104 research outputs found

    Hypolimnetic withdrawal coupled with oxygenation as lake restoration measures : the successful case of Lake Varese (Italy)

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    Lake Varese is a relatively small lake, belonging to the drainage basin of lake Maggiore (northern Italy). It has had a long history (since 1960s) of water quality deterioration as the result of cultural eutrophication. In 1967 a restoration project was designed, including a sewerage network, an O-ring sewage diversion system, and a centralised wastewater treatment plant with phosphorus and nitrogen control. Since the 1990's, the lake has been the object of a cooperative research program supported by the European Commission, the Italian Ministry of the Environment, the Lombardy Region, and the Varese Province. The subsequent studies revealed that the lake responded to the decreased external nutrient loads. Besides, mathematical models predicted a rather long period (30 years) to attain the restoration goal, recognising the importance of internal P loading from sediments. Also, it was predicted that the application of in-lake measures would be beneficial in accelerating lake recovery. Recently, two measures have been suggested, i.e. hypolimnetic withdrawal in the deepest section (maximum depth: 26 m) and oxygenation in the shallower section, during summer stratification. Lake Varese constitutes the first case in Italy where in-lake methods are used to counteract the problems caused by excessive nutrient enrichment in a relative large system (lake surface: 14.52 km2). In this paper, preliminary results of the first two years of operation (2000/2001) are summarised. The results are greatly encouraging. Lake water quality characteristics are as follows: Secchi transparency increased from 3.2 m to 4.9 m; annual mean total P concentrations decreased from 180 mg/m3 to 70 mg/m3; average chlorophyll values decreased from 40 mg/m3 to 17 mg/m3; the frequency of nuisance algal blooms declined to half in comparison to the 1990's and the algal density declined by a factor of 4, and anoxia periods decreased in time and space. Moreover, it has been evaluated that nutrient loads from lake Varese, due to the selected water discharges, did not affect the total nutrient budget of lake Maggiore and the downstream water quality.El lago Varese es un lago relativamente pequeño, situado en la cuenca de drenaje del lago Maggiore (norte de Italia). Presenta una larga historia (desde los años 60) de degradación de la calidad del agua como resultado de una eutrofización cultural. En 1967 se diseñó un proyecto de restauración, incluyendo una red de alcantarillado, un sistema en anillo de desvío de aguas residuales, y una planta centralizada de tratamiento de aguas residuales con control de fósforo y nitrógeno. Desde los años 90, el lago ha sido objeto de un programa de cooperación científica financiado por la Comisión Europea, el Ministerio de Medio Ambiente de Italia, la Región de Lombardy y la provincia de Varese. Los estudios resultantes mostraron la respuesta del lago a la disminución de la carga de nutrientes externa. Además, los modelos matemáticos predijeron un período bastante largo (30 años) para lograr el objetivo de restauración, reconociendo la importancia de la carga interna de P de los sedimentos. También, se predijo que la aplicación de medidas en el propio lago sería beneficiosa en la aceleración de la recuperación del lago. Recientemente, se han propuesto dos medidas, i.e. drenaje hipolimnético en la cubeta más profunda (profundidad máxima: 26 m) y oxigenación en la zona más somera, durante la estratificación estival. El lago Varese constituye el primer caso en Italia donde se han adoptado medidas en el propio lago para contrarrestar los problemas causados por un enriquecimiento excesivo de nutrientes en un sistema relativamente grande (superficie del lago: 14.52 km2). En este artículo se resumen los resultados preliminares de los dos primeros años de actuación (2000/2001). Los resultados son enormemente alentadores. Las características de la calidad del agua del lago son las siguientes: la transparencia del Secchi aumentó de 3.2 a 4.9 m; las concentraciones medias anuales de P total disminuyeron de 180 mg/m3 a 70 mg/m3; los valores medios de clorofila disminuyeron de 40 mg/m3 a 17 mg/m3; la frecuencia de florecimiento de algas se redujo a la mitad en comparación con los años 90 y la densidad de algas se dividió por un factor de 4, y los períodos de anoxia disminuyeron en el tiempo y en el espacio. Además, se ha comprobado que la carga de nutrientes procedente del lago Varese, a causa de las descargas de agua selectivas, no afectó al balance total de nutrientes del lago Maggiore ni a la calidad del agua del río aguas abajo

    Epidemiology of Strongyloides stercoralis in northern Italy: Results of a multicentre case-control study, February 2013 to July 2014

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    Strongyloides stercoralis is a soil-transmitted helminth widely diffused in tropical and subtropical regions of the world. Autochthonous cases have been also diagnosed sporadically in areas of temperate climate. We aimed at defining the epidemiology of strongyloidiasis in immigrants and Italians living in three northern Italian Regions. Screening for S. stercoralis infection was done with serology, confirmation tests were a second serological method or stool agar culture. A case-control approach was adopted and patients with a peripheral eosinophil count 65 500/mcL were classified as cases. Of 2,701 individuals enrolled here 1,351 were cases and 1,350 controls; 86% were Italians, 48% women. Italians testing positive were in 8% (97/1,137) cases and 1% (13/1,178) controls (adjusted odds ratio (aOR) 8.2; 95% confidence interval (CI): 4.5-14.8), while positive immigrants were in 17% (36/214) cases and in 2% (3/172) controls (aOR 9.6; 95% CI: 2.9-32.4). Factors associated with a higher risk of infection for all study participants were eosinophilia (p < 0.001) and immigration (p = 0.001). Overall, strongyloidiasis was nine-times more frequent in individuals with eosinophilia than in those with normal eosinophil count

    Dysregulation of the immune response in TGF-β signalopathies

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    The transforming growth factor-β (TGF-β) family of cytokines exerts pleiotropic functions during embryonic development, tissue homeostasis and repair as well as within the immune system. Single gene defects in individual component of this signaling machinery cause defined Mendelian diseases associated with aberrant activation of TGF-β signaling, ultimately leading to impaired development, immune responses or both. Gene defects that affect members of the TGF-β cytokine family result in more restricted phenotypes, while those affecting downstream components of the signaling machinery induce broader defects. These rare disorders, also known as TGF-β signalopathies, provide the unique opportunity to improve our understanding of the role and the relevance of the TGF-β signaling in the human immune system. Here, we summarize this elaborate signaling pathway, review the diverse clinical presentations and immunological phenotypes observed in these patients and discuss the phenotypic overlap between humans and mice genetically deficient for individual components of the TGF-β signaling cascade

    A large case series of travel-related Mansonella perstans (vector-borne filarial nematode): a TropNet study in Europe

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    Mansonella perstans; Travel; TreatmentMansonella perstans; Viaje; TratamientoMansonella perstans; Viatge; TractamentBackground Infection with Mansonella perstans is a neglected filariasis, widely distributed in sub-Saharan Africa, characterized by an elusive clinical picture; treatment for mansonellosis is not standardized. This retrospective study aimed to describe the clinical features, treatment schemes and evolution, of a large cohort of imported cases of M. perstans infection seen in four European centres for tropical diseases. Methods Mansonella perstans infections, diagnosed by identification of blood microfilariae in migrants, expatriates and travellers, collected between 1994 and 2018, were retrospectively analysed. Data concerning demographics, clinical history and laboratory examinations at diagnosis and at follow-up time points were retrieved. Results A total of 392 patients were included in the study. Of the 281 patients for whom information on symptoms could be retrieved, 150 (53.4%) reported symptoms, abdominal pain and itching being the most frequent. Positive serology and eosinophilia were present in 84.4% and 66.1%, respectively, of those patients for whom these data were available. Concomitant parasitic infections were reported in 23.5% of patients. Treatment, administered to 325 patients (82.9%), was extremely heterogeneous between and within centres; the most commonly used regimen was mebendazole 100 mg twice a day for 1 month. A total of 256 (65.3%) patients attended a first follow-up, median 3 months (interquartile range 2–12) after the first visit; 83.1% of patients having received treatment based on mebendazole and/or doxycycline, targeting Wolbachia, became amicrofilaremic, 41.1–78.4% of whom within 12 months from single treatment. Conclusions Lack of specific symptoms, together with the inconstant positivity of parasitological and antibody-based assays in the infected population, makes the clinical suspicion and screening for mansonellosis particularly difficult. Prospective studies evaluating prevalence of infection in migrants from endemic areas, infection-specific morbidity, presence of Wolbachia endosymbionts in M. perstans populations from different geographical areas and efficacy of treatment regimens are absolutely needed to optimize the clinical management of infection.The publication of this study was funded by Italian Ministry of Health Fondi Ricerca Corrente–L2 to IRCCS Sacro Cuore Don Calabria Hospital

    Daylight entanglement-based quantum key distribution with a quantum dot source

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    Entanglement-based quantum key distribution can enable secure communication in trusted node-free networks and over long distances. Although implementations exist both in fiber and in free space, the latter approach is often considered challenging due to environmental factors. Here, we implement a quantum communication protocol during daytime for the first time using a quantum dot source. This technology presents advantages in terms of narrower spectral bandwidth-beneficial for filtering out sunlight-and negligible multiphoton emission at peak brightness. We demonstrate continuous operation over the course of three days, across an urban 270 m-long free-space optical link, under different light and weather conditions

    Epidemiology and pathogenesis of maternal-fetal transmission of Trypanosoma cruzi and a case for vaccine development against congenital Chagas disease

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    Trypanos o ma cruzi (T. cruzi or Tc) is the causative agent of Chagas disease (CD). It is common for patients to suffer from non-specific symptoms or be clinically asymptomatic with acute and chronic conditions acquired through various routes of transmission. The expecting women and their fetuses are vulnerable to congenital transmission of Tc. Pregnant women face formidable health challenges because the frontline antiparasitic drugs, benznidazole and nifurtimox, are contraindicated during pregnancy. However, it is worthwhile to highlight that newborns can be cured if they are diagnosed and given treatment in a timely manner. In this review, we discuss the pathogenesis of maternal-fetal transmission of Tc and provide a justification for the investment in the development of vaccines against congenital CD.Fil: Rios, Lizette. University of Texas Medical Branch; Estados UnidosFil: Campos, Emiliano Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Menon, Ramkumar. University of Texas Medical Branch; Estados UnidosFil: Zago, María Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Garg, Nisha J.. University of Texas Medical Branch; Estados Unido

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
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