coriacea) are an endangered marine species that may experience prolonged exposures to environmental contaminants including Cr(VI). Human activities have led to global Cr(VI) contamination of the marine environment. While Cr(VI) has been identified as a known human carcinogen, the health effects in marine species are poorly understood. In this study, we assessed the cytotoxic and genotoxic effects of particulate and soluble Cr(VI) in leatherback sea turtle lung cells. Both particulate and soluble Cr(VI) induced a concentration-dependent increase in cytotoxicity. Next, using a chromosome aberration assay, we assessed the genotoxic effects of Cr(VI) in leatherback sea turtle lung cells. Particulate and soluble Cr(VI) induced a concentration-dependent increase in clastogenicity in leatherback sea turtle lung cells. These data indicate that Cr(VI) may be a health concern for leatherback sea turtles and other long-lived marine species. Additionally, these data provide foundational support to use leatherback sea turtles as a valuable model species for monitoring the health effects of Cr(VI) in the environment and possibly as an indicator species to assess environmental human exposures and effects.

Supplementation of grazing beef cows during gestation as a strategy to improve skeletal muscle development of the offspring.

The appropriate supply of nutrients in pregnant cows has been associated with the optimal development of foetal tissues, performance of their progeny and their meat quality. The aim of this study was to evaluate supplementation effects of grazing cows in different stages of gestation on skeletal muscle development and performance of the progeny. Thereby, 27 Nellore cows were divided into three groups (n=9 for each group) and their progeny as follows: UNS, unsupplemented during gestation; MID, supplemented from 30 to 180 days of gestation; LATE, supplemented from 181 to 281 days of gestation. The percentage composition of the supplement provided for the matrices was the following: ground corn (26.25%), wheat bran (26.25%) and soya bean meal (47.5%). The supplement was formulated to contain 30% CP. Supplemented matrices received 150 kg of supplement (1 and 1.5 kg/day for cows in the MID and LATE groups, respectively). After birth, a biopsy was performed to obtain samples of skeletal muscle tissue from calves to determine number and size of muscle fibres and for messenger RNA (mRNA) expression analysis. The percentage composition of the supplement provided for the progeny was the following: ground corn grain (30%), wheat bran (30%), soya bean meal (35%) and molasses (5%). The supplement was formulated to contain 25% CP and offered in an amount of 6 g/kg BW. Performance of the progeny was monitored throughout the suckling period. Means were submitted to ANOVA and regression, and UNS, MID and LATE periods of supplementation were compared. Differences were considered at P0.10). Similarly, no differences were observed between calves for nutrient intake (P>0.10). However, greater subcutaneous fat thickness (P=0.006) was observed in the calves of LATE group. The ribeye area (P=0.077) was greater in calves born from supplemented compared with UNS cows. The supplementation of pregnant cows did not affect the muscle fibre size of their progeny (P=0.208). On the other hand, calves born from dams supplemented at mid-gestation had greater muscle fibre number (P=0.093) compared with calves from UNS group. Greater mRNA expression of peroxysome proliferator-activated receptor α (P=0.073) and fibroblast growth factor 2 (P=0.003) was observed in the calves born from MID cows. Although strategic supplementation did not affect the BW of offspring, it did cause changes in carcass traits, number of myofibres, and mRNA expression of a muscle hypertrophy and lipid oxidation markers in skeletal muscle of the offspring.

Réplica a «Tratamiento de la hiperuricemia asintomática» / Reply to «Treatment of asymptomatic hyperuricaemia»

No disponible

La ecografía en el diagnóstico de la hiperuricemia asintomática y la gota / Ultrasound in the diagnosis of asymptomatic hyperuricaemia and gout

El aumento de la concentración sérica de uratos (hiperuricemia, mayor o igual a 7,0mg/dL) ocasiona cristales que promueven inflamación y lesión articular. La ecografía puede poner de manifiesto estos depósitos de urato. Su presencia obliga a considerar que un paciente con hiperuricemia en realidad padece gota asintomática, y que un enfermo con gota sin tofos subcutáneos puede tener gota tofácea. La información que ofrece la ecografía (signo del «doble contorno» y de concreciones hiperecogénicas simulando nubes) posibilita una clasificación de la hiperuricemia y de la gota más precisas. Además, esta información puede dar lugar a modificaciones relevantes en cuanto al proceder diagnóstico y terapéutico en los enfermos con hiperuricemia y gota (AU)

The increase in serum urate concentrations (hyperuricaemia, ≥7.0mg/dL) creates crystals, which promote inflammation and joint lesions. Ultrasonography can reveal these urate deposits. The presence of crystals suggests that a patient with hyperuricaemia is actually experiencing asymptomatic gout, and that a patient with gout without subcutaneous tophi could experience tophaceous gout. The information offered by ultrasound (double contour sign and hyperechoic concretions mimicking clouds) enables a more specific classification of hyperuricaemia and gout. Additionally, this information can lead to relevant changes in terms of the diagnosis and therapeutic approach for patients with hyperuricaemia and gout (AU)

Ultrasound in the diagnosis of asymptomatic hyperuricaemia and gout. / La ecografía en el diagnóstico de la hiperuricemia asintomática y la gota.

The increase in serum urate concentrations (hyperuricaemia, ≥7.0mg/dL) creates crystals, which promote inflammation and joint lesions. Ultrasonography can reveal these urate deposits. The presence of crystals suggests that a patient with hyperuricaemia is actually experiencing asymptomatic gout, and that a patient with gout without subcutaneous tophi could experience tophaceous gout. The information offered by ultrasound (double contour sign and hyperechoic concretions mimicking clouds) enables a more specific classification of hyperuricaemia and gout. Additionally, this information can lead to relevant changes in terms of the diagnosis and therapeutic approach for patients with hyperuricaemia and gout.

Linear viscoelastic behaviour of oil-in-water food emulsions stabilised by tuna-protein isolates.

This work deals with the manufacture of oil-in-water food emulsions stabilised by tuna proteins. The influence of protein and oil concentrations on the linear viscoelastic properties and microstructure of these emulsions was analysed. Stable emulsions with suitable linear viscoelastic response and microstructural characteristics were formulated with 70 wt.% oil and, at least, 0.25 wt.% tuna protein. Similarly, emulsions with oil concentrations between 45 and 70 wt.% were prepared using 0.50 wt.% protein. All these emulsions showed a predominantly elastic response in the linear viscoelastic region and a well-developed plateau region in its mechanical spectrum. Rheological and droplet size distribution results pointed out an extensive droplet flocculation, due to interactions among emulsifier molecules located at the oil-water interface of adjacent droplets. As a result, the linear viscoelastic behaviour was controlled by protein-protein interactions, allowing the use of the plateau modulus to successfully normalise both the storage and loss moduli as a function of frequency onto a master curve, irrespective of the selected emulsion formulation.

New strategy for a suitable fast stabilization of the biomethanization performance.

The start-up strategies for thermophilic anaerobic reactors usually consist of an initial mesophilic stage (35°C), with an approximate duration of 185 days, and a subsequent thermophilic stage (55°C), which normally requires around 60 days to achieve the system stabilizatio. During the first 8-10 days of the mesophilic stage, the reactor is not fed so that the inoculum, which is generally a mesophilic anaerobic sludge, may be adapted to the organic solid waste. Between mesophilic and thermophilic conditions the reactor is still not fed in an effort to prevent possible imbalances in the proces. As a consequence, the start-up and stabilization of the biomethanization performance described in the literature require, at least, around 245 days. In this sense, a new strategy for the start-up and stabilization phases is presented in this study. This approach allows an important reduction in the overall time necessary for these stages in an anaerobic continuous stirred tank reactor (CSTR) operated at thermophilic-dry conditions for treating the organic fraction of the municipal solid waste (OFMSW): 60 days versus 245 days of conventional strategies. The new strategy uses modified SEBAC technology to adapt an inoculum to the OFMSW and the operational conditions prior to seeding the CSTR.

Dry-thermophilic anaerobic digestion of simulated organic fraction of municipal solid waste: process modeling.

Solid retention time (SRT) is a very important operational variable in continuous and semicontinuous waste treatment processes since the organic matter removal efficiency--expressed in terms of percentage of Dissolved Organic Carbon (% DOC) or Volatile Solids (% VS) removed--and the biogas or methane production are closely related with the SRT imposed. Optimum SRT is depending on the waste characteristics and the microorganisms involved in the process and, hence, it should be determined specifically in each case. In this work a series of experiments were carried out to determine the effect of SRT, from 40 to 8 days, on the performance of the dry (30% Total Solids) thermophilic (55°C) anaerobic digestion of organic fraction of Municipal Solid Wastes (OFMSW) operating at semicontinuous regime of feeding. The experimental results show than 15days is the optimum SRT (the best between all proved) for this process. Besides, data of organic matter concentration and methane production versus SRT have been used to obtain the kinetic parameters of the kinetic model of Romero García (1991): the maximum specific growth rate of the microorganisms (µmax=0.580 days(-1)) and the fraction of substrate non-biodegradable (α=0.268).

Thomson scattering diagnostic upgrade on DIII-D.

The DIII-D Thomson scattering system has been upgraded. A new data acquisition hardware was installed, adding the capacity for additional spatial channels and longer acquisition times for temperature and density measurements. Detector modules were replaced with faster transimpedance circuitry, increasing the signal-to-noise ratio by a factor of 2. This allows for future expansion to the edge system. A second phase upgrade scheduled for 2010-2011 includes the installation of four 1 J/pulse Nd:YAG lasers at 50 Hz repetition rate. This paper presents the first completed phase of the upgrade and performance comparison between the original system and the upgraded system. The plan for the second phase is also presented.

Start-up of thermophilic-dry anaerobic digestion of OFMSW using adapted modified SEBAC inoculum.

The work presented here concerns the start-up and stabilization stages of a Continuous Stirred Tank Reactor (CSTR) semicontinuously fed for the treatment of the Organic Fraction of Municipal Solid Waste (OFMSW) through anaerobic digestion at thermophilic temperature range (55 degrees C) and dry conditions (30% Total Solids). The procedure reported involves two novel aspects with respect to other start-up and stabilization protocols reported in the literature. The novel aspects concern the adaptation of the inoculum to both the operating conditions (thermophilic and dry) and to the type of waste by employing a modified SEBAC (Sequential Batch Anaerobic Composting) system and, secondly, the direct start-up of the process in a thermophilic temperature regime and feeding of the system from the first day of operation. In this way a significant reduction in the start-up time and stabilization is achieved i.e. 110 days in comparison to 250 days for the processes reported by other authors for the same type of waste and digester. The system presents suitable operational conditions to stabilize the reactor at SRT of 35 days, with a maximum biogas production of 1.944 LR/L.d with a CH(4) and CO(2) percentage of 25.27% and 68.15%, respectively.

Fecal pollution in coastal marine sediments from a semi-enclosed deep embayment subjected to anthropogenic activities: an issue to be considered in environmental quality management frameworks development.

Sewage discharge is a major source of pollution in marine environments. Urban wastewaters can directly enter marine environments carrying pathogen organisms, organic loads, and nutrients. Because marine sediments can act as the ultimate fate of a wide range of pollutants, environmental quality assessment in this compartment can help to identify pollution problems in coastal areas. In the present study, characterization of surficial marine sediments allowed assessment of fecal pollution in a semi-enclosed deep embayment that is subjected to anthropogenic activities. Physicochemical parameters and fecal indicators presented a great spatial heterogeneity. Fecal coliform and Clostridium perfringens showed accumulation in an extensive area, not only in proximity to sewage discharge points, but also in sediments at 100 meters depth. Results included herein demonstrated that, in coastal areas, urban wastewater discharge can affect the whole ecosystem through accumulation of fecal matter in bottom sediments. Application of multivariate techniques provided useful information with applicability for management of coastal areas in such complex systems. Environmental implications of wastewater discharge in coastal areas indicate the need to implement and include sediment quality control strategies in legislative frameworks.

Inhibitory effects of non-ionic surfactants on the microbial activity of activated sludge system.

The purpose of the present work was to study the influence of a non-ionic surfactant, a nonylphenol with four ethoxylated units (NP4EO), on the activity of the microbial population present in a laboratory-scale activated sludge unit. Traditional control methods for this type of unit were used (measurement of suspended solids and chemical oxygen demand) as well as specific techniques for the measurement of bacterial activity (dehydrogenase activity and specific oxygen uptake rate) and the results were compared. It was shown that the Specific Oxygen Uptake Rate (SOUR) is the simplest and quickest way to carry out routine control of activated sludge activity, while measuring dehydrogenase activity provides more complete control. The results obtained indicated that there was no inhibition of microbial activity at a concentration of 5 ppm of NP4EO, which was not the case with a concentration of 10 ppm.

Sublethal and lethal toxicity in juvenile Senegal sole (Solea senegalensis) exposed to copper: a preliminary toxicity range-finding test.

Static bioassay test for acute toxicity of copper in Senegal sole juveniles (Solea senegalensis) was conducted. The 96h LC(50) value of metal was found to be 0.32mg/L Cu. The intensity of histological alterations was increased gradually with the copper concentration and the exposure time. Numerous aneurysms, hypertrophy, hyperplasia and fusion of the lamellar epithelium in gills and a disorganization of the hepatic parenchyma and vacuolization in liver were common lesions in S. senegalensis juveniles exposed to copper. The results of the study indicate the sensitivity of juvenile S. senegalensis to copper (II), the persistence of sublethal effects and histology as a tool capable of revealing the sublethal effects of heavy metals on the environment and aquatic biota.