Assessment of the Relationship Between Inflammation and Glomerular Filtration Rate.

Background: Chronic kidney disease (CKD) is a global health problem. As it progresses to end stages, renal replacement therapy is required but ultimately, the best treatment is transplantation. Decreased renal function has been associated with an inflammatory state associated to primary CKD and in kidney transplant recipients (KTRs). Objective: To establish how the serum concentrations of some cytokines, such as interleukin (IL)-2, IL-8, IL-22, IL-17α, interferon-gamma, IL-4, and transforming growth factor-ß, correlate with various CKD stages. Methods: One hundred and forty-one KTRs between the ages of 18 and 75 years were included in the study. We also included 112 live kidney donors, 37 CKD PGCKD+3, and 76 GPhealthy. Participants were grouped according to their glomerular filtration rate (GFR) and their circulating cytokine levels, previously quantified by ELISA. Results: By linear regression analysis, we established the relation of each cytokine with the GFR. Transforming growth factor-ß correlated positively with the GFR in the study population, except in healthy individuals. A negative correlation of IL-8 and IL-17α and GFR was found in all cases. Conclusions: Whether these cytokines (IL-8 and IL-17α) could be used as inflammatory biomarkers indicating CKD progression, regardless of the type of population, remains to be prospectively determined.

Contexte: L'insuffisance rénale chronique (IRC) est un problème de santé mondial. Une thérapie de remplacement rénal est nécessaire au fur et à mesure que la maladie évolue vers les stades terminaux. Mais, en définitive, le meilleur traitement reste la transplantation. La réduction de la fonction rénale a été associée à un état inflammatoire associé à l'IRC primaire; une association observée aussi chez les receveurs d'une greffe de rein. Objectif: Déterminer la façon dont les concentrations sériques de certaines cytokines, notamment IL-2, IL-8, IL-22, IL-17a, IFN-γ, IL-4 et TGF-ß, corrèlent avec divers stades de l'IRC. Méthodologie: Ont été inclus dans l'étude 141 receveurs d'une greffe rénale âgés de 18 à 75 ans, 112 donneurs vivants de rein, 37 personnes atteintes d'IRC (PGIRC+3) et 76 personnes en bonne santé (PGen santé). Les sujets ont été regroupés en fonction de leur débit de filtration glomérulaire (DFGe) et de leur taux de cytokines en circulation, quantifiés préalablement par ELISA. Résultats: Une analyse de régression linéaire a servi à établir la relation entre chaque cytokine et le DFGe. Dans la population étudiée, une corrélation positive a été observée entre TGF-ß et le DFGe, sauf chez les individus sains. Dans tous les cas, la corrélation s'est avérée négative entre le DFGe et les taux d'IL-8 et d'IL-17a. Conclusion: Il reste à déterminer prospectivement si ces cytokines (IL-8 et IL-17a) pourraient être utilisées comme biomarqueurs inflammatoires pour indiquer la progression de l'IRC, quelle que soit la population.

Implications of crop model ensemble size and composition for estimates of adaptation effects and agreement of recommendations.

Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.

[Metatarsal and toe fractures]. / Mittel- und Vorfußfrakturen.

Metatarsal and toe fractures are the most frequent injuries of the foot skeleton. Nondislocated fractures can be conservatively treated with good success. Long-term relief and immobilization including the ankle joint are unnecessary. Metatarsal fractures close to the base are nearly always associated with Lisfranc luxation and treatment must also take the instability of the tarsometatarsal joints into consideratíon. Basal fractures of the 5th metatarsal bone require a differentiated consideration. The correct classification is necessary in order to initiate an adequate treatment. In general, intra-articular layer formation, inclination >10° and shortening between 3 mm and 5 mm, taking the position of the head of the metatarsal bone into consideration, are recommended as indications for surgery. Operative treatment of toe fractures is only rarely necessary.

Minimally invasive internal fixation of calcaneal fractures or subtalar joint arthrodesis using the Calcanail®.

OBJECTIVE: A minimally invasive technique to prevent soft tissue problems using a calcaneal nail (Calcanail®, FH Orthopedics, Heimsbrunn, France) for calcaneal fractures or in subtalar joint arthrodesis is described. INDICATIONS: Displaced extra-articular calcaneal fractures involving the tuberosity fragment and in displaced intra-articular calcaneal fractures with impression and/or displacement of the subtalar joint surface. Subtalar joint arthrodesis for posttraumatic subtalar osteoarthritis. CONTRAINDICATIONS: Severely displaced fractures type Sanders IV with the purpose of internal fixation; peripheral calcaneal fractures; general contraindications for operative treatment. SURGICAL TECHNIQUE: Minimally invasive reduction of calcaneal fractures using a special distractor and a graft pusher through a calcaneal working channel. Fixation performed via the insertion of the Calcanail® and the two locking screws, optional additional screws. Subtalar joint arthrodesis with a Calcanail® used with optional three locking screws to fix the talus and calcaneus creating an angular stable construct. POSTOPERATIVE MANAGEMENT: Mobilization and restricted weight-bearing for 6 weeks in the patient's own shoes after fracture fixation or in a walker after arthrodesis. RESULTS: Preliminary results of 69 cases from three surgical centers have already been published. From 2013-2017, the technique was used in 48 of our own patients (42 calcaneal fracture reduction and fixation; 6 for subtalar joint arthrodesis). Mean postoperative hospital stay was 7 days for fracture reduction without any need of additional operations. During follow-up, 6 implant removals and 2 secondary subtalar fusions were noticed. All 6 cases of subtalar joint arthrodesis were planned in posttraumatic subtalar osteoarthritis.

[Typical fractures and dislocations of the elbow joint and their treatment]. / Typische Frakturen und Luxationen am Ellenbogengelenk und deren Behandlung.

Diagnosis and treatment of injuries to the elbow joint place high demands on the treating physicians. The complex anatomy of the elbow joint enables a wide range of movement and complex functions in everyday and professional life. These must be restored in the event of injury.Clinical and imaging-based diagnostic procedures serve to classify typical injuries of this joint according to a large variety of different pathologies. These include fractures of the distal humerus, the proximal ulna, and the radial head, as well as dislocations and dislocation fractures.The following article gives an overview of the most common of these injuries.

Mortalidad por enfermedad renal crónica y su relación con la diabetes en México / Chronic kidney disease mortality and its relation to diabetes in Mexico

Resumen OBJETIVO Analizar el efecto en México de la mortalidad producida por la enfermedad renal crónica secundaria a la diabetes mellitus. MATERIAL Y MÉTODO Estudio observacional efectuado de 1998 a 2014, en el que se tomó como base un registro nacional correspondiente a un lapso relativamente prolongado de 17 años, reconociendo a esta enfermedad en tanto entidad nosológica diferenciada, utilizando como metodología de análisis la minería de datos, y evitando en lo posible las ambigüedades o limitaciones detectadas en los estudios previamente publicados. RESULTADOS En las dos últimas décadas se han duplicado la prevalencia y las tasas de mortalidad por enfermedad renal crónica en la República Mexicana, lo que supone un elevado costo humano y financiero, además de que esta enfermedad reduce significativamente la calidad y la esperanza de vida de la población adulta mexicana. CONCLUSIONES Es necesario optimizar las estrategias de atención del paciente con enfermedad renal crónica sin descartar el uso de estrategias de prevención eficaces, dirigidas a la población general.

Abstract OBJECTIVE To analyze the impact in Mexico of the mortality produced by chronic renal failure secondary to diabetes mellitus. MATERIAL AND METHOD An observational study was done from 1998 to 2014 on the basis of a national registry corresponding to a relatively long period of 17 years, recognizing this pathology as a differentiated nosological entity, using the data mining as methodology of analysis, and avoiding as far as possible the ambiguities or limitations detected in previously published studies. RESULTS In the last two decades, the prevalence and mortality rates for chronic renal failure has doubled in Mexico, which means a high human and financial cost, in addition to the fact that this disease significantly reduces the quality of life and the life expectancy of the Mexican adult population. CONCLUSION It is necessary to optimize the care strategies for patients with chronic renal failure, without ruling out the use of effective prevention strategies focused on the general population.

Progress in modelling agricultural impacts of and adaptations to climate change.

Modelling is a key tool to explore agricultural impacts of and adaptations to climate change. Here we report recent progress made especially referring to the large project initiatives MACSUR and AgMIP; in particular, in modelling potential crop impacts from field to global using multi-model ensembles. We identify two main fields where further progress is necessary: a more mechanistic understanding of climate impacts and management options for adaptation and mitigation; and focusing on cropping systems and integrative multi-scale assessments instead of single season and crops, especially in complex tropical and neglected but important cropping systems. Stronger linking of experimentation with statistical and eco-physiological crop modelling could facilitate the necessary methodological advances.

Long-term survival of kidney grafts in lupus nephritis: a Mexican cohort.

Kidney transplant for patients with lupus nephritis (LN) has satisfactory outcomes in studies with short-term or mid-term follow up. Nevertheless, information about long-term outcomes is scarce. We performed a retrospective matched-pair cohort study in 74 LN recipients compared with 148 non-LN controls matched by age, sex, immunosuppressive treatment, human leukocyte antigen (HLA) matches, and transplant period in order to evaluate long-term outcomes of kidney transplant in LN recipients. Matched pairs were predominantly females (83%), median age at transplant surgery of 32 years (interquartile range 23-38 years), and 66% received a graft from a living related donor. Among LN recipients, 5-, 10-, 15-, and 20-year graft survival was 81%, 79%, 57% and 51%, respectively, and it was similar to that observed in controls (89%, 78%, 64%, and 56%, respectively). Graft loss (27% vs. 21%, p = 0.24) and overall survival ( p = 0.15) were not different between LN recipients and controls. Also, there was no difference in episodes of immunological rejection, thrombosis, or infection. Only six LN recipients had biopsy-proven lupus recurrence and three of them had graft loss. In a cohort with a long follow up of kidney transplant recipients, LN recipients had similar long-term graft survival and overall outcomes compared with non-lupus recipients when predictors are matched between groups.

[Operative techniques and results of tibial pilon fractures]. / Operationstechnik und deren Ergebnisse der Pilon-tibiale-Fraktur.

BACKGROUND: The anatomical reconstruction of tibial pilon fractures is a major challenge with respect to preoperative planning, time management and the intraoperative procedure. OBJECTIVE: Presentation of the various surgical procedures available and the clinical outcome. MATERIAL AND METHODS: The established open reduction and internal plate fixation procedures form the basis for new minimally invasive treatment concepts. The current results of comparative studies and basic literature are discussed. RESULTS: The treatment result depends on the severity of the initial fracture and accompanying soft tissue damage. Essential is an anatomical reduction with an articular displacement of less than 2 mm. Overall, only approximately half of all patients return to work within 1 year. The fixation procedure used is not relevant for this purpose. Both plate fixation and the combination of external fixator plus minimally invasive articular reconstruction with and without arthroscopy achieve equivalent results. CONCLUSION: Good clinical results can be achieved by an accurate preoperative planning with respect to the surgical procedure, time of surgery and the surgical steps. In cases of disregarding these points and inadequate surgical expertise, loss of function and reduced quality of life are impending.

[Fractures of the olecranon]. / Die Olekranonfraktur.

OBJECTIVE: Fractures of the olecranon are the most common fractures of the elbow in adults. Due to the dislocating force of the triceps muscle, internal fixation is the treatment of choice. INDICATIONS: All fractures of the olecranon without contraindications. CONTRAINDICATIONS: Infection and severe soft tissue damage. SURGICAL TECHNIQUE: Dorsal approach to the olecranon with the patient in a prone position. Open reduction and internal fixation with tension band wiring or plate fixation according to fracture pattern. POSTOPERATIVE MANAGEMENT: Treatment goal is early functional mobilization. No load bearing allowed for 6-8 weeks; full load bearing is allowed after fracture healing. RESULTS: The quality of published studies concerning the surgical treatment of olecranon fractures is poor. Published functional results are predominantly good and excellent. Hardware removal was often required.

Prognostic significance of renal vascular pathology in lupus nephritis.

We performed a retrospective cohort analysis to define the prognostic significance of vascular lesions documented in renal biopsies of lupus nephritis patients. A total of 429 patients were segregated into five groups: (1) no vascular lesions (NVL), (2) arterial sclerosis (AS), (3) non-inflammatory necrotizing vasculitis (NNV), (4) thrombotic microangiopathy (TMA), and (5) true renal vasculitis (TRV). Renal outcomes were analyzed by Cox regression models, and correlations between vascular lesions and activity/chronicity scores were determined by Spearman's coefficients. A total of 200 (46.6%) had NVL, 189 (44.0%) AS, six NNV (1.4%), 23 (5.4%) TMA, and 11 (2.6%) TRV. Patients with NVL were younger, with higher renal function; patients with TMA and TRV had lower renal function and higher arterial pressure at baseline. Antiphospholipid syndrome and positive lupus anticoagulant were more frequently observed in the TMA group. Five-year renal survival was 83% for NVL, 63% for AS, 67% for NNV, 31% for TMA, and 33% for TRV. NNV and TRV were significantly correlated with activity scores, while AS and chronic TMA were correlated with chronicity scores. Renal vascular lesions are associated with renal outcomes but do not behave as independent factors. The addition of vascular lesions to currently used scores should be further explored.

Renal flare prediction and prognosis in lupus nephritis Hispanic patients.

We performed a retrospective cohort analysis focusing on lupus nephritis renal flare incidence and outcome predictors. One hundred and eighteen patients with biopsy-proven lupus nephritis were segregated by induction/maintenance regimes. The primary outcome was the proportion of patients experiencing renal flare. Secondary assessment included doubling of serum creatinine and development of end-stage renal disease. After a median follow-up of 31 months (interquartile range 21-46) from the date of response to induction therapy, 47 patients (39.8%) developed a renal flare. Azathioprine-maintained patients had a higher risk of renal flare compared with mycophenolate mofetil-maintained patients (hazard ratio 2.53, 95% confidence interval 1.39-4.59, p < 0.01). Age (hazard ratio 0.96, 0.92-0.99, p = 0.03), serum creatinine at presentation (hazard ratio 1.76, 1.13-2.76, p = 0.01), complete remission after induction therapy (hazard ratio 0.28, 0.14-0.56, p < 0.001) and azathioprine maintenance therapy (hazard ratio 4.78, 2.16-10.6, p < 0.001) were associated with renal flare on multivariate analysis. Ten patients progressed to end-stage renal disease (8.5%) by a median 32.5 months. Age (hazard ratio 0.88, 0.77-0.99, p = 0.05), complete remission after induction therapy (hazard ratio 0.08, 0.01-0.94, p = 0.04) and severe nephritic flare (hazard ratio 13.6, 1.72-107.7, p = 0.01) were associated with end-stage renal disease development. Azathioprine maintenance therapy is associated with a higher incidence of relapse in the Mexican-mestizo population. Younger age and nephritic flares predict development of end-stage renal disease.

The effects of cinacalcet on blood pressure, mortality and cardiovascular endpoints in the EVOLVE trial.

Patients with end-stage renal disease often have derangements in calcium and phosphorus homeostasis and resultant secondary hyperparathyroidism (sHPT), which may contribute to the high prevalence of arterial stiffness and hypertension. We conducted a secondary analysis of the Evaluation of Cinacalcet Hydrochloride Therapy to Lower Cardiovascular Events (EVOLVE) trial, in which patients receiving hemodialysis with sHPT were randomly assigned to receive cinacalcet or placebo. We sought to examine whether the effect of cinacalcet on death and major cardiovascular events was modified by baseline pulse pressure as a marker of arterial stiffness, and whether cinacalcet yielded any effects on blood pressure. As reported previously, an unadjusted intention-to-treat analysis failed to conclude that randomization to cinacalcet reduces the risk of the primary composite end point (all-cause mortality or non-fatal myocardial infarction, heart failure, hospitalization for unstable angina or peripheral vascular event). However, after prespecified adjustment for baseline characteristics, patients randomized to cinacalcet experienced a nominally significant 13% lower adjusted risk (95% confidence limit 4-20%) of the primary composite end point. The effect of cinacalcet was not modified by baseline pulse pressure (Pinteraction=0.44). In adjusted models, at 20 weeks cinacalcet resulted in a 2.2 mm Hg larger average decrease in systolic blood pressure (P=0.002) and a 1.3 mm Hg larger average decrease in diastolic blood pressure (P=0.002) compared with placebo. In summary, in the EVOLVE trial, the effect of cinacalcet on death and major cardiovascular events was independent of baseline pulse pressure.

Use of crop simulation modelling to aid ideotype design of future cereal cultivars.

A major challenge of the 21st century is to achieve food supply security under a changing climate and roughly a doubling in food demand by 2050 compared to present, the majority of which needs to be met by the cereals wheat, rice, maize, and barley. Future harvests are expected to be especially threatened through increased frequency and severity of extreme events, such as heat waves and drought, that pose particular challenges to plant breeders and crop scientists. Process-based crop models developed for simulating interactions between genotype, environment, and management are widely applied to assess impacts of environmental change on crop yield potentials, phenology, water use, etc. During the last decades, crop simulation has become important for supporting plant breeding, in particular in designing ideotypes, i.e. 'model plants', for different crops and cultivation environments. In this review we (i) examine the main limitations of crop simulation modelling for supporting ideotype breeding, (ii) describe developments in cultivar traits in response to climate variations, and (iii) present examples of how crop simulation has supported evaluation and design of cereal cultivars for future conditions. An early success story for rice demonstrates the potential of crop simulation modelling for ideotype breeding. Combining conventional crop simulation with new breeding methods and genetic modelling holds promise to accelerate delivery of future cereal cultivars for different environments. Robustness of model-aided ideotype design can further be enhanced through continued improvements of simulation models to better capture effects of extremes and the use of multi-model ensembles.

[Biaxial reconstruction nail for pertrochanteric femoral fractures. Osteosynthesis]. / Biaxialer Rekonstruktionsnagel für pertrochantäre Femurfrakturen. Osteosynthese.

BACKGROUND: The steady rise in life expectancy of our population leads to an exponential increase in proximal femoral fractures. The growing increase of comorbidities in these patients requires continuous development of modern implant systems for internal fixation of proximal femoral fractures. MATERIALS AND METHODS: In this study we enrolled 116 patients with pertrochanteric femoral fractures who were treated with a proximal femoral nail (Targon PF, Aesculap) over a period of 1 year. The indications for this implant system were set at unstable fracture types. Data of the operative and postoperative course were collected prospectively. RESULTS: The average age of the 116 predominantly female subjects was 77±14 years and the most commonly observed fracture subtype was 31-A1.2. The follow-up rate was 55 %. We observed a decrease in the postoperative modified Harris hip score of 22.7 %. The 1-year mortality was 21.6 %. CONCLUSIONS: The results of this study showed a low rate of perioperative complications and implant loss anda decline in patient mobility was typically observed within 1 year.

Changes in time of sowing, flowering and maturity of cereals in Europe under climate change.

The phenological development of cereal crops from emergence through flowering to maturity is largely controlled by temperature, but also affected by day length and potential physiological stresses. Responses may vary between species and varieties. Climate change will affect the timing of cereal crop development, but exact changes will also depend on changes in varieties as affected by plant breeding and variety choices. This study aimed to assess changes in timing of major phenological stages of cereal crops in Northern and Central Europe under climate change. Records on dates of sowing, flowering, and maturity of wheat, oats and maize were collected from field experiments conducted during the period 1985-2009. Data for spring wheat and spring oats covered latitudes from 46 to 64°N, winter wheat from 46 to 61°N, and maize from 47 to 58°N. The number of observations (site-year-variety combinations) varied with phenological phase, but exceeded 2190, 227, 2076 and 1506 for winter wheat, spring wheat, spring oats and maize, respectively. The data were used to fit simple crop development models, assuming that the duration of the period until flowering depends on temperature and day length for wheat and oats, and on temperature for maize, and that the duration of the period from flowering to maturity in all species depends on temperature only. Species-specific base temperatures were used. Sowing date of spring cereals was estimated using a threshold temperature for the mean air temperature during 10 days prior to sowing. The mean estimated temperature thresholds for sowing were 6.1, 7.1 and 10.1°C for oats, wheat and maize, respectively. For spring oats and wheat the temperature threshold increased with latitude. The effective temperature sums required for both flowering and maturity increased with increasing mean annual temperature of the location, indicating that varieties are well adapted to given conditions. The responses of wheat and oats were largest for the period from flowering to maturity. Changes in timing of cereal phenology by 2040 were assessed for two climate model projections according to the observed dependencies on temperature and day length. The results showed advancements of sowing date of spring cereals by 1-3 weeks depending on climate model and region within Europe. The changes were largest in Northern Europe. Timing of flowering and maturity were projected to advance by 1-3 weeks. The changes were largest for grain maize and smallest for winter wheat, and they were generally largest in the western and northern part of the domain. There were considerable differences in predicted timing of sowing, flowering and maturity between the two climate model projections applied.

Shifts in comparative advantages for maize, oat and wheat cropping under climate change in Europe.

Climate change is anticipated to affect European agriculture, including the risk of emerging or re-emerging feed and food hazards. Indirectly, climate change may influence such hazards (e.g. the occurrence of mycotoxins) due to geographic shifts in the distribution of major cereal cropping systems and the consequences this may have for crop rotations. This paper analyses the impact of climate on cropping shares of maize, oat and wheat on a 50-km square grid across Europe (45-65°N) and provides model-based estimates of the changes in cropping shares in response to changes in temperature and precipitation as projected for the time period around 2040 by two regional climate models (RCM) with a moderate and a strong climate change signal, respectively. The projected cropping shares are based on the output from the two RCMs and on algorithms derived for the relation between meteorological data and observed cropping shares of maize, oat and wheat. The observed cropping shares show a south-to-north gradient, where maize had its maximum at 45-55°N, oat had its maximum at 55-65°N, and wheat was more evenly distributed along the latitudes in Europe. Under the projected climate changes, there was a general increase in maize cropping shares, whereas for oat no areas showed distinct increases. For wheat, the projected changes indicated a tendency towards higher cropping shares in the northern parts and lower cropping shares in the southern parts of the study area. The present modelling approach represents a simplification of factors determining the distribution of cereal crops, and also some uncertainties in the data basis were apparent. A promising way of future model improvement could be through a systematic analysis and inclusion of other variables, such as key soil properties and socio-economic conditions, influencing the comparative advantages of specific crops.

Sensitivity of barley varieties to weather in Finland.

Global climate change is predicted to shift seasonal temperature and precipitation patterns. An increasing frequency of extreme weather events such as heat waves and prolonged droughts is predicted, but there are high levels of uncertainty about the nature of local changes. Crop adaptation will be important in reducing potential damage to agriculture. Crop diversity may enhance resilience to climate variability and changes that are difficult to predict. Therefore, there has to be sufficient diversity within the set of available cultivars in response to weather parameters critical for yield formation. To determine the scale of such 'weather response diversity' within barley (Hordeum vulgare L.), an important crop in northern conditions, the yield responses of a wide range of modern and historical varieties were analysed according to a well-defined set of critical agro-meteorological variables. The Finnish long-term dataset of MTT Official Variety Trials was used together with historical weather records of the Finnish Meteorological Institute. The foci of the analysis were firstly to describe the general response of barley to different weather conditions and secondly to reveal the diversity among varieties in the sensitivity to each weather variable. It was established that barley yields were frequently reduced by drought or excessive rain early in the season, by high temperatures at around heading, and by accelerated temperature sum accumulation rates during periods 2 weeks before heading and between heading and yellow ripeness. Low temperatures early in the season increased yields, but frost during the first 4 weeks after sowing had no effect. After canopy establishment, higher precipitation on average resulted in higher yields. In a cultivar-specific analysis, it was found that there were differences in responses to all but three of the studied climatic variables: waterlogging and drought early in the season and temperature sum accumulation rate before heading. The results suggest that low temperatures early in the season, delayed sowing, rain 3-7 weeks after sowing, a temperature change 3-4 weeks after sowing, a high temperature sum accumulation rate from heading to yellow ripeness and high temperatures (⩾25°C) at around heading could mostly be addressed by exploiting the traits found in the range of varieties included in the present study. However, new technology and novel genetic material are needed to enable crops to withstand periods of excessive rain or drought early in the season and to enhance performance under increased temperature sum accumulation rates prior to heading.

New evidence relating to the health impact of reducing salt intake.

This paper is a Position Statement from an 'ad hoc' Scientific Review Subcommittee of the PAHO/WHO Regional Expert Group on Cardiovascular Disease Prevention through Dietary Salt Reduction. It is produced in response to requests from representatives of countries of the Pan-American Region of WHO needing clarification on two recent publications casting doubts on the appropriateness of population wide policies to reduce salt intake for the prevention of cardiovascular disease. The paper provides a brief background, a critical appraisal of the recent reports and explanations as why the implications have been mis-interpreted. The paper concludes that the benefits of salt reduction are clear and consistent, and reinforces the recommendations outlined by PAHO/WHO and other organizations worldwide for a population reduction in salt intake to prevent strokes, heart attacks and other cardiovascular events.