1,079 research outputs found

    Verifiable Learning for Robust Tree Ensembles

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    Verifying the robustness of machine learning models against evasion attacks at test time is an important research problem. Unfortunately, prior work established that this problem is NP-hard for decision tree ensembles, hence bound to be intractable for specific inputs. In this paper, we identify a restricted class of decision tree ensembles, called large-spread ensembles, which admit a security verification algorithm running in polynomial time. We then propose a new approach called verifiable learning, which advocates the training of such restricted model classes which are amenable for efficient verification. We show the benefits of this idea by designing a new training algorithm that automatically learns a large-spread decision tree ensemble from labelled data, thus enabling its security verification in polynomial time. Experimental results on public datasets confirm that large-spread ensembles trained using our algorithm can be verified in a matter of seconds, using standard commercial hardware. Moreover, large-spread ensembles are more robust than traditional ensembles against evasion attacks, at the cost of an acceptable loss of accuracy in the non-adversarial setting

    Cadmium and other hazardous elements in phosphatic fertilizers in conformity to the new European Regulation 2019/1009

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    The current European Fertilizers Regulation EC n. 2003/2003 does not include any direction for the content in cadmium [1]. On 25 June 2019, the new EU Fertilizing Products and Amending Regulation (EU-FPR) 2019/1009 was promulgated by the European Parliament and the Council, fixing an initial and temporary limit for Cd content in inorganic macronutrient fertilizer to 60 mgCd ∙ kgP2O5-1 [2]. The new European limit for Cd would be the most stringent in the world and only 15% of the phosphorite deposits currently exploited exhibits a low cadmium content complying with the new standard once processed to fertilizer. Since there are no substitutes for phosphate rock in phosphatic fertilizer production [3,4], the outcome of the new standard application would make unsustainable the supply of phosphatic fertilizers. This will result in a short-term measure that goes beyond the long-term sustainability objective of the proposal. In addition, the new standard will inevitably and disproportionately penalise some producers, mainly from developing countries in North Africa. It is therefore important to investigate for Cd and other hazardous elements content in fertilizers used for food production. The present research has analysed a total of 41 samples of fertilizers both for hobby and professional use obtained from the Italian market. Producers of Western and Middle Eastern Europe use the same phosphorite deposits to obtain fertilizers, thus the results of this investigation can be extended to the whole area. Obtained samples were initially pulverized in a ball mill and subjected to acid digestion in a microwave oven. Different acid digestion methods (HNO3 - HF - aqua regia - H2O2) were developed and tested for processing phosphate rock, inorganic and organo-mineral fertilizers to optimize the dissolution of different matrices. Standard reference materials, NIST SRM-695 (NPK fertilizer) and BCR-032 (Morocco phosphate rock) were processed using the same methods. Elemental analyses were performed in ICP-OES (Na, Mg, Al, Si, P, S, K, Ca, Fe, Se, Hg) and ICP-MS (Li, Be, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd, Sn, Sb, Ba, Tl, Pb, Bi, U). The first results showed very low Cd concentrations in hobby products. This commercial sector is known to import low-cost phosphate rock from Russia or Cola Peninsula, with a lower nutrient quality, but also a lower Cd content in comparison with professional products. Uranium content was found in relatively high concentrations and a radioactivity study has been considered as a logical extension of this research. The next analysis of more samples collected in spring will account for different fertilizer types used in distinct agricultural phases. [1] European Union. Off. J. Eur. Union. 2003, EUR-Lex - 32003R2003. [2] European Union. Off. J. Eur. Union. 2019, EUR-Lex - 32019R1009. [3] Mar, S.S., Okazaki, M. Microchem. J. 2012, 104, 17–21. [4] Ulrich, A.E. Sci. Total Environ. 2019, 650(1), 541–545

    Interval Sentinel Lymph Nodes: An Unusual Localization in Patients with Cutaneous Melanoma

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    Background. Recent studies have demonstrated that there exists a great variation in the lymphatic drainage in patients with malignant melanoma. Some patients have drainage to lymph nodes outside of conventional nodal basins. The lymph nodes that exist between a primary melanoma and its regional nodal basin are defined “interval nodes”. Interval node occurs in a small minority of patients with forearm melanoma. We report our experience of the Melanoma Unit of University Hospital Spedali Civili Brescia, Italy. Methods. Lymphatic mapping using cutaneous lymphoscintigraphy (LS) has become a standard preoperative diagnostic procedure to locate the sentinel lymph nodes (SLNs) in cutaneous melanoma. We used LS to identify sentinel lymph nodes biopsy (SLNB) in 480 patients. Results. From over 2100 patients affected by cutaneous melanoma, we identified 2 interval nodes in 480 patients with SLNB . The melanomas were both located in the left forearm. The interval nodes were also both located in the left arm. Conclusion. The combination of preoperative LS and intraoperative hand-held gamma detecting probe plays a remarkable role in identifying these uncommon lymph node locations. Knowledge of the unusual drainage patterns will help to ensure the accuracy and the completeness of sentinel nodes identification

    Long-term topical management of psoriasis: the road ahead

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    AbstractTopical therapies have been available for the treatment of psoriasis for several decades. Despite this and the availability of several types of topicals, with varying potency, and numerous ..

    Dengue Virus Type 3 Adaptive Changes during Epidemics in Sao Jose de Rio Preto, Brazil, 2006–2007

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    Global dengue virus spread in tropical and sub-tropical regions has become a major international public health concern. It is evident that DENV genetic diversity plays a significant role in the immunopathology of the disease and that the identification of polymorphisms associated with adaptive responses is important for vaccine development. The investigation of naturally occurring genomic variants may play an important role in the comprehension of different adaptive strategies used by these mutants to evade the human immune system. In order to elucidate this role we sequenced the complete polyprotein-coding region of thirty-three DENV-3 isolates to characterize variants circulating under high endemicity in the city of Sao Jose de Rio Preto, Brazil, during the onset of the 2006-07 epidemic. By inferring the evolutionary history on a local-scale and estimating rates of synonymous (dS) and nonsynonimous (dN) substitutions, we have documented at least two different introductions of DENV-3 into the city and detected 10 polymorphic codon sites under significant positive selection (dN/dS > 1) and 8 under significant purifying selection (dN/dS < 1). We found several polymorphic amino acid coding sites in the envelope (15), NS1 (17), NS2A (11), and NS5 (24) genes, which suggests that these genes may be experiencing relatively recent adaptive changes. Furthermore, some polymorphisms correlated with changes in the immunogenicity of several epitopes. Our study highlights the existence of significant and informative DENV variability at the spatio-temporal scale of an urban outbreak

    Effects of cannabinoid drugs on the deficit of prepulse inhibition of startle in an animal model of schizophrenia: the SHR strain

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    Clinical and neurobiological findings suggest that the cannabinoids and the endocannabinoid system may be implicated in the pathophysiology and treatment of schizophrenia. We described that the spontaneously hypertensive rats (SHR) strain presents a schizophrenia behavioral phenotype that is specifically attenuated by antipsychotic drugs, and potentiated by proschizophrenia manipulations. Based on these findings, we have suggested this strain as an animal model of schizophrenia. the aim of this study was to evaluate the effects of cannabinoid drugs on the deficit of prepulse inhibition (PPI) of startle, the main paradigm used to study sensorimotor gating impairment related to schizophrenia, presented by the SHR strain. the following drugs were used: (1) WIN55212,2 (cannabinoid agonist), (2) rimonabant (CB1 antagonist), (3) AM404 (anandamide uptake inhibitor), and (4) cannabidiol (CBD; indirect CB1/CB2 receptor antagonist, among other effects). VVistar rats (VVRs) and SHRs were treated with vehicle (VEH) or different doses of WIN55212 (0.3, 1, or 3 mg/kg), rimonabant (0.75, 1.5, or 3 mg/kg), AM404 (1, 5, or 10 mg/kg), or CBD (15, 30, or 60 mg/kg). VEH-treated SHRs showed a decreased PPI when compared to VVRs. This PPI deficit was reversed by 1 mg/kg WIN and 30 mg/kg CBD. Conversely, 0.75 mg/kg rimonabant decreased PPI in SHR strain, whereas AM404 did not modify it. Our results reinforce the role of the endocannabinoid system in the sensorimotor gating impairment related to schizophrenia, and point to cannabinoid drugs as potential therapeutic strategies.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Pharmacol, BR-04039032 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychiat, Lab Interdisciplinar Neurociencias Clin, BR-04039032 São Paulo, BrazilUniv São Paulo, Dept Neurosci & Behav, BR-14049 Ribeirao Preto, BrazilNatl Council Sci & Technol Dev, Natl Inst Sci & Technol Translat Med, Ribeirao Preto, BrazilUniversidade Federal de São Paulo, Dept Pharmacol, BR-04039032 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychiat, Lab Interdisciplinar Neurociencias Clin, BR-04039032 São Paulo, BrazilFAPESP: FAPESP - 2010/07994-3Web of Scienc

    Clinical and molecular characterization of 40 patients with classic Ehlers--Danlos syndrome: identification of 18 COL5A1 and 2 COL5A2 novel mutations.

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    Classic Ehlers-Danlos syndrome (cEDS) is a rare autosomal dominant connective tissue disorder that is primarily characterized by skin hyperextensibility, abnormal wound healing/atrophic scars, and joint hypermobility. A recent study demonstrated that more than 90% of patients who satisfy all of these major criteria harbor a type V collagen (COLLV) defect. This cohort included 40 patients with cEDS who were clinically diagnosed according to the Villefranche nosology. The flowchart that was adopted for mutation detection consisted of sequencing the COL5A1 gene and, if no mutation was detected, COL5A2 analysis. In the negative patients the presence of large genomic rearrangements in COL5A1 was investigated using MLPA, and positive results were confirmed via SNP-array analysis. We report the clinical and molecular characterization of 40 patients from 28 families, consisting of 14 pediatric patients and 26 adults. A family history of cEDS was present in 9 patients. The majority of the patients fulfilled all the major diagnostic criteria for cEDS; atrophic scars were absent in 2 females, skin hyperextensibility was not detected in a male and joint hypermobility was negative in 8 patients (20% of the entire cohort). Wide inter- and intra-familial phenotypic heterogeneity was observed. We identified causal mutations with a detection rate of approximately 93%. In 25/28 probands, COL5A1 or COL5A2 mutations were detected. Twenty-one mutations were in the COL5A1 gene, 18 of which were novel (2 recurrent). Of these, 16 mutations led to nonsense-mediated mRNA decay (NMD) and to COLLV haploinsufficiency and 5 mutations were structural. Two novel COL5A2 splice mutations were detected in patients with the most severe phenotypes. The known p. (Arg312Cys) mutation in the COL1A1 gene was identified in one patient with vascular-like cEDS. Our findings highlight that the three major criteria for cEDS are useful and sufficient for cEDS clinical diagnosis in the large majority of the patients. The borderline patients for whom these criteria fail can be diagnosed when minor signs of connective tissue diseases and family history are present and when genetic testing reveals a defect in COLLV. Our data also confirm that COL5A1 and COL5A2 are the major, if not the only, genes involved in cEDS
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