Precision management of pollination services to blueberry crops.

While the cultivated area of pollinator-dependent crops is increasing, pollinator availability is decreasing, leading to problems in many agroecosystems. For this reason, pollinator-dependent crop growers often rent beehives to support their pollination requirements to sustain fruit productivity. However, the efficiency of those pollination systems has not been extensively studied. Here, we compared the effect of "precision" pollination (i.e., application of pesticides coordinated with growers, audit of hives, dietary supplementation and individual distribution of hives) with conventional practices (i.e., pesticides applications without coordination with growers and no audit of hives, low maintenance of hives and hives distributed in large groups) on the mean level of pollination and fruit production and quality in blueberry crops. In nine blueberry fields, we measured bee visitation rate to flowers, fruit set, fruit firmness and fruit weight. On average, precision-pollinated plots had 70% more bee visits to flowers and produced 13% more fruits that were 12% heavier and 12% firmer than those obtained through conventional practices. These results showed that pollination efficiency could be improved if key management related to bee strength, distribution and health care are taken into account. Due to these results, we encourage growers and beekeepers to include precision pollination practices to both increase the productivity of blueberry fields and the wellbeing of honey bees within agroecosystems.

Ecology of the collapse of Rapa Nui society.

Collapses of food producer societies are recurrent events in prehistory and have triggered a growing concern for identifying the underlying causes of convergences/divergences across cultures around the world. One of the most studied and used as a paradigmatic case is the population collapse of the Rapa Nui society. Here, we test different hypotheses about it by developing explicit population dynamic models that integrate feedbacks between climatic, demographic and ecological factors that underpinned the socio-cultural trajectory of these people. We evaluate our model outputs against a reconstruction of past population size based on archaeological radiocarbon dates from the island. The resulting estimated demographic declines of the Rapa Nui people are linked to the long-term effects of climate change on the island's carrying capacity and, in turn, on the 'per-capita food supply'.

Inflammatory bowel disease in Mexico: Epidemiology, burden of disease, and treatment trends. / Epidemiología, carga de la enfermedad y tendencias de tratamiento de la enfermedad inflamatoria intestinal en México.

INTRODUCTION AND AIMS: There is no systematized information for determining/monitoring the burden of inflammatory bowel disease in Mexico. The aim of the present study was to estimate the annual burden of inflammatory bowel disease on the Mexican National Healthcare System, by number of patients seen, hospitalizations, and specific deaths, stratified into age groups. MATERIALS AND METHODS: Utilizing specific databases of the Mexican National Healthcare System registries coded as ICD-10: K50 and K51, we retrieved and analyzed the data corresponding to the patients seen and hospitalized in 2015, stratified by age group, as well as the specific deaths. Treatment trends among physicians were also examined. RESULTS: In 2015, 5,009 women (8.1) and 4,944 men (8.4) with Crohn's disease received medical attention (prevalence of cases seen) and 35.1% of those patients were ≥50years of age. In that same period, 17,177 women (27.7) and 15,883 men (26.9) with ulcerative colitis were seen and 31.6% of those patients were ≥50years of age. The hospitalized cases (prevalence of hospitalized cases) were 1,097 patients (0.91) with Crohn's disease and 43.7% of those patients were ≥50years of age; and 5,345 patients (4.42) with ulcerative colitis and 47.6% of those patients were ≥50years of age. Deaths (specific mortality rate) were: 32 women (0.52) and 36 men (0.50) due to Crohn's disease, and 267 women (4.31) and 186 men (3.15) due to ulcerative colitis. CONCLUSIONS: Inflammatory bowel disease is a burden on the health of Mexican adults and the Mexican National Healthcare System, and it is expected to increase over the next 15years.

Three-dimensional computational fluid dynamics modeling of particle uptake by an occupational air sampler using manually-scaled and adaptive grids.

This work presents fluid flow and particle trajectory simulation studies to determine the aspiration efficiency of a horizontally oriented occupational air sampler using computational fluid dynamics (CFD). Grid adaption and manual scaling of the grids were applied to two sampler prototypes based on a 37-mm cassette. The standard k-ε model was used to simulate the turbulent air flow and a second order streamline-upwind discretization scheme was used to stabilize convective terms of the Navier-Stokes equations. Successively scaled grids for each configuration were created manually and by means of grid adaption using the velocity gradient in the main flow direction. Solutions were verified to assess iterative convergence, grid independence and monotonic convergence. Particle aspiration efficiencies determined for both prototype samplers were undistinguishable, indicating that the porous filter does not play a noticeable role in particle aspiration. Results conclude that grid adaption is a powerful tool that allows to refine specific regions that require lots of detail and therefore better resolve flow detail. It was verified that adaptive grids provided a higher number of locations with monotonic convergence than the manual grids and required the least computational effort.

Favourable impact of regular swimming in young people with haemophilia: experience derived from 'Desafio del Caribe' project.

Swimming is beneficial for persons with haemophilia (PWH) providing good maintenance of the cardiovascular and musculoskeletal system and improving many psychological characteristics. In the Desafío del Caribe Project, young PWH from Venezuela and Mexico took part in an open water competition in the Gulf of Mexico under a multidisciplinary team supervision. Eight severe haemophilia A, two moderate haemophilia A, one severe haemophilia B and two moderate haemophilia B subjects were included. Haematological, musculoskeletal and psychological evaluations were carried out before and during training for the competition. Training program included physical exercise routines and swimming practices that alternated between pools and open water. Swimmers had coverage with factor concentrates before pool and open water trainings. In physiatric evaluations, the Hemophilia Joint Health Score (HJHS) was used. The objective of the psychology area was to analyse self-esteem, precompetition anxiety, coping mechanisms and relaxation levels. The need of factor prophylaxis before intense trainings was confirmed. In the musculoskeletal system a decrease of elbow pain as well as an increase of muscle strength in the ankles were observed. In the psychological area significant differences between the first and second test in self-esteem levels, cognitive anxiety and group cohesion were found. PWH must be provided with orientation and encouragement to practice swimming regularly. High competition exercise must be supervised by a multidisciplinary team which must evaluate the pros and cons of the activity to make relevant recommendations.

Effect of wind speed and relative humidity on atmospheric dust concentrations in semi-arid climates.

Atmospheric particulate have deleterious impacts on human health. Predicting dust and aerosol emission and transport would be helpful to reduce harmful impacts but, despite numerous studies, prediction of dust events and contaminant transport in dust remains challenging. In this work, we show that relative humidity and wind speed are both determinants in atmospheric dust concentration. Observations of atmospheric dust concentrations in Green Valley, AZ, USA, and Juárez, Chihuahua, México, show that PM10 concentrations are not directly correlated with wind speed or relative humidity separately. However, selecting the data for high wind speeds (>4m/s at 10 m elevation), a definite trend is observed between dust concentration and relative humidity: dust concentration increases with relative humidity, reaching a maximum around 25% and it subsequently decreases with relative humidity. Models for dust storm forecasting may be improved by utilizing atmospheric humidity and wind speed as main drivers for dust generation and transport.

Musculoskeletal evaluation in severe haemophilia A patients from Latin America.

There is a paucity of literature on haemophilia treatment in Latin American countries, a region characterized by rapidly improving systems of care, but with substantial disparities in treatment between countries. The aim of this study was to evaluate the musculoskeletal status of haemophilia patients from Latin America and to examine the relationship between musculoskeletal status and treatment practices across countries. The Committee of Latin America on the Therapeutics of Inhibitor Groups conducted a survey of its member country representatives on key aspects of haemophilia treatment in 10 countries. Musculoskeletal status of patients was obtained during routine comprehensive evaluations between March 2009 and March 2011. Eligible patients had severe haemophilia A (factor VIII <1%) without inhibitors (<0.6 BU mL(-1) ) and were ≥5 years of age. Musculoskeletal status was compared between three groups of countries, based primarily on differences in the availability of long-term prophylaxis. Overall, 143 patients (5-66 years of age) were enrolled from nine countries. In countries where long-term prophylaxis had been available for at least 10 years (Group A), patients aged 5-10 years had significantly better mean World Federation of Hemophilia clinical scores, fewer target joints and fewer affected joints than patients from countries where long-term prophylaxis has been available for about 5 years (Group B) or was not available (Group C). In Latin America, the musculoskeletal status of patients with severe haemophilia without inhibitors has improved significantly in association with the provision of long-term prophylaxis. As more countries in Latin America institute this practice, further improvements are anticipated.

Identification of factor VIII gene mutations in patients with severe haemophilia A in Venezuela: identification of seven novel mutations.

Haemophilia A is caused by mutations in the gene encoding coagulation factor VIII (FVIII). In severe Haemophilia A (sHA), two inversions are responsible for approximately 50% of the genetic alterations (intron 22 and intron 1 inversions). The other mutations are extremely diverse and each affected family generally has its own mutation. Our aim was to detect the genetic alterations present in the FVIII gene (F8) in 54 unrelated male patients with sHA in Venezuela. We initially detected the presence of the intron 22 inversion by performing inverse PCR, and the negative patients for this inversion were analysed for the intron 1 inversion by PCR. Patients negative for both inversions were analysed using Conformation Sensitive Gel Electrophoresis for mutations in all exons, promoter region and 3'-UTR. sHA causative mutations were identified in 49 patients. Intron-22 and -1 inversions were detected in 41% and 0% of patients respectively. Besides these two mutations, 25 different mutations were identified, including nine nonsense, four small deletions, two small insertions, four missense, three splicing mutations and three large deletions. Seven novel mutations were identified, including two nonsense mutations, two small deletions, one small insertion, one missense mutation and one splicing mutation. Thirty one percent of the patients with identified mutations developed inhibitors against exogenous FVIII. This is the first report of F8 mutations in patients with sHA in Venezuela; the data from this study suggests that the spectrum of gene defects found in these patients is as heterogeneous as reported previously for other populations.

Elective surgery in patients with congenital coagulopathies and inhibitors: experience of the National Haemophilia Centre of Venezuela.

Elective surgery in patients with congenital haemophilia with inhibitors carries a high risk of bleeding. However, inhibitor patients also have a high risk of haemarthroses and other orthopaedic complications, and surgery could improve their quality of life. Successful elective surgery has been reported in inhibitor patients under haemostatic cover with plasma-derived activated prothrombin complex concentrate (pd-aPCC) or recombinant activated factor VII (rFVIIa). Recombinant FVIIa has recently become available in Venezuela and, unlike pd-aPCC, has not been associated with an anamnestic response. The aim of this study was to assess our experience using rFVIIa as a first-line and sustained treatment in elective invasive surgical procedures at the National Haemophilia Centre in Venezuela. Surgical procedures were classified as major or minor, under haemostatic cover with rFVIIa. A total of 13 patients (12 with haemophilia A with high-responding inhibitors and one with von Willebrand's disease type 3) underwent a total of 19 surgical procedures under rFVIIa cover. Thirteen procedures were classified as major surgeries. Intraoperative haemostasis was achieved in the majority of patients. Only two patients required an additional dose of rFVIIa, at 30 min and 75 min, respectively, with good results. Postoperative haemostasis was considered effective in 16 of 18 (89%) of the procedures in haemophilia A patients. Treatment was considered to be ineffective in two patients because of excessive postoperative bleeding. Data from the study provide no safety concerns, and demonstrate that rFVIIa provides effective haemostatic cover in elective surgery in patients with inhibitors; research is ongoing to determine the optimal dose for such procedures.

Synthesis of amphiphilic dendrons and their interactions in aqueous solutions with cetyltrimethylammonium p-toluenesulfonate (CTAT).

In this work, we report synthesis and rheology of an interesting structured fluid based on the self-assembly of amphiphilic dendrons and wormlike micelles. Two amphiphilic dendrons were synthesized by the combination of aliphatic chains and polar dendritic heads. They showed different degrees of hydrophobicity and formed micelles in aqueous solution at critical micelle concentrations (CMC) of 25 and 125 ppm. The dendrons were soluble in water up to a concentration of approximately 1200 ppm, and produced no measurable increase in the viscosity of the solvent. The rheology of solutions of mixtures of each dendron with cetyltrimethylammonium p-toluenesulfonate (CTAT, a cationic surfactant) was characterized in simple shear flow. In the concentration range in which CTAT forms semidilute solutions of wormlike micelles, dendron addition produced a substantial synergy in zero-shear rate viscosity. Parallel-plate oscillatory shear measurements demonstrated that the CTAT/dendron mixtures are significantly more elastic than CTAT solutions. The viscosity synergy occurs at dendron concentrations lower than their CMC, and it is stronger for the more hydrophobic dendron. This suggests that the interactions between dendrons and wormlike micelles are basically hydrophobic, which implies attachment of dendron micelles to wormlike CTAT micelles in a manner similar to micellization of surfactants on polyelectrolytes.

Shear and extensional rheology of solutions of mixtures of poly(ethylene oxide) and anionic surfactants in ionic environments.

Interactions between a high molecular weight poly(ethylene oxide) (PEO) and the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in aqueous solutions were investigated by shear and extensional rheometry. Results for mixtures between PEO and sodium dodecyl sulfate (SDS) are also presented for comparison purposes. Addition of anionic surfactants to PEO solutions above the critical aggregation concentration (CAC), at which micellar aggregates attach to the polymer chain, results in an increase in shear viscosity due to PEO coil expansion, and a strengthening of interchain interactions. In extensional flows, these interactions result in a decrease of the critical shear rate for the onset of the characteristic extension thickening of the PEO solutions that is due to transient entanglements of polymer molecules. The relaxation times associated with these transient entanglements are not directly proportional to the shear viscosity of the solutions, but rather vary more rapidly with surfactant concentration. In the presence of an electrolyte, coil contraction results in lower shear viscosities and a decrease in the extension thickening effects at surfactant concentrations just beyond the CAC. The relaxation times associated with transient entanglement reach a minimum at the same surfactant concentration as the shear viscosity, which indicates that coil contraction is responsible for the observed effects in both types of flow. However, the increase in extensional-flow entanglement relaxation times is much more abrupt than the decrease in shear viscosity. All these results point to a greater sensitivity of extensional flows on the molecular conformation of PEO/surfactant complexes.

Shear rheology and porous media flow of wormlike micelle solutions formed by mixtures of surfactants of opposite charge.

The rheology of solutions of wormlike micelles formed by oppositely charged surfactant mixtures (cationic cetyl trimethylammonium p-toluene sulfonate, CTAT, and anionic sodium dodecyl sulfate, SDS), in the dilute and semi-dilute regimes, were studied under simple shear and porous media flows. Aqueous mixtures of CTAT and SDS formed homogeneous solutions for SDS/CTAT molar ratios below 0.12. Solutions of mixtures exhibited a strong synergistic effect in shear viscosity, especially in the semi-dilute regime with respect to wormlike micelles, reaching a four order of magnitude increase in the zero-shear rate viscosity for solutions with 20 mM CTAT. Oscillatory shear results demonstrated that the microstructure of CTAT wormlike micelles is sensitive to SDS addition. The cross-over relaxation times of wormlike micelles of 20 mM CTAT solutions increased by three orders of magnitude with the addition of up to 2 mM of SDS, and the solutions became increasingly elastic. The shear thickening process observed in shear rheology became more pronounced in porous media flow due to the formation of stronger cooperative structures induced by the extensional component of the flow.

Synergistic effects in flows of mixtures of wormlike micelles and hydroxyethyl celluloses with or without hydrophobic modifications.

This work presents experimental results on simple shear and porous media flow of aqueous solutions of two hydroxyethyl celluloses (HEC) and two hydrophobically modified hydroxyethyl celluloses (HMHEC) with different molecular weights. Mixtures of these polymers with a cationic surfactant, cetyltrimethylammonium p-toluenesulfonate (CTAT) were also studied. Emphasis was given to the range of surfactant concentrations in which wormlike micelles are formed. The presence of hydrophobic groups, the effect of the molecular weight of the polymers, the surfactant and polymer concentrations, and the effect of the flow field type (simple shear versus porous media flow) were the most important variables studied. The results show that the shear viscosity of HEC/CTAT solutions is higher than the viscosities of surfactant and polymer solutions at the same concentrations, but surface tension measurements indicate that no complex formation occurs between CTAT and HEC. On the other hand, a complex driven by hydrophobic interactions was detected by surface tension measurements between CTAT and HMHEC. In this case, the viscosity of the mixture increases significantly more (up to four orders of magnitude at high CTAT concentrations) in comparison with HEC/CTAT aqueous solutions. Increments in the molecular weight of the polymers increase the interaction with CTAT and the shear viscosity of the solution, but make phase separation more feasible. In porous media flow, the polymer/CTAT mixtures exhibited higher apparent viscosities than in simple shear flows. This result suggests that the extensional component of the flow field in porous media flows leads to a stronger interaction between the polymer and the wormlike micelles, probably as a consequence of change of conformation and growth of the micelles.

Chemical synoviorthesis with oxytetracycline clorhydrate (Emicine) in recurrent haemarthrosis.

This is a non-controlled experimental prospective clinical study that evaluates the satisfactory results in the chemical synovectomy (synoviorthesis) with oxytetracycline clorhydrate (Emicine, Lab. Pfizer Ltda, Guarulhos, Sao Paulo, Brazil) in recurrence haemarthrosis in different joints, demonstrating that it is an effective method in the treatment of these recurrent haemarthrosis in haemophilia. 84 patients of whom 77 concluded the full course of treatment. 82 joints were injected. The dosage injected was 5 cm(3) of the drug (25 mg) in 5 cm(3) of anaesthesia for the knee, 2 cm(3) with 1 cm(3) of anaesthesia for the elbow and 1 cm(3) plus 1 cm(3) of anaesthesia for the ankle. These injections were administered once weekly with a reinforcement in 1 month. In case of failure the same can be administered repeatedly. Subjective parameters included pain, range of movement and use of the joint involved. Pain decreased from a mean of 6.5 to 0.9 (Likert scale). Range of movement increased from 5.9 to 9 and joint use increased from 5.9 to 9.2. Objective parameters included joint diameter and range of movement. Range of movement for flexion and extension improved from 72.2 and 149.2 to 73.7 and 167, respectively, for the knees. From 57.3 and 160 to 66.6 and 170, respectively, for the shoulder. And, from 22.7 and 10.8 to 34 and 18.6, respectively, for the ankle. This procedure has multiple advantages such as immediate therapeutic effect, short period of treatment, easy technique, much less AHF coverage (30% above coagulation level), less costly than radiocolloid treatment, which make it a perfect alternative treatment for developing countries.

Trombofilias: condiciones emergentes de impacto reproductivo / Thrombophilias: emerging impact of reproductive conditions

La intención de esta publicación ha sido revisar la relación existente entre las condiciones pro-trombóticas conocidas como trombofilias y algunas de las patologías más severas que pueden ocurrir durante la gestación. El embarazo puede ser considerado como un examen para evaluar la capacidad funcional de todos los órganos y sistemas. Las trombofilias pueden afectar desde la implantación, formación y funcionamiento de la placenta, manifestándose como abortos a repetición, cuadros hipertensivos severos, restricción de crecimiento y hasta la muerte fetal. Estas enfermedades, al estar relacionadas a trombofilias, abren una ventana a la posibilidad de establecer nuevas estrategias de prevención y tratamiento.

Síndrome de anticuerpos antifosfolípidos / Antiphospholipid antibody syndrome

La intención de esta publicación ha sido revisar una patología emergente y de impacto reproductivo como es el síndrome antifosfolípidos. Especialmente nuestro enfoque es hacia su relación con patología obstétrica y su enfrentamiento en el embarazo. Además se revisan sus nuevos criterios diagnósticos y las nuevas estrategias para su estudio y tratamiento los que han logrado modificar en forma considerable el pronóstico y consecuencias de la enfermedad durante la gestación y el puerperio.

Trombofilias congénitas impacto reproductivo y perspectivas de tratamiento / Congenital thrombophilias reproductive impact and treatment

La intención de esta publicación ha sido revisar la relación existente entre las condiciones pro-trombóticas hereditarias conocidas como trombofilias congénitas y algunas de las patologías más severas que pueden ocurrir durante la gestación. Las trombofilias pueden afectar desde la implantación, formación y funcionamiento de la placenta, manifestándose como abortos a repetición, cuadros hipertensivos severos, restricción de crecimiento y hasta la muerte fetal. Estas enfermedades, al estar relacionadas a trombofilias, abren una ventana a la posibilidad de establecer nuevas estrategias de prevención, diagnóstico y tratamiento.

Prevalencia, percepción de síntomas y factores de riesgo de lesiones músculo-esqueléticas en trabajadores expuestos y no expuestos a bajas temperaturas / Prevalence, perception of symptoms and factors of risk of musculoskeletal injuries in cold exposed and non-cold exposed workers

En industrias expuestas a bajas temperaturas no existe información concerniente a esclarecer la presencia de una relación entre exposición a frío y generación de lesiones del aparato músculo-esquelético. Se estableció la definición de un Grupo de Exposición a condiciones de producción con bajas temperaturas y un Grupo de Control sin exposición. Se determinaron tareas críticas de generación de lesiones, siendo evaluadas mediante la aplicación de herramientas como RULA, OCRA, Ecuación Niosh-1991 y Guía para el manejo manual de cargas. Además se determinó la prevalencia de atenciones médicas y la evidencia clínica de lesiones por estos factores y se constató la percepción de síntomas de lesiones músculo-esqueléticas, presencia de factores de riesgo capaces de generar lesiones músculo-esqueléticas. Se determinó una prevalencia significativa (p<0,05) de presentaciones para atención médica en el grupo expuesto, y la percepción de lesiones músculo-esqueléticas es significativamente mayor (p<0,05) en trabajadores expuestos. Este estudio señala el precedente de la existencia de desórdenes músculo-esqueléticos en estas actividades, a partir de lo cual se puede diseñar tácticas de formación continua y vigilancia permanente en la implementación de un Programa de Vigilancia Epidemiológica que establezca criterios comunes de evaluación de estas actividades.

A definition was made of Group of Exposure to production conditions under low temperatures and of Control Group with no exposition. Critical tasks that originate injuries were determined and assessed by the aplication of tools such as RULA, OCRA, Niosh-1991 Equation and the Guide for the Manual Handling of Loads. Also, the prevalence of medical attentions and the clinic evidence of injuries from these factors were determined and the perception of symptoms of muscleskeletal injuries and presence of risk factors capable of generating musculoskeletal injuries were confirmed. A significant prevalence (p<0.05) of request of medical attention in exposed group was determined, and the perception of muscle-skeletal injuries is significantly higher (p<0.05) in exposed workers.This paper points out the precedent of the existence of musculoskeletal injuries disorders in these activities, from which tactics of continuous education and permanent surveillance may be designed, in the implementation of an Epidemiological Surveillance Program that establishes common assessment criteria for these activities.

Effect of ionic strength on the rheological behavior of aqueous cetyltrimethylammonium p-toluene sulfonate solutions.

The influence of ionic environment on the rheological properties of aqueous cetyltrimethylammonium p-toluene sulfonate (CTAT) solutions has been studied under three different flow fields: simple shear, opposed-jets flow and porous media flow. Emphasis was placed in the experiments on a range of CTAT concentration in which wormlike micelles were formed. It is known that these solutions exhibit shear thickening in the semi-dilute regime, which has been explained in terms of the formation of shear-induced, cooperative structures involving wormlike micelles. In simple shear flow, the zero shear viscosity exhibits first an increase with salt addition followed by a decrease, while the critical shear rate for shear thickening increases sharply at low salt contents and tends to saturate at relatively high ionic strengths. The results are explained in terms of a competition between micellar growth induced by salt addition and changes in micellar flexibility caused by ionic screening effects. Dynamic light scattering results indicate that micelles grow rapidly upon salt addition but eventually achieve a constant size under static conditions. These observations suggest that the wormlike micelles continuously grow with salt addition, but, as they become more flexible due to electrostatic screening, the wormlike coils tend to adopt a more compact conformation. The trends observed in the apparent viscosities measured in porous media flows seem to confirm these hypotheses-but viscosity increases in the shear thickening region-and are magnified by micelle deformation induced by the elongational nature of the local flow in the pores. In opposed-jets flow, the solutions have a behavior that is close to Newtonian, which suggests that the range of strain rates employed makes the flow strong enough to destroy or prevent the formation of cooperative micellar structures.