38 research outputs found

    ¿El Mesozooplancton controla al fitoplancton y cianobacterias en el Embalse Paso de las Piedras?

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    Resulta relevante investigar ecológicamente el embalse Paso de las Piedras no sólo por su valor como reservorio de agua para consumo humano sino también para analizar estrategias que resuelvan/aminoren las proliferaciones de cianobacterias que alteran la calidad del agua. En este estudio se evaluó la interacción trófica entre el mesozooplancton y el fitoplancton - cianobacterias en términos de biomasa, con datos de 8 muestreos de un ciclo anual. Se realizaron correlaciones entre variables ambientales y bióticas. Estos primeros resultados sugieren que el mesozooplancton controla al fitoplancton y cianobacterias a través de su presión de pastoreo desde la primavera hasta fines del verano. Sin embargo, se requieren más estudios para corroborar estos resultados y además para estudiar el efecto del pastoreo de distintos grupos de edad de Odontesthes bonariensis sobre las especies del mesozooplancton presentes en el lago.Fil: Fritz, Laura Jesica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Estrada, Vanina Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Di Maggio, Jimena Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Díaz, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Hoffmeyer, Monica Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaX Congreso de Ecología y Manejo de Ecosistemas Acuáticos PampeanosAzulArgentinaUniversidad Nacional del Centro de la Provincia de Buenos Aires Facultad de Ciencias Exacta

    Preemptive simultaneous pancreas kidney transplantation has survival benefit to patients

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    Several organ allocation protocols give priority to wait-listed simultaneous kidney-pancreas (SPK) transplant recipients to mitigate the higher cardiovascular risk of patients with diabetes mellitus on dialysis. The available information regarding the impact of preemptive simultaneous kidney-pancreas transplantation on recipient and graft outcomes is nonetheless controversial. To help resolve this, we explored the influence of preemptive simultaneous kidney-pancreas transplants on patient and graft survival through a retrospective analysis of the OPTN/UNOS database, encompassing 9690 simultaneous transplant recipients between 2000 and 2017. Statistical analysis was performed applying a propensity score analysis to minimize bias. Of these patients, 1796 (19%) were transplanted preemptively. At ten years, recipient survival was significantly superior in the preemptive group when compared to the non-preemptive group (78.9% vs 71.8%). Dialysis at simultaneous kidney-pancreas transplantation was an independent significant risk for patient survival (hazard ratio 1.66 [95% confidence interval 1.32-2.09]), especially if the dialysis duration was 12 months or longer. Preemptive transplantation was also associated with significant superior kidney graft survival compared to those on dialysis (death-censored: 84.3% vs 75.4%, respectively; estimated half-life of 38.57 [38.33 -38.81] vs 22.35 [22.17 - 22.53] years, respectively). No differences were observed between both groups neither for pancreas graft survival nor for post-transplant surgical complications. Thus, our results sustain the relevance of early referral for pancreas transplantation and the importance of pancreas allocation priority in reducing patient mortality after simultaneous kidney-pancreas transplantation

    Incidence of severe breakthrough SARS-CoV-2 infections in vaccinated kidney transplant and haemodialysis patients

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    Introduction: Given the increased COVID-19 observed in kidney transplant recipients (KTRs) and haemodialysis patients, several studies have tried to establish the efficacy of mRNA vaccines in these populations by evaluating their humoral and cellular responses. However, there is currently no information on clinical protection (deaths and hospitalizations), a gap that this study aims to fill. Methods: Observational prospective study involving 1,336 KTRs and haemodialysis patients from three dialysis units affiliated to Hospital Clínic of Barcelona, Spain, vaccinated with two doses of mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 mRNA vaccines. The outcomes measured were SARS-CoV-2 infection diagnosed by a positive RT-PCR fourteen days after the second vaccine dose, hospital admissions derived from infection, and a severe COVID-19 composite outcome, defined as either ICU admission, invasive and non-invasive mechanical ventilation, or death. Results: Six per cent (18/302) of patients on haemodialysis were infected, of whom four required hospital admission (1.3%), only one (0.3%) had severe COVID-19, and none of them died. In contrast, 4.3% (44/1034) of KTRs were infected, and presented more hospital admissions (26 patients, 2.5%), severe COVID-19 (11 patients, 1.1%) or death (4 patients, 0.4%). KTRs had a significantly higher risk of hospital admission than HD patients, and this risk increased with age and male sex (HR 3.37 and 4.74, respectively). Conclusions: The study highlights the need for booster doses in KTRs. In contrast, the haemodialysis population appears to have an adequate clinical response to vaccination, at least up to four months from its administration

    Humoral and Cellular Immune Responses After a 3-dose Course of mRNA-1273 COVID-19 Vaccine in Kidney Transplant Recipients: A Prospective Cohort Study.

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    In kidney transplant recipients, there is discordance between the development of cellular and humoral response after vaccination against SARS-CoV-2. We sought to determine the interplay between the 2 arms of adaptive immunity in a 3-dose course of mRNA-1273 100 μg vaccine. Methods: Humoral (IgG/IgM) and cellular (N- and S-ELISpot) responses were studied in 117 kidney and 12 kidney-pancreas transplant recipients at the following time points: before the first dose, 14 d after the second dose' and before and after the third dose, with a median of 203 and 232 d after the start of the vaccination cycle, respectively. Results: After the second dose, 26.7% of naive cases experienced seroconversion. Before the third dose and in the absence of COVID-19, this percentage increased to 61.9%. After the third dose, seroconversion occurred in 80.0% of patients. Naive patients who had at any time point a detectable positivity for S-ELISpot were 75.2% of the population, whereas patients who maintained S-ELISpot positivity throughout the study were 34.3%. S-ELISpot positivity at 42 d was associated with final seroconversion (odds ratio' 3.14; 95% confidence interval' 1.10-8.96; P = 0.032). Final IgG titer was significantly higher in patients with constant S-ELISpot positivity (P < 0.001). Conclusions: A substantial proportion of kidney transplant recipients developed late seroconversion after 2 doses. Cellular immunity was associated with the development of a stronger humoral respons

    The impact of human expert visual inspection on the discovery of strong gravitational lenses

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    We investigate the ability of human ’expert’ classifiers to identify strong gravitational lens candidates in Dark Energy Survey like imaging. We recruited a total of 55 people that completed more than 25% of the project. During the classification task, we present to the participants 1489 images. The sample contains a variety of data including lens simulations, real lenses, non-lens examples, and unlabeled data. We find that experts are extremely good at finding bright, well-resolved Einstein rings, whilst arcs with g-band signal-to-noise less than ∼25 or Einstein radii less than ∼1.2 times the seeing are rarely recovered. Very few non-lenses are scored highly. There is substantial variation in the performance of individual classifiers, but they do not appear to depend on the classifier’s experience, confidence or academic position. These variations can be mitigated with a team of 6 or more independent classifiers. Our results give confidence that humans are a reliable pruning step for lens candidates, providing pure and quantifiably complete samples for follow-up studies

    Health providers pass knowledge and abilities acquired by training in obstetric emergencies to their peers: the average treatment on the treated effect of PRONTO on delivery attendance in Mexico

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    Abstract Background A significant proportion of newborn and maternal deaths can be prevented through simple and cost-effective strategies. The main aim of this study was to evaluate the impact of the PRONTO obstetric-emergency management training for improving evidence-based birth attendance practices among providers attending the training at 12 hospitals in three states of Mexico from 2010 to 2012, and to estimate dissemination of the training within the hospitals. Methods The average treatment on the treated effect of the PRONTO intervention for the probability of performing certain practices during birth attendance was estimated in a sample of 310 health providers. Impact estimates were obtained by performing provider-level matching using a mixed Mahalanobis distance one-to-one nearest-neighbor and exact matching approach. A secondary analysis estimated the positive externalities caused by the intervention in the treated hospitals using the same analytical approach. Provider-level fixed effects regression models were used to estimate the rate of decay of the probability of performing the examined practices. Results Providers attending the PRONTO training showed significant increases in the probability of performing the complete active management of the third stage of labor, especially the first and third steps, and skin-to-skin-contact. There was a negative and significant effect on the probability of performing uterine sweeping. Providers who did not attend the training in treated hospitals also showed marked significant changes in the same practices, except for uterine sweeping. There was no evidence of a significant decay of the probability of performing the routine practices over time among the treated providers. Conclusions PRONTO is efficacious in changing trained providers’ behavior, but not on all practices, suggesting that some practices are deeply ingrained. The results also suggest that information on practices is effectively transmitted to peers within treated hospitals. Previous findings of the dilution of the effect of PRONTO on some practices seem to be more related to the rotation of personnel (mainly interns) rather than providers returning to their former habits. Trial registration NCT01477554. Registered on November 18, 2011; retrospectively registered

    Towards an Inclusive and Evidence-Based Definition of the Maternal Mortality Ratio: An Analysis of the Distribution of Time after Delivery of Maternal Deaths in Mexico, 2010-2013.

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    Progress towards the Millennium Development Goal No. 5 was measured by an indicator that excluded women who died due to pregnancy and childbirth after 42 days from the date of delivery. These women suffered from what are defined as late deaths and sequelae-related deaths (O96 and O97 respectively, according to the International Classification of Diseases, 10th revision). Such deaths end up not being part of the numerator in the calculation of the Maternal Mortality Ratio (MMR), the indicator that governments and international agencies use for reporting. The issue is not trivial since these deaths account for a sizeable fraction of all maternal deaths in the world and show an upward trend over time in many countries. The aim of this study was to analyze empirical data on maternal deaths that occurred between 2010 and 2013 in Mexico, linking databases of the Deliberate Search and Reclassification of Maternal Deaths (BIRMM) and the Birth Information Subsystem (SINAC) of the Ministry of Health. Data were analyzed by negative binomial regression, survival analysis and multiple cause analysis. While the reported MMR decreased by 5% per year between 2010 and 2013, the MMR due to late and sequelae-related deaths doubled from 3.5 to 7 per 100,000 live-births in 2013 (p <0.01). A survival analysis of all maternal deaths revealed nothing particular around the 42 day threshold, other than the exclusion of 18% of women who died due to childbirth in 2013. The multiple cause analysis showed a strong association between the excluded deaths and obstetric causes. It is suggested to review the construction of the MMR to make it a more inclusive and dignified measurement of maternal mortality by including all deaths due to pregnancy and childbirth into the Maternal Death definition

    Association between body mass index and aggressiveness of papillary thyroid carcinoma

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    The aim of the study was to evaluate the association of the body mass index (BMI) with the clinical-pathological characteristics and the recurrence of papillary thyroid carcinoma. The cohort consisted of 208 patients with papillary thyroid carcinoma diagnosed in 2003-2014, in Buenos Aires, Argentina. The patients were grouped according to the BMI as follows: BMI <18.5 kg/m2 (low weight); BMI ≥ 18.5 and < 25 kg/m2 (normal weight); BMI ≥ 25 and < 30 kg/m2 (overweight); BMI ≥ 30 kg/m2 (obesity). Two experienced pathologists reviewed and cross-checked all pathology specimens to confirm diagnosis, tumor characteristics and extent of the disease. All patients were followed every 6 months for 2 years, and annually thereafter. Recurrences were searched by using diagnostic imaging and histological confi rmation when necessary. Regression analysis was applied to defi ne associations of BMI with clinical, pathological, and prognosis features of the disease. A 5-point increase in BMI was significantly associated with tumor size (OR 1.21; 95% CI 1.1-1.5; p = 0.01) and greater extranodal extension in cervical metastases (OR 1.11; 95% CI 1.06-1.21; p = 0.03). The analysis of prognostic variables showed no association between increase in BMI and risk of recurrence (HR 1.11; 95% CI 0.91-1.22). In conclusion, we found that BMI relates directly with tumor size and extranodal extension, but not with recurrenc
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