53 research outputs found
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Response of the Asian Summer Monsoons to a High-latitude Thermal Forcing: Mechanisms and Nonlinearities
This study investigates mechanisms and nonlinearities in the response of the Asian Summer Monsoons (ASM) to high-latitude thermal forcings of different amplitudes. Using a suite of runs carried out with an intermediate-complexity atmospheric general circulation model, we find that the imposed forcings produce a strong precipitation response over the eastern ASM but a rather weak response over the southern ASM. The forcing also causes a precipitation dipole with wet conditions over the eastern Tibetan Plateau (TP) and dry conditions over the Bay of Bengal (BoB) and southeast Asia. A moderate increase of precipitation along the southern margin of the TP is also produced. Simulations designed to isolate the causal mechanisms show that thermodynamic interactions involving the tropical surface oceans are far less important than the water-vapour feedback for the transmission of information from the high-latitudes to the ASM. Additionally, we assess the nonlinearity of the ASM precipitation response to the forcing amplitude using a novel application of the empirical orthogonal function method. The response can be decomposed in two overlapping patterns. The first pattern represents a precipitation dipole with wet conditions over the eastern TP and dry conditions over BoB, which linearly increases with forcing amplitude becoming quasi-stationary for large forcing amplitudes (i.e. amplitudes leading to Arctic temperature anomalies larger than 10 degrees C). The second pattern is associated with increased precipitation over the southeastern TP and is nonlinearly dependent on forcing, being most important for intermediate forcing amplitudes (i.e. amplitudes leading to Arctic temperature anomalies between 5 and 10 degrees C)
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Respective impacts of Arctic sea ice decline and increasing greenhouse gases concentration on Sahel precipitation
The impact of climate change on Sahel precipitation is uncertain and has to be widely documented. Recently, it has been shown that Arctic sea ice loss leverages the global warming effects worldwide, suggesting a potential impact of Arctic sea ice decline on tropical regions. However, defining the specific roles of increasing greenhouse gases (GHG) concentration and declining Arctic sea ice extent on Sahel climate is not straightforward since the former impacts the latter. We avoid this dependency by analysing idealized experiments performed with the CNRM-CM5 coupled model. Results show that the increase in GHG concentration explains most of the Sahel precipitation change. We found that the impact due to Arctic sea ice loss depends on the level of atmospheric GHG concentration. When the GHG concentration is relatively low (values representative of 1980s), then the impact is moderate over the Sahel. However, when the concentration in GHG is levelled up, then Arctic sea ice loss leads to increased Sahel precipitation. In this particular case the ocean-land meridional gradient of temperature strengthens, allowing a more intense monsoon circulation. We linked the non-linearity of Arctic sea ice decline impact with differences in temperature and sea level pressure changes over the North Atlantic Ocean. We argue that the impact of the Arctic sea ice loss will become more relevant with time, in the context of climate change
The Italian Unitary Society of Colon-proctology (SIUCP: Società Italiana Unitaria di Colonproctologia) guidelines for the management of anal fissure
Introduction: The aim of these evidence-based guidelines is to present a consensus position from members of the Italian Unitary Society of Colon-Proctology (SIUCP: Società Italiana Unitaria di Colon-Proctologia) on the diagnosis and management of anal fissure, with the purpose to guide every physician in the choice of the best treatment option, according with the available literature. Methods: A panel of experts was designed and charged by the Board of the SIUCP to develop key-questions on the main topics covering the management of anal fissure and to performe an accurate search on each topic in different databanks, in order to provide evidence-based answers to the questions and to summarize them in statements. All the clinical questions were discussed by the expert panel in different rounds through the Delphi approach and, for each statement, a consensus among the experts was reached. The questions were created according to the PICO criteria, and the statements developed adopting the GRADE methodology. Conclusions: In patients with acute anal fissure the medical therapy with dietary and behavioral norms is indicated. In the chronic phase of disease, the conservative treatment with topical 0.3% nifedipine plus 1.5% lidocaine or nitrates may represent the first-line therapy, eventually associated with ointments with film-forming, anti-inflammatory and healing properties such as Propionibacterium extract gel. In case of first-line treatment failure, the surgical strategy (internal sphincterotomy or fissurectomy with flap), may be guided by the clinical findings, eventually supported by endoanal ultrasound and anal manometry
The Italian Unitary Society of Colon-Proctology (Società Italiana Unitaria di Colonproctologia) guidelines for the management of acute and chronic hemorrhoidal disease
The aim of these evidence-based guidelines is to present a consensus position from members of the Italian Unitary Society of Colon-Proctology (Società Italiana Unitaria di Colon-Proctologia, SIUCP) on the diagnosis and management of hemorrhoidal disease, with the goal of guiding physicians in the choice of the best treatment option. A panel of experts was charged by the Board of the SIUCP to develop key questions on the main topics related to the management of hemorrhoidal disease and to perform an accurate and comprehensive literature search on each topic, in order to provide evidence-based answers to the questions and to summarize them in statements. All the clinical questions were discussed by the expert panel in multiple rounds through the Delphi approach and, for each statement, a consensus among the experts was reached. The questions were created according to PICO (patients, intervention, comparison, and outcomes) criteria, and the statements were developed adopting the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) methodology. In cases of grade 1 hemorrhoidal prolapse, outpatient procedures including hemorrhoidal laser procedure and sclerotherapy may be considered the preferred surgical options. For grade 2 prolapse, nonexcisional procedures including outpatient treatments, hemorrhoidal artery ligation and mucopexy, laser hemorrhoidoplasty, the Rafaelo procedure, and stapled hemorrhoidopexy may represent the first-line treatment options, whereas excisional surgery may be considered in selected cases. In cases of grades 3 and 4, stapled hemorrhoidopexy and hemorrhoidectomy may represent the most effective procedures, even if, in the expert panel opinion, stapled hemorrhoidopexy represents the gold-standard treatment for grade 3 hemorrhoidal prolapse
European candidaemia is characterised by notable differential epidemiology and susceptibility pattern: Results from the ECMM Candida III study.
The objectives of this study were to assess Candida spp. distribution and antifungal resistance of candidaemia across Europe. Isolates were collected as part of the third ECMM Candida European multicentre observational study, conducted from 01 to 07-07-2018 to 31-03-2022. Each centre (maximum number/country determined by population size) included ∼10 consecutive cases. Isolates were referred to central laboratories and identified by morphology and MALDI-TOF, supplemented by ITS-sequencing when needed. EUCAST MICs were determined for five antifungals. fks sequencing was performed for echinocandin resistant isolates. The 399 isolates from 41 centres in 17 countries included C. albicans (47.1%), C. glabrata (22.3%), C. parapsilosis (15.0%), C. tropicalis (6.3%), C. dubliniensis and C. krusei (2.3% each) and other species (4.8%). Austria had the highest C. albicans proportion (77%), Czech Republic, France and UK the highest C. glabrata proportions (25-33%) while Italy and Turkey had the highest C. parapsilosis proportions (24-26%). All isolates were amphotericin B susceptible. Fluconazole resistance was found in 4% C. tropicalis, 12% C. glabrata (from six countries across Europe), 17% C. parapsilosis (from Greece, Italy, and Turkey) and 20% other Candida spp. Four isolates were anidulafungin and micafungin resistant/non-wild-type and five resistant to micafungin only. Three/3 and 2/5 of these were sequenced and harboured fks-alterations including a novel L657W in C. parapsilosis. The epidemiology varied among centres and countries. Acquired echinocandin resistance was rare but included differential susceptibility to anidulafungin and micafungin, and resistant C. parapsilosis. Fluconazole and voriconazole cross-resistance was common in C. glabrata and C. parapsilosis but with different geographical prevalence
Global guideline for the diagnosis and management of candidiasis: an initiative of the ECMM in cooperation with ISHAM and ASM
Candida species are the predominant cause of fungal infections in patients treated in hospital, contributing substantially to morbidity and mortality. Candidaemia and other forms of invasive candidiasis primarily affect patients who are immunocompromised or critically ill. In contrast, mucocutaneous forms of candidiasis, such as oral thrush and vulvovaginal candidiasis, can occur in otherwise healthy individuals. Although mucocutaneous candidiasis is generally not life-threatening, it can cause considerable discomfort, recurrent infections, and complications, particularly in patients with underlying conditions such as diabetes or in those taking immunosuppressive therapies. The rise of difficult-to-treat Candida infections is driven by new host factors and antifungal resistance. Pathogens, such as Candida auris (Candidozyma auris) and fluconazole-resistant Candida parapsilosis, pose serious global health risks. Recent taxonomic revisions have reclassified several Candida spp, potentially causing confusion in clinical practice. Current management guidelines are limited in scope, with poor coverage of emerging pathogens and new treatment options. In this Review, we provide updated recommendations for managing Candida infections, with detailed evidence summaries available in the appendix. [Abstract copyright: Copyright © 2025 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.
Sensitivity of the tropical climate to an interhemispheric thermal gradient: the role of tropical ocean dynamics
This study aims to determine the role of the tropical ocean dynamics in the
response of the climate to extratropical thermal forcing. We analyse and
compare the outcomes of coupling an atmospheric general circulation model (AGCM) with two ocean models of different complexity. In the first
configuration the AGCM is coupled with a slab ocean model while in the second
a reduced gravity ocean (RGO) model is additionally coupled in the tropical
region. We find that the imposition of extratropical thermal forcing (warming in the Northern Hemisphere and cooling in the Southern Hemisphere
with zero global mean) produces, in terms of annual means, a weaker response
when the RGO is coupled, thus indicating that the tropical ocean dynamics
oppose the incoming remote signal. On the other hand, while the slab ocean
coupling does not produce significant changes to the equatorial Pacific sea
surface temperature (SST) seasonal cycle, the RGO configuration generates
strong warming in the central-eastern basin from April to August
balanced by cooling during the rest of the year, strengthening the seasonal
cycle in the eastern portion of the basin. We hypothesize that such changes
are possible via the dynamical effect that zonal wind stress has on the
thermocline depth. We also find that the imposed extratropical pattern
affects El Niño–Southern Oscillation, weakening its amplitude and
low-frequency behaviour
La Niña events before and after 1979 and their impact in southeastern South America during austral summer: role of the Indian Ocean
New estimation of critical insolation–CO<sub>2</sub> relationship for triggering glacial inception
It has been previously proposed that glacial inception represents a bifurcation transition between interglacial and glacial states and is governed by the nonlinear dynamics of the climate–cryosphere system. To trigger glacial inception, the orbital forcing (defined as the maximum of summer insolation at 65° N and determined by Earth’s orbital parameters) must be lower than a critical level, which depends on the atmospheric CO2 concentration. While paleoclimatic data do not provide a strong constraint on the dependence between CO2 and critical insolation, its accurate estimation is of fundamental importance for predicting future glaciations and the effect that anthropogenic CO2 emissions might have on them. In this study, we use the novel Earth system model of intermediate complexity CLIMBER-X with interactive ice sheets to produce a new estimation of the critical insolation–CO2 relationship for triggering glacial inception. We perform a series of experiments in which different combinations of orbital forcing and atmospheric CO2 concentration are maintained constant in time. We analyze for which combinations of orbital forcing and CO2 glacial inception occurs and trace the critical relationship between them, separating conditions under which glacial inception is possible from those where glacial inception is not materialized. We also provide a theoretical foundation for the proposed critical insolation–CO2 relation. We find that the use of the maximum summer insolation at 65° N as a single metric for orbital forcing is adequate for tracing the glacial inception bifurcation. Moreover, we find that the temporal and spatial patterns of ice sheet growth during glacial inception are not always the same but depend on the critical insolation and CO2 level. The experiments evidence the fact that during glacial inception, ice sheets grow mostly in North America, and only under low CO2 conditions are ice sheets also formed over Scandinavia. The latter is associated with a weak Atlantic Meridional Overturning Circulation (AMOC) for low CO2. We find that the strength of AMOC also affects the rate of ice sheet growth during glacial inception.</p
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