319 research outputs found

    Development of a measurement platformon a light airplane and analysis of airborne measurementsin the atmospheric boundary layer

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    In the present paper we provide an overview of a long term research project aimed at setting up a suitable platform for measurements in the atmospheric boundary layer on a light airplane along with some preliminary results obtained from fi eld campaigns at selected sites. Measurements of air pressure, temperature and relative humidity have been performed in various Alpine valleys up to a height of about 2500 m a.m.s.l. By means of GPS resources and specifi c post-processing procedures careful positioning of measurement points within the explored domain has been achieved. The analysis of collected data allowed detailed investigation of atmospheric vertical structures and dynamics typical of valley environment, such as morning transition from ground based inversion to fully developed well mixed convective boundary layer. Based on data collected along fl ights, 3D fi elds of the explored variables have been detected and identifi ed through application of geostatistical techniques (Kriging). The adopted procedures allowed evaluation of the intrinsic statistical structure of the spatial distribution of measured quantities and the estimate of the values of the same variable at unexplored locations by suitable weighted average of data recorded at close locations. Results thus obtained are presented and discussed

    Development of a measurement platformon a light airplane and analysis of airborne measurementsin the atmospheric boundary layer

    Get PDF
    In the present paper we provide an overview of a long term research project aimed at setting up a suitable platform for measurements in the atmospheric boundary layer on a light airplane along with some preliminary results obtained from fi eld campaigns at selected sites. Measurements of air pressure, temperature and relative humidity have been performed in various Alpine valleys up to a height of about 2500 m a.m.s.l. By means of GPS resources and specifi c post-processing procedures careful positioning of measurement points within the explored domain has been achieved. The analysis of collected data allowed detailed investigation of atmospheric vertical structures and dynamics typical of valley environment, such as morning transition from ground based inversion to fully developed well mixed convective boundary layer. Based on data collected along fl ights, 3D fi elds of the explored variables have been detected and identifi ed through application of geostatistical techniques (Kriging). The adopted procedures allowed evaluation of the intrinsic statistical structure of the spatial distribution of measured quantities and the estimate of the values of the same variable at unexplored locations by suitable weighted average of data recorded at close locations. Results thus obtained are presented and discussed

    Efficacy of afoxolaner (NexGard®) in preventing the transmission of Leishmania infantum and Dirofilaria immitis to sheltered dogs in a highly endemic area

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    Background: Leishmania infantum and Dirofilaria immitis are among the most important canine vector-borne pathogens (CVBPs) of zoonotic concern in Europe. In endemic areas for both of these CVBPs, the use of systemic ectoparasiticides, such as afoxolaner (NexGard®; Boehringer Ingelheim Animal Health), may have the potential for controlling these infections. The aim of this study was to assess, for the first time, the insecticidal efficacy of NexGard® in decreasing the transmission of D. immitis and L. infantum to sheltered dogs living in a hyperendemic area, compared to the year before treatment, as well as its impact on the abundance of mosquito and sand fly populations. Methods: All dogs (n = 179) enrolled in the study were divided into two groups based on their infection status at enrollment: a non-infected group (G1) and an infected group (G2; infected with D. immitis, L. infantum or both). The study was conducted from March 2020 to March 2021. In order to exclude all animals infected with L. infantum and D. immitis before March 2020 (sampling time: T0), dogs in G1 were sampled in June (T1; i.e. T0 + 90 days) and in October 2020 (T2; i.e. T0 + 210 days). From March to September 2020, all animals (G1 and G2) were weighed and treated monthly with NexGard®. Animals in G1 were tested for the last time in March 2021 (T3; i.e. T0 + 330 days) for assessing post-treatment incidence rate of infection and prevention efficacy. Results: The post-treatment incidence of D. immitis was 3.7% (1/27; 95% confidence interval [CI]: 0.2–18.1) and that of L. infantum was 3.6% (3/83; 95% CI: 1.0–10.1). Considering the annual incidence in 2019 and 2020, the protective efficacy against D. immitis and L. infantum infections was 94.2 and 64%, respectively. Of the female mosquitoes collected (n = 146), only one pool out of 50 tested positive for D. immitis DNA, whereas out of 1252 female Sergentomya minuta specimens collected, only four tested positive for L. infantum (0.3%). Conclusions: Afoxolaner is efficacious in decreasing the rate of transmission of both D. immitis and L. infantum; however, comparison of the pre- and post-treatment period demonstrated that there was a significant difference only in the seasonal incidences of D. immitis infection. Preventive measures are recommended throughout the year in endemic areas to reduce the risk of pathogen transmission to animals and humans. Graphical abstract: [Figure not available: see fulltext.]

    Enhancing the excitation gap of a quantum-dot-based Kitaev chain

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    Connecting double quantum dots via a semiconductor-superconductor hybrid segment offers a platform for creating a two-site Kitaev chain that hosts a pair of "poor man's Majoranas" at a finely tuned sweet spot. However, the effective couplings, which are mediated by Andreev bound states in the hybrid, are generally weak in the tunneling regime. As a consequence, the excitation gap is limited in size, presenting a formidable challenge for using this platform to demonstrate non-Abelian statistics of Majoranas and realizing error-resilient topological quantum computing. In this work, we systematically study the effects of increasing the coupling between the dot and the hybrid segment. In particular, the proximity effect transforms the dot orbitals into Yu-Shiba-Rusinov states, forming a new spinless fermion basis for a Kitaev chain, and we derive a theory for their effective coupling. As the coupling strength between the dots and the hybrid segment increases, we find a significant enhancement of the excitation gap and reduced sensitivity to local perturbations. Although the hybridization of the Majorana wave function with the central Andreev bound states increases strongly with increasing coupling, the overlap of Majorana modes on the outer dots remains small, which is a prerequisite for potential qubit experiments. We discuss how the strong-coupling regime shows in experimentally accessible quantities, such as the local and non-local conductance, and provide a protocol for tuning a double-dot system into a sweet spot with a large excitation gap.Comment: 12 pages, 9 figure

    Leishmania infantum and Dirofilaria immitis infections in Italy, 2009-2019: Changing distribution patterns

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    Background: For long time, canine leishmaniosis (CanL) was considered endemic in the southern, central, and insular regions of Italy, whereas heartworm disease (HW) caused by Dirofilaria immitis was considered endemic in the northern region and in the swampy Po Valley. Following the reports of new foci of both diseases, in this study we update the distribution patterns and occurrence of new foci of CanL and HW discussing the main drivers for the changes in the epidemiology of these two important zoonotic canine vector-borne diseases. Methods: Based on the statistical analyses of serological assays (n = 90,633) on L. infantum exposure and D. immitis infection performed by two reference diagnostic centres in Italy over a ten-year period (2009-2019) irrespective of the anamnesis of dogs. The distribution patterns of both parasites are herein presented along with the occurrence of new foci. Results: Results highlighted the changing distribution patterns of L. infantum vs D. immitis infection in Italy. CanL is endemic in some areas of northern regions and HW has endemic foci in central and southern regions and islands. Significant differences in L. infantum exposure and HW infection prevalence among the study macroareas were detected. The overall results of the positive tested samples were 28.2% in southern Italy and islands, 29.6% in central Italy and 21.6% in northern Italy for L. infantum and 2.83% in northern Italy, 7.75% in central Italy and 4.97% in southern Italy and islands for HW. HW positivity significantly varied over years (χ 2 = 108.401, df = 10, P < 0.0001), gradually increasing from 0.77% in 2009 to 8.47% in 2016-2017. Conclusions: New potential epidemiological scenarios are discussed according to a range of factors (e.g. environmental modifications, occurrence of competent insect vectors, transportation of infected animals to non-endemic areas, chemoprophylaxis or vector preventative measures), which may affect the current distribution. Overall, the results advocate for epidemiological surveillance programmes, more focussed preventative and control measures even in areas where few or no cases of both diseases have been diagnosed.[Figure not available: see fulltext.

    Clinical, haematological and biochemical findings in tigers infected by leishmania infantum

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    Background: A large number of animal species are susceptible to Leishmania infantum (Kinetoplastida, Trypanosomatidae) in endemic areas, including domestic and wild felids such as tigers (Panthera tigris). Knowledge on the infection of this endangered species is still at its infancy, and therefore this study aims to identify clinical presentation and clinicopathological findings of tigers naturally infected by L. infantum. Results: Tigers either L. infantum-positive (group A) or -negative (group B) were apparently healthy or presented visceral leishmaniasis unrelated conditions, except for one animal in which a large non-healing cutaneous lesion was observed. However, histological exam and immunohistochemistry carried out on the lesion excluded the presence of L. infantum amastigotes. Biochemical analysis showed that the average concentration of total proteins, globulins and haptoglobin were significantly higher (p < 0.01, p = 0.01 and p = 0.02, respectively), while the albumin/globulin ratio significantly lower (p = 0.05) in group A compared with group B. The biochemical alterations were partially confirmed by the serum protein electrophoresis results revealing a significant increase in the total protein value (p = 0.01) and hypergammaglobulinemia (p = 0.03) but an unmodified albumin/globulin ratio in group A. Conclusions: In this study tigers infected by L. infantum have shown to be mainly asymptomatic. The absence of clinical signs may lead veterinarians to overlook leishmaniasis in animals kept in captivity. Therefore, diagnostic and screening tests as serology should be part of routinely surveillance programs to be performed on tigers in zoological gardens located in endemic areas. Though only few protein-related laboratory abnormalities were recorded in infected animals, they could provide diagnostic clues for a first suspicion of L. infantum infection in tigers. Indeed, considering the high risk of zoonotic transmission in heavily frequented environment as zoos, a prompt diagnosis of L. infantum infection is of pivotal importance

    Hyperendemic Dirofilaria immitis infection in a sheltered dog population: an expanding threat in the Mediterranean region

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    A study on the occurrence of Dirofilaria immitis and its vectors was carried out in order to assess the prevalence of the disease in dogs in previously non-endemic areas of southern Italy. Blood samples (n = 385) and mosquitoes (n = 1540) were collected in two dog shelters and analysed by Knott's test and duplex real-time PCR, respectively. Dirofilaria immitis was the most prevalent filarioid (44.2%), while Culex pipiens was the most prevalent mosquito species (68.8%). This high prevalence of D. immitis infection confirms this location as one of the most hyperendemic foci of dirofilariosis in Europe

    Combination of ultrasound and molecular testing in malignancy risk estimate of Bethesda category IV thyroid nodules: results from a single-institution prospective study

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    Purpose: Malignancy prediction in indeterminate thyroid nodules is still challenging. We prospectively evaluated whether the combination of ultrasound (US) risk stratification and molecular testing improves the assessment of malignancy risk in Bethesda Category IV thyroid nodules. Methods: Ninety-one consecutively diagnosed Bethesda Category IV thyroid nodules were prospectively evaluated before surgery by both ACR- and EU-TIRADS US risk-stratification systems and by a further US-guided fine-needle aspiration cytology (FNAC) for the following molecular testing: BRAFV600E, N-RAS codons 12/13, N-RAS codon 61, H-RAS codons 12/13, H-RAS codon 61, K-RAS codons 12/13, and K-RAS codon 61 point-mutations, as well as PAX8/PPARÎł, RET/PC1, and RET/PTC 3 rearrangements. Results: At histology, 37% of nodules were malignant. No significant association was found between malignancy and either EU- or ACR-TIRADS. In total, 58 somatic mutations were identified, including 3 BRAFV600E (5%), 5 N-RAS 12/13 (9%), 13 N-RAS 61 (22%), 7 H-RAS 12/13 (12%), 11 H-RAS 61 (19%), 6 K-RAS 12/13 (10%), 8 K-RAS 61 (14%) mutations and 2 RET/PTC1 (4%), 0 RET/PTC 3 (0%), 3 PAX8/PPARÎł (5%) rearrangements. At least one somatic mutation was found in 28% and 44% of benign and malignant nodules, respectively, although malignancy was not statistically associated with the outcome of the mutational test. However, the combination of ACR-, but not EU-, TIRADS with the presence of at least one somatic mutation, was significantly associated with malignant histology (P = 0.03). Conclusion: US risk stratification and FNAC molecular testing may synergistically contribute to improve malignancy risk estimate of Bethesda category IV thyroid nodules

    MTOR, p70S6K, AKT, and ERK1/2 levels predict sensitivity to mTOR and PI3K/mTOR inhibitors in human bronchial carcinoids

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    Bronchial carcinoids (BCs) are rare neuroendocrine tumors that are still orphans of medical treatment. Human BC primary cultures may display resistance to everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), in terms of cell viability reduction. Our aim was to assess whether the novel dual phosphatidylinositol 3-kinase (PI3K)/mTOR inhibitor NVP-BEZ235 is effective in everolimus-resistant human BC tissues and cell lines. In addition, we searched for possible markers of the efficacy of mTOR inhibitors that may help in identifying the patients who may benefit from treatment with mTOR inhibitors, sparing them from ineffective therapy. We found that NVP-BEZ235 is twice as potent as everolimus in reducing cell viability and activating apoptosis in human BC tissues that display sensitivity to mTOR inhibitors, but is not effective in everolimus-resistant BC tissues and cell lines that bypass cyclin D1 downregulation and escape G0/G1 blockade. Rebound AKT activation was not observed in response to treatment with either mTOR inhibitor in the 'resistant' BC cells. In addition to total mTOR levels, putative markers of the sensitivity of BCs to mTOR inhibitors are represented by AKT, p70S6K (RPS6KB2), and ERK1/2 (MAPK3/1) protein levels. Finally, we validated these markers in an independent BC group. These data indicate that the dual PI3K/mTOR inhibitor NVP-BEZ235 is more potent than everolimus in reducing the proliferation of human BC cells. 'Resistant' cells display lower levels of mTOR, p70S6K, AKT, and ERK1/2, indicating that these proteins may be useful as predictive markers of resistance to mTOR and PI3K/mTOR inhibitors in human BCs. \ua9 2013 Society for Endocrinology
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