37 research outputs found

    Copula-based probabilistic assessment of intensity and duration of cold episodes: A case study of Malayer vineyard region

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    Frost, particularly during the spring, is one of the most damaging weather phenomena for vineyards, causing significant economic losses to vineyards around the world each year. The risk of tardive frost damage in vine-yards due to changing climate is considered as an important threat to the sustainable production of grapes. Therefore, the cold monitoring strategies is one of the criteria with significant impacts on the yields and prosperity of horticulture and raisin factories. Frost events can be characterized by duration and severity. This paper investigates the risk and impacts of frost phenomenon in the vineyards by modeling the joint distribution of duration and severity factors and analyzing the influential parameter’s dependency structure using capabilities of copula functions. A novel mathematical framework is developed within this study to understand the risk and uncertainties associate with frost events and the impacts on yields of vineyards by analyzing the non-linear dependency structure using copula functions as an efficient tool. The developed model was successfully vali-dated for the case study of vineyard in Malayer city of Iran. The copula model developed in this study was shown to be a robust tool for predicting the return period of the frost events

    Global Perspectives on Task Shifting and Task Sharing in Neurosurgery.

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    BACKGROUND: Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-neurosurgeons, is ongoing in many hospital systems in which neurosurgeons are scarce. Although TS/S can increase access to treatment, it remains highly controversial. This survey investigated perceptions of neurosurgical TS/S to elucidate whether it is a permissible temporary solution to the global workforce deficit. METHODS: The survey was distributed to a convenience sample of individuals providing neurosurgical care. A digital survey link was distributed through electronic mailing lists of continental neurosurgical societies and various collectives, conference announcements, and social media platforms (July 2018-January 2019). Data were analyzed by descriptive statistics and univariate regression of Likert Scale scores. RESULTS: Survey respondents represented 105 of 194 World Health Organization member countries (54.1%; 391 respondents, 162 from high-income countries and 229 from low- and middle-income countries [LMICs]). The most agreed on statement was that task sharing is preferred to task shifting. There was broad consensus that both task shifting and task sharing should require competency-based evaluation, standardized training endorsed by governing organizations, and maintenance of certification. When perspectives were stratified by income class, LMICs were significantly more likely to agree that task shifting is professionally disruptive to traditional training, task sharing should be a priority where human resources are scarce, and to call for additional TS/S regulation, such as certification and formal consultation with a neurosurgeon (in person or electronic/telemedicine). CONCLUSIONS: Both LMIC and high-income countries agreed that task sharing should be prioritized over task shifting and that additional recommendations and regulations could enhance care. These data invite future discussions on policy and training programs

    Intrinsic variability of the Antarctic Circumpolar Current System: low- and high-frequency fluctuations of the Argentine Basin flow

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    In this paper, the variability of the Antarctic Circumpolar Current system produced by purely intrinsic nonlinear oceanic mechanisms is studied through a sigma-coordinate ocean model, implemented in a large portion of the Southern Ocean at an eddy-permitting resolution under steady surface heat and momentum fluxes. The mean transport through Drake Passage and the structure of the main Antarctic Circumpolar Current fronts are well reproduced by the model. Intrinsic variability is found to be particularly intense in the Subantarctic Front and in the Argentine Basin, on which further analysis is focused. The low-frequency variability at interannual time scales is related to bimodal behavior of the Zapiola Anticyclone, with transitions between a strong and collapsed anticyclonic circulation in substantial agreement with altimeter observations. Variability on smaller time scales shows clear evidence of topographic Rossby mode propagation along the eastern and southern flanks of the Zapiola Rise and of mesoscale eddies, also in agreement with satellite altimeter observations. The analysis of the relationship between the low- and high-frequency variability suggests possible mechanisms of mutual interaction

    High Mobility Group A (HMGA): Chromatin Nodes Controlled by a Knotty miRNA Network

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    High mobility group A (HMGA) proteins are oncofoetal chromatin architectural factors that are widely involved in regulating gene expression. These proteins are unique, because they are highly expressed in embryonic and cancer cells, where they play a relevant role in cell proliferation, stemness, and the acquisition of aggressive tumour traits, i.e., motility, invasiveness, and metastatic properties. The HMGA protein expression levels and activities are controlled by a connected set of events at the transcriptional, post-transcriptional, and post-translational levels. In fact, microRNA (miRNA)-mediated RNA stability is the most-studied mechanism of HMGA protein expression modulation. In this review, we contribute to a comprehensive overview of HMGA-targeting miRNAs; we provide detailed information regarding HMGA gene structural organization and a comprehensive evaluation and description of HMGA-targeting miRNAs, while focusing on those that are widely involved in HMGA regulation; and, we aim to offer insights into HMGA-miRNA mutual cross-talk from a functional and cancer-related perspective, highlighting possible clinical implications

    Intrinsic variability of the Antarctic Circumpolar Current system: low- and high-frequency fluctuations of the Argentine Basin flow

    No full text
    In this paper, the variability of the Antarctic Circumpolar Current system produced by purely intrinsic nonlinear oceanic mechanisms is studied through a sigma-coordinate ocean model, implemented in a large portion of the Southern Ocean at an eddy-permitting resolution under steady surface heat and momentum fluxes. The mean transport through the Drake Passage and the structure of the main Antarctic Circumpolar Current fronts are well reproduced by the model. Intrinsic variability is found to be particularly intense in the Subantarctic Front and in the Argentine Basin, on which further analysis is focused. The low-frequency variability at interannual timescales is related to bimodal behavior of the Zapiola Anticyclone, with transitions between a strong and collapsed anticyclonic circulation in substantial agreement with altimeter observations. Variability on smaller timescales shows clear evidence of topographic Rossby-wave propagation along the eastern and southern flanks of the Zapiola Rise and of mesoscale eddies, also in agreement with altimeter observations. The analysis of the relationship between the low- and high-frequency variability suggests possible mechanisms of mutual interaction

    Multimodel analysis of the response of the AMOC under an increase of radiative forcing and its symmetrical reversal

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    The response of the Atlantic meridional overturning circulation (AMOC) to an increase of radiative forcing (ramp-up) and a subsequent reversal of radiative forcing (ramp-down) is analyzed for four different global climate models. Due to changes in ocean temperature and hydrological cycle, all models show a weakening of the AMOC during the ramp-up phase. Once the external forcing is reversed, the results become model dependent. For IPSL-CM5A-LR, the AMOC continues its weakening trend for most of the ramp-down experiment. For HadGEM2-ES, the AMOC trend reverses once the external forcing also reverses, without recovering its initial value. For EC-EARTH and MPI-ESM-LR the recovery is anomalously strong yielding an AMOC overshoot. A robust linear dependency can be established between AMOC and density difference between North Atlantic (NA) deep water formation region and South Atlantic (SA). In particular, AMOC evolution is primarily controlled by a meridional salinity contrast between these regions. During the warming scenario, the subtropical Atlantic becomes saltier while the NA experiences a net freshening which favours an AMOC weakening. The different behaviour in the models during the ramp-down is dependent on the response of the ocean at the boundaries of NA and SA. The way in which the positive salinity anomaly stored in the subtropical Atlantic during the ramp-up is subsequently released elsewhere, characterizes the recovery. An out-of-phase response of the salinity transport at 48∘N and 34∘S boundaries is able to control the meridional density contrast between NA and SA during the transient experiments. Such a non-synchronized response is mainly controlled by changes in gyre salinity transport rather than by changes in overturning transport, thus suggesting a small role of the salt advection feedback in the evolution of the AMOC

    Feeding behaviour of Anopheles messeae/daciae and Anopheles maculipennis s.s. in Northeastern Italy

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    INTRODUCTION. Since the malaria eradication, the species composition of the Anopheles maculipennis complex in North-eastern Italy has changed considerably and, to date, the two main species are represented by Anopheles messeae/daciae and Anopheles maculipennis s.s. (Calzolari et al., 2021 Sci Rep. 11: 6421). The aim of this study was to investigate the feeding choices of these two species. MATERIALS AND METHODS. Mosquitoes belonging to Maculipennis complex were collected in 19 sites in Veneto region (2018-2020) by hand aspiration and trapping. All specimens were morphologically identified and a sub-sample of engorged An. maculipennis s.l. females was identified at species level by molecular analysis. Blood meal origin was identified by PCR and cox1 gene sequencing. Feeding choice of An. messeae/daciae was investigated in a site rich in animal diversity by calculating the forage ratio (FR) and feeding index (FI). RESULTS AND CONCLUSION. A total of 1,094 engorged An. maculipennis s.l. were collected, 267 of which were identified at species level (242 An. messeae/daciae, 25 An. maculipennis s.s.). For 127 specimens (115 An. messeae/daciae and 12 An. maculipennis s.s.) it was possible to identify the origin of the blood meal, from 13 and 3 different host species respectively. Both Anopheles species fed mainly on horse (45.2% An. messeae/daciae and 33.3% An. maculipennis s.s.) and cow (30.4% An. messeae/daciae and 58.3% An. maculipennis s.s). Despite these proportions, An. messeae/daciae FR indicates host preference for buffalo (21.2), horse (8.4), man and pig (5.3); the pairwise-comparison of human FI with each host reveals its preference for humans compared to chicken (79.5), rabbit (7.3) and dog (8.0). Our results show that, due to its opportunistic feeding behavior, An. messeae/daciae shows its potential role as a vector of human and zoonotic diseases in Italy

    Targeting the intrinsically disordered architectural High Mobility Group A (HMGA) oncoproteins in breast cancer: learning from the past to design future strategies

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    Introduction: Triple-negative breast cancer (TNBC) is the most difficult breast cancer subtype to treat because of its heterogeneity and lack of specific therapeutic targets. High Mobility Group A (HMGA) proteins are chromatin architectural factors that have multiple oncogenic functions in breast cancer, and they represent promising molecular therapeutic targets for this disease. Areas covered: We offer an overview of the strategies that have been exploited to counteract HMGA oncoprotein activities at the transcriptional and post-transcriptional levels. We also present the possibility of targeting cancer-associated factors that lie downstream of HMGA proteins and discuss the contribution of HMGA proteins to chemoresistance. Expert opinion: Different strategies have been exploited to counteract HMGA protein activities; these involve interfering with their nucleic acid binding properties and the blocking of HMGA expression. Some approaches have provided promising results. However, some unique characteristics of the HMGA proteins have not been exploited; these include their extensive protein-protein interaction network and their intrinsically disordered status that present the possibility that HMGA proteins could be involved in the formation of proteinaceous membrane-less organelles (PMLO) by liquid-liquid phase separation. These unexplored characteristics could open new pharmacological avenues to counteract the oncogenic contributions of HMGA proteins

    Evolution of the beta-defensin 2 gene in higher primates

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    With the aim of further investigating the molecular evolution of beta defensin genes, after having analysed beta defensin 1 (DEFB1) in humans and several nonhuman primate species, we have studied the evolution of the beta defensin 2 gene (DEFB2), which codifies for a peptide with antimicrobial and chemoattractant activity, in humans and 16 primate species. We have found evidence of positive selection during the evolution of orthologous DEFB2 genes at two points on a phylogenetic tree relating these primates: during the divergence of the platyrrhines from the catarrhines and during the divergence of the Cercopithecidae from the Hylobatidae, Great Apes and humans. Furthermore, amino acid variations in Old World Monkeys seem to centre either on residues that are involved in oligomerisation in the human molecule, or that are conserved (40\u201380%) in beta-defensins in general. It is thus likely that these variations affect the biological function of the molecules and suggest that their synthesis and functional analysis might reveal interesting new information as to their role in innate immunity
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