16 research outputs found

    A new simple topo-climatic model to predict surface displacement in paraglacial and periglacial mountains of the European Alps: The importance of ground heating index and floristic components as ecological indicators

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    Landscape evolution is occurring at rapid rates in alpine areas in response to recent climate warming, also due to the susceptibility and the heterogeneity of these environments. Here we present a prediction model of surface displacements that takes into account both topographic and climatic variables. Observed points of surficial displacements have been associated to non-climatic (altitude, slope, solar radiation, till deposit type, deposit age, vegetation coverage) and climatic (days of snow permanence, ground surface temperature index, ground heating index, ground cooling index) variables through a general regression model in the European central Alps. The model output shows the importance of slope and ground heating index (GHI) \u2013 an estimation of the amount of energy transferred to the ground, to predict surface displacements independently from the type of considered processes. In particular, the general regression model shows that steep zones with high GHI are more susceptible to undergo periglacial and paraglacial processes producing surface displacements. As expected, slope is fundamental to trigger processes such as gravitation, nivation, solifluction and their interactions. The results of our model emphasize the key role of GHI, highlighting the importance of climate in controlling the surface displacement. Indeed, in areas in which GHI is higher, the ground can remain snow free for a longer time and snow melting can be faster, the former favoring more runoff and slopewash, and the latter promoting the saturation of the deposits consequent to a higher intensity of solifluction and/or mass movements processes. Within the study area, the sites with the largest displacements (>35 cm) were detected where permafrost degradation occurred since 1990. This permafrost degradation process could remain one of the main triggering factors of future surface displacements. Our results confirm that when movement involves material with coarse texture (pebbles and boulders) exceeding the rooting depth, only tolerant plant species can withstand the high movement rates. The areas where this can happen (like rock glaciers or screes) act as a physical barrier to grasslands species not adapted to surface displacements and trying to shift towards higher altitude in response to climate warming. However, plant species not considered as indicators of movement (such as graminoids), can develop also with large surface displacements in specific geomorphic conditions. Therefore, the combination of surface displacement type (deep vs surficial), material texture (fine vs coarse) and vegetation cover (high vs low) and floristic composition can be used as a valuable ecological indicator of movement. Our results suggest that both landscape degradation and vegetation displacement can be rapid especially where the air warming was strong as in the selected study area

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Needle ice formation, induced frost heave, and frost creep: A case study through photogrammetry at Stelvio Pass (Italian Central Alps)

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    Needle ice growth is one of the more widespread and easily visible, but less studied, climate related processes shaping soil evolution, surface dynamics and ecosystem changes in the alpine environments. Here, we show the results of the monitoring of needle ice development at four plots located at 2670m a.s.l. close to the Stelvio Pass in the Italian Central Alps during 2016. Needle Ice formation and evolution with time was monitored through the photogrammetric technique of the Structure from Motion (SfM). Our monitoring data included also quantitative measurements of some selected physical and climatic parameters like air temperature, ground temperature and ground water content at depths of 2 and 5 cm. Our data demonstrate that needle ice can develop with a relatively low ground water content (13.2%), at a relatively high minimum ground temperature ( 120.3 \ub0C) and with a low cooling rate (< 1.8 \ub0C h 121). Moreover, for the first time, we observed that needle ice can form below a thin snow cover (< 25 mm) that can enhance the sensible heat flow from the ground to the atmosphere and, therefore, promote the cooling of the near surface ground. Statistically, the minimum air temperature results in the leading factor for the needle ice growth. The total frost heave seems to be related to the abundance of fine material (although we couldn't demonstrate it statistically). The absence of statistically significant relationships between frost heave and frost creep could be probably due to the importance of the observed needle ice toppling and the possible sliding of the clasts during the melting phases

    Small ruminant lentivirus genotype E is widespread in Sarda goat

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    8 p., 3 figures, 2 tables and bibliographyThe highly divergent SRLV genotype E has recently been characterized in Italy as a low pathogenic caprine lentivirus in the Roccaverano breed. The availability of a genotype specific diagnostic test based on a comparative assay, using a combination of genotype specific recombinant antigens allows a wide serosurvey in other goat populations. The island of Sardinia still has the highest small ruminant population of any Italian region and crossbreeding has been limited to goats, mainly with the Maltese breed. A serological survey was carried out on sheep flocks and goat herds, using individual sera as well as a bulk milk-adapted procedure. Genotype E was identified inmore than 50% of goat herds and none of the sheep flocks thus supporting the idea that this genotype is specifically associated with the goat species. The full-length proviral sequence of a Sardinian isolate revealed and confirmed the deletion of dUTPase subunit and the absence of both vpr gene and the 71 bp repeat of the LTR. Genetic similarity of this isolate with the prototype strain Roccaverano was not more than 84%, supporting the designation of two subtypes within genotype E. Nevertheless, in vitro properties of the Sardinian strain were different from those of the Roccaverano strain in terms of ability to infect synovial membrane and produce syncitia. Remarkable differences in the HV1 and HV2 of the env gene were recorded, with the Sardinian isolate displaying sequence motif more similar to arthritic strains. Data presented suggest diffusion of genotype E is wider than previously thought.This work has been partially funded by the Italian Ministry of Health, "Ricerca Corrente" program id IZSSA/03.Peer reviewe

    Molecular Typing of Pathogenic Leptospira Species Isolated from Wild Mammal Reservoirs in Sardinia

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    Leptospirosis is a global zoonosis caused by pathogenic species of Leptospira that infect a large spectrum of domestic and wild animals. This study is the first molecular identification, characterization, and phylogeny of Leptospira strains with veterinary and zoonotic impact in Sardinian wild hosts. All samples collected were cultured and analyzed by multiplex real time polymerase chain reaction (qPCR). Sequencing, phylogenetic analyses (based on rrs and secY sequences), and Multilocus Sequence Typing (MLST) based on the analysis of seven concatenated loci were also performed. Results revealed the detection of Leptospira DNA and cultured isolates in 21% and 4% of the samples examined, respectively. Sequence analysis of Leptospira positive samples highlighted the presence of the interrogans and borgpetersenii genospecies that grouped in strongly supported monophyletic clades. MLST analyses identified six different Sequence Types (ST) that clustered in two monophyletic groups specific for Leptospirainterrogans, and L. borgpetersenii. This study provided about the prevalence of leptospires in wild mammals in Sardinia, and increased our knowledge of this pathogen on the island. Monitoring Leptospira strains circulating in Sardinia will help clinicians and veterinarians develop strategic plans for the prevention and control of leptospiral infections

    New Insights on Leptospira Infections in a Canine Population from North Sardinia, Italy: A Sero-Epidemiological Study

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    Leptospirosis is a widespread zoonosis recognized as a re-emerging infectious disease in a wide variety of animal species, including humans and dogs. No data exist regarding the presence of Leptospira species in the canine population of Sardinia Island. This study reports the first sero-survey for leptospirosis in kennel and owned dogs from six areas of the north of Sardinia. Sera from 1296 dogs were tested by microscopic agglutination test (MAT) specific for nine different serovars that are known to be well widespread in the Mediterranean environment. Moreover, kidney homogenates from rodents collected from the study area were also analyzed by LipL32 real-time PCR and multi-locus sequence type (MLST) on the basis of the analysis of seven concatenated loci. A total of 13% of the examined sera (95%CI: 11–15) tested positive for one or more serovars of Leptospira MAT detected; antibodies for serogroup Icterohaemorrhagiae (57%; 95%CI: 49–65) were the most common, followed by serovars Bratislava (22%; 95%CI: 16–28), Canicola (14%; 95%CI: 9–19), and Grippotyphosa (7%; 95%CI: 3–11). MLST analyses on isolates from rodents identified L. interrogans and L. borgpetersenii genomospecies. Different serovars belonging to pathogenic Leptospira serogroups are circulating in dogs from the island. Moreover, data obtained from rodents, indicated that rodents likely act as reservoir of spirochetes. Further sero-epidemiological studies are needed in order to obtain data from other collection sites in Sardinia and to increase the information on Leptospira species circulating in this area

    Small Ruminant Lentivirus (SRLV) genotype E is widespread in Sarda goat

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    Comunicación presentada en el 4th European Congreso of Virology, celebrado en Cernobbio (Italia) del 7 al 11 de abril de 2010.Peer Reviewe

    Adjuvant chemotherapy in stage I-II uterine leiomyosarcoma: A multicentric retrospective study of 140 patients

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    Objective About 50-60% of patients with stage I-II uterine leiomyosarcoma (ULMS), primarily treated with surgery, relapse and die from progressive disease. In this retrospective study we describe the impact of adjuvant chemotherapy in this subset of patients. Methods 140 women treated from 1976 to 2011 were included in the study. Univariate and multivariate analysis were used to test the association of clinical features and adjuvant treatments with overall survival (OS) and disease-free survival (DFS). Results 62 women did not receive any further treatment after hysterectomy, 14 had radiotherapy (RT), 52 chemotherapy and 12 chemo-radiotherapy. Chemotherapy based on doxorubicin and ifosfamide combination was used in 54 cases. After a median follow-up of 63 months, 87 women (62%) have relapsed, and 62 (44%) have died. The vast majority of patients who relapsed had distant recurrences (72%). The 5 year median DFS and OS were 43% and 64% respectively. After 5 years of follow up 68.7% of women treated with chemotherapy (± RT) vs 65.6% of patients only observed were alive (p = 0.521). In the univariate analysis no factors had a statistical impact on DFS, while number of mitosis (> 20 × 10HPF), age (> 60 years) and adjuvant radiotherapy were found as negative prognostic factors for OS. In the multivariate analysis only mitosis and age remained significant for OS. Conclusion Adjuvant chemotherapy was not associated with a significant survival benefit and should not be considered as standard of care for patients with stage I-II ULMS until randomized clinical studies will give further information

    Presence of pathogenic Leptospira spp. in the reproductive system and fetuses of wild boars (Sus scrofa) in Italy.

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    Leptospirosis is a re-emerging and globally spread zoonosis caused by pathogenic genomospecies of Leptospira. Wild boar (Sus scrofa) are an important Leptospira host and are increasing in population all over Europe. The aim of this investigation was to evaluate Leptospira spp. infection in the reproductive systems of wild boar hunted in two Italian regions: Tuscany and Sardinia. From 231 animals, reproductive system tissue samples (testicles, epididymides, uteri) as well as placentas and fetuses were collected. Bacteriological examination and Real-Time PCR were performed to detect pathogenic Leptospira (lipL32 gene). Leptospires were isolated from the testicles and epididymides of one adult and two subadult wild boar. Four isolates from the two subadult males were identified as Leptospira interrogans serogroup Australis by MLST, whereas Leptospira kirschneri serogroup Grippotyphosa was identified from the adult testicles and epididymis. Using Real-Time PCR, 70 samples were positive: 22 testicles (23.16%) and 22 epididymides (23.16%), 10 uteri (7.35%), 3 placentas (6.66%), and 13 fetuses (28.88%). Amplification of the rrs2 gene identified L. interrogans and L. kirschneri species. The results from this investigation confirmed that wild boar represent a potential source of pathogenic Leptospira spp. Isolation of Leptospira serogroups Australis and Grippotyphosa from the male reproductive system and the positive Real-Time PCR results from both male and female samples could suggest venereal transmission, as already demonstrated in pigs. Furthermore, placentas and fetuses were positive for the lipL32 target, and this finding may be related to a possible vertical transmission of pathogenic Leptospira
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