2,715 research outputs found
Contaminación de las fuentes de agua y sus efectos en el sistema nervioso y la conducta : impacto en el desarrollo poblacional
Fil: Yorio, Alberto A. Universidad de Buenos Aires. Facultad de Psicología; ArgentinaFil: Muzio, Rubén N. Universidad de Buenos Aires. Facultad de Psicología; ArgentinaLas soluciones eficaces para enfrentar el problema de la contaminación de las aguas deben contemplar el desarrollo de obras de infraestructura de plantas potabilizadoras de desalinización que lleguen a obtener agua con cifras aceptadas como potables. Otra consideración significativa a tener en cuenta, derivada de la existencia de arsénico en aguas y suelos, es la posible contaminación de alimentos de origen vegetal y animal que crecen y se crían en el área. En los últimos años se han desarrollado tecnologías que pueden ayudar a resolver estos problemas
Data-driven analysis for understanding ultrahigh energy cosmic ray source spectra
One of the most challenging open questions regarding the origin of ultrahigh
energy cosmic rays (UHECRs) deals with the shape of the source emission
spectra. A commonly-used simplifying assumption is that the source spectra of
the highest energy cosmic rays trace a Peters cycle, in which the maximum
cosmic-ray energy scales linearly with , i.e., with the charge of the UHECR
in units of the proton charge. However, this would only be a natural assumption
for models in which UHECRs escape the acceleration region without suffering
significant energy losses. In most cases, however, UHECRs interact in the
acceleration region and/or in the source environment changing the shape of the
source emission spectra. Energy losses are typically parameterized in terms of
and the UHECR baryon number , and therefore one would expect the source
emission spectra to be a function of both and . Taking a pragmatic
approach, we investigate whether existing data favor any region of the
parameter space. Using data from the Pierre Auger Observatory, we carry out a
maximum likelihood analysis of the observed spectrum and nuclear composition to
shape the source emission spectra for the various particle species. We also
study the impact of possible systematic uncertainties driven by hadronic models
describing interactions in the atmosphere
A Peters cycle at the end of the cosmic ray spectrum?
We investigate the degree to which current ultrahigh energy cosmic ray
observations above the ankle support a common maximum rigidity for all nuclei,
often called a Peters cycle, over alternative scenarios for the cosmic ray
spectra escaping sources. We show that a Peters cycle is not generally
supported by the data when compared with these alternatives. We explore the
observational signatures of non-Peters cycle scenarios, and the opportunities
to explore both ultrahigh energy cosmic ray source conditions, as well as,
physics beyond the Standard model they present
Paraneoplastic Acanthosis Nigricans Maligna
Acanthosis Nigricans Maligna (ANM) is a paraneoplastic syndrome, defined as a condition that arises in association
with a malignancy elsewhere in the body but without malignant nature per se. It’s a rare dermatopathy that occurs in
men and women over age 40, without racial predilection or known familial association. Clinically, ANM showed symmetric,hyperpigmented plaques with variable amounts of epidermal hypertrophy, ranging in color from yellow to brown or black, often with overlaid papillomas. The most common affected sites are body flexures and the posterior neck, but also mucosal surface involvement is frequent and may be the only clinical symptom present. Any mucosal surface can be involved, and as regards the oral cavity, disease affects the lips, tongue, palate, buccal and gingival mucosa.ANM is primarily associated with adenocarcinomas, mostly of gastric origin. Accordingly, the progression of the tumor will lead to a worsening of the ANM, while regress in case of tumour treatment, and resurface with recurrence and metastases.
A 62-year-old man was referred for evaluation of papillomatous lesions of the oral mucosa, appeared in previous
months. The patient was diagnosed a gastric adenocarcinoma at an advanced stage 6 months before. Clinical examination showed diffuse papillomatous or wart-like areas of normal mucosal color and soft consistency involving lips,oral mucosa and hard palate. The tongue and the vestibular mucosa were thickened and furrowed. The lesions are
asymptomatic. A biopsy was performed, and histopathological analysis revealed acanthosis and papillomatosis, hyperkeratosis,and lymphohistiocytic infiltrate. The patient was clinically diagnosed with ANM, according to clinical and histologic findings, and the patient’s medical history. Isotretinoin 0,05% was prescribed for local therapy. The patient
did not return to follow-up due to complications of gastric adenocarcinoma, and died 6 months late
Analysis of unsteady behaviour in shockwave turbulent boundary layer interaction
International audienceThe unsteady behaviour in shockwave turbulent boundary layer interaction is investigated by analysing results from a large eddy simulation of a supersonic turbulent boundary layer over a compression-expansion ramp. The interaction leads to a very-low-frequency motion near the foot of the shock, with a characteristic frequency that is three orders of magnitude lower than the typical frequency of the incoming boundary layer. Wall pressure data are first analysed by means of Fourier analysis, highlighting the low-frequency phenomenon in the interaction region. Furthermore, the flow dynamics are analysed by a dynamic mode decomposition which shows the presence of a low-frequency mode associated with the pulsation of the separation bubble and accompanied by a forward-backward motion of the shock
Lo studio FAST: FAringotonsillite STreptococcica in età pediatrica Impatto farmacoeconomico delle Linee Guida dell'American Academy of Pediatrics sulla pratica clinica di 600 pediatri italiani
The American Academy of Pediatrics (AAP) has recently published its new guidelines for the treatment of pediatric tonsillopharyngitis; a diagnostic test for the detection of streptococci is recommended, followed by a treatment with penicillins (10 days) or cephalosporins (5 days) in case of positivity, and by no treatment otherwise. The success of a guideline, in general, depends on its diffusion in practice and on its adaptability to different local settings. The aim of the present study (FAST) was the evaluation of the clinical and economical impact of the application of the AAP guidelines in the Italian reality. The study was conducted with the cooperation of 600 pediatricians, uniformly distributed on the Italian territory, and involved 3072 patients. The pediatricians were left free to decide whether to follow the guidelines or not. The results of the analysis indicate that only some 20% of the pediatricians adhered to the suggested protocol; the total cost (calculated in the perspective of the National Health System, with a time horizon of about 3 months) per patient, nonetheless, resulted inferior in the group treated according to the proposed protocol (50,45 • vs. 53,30 •). Furthermore, a lower incidence of complications occurred in these patients. Among the "off-protocol" behaviors, two showed particularly evident misuse of health resources: inappropriate treatment after test positivity (59,15 •/patient), and treatment after test negativity (14% of the total population). Another interesting, although not surprising, result of this study was the evidence that penicillins are as effective as cephalosporins in the short-term, but significantly inferior in terms of complications, positivity for streptococci at the control test, and complications detected at follow-up
Dietary fiber and gut microbiota in renal diets
Nutrition is crucial for the management of patients affected by chronic kidney disease (CKD) to slow down disease progression and to correct symptoms. The mainstay of the nutritional approach to renal patients is protein restriction coupled with adequate energy supply to prevent malnutrition. However, other aspects of renal diets, including fiber content, can be beneficial. This paper summarizes the latest literature on the role of different types of dietary fiber in CKD, with special attention to gut microbiota and the potential protective role of renal diets. Fibers have been identified based on aqueous solubility, but other features, such as viscosity, fermentability, and bulking effect in the colon should be considered. A proper amount of fiber should be recommended not only in the general population but also in CKD patients, to achieve an adequate composition and metabolism of gut microbiota and to reduce the risks connected with obesity, diabetes, and dyslipidemia
Possible link between Hashimoto's thyroiditis and oral lichen planus: a novel association found
none5Lo Muzio L.; Santarelli A.; Campisi G.; Lacaita MG.; Favia G.Lo Muzio, L.; Santarelli, Andrea; Campisi, G.; Lacaita, M. G.; Favia, G
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