1,651 research outputs found
Decadal trends in air-sea CO2 exchange in the Ross Sea (Antarctica)
Abstract Highly productive Antarctic shelf systems, like the Ross Sea, play important roles in regional carbon budgets, but the drivers of local variations are poorly quantified. We assess the variability in the Ross Sea carbon cycle using a regional physical‐biogeochemical model. Regionally, total partial pressure of CO2 (pCO2) increases are largely controlled by the biological pump and broadly similar to those in the offshore Southern Ocean. However, this masks substantial local variability within the Ross Sea, where interannual fluctuations in total pCO2 are driven by the biological pump and alkalinity, whereas those for anthropogenic pCO2 are related to physical processes. Overall, the high degree of spatial variability in the Ross Sea carbon cycle causes extremes in aragonite saturation that can be as large as long‐term trends. Therefore, Antarctic shelf polynya systems like the Ross Sea will be strongly affected by local processes in addition to larger‐scale phenomena
Dynamic facial expressions of emotions are discriminated at birth
The ability to discriminate between different facial expressions is fundamental since the first stages of postnatal life. The aim of this study is to investigate whether 2-days-old newborns are capable to discriminate facial expressions of emotions as they naturally take place in everyday interactions, that is in motion. When two dynamic displays depicting a happy and a disgusted facial expression were simultaneously presented (i.e., visual preference paradigm), newborns did not manifest any visual preference (Experiment 1). Nonetheless, after being habituated to a happy or disgusted dynamic emotional expression (i.e., habituation paradigm), newborns successfully discriminated between the two (Experiment 2). These results indicate that at birth newborns are sensitive to dynamic faces expressing emotions
Application of biological growth risk models to the management of built heritage
La qualità degli spazi interni è fortemente legata alle condizioni igrotermiche che influenzano il comfort degli utenti e i rischi di conservazione del patrimonio edilizio. Inoltre, una gestione incurante di spazi espositivi con numerosi accessi può causare carichi eccessivi di umidità, e conseguenti fenomeni di degrado. In questo lavoro, è stata considerata una sala espositiva rappresentativa del patrimonio costruito. Il rischio di proliferazione biologica è indagato nelle condizioni climatiche di Milano e Barcellona, con diversi ratei di ventilazione e numero di visitatori. I risultati delineano la necessità di politiche informate da analisi avanzate per prevenire il rischio igrotermico, in assenza di impianti, che non è sempre possibile integrare nel patrimonio edilizio storico.The quality of the interior spaces is strongly related to the hygro-thermal conditions which affect the users’ comfort, and may yield to preservation risk for the built heritage. Moreover, careless management of exposition spaces with excessive occupancy may result in moisture loads that promote degradation. In this paper, as a case study, an exposition hall representative of the built heritage is considered. The microbiological growth risk is investigated at two different climate conditions, namely Milan and Barcelona, considering varying ventilation rates and number of visitors. The results outline the need of policies informed by advanced analyses to prevent hygro-thermal risk in the absence of dedicated building services, that cannot always be integrated in built heritage
Intentional weight loss in overweight and obese individuals and cognitive function: a systematic review and meta-analysis.
High adiposity in middle age is associated with higher dementia risk. The association between weight loss and cognitive function in older adults is still controversial. A meta-analysis was undertaken to estimate the effectiveness of intentional weight loss on cognitive function in overweight and obese adults. A structured strategy was used to search randomized and non-randomized studies reporting the effect of intentional and significant weight loss on cognitive function in overweight and obese subjects. Information on study design, age, nutritional status, weight-loss strategy, weight lost and cognitive testing was extracted. A random-effect meta-analysis was conducted to obtain summary effect estimates for memory and attention-executive domains. Twelve studies met inclusion criteria. Seven were randomized trials and the remaining five included a control group. A low-order significant effect was found for an improvement in cognitive performance with weight loss in memory (effect size 0.13, 95% CI 0.00-0.26, P=0.04) and attention/executive functioning (effect size 0.14, 95% CI 0.01-0.27, P<0.001). Studies were heterogeneous in study design, sample selection, weight-loss intervention and assessment of cognitive function. Weight loss appears to be associated with low-order improvements in executive/attention functioning and memory in obese but not in overweight individual
Thermal and Economic Efficiency of Progressive Retrofit Strategies for School Buildings by a Statistical Analysis based Tool
Design alternatives in air conditioned buildings may be easily compared just by summing the hourly consumption of primary energy, while quantitative approachs for bioclimatic design strategies are difficult to be assessed and compared. A actively heated and passively cooled school building is considered as an application field of a novel methodology to promote an informed choice about the retrofit strategies to be adopted for buildings, defined as the Gained Comfort Cost (GCC). A functional and significant unit (i.e. a classroom), is used to test different energy retrofit solutions and their performances were compared with a baseline, in terms of the capacity to reduce the indoor air temperature variation. The novel methodology is a visual tool allowing to understand the “distance” of indoor conditions from comfort; the retrofit strategies are promoted to reduce this distance considering however the associated costs (LCC) to deal with actual feasibility
Poly(I:C) and CpG-ODN combined aerosolization to treat lung metastases and counter the immunosuppressive microenvironment
The immunostimulatory ability of synthetic oligonucleotides containing CpG motifs (CpG-ODN), agonists of Toll-like receptor 9 (TLR9), can be harnessed to promote antitumor immunity by their application at the tumor site to stimulate local activation of innate immunity; however, particularly in the lung, tumor-associated immunosuppression can subvert such antitumor innate immune responses. To locally maintain continuous activation of innate subpopulations while inhibiting immunosuppressive cells, we evaluated aerosol delivery CpG-ODN combined with Poly(I:C), a TLR3 agonist able to convert tumor-supporting macrophages to tumoricidal effectors, in the treatment of B16 melanoma lung metastases in C57BL/6 mice. Aerosolization of CpG-ODN with Poly(I:C) into the bronchoalveolar space reduced the presence of M2-associated arginase- and IL-10-secreting macrophages in tumor-bearing lungs and increased the antitumor activity of aerosolized CpG-ODN alone against B16 lung metastases without apparent signs of toxicity or injury of the bronchial-bronchiolar structures and alveolar walls. Moreover, CpG-ODN/Poly(I:C) aerosol combined with dacarbazine, a therapeutic agent used in patients with inoperable metastatic melanoma able to exert immunostimulatory effects, led to a significant increase in antitumor activity as compared to treatments with aerosolized CpG-ODN/Poly(I:C) or dacarbazine alone. This effect was related to an enhanced recruitment and cytotoxic activity of tumor-infiltrating NK cells in the lung. Our results point to aerosol delivery as a convenient approach for repeated applications of immunostimulants in patients with lung metastases to maintain a continuous local activation of innate immune cells while suppressing polarization of tumor-infiltrating macrophages to an M2 phenotype
Ultrafast Studies of Hot-Hole Dynamics in Au/p-GaN Heterostructures
Harvesting non-equilibrium hot carriers from photo-excited metal
nanoparticles has enabled plasmon-driven photochemical transformations and
tunable photodetection with resonant nanoantennas. Despite numerous studies on
the ultrafast dynamics of hot electrons, to date, the temporal evolution of hot
holes in metal-semiconductor heterostructures remains unknown. An improved
understanding of the carrier dynamics in hot-hole-driven systems is needed to
help expand the scope of hot-carrier optoelectronics beyond hot-electron-based
devices. Here, using ultrafast transient absorption spectroscopy, we show that
plasmon-induced hot-hole injection from gold (Au) nanoparticles into the
valence band of p-type gallium nitride (p-GaN) occurs within 200 fs, placing
hot-hole transfer on a similar timescale as hot-electron transfer. We further
observed that the removal of hot holes from below the Au Fermi level exerts a
discernible influence on the thermalization of hot electrons above it, reducing
the peak electronic temperature and decreasing the electron-phonon coupling
time relative to Au samples without a pathway for hot-hole collection. First
principles calculations corroborate these experimental observations, suggesting
that hot-hole injection modifies the relaxation dynamics of hot electrons in Au
nanoparticles through ultrafast modulation of the d-band electronic structure.
Taken together, these ultrafast studies substantially advance our understanding
of the temporal evolution of hot holes in metal-semiconductor heterostructures
and suggest new strategies for manipulating and controlling the energy
distributions of hot carriers on ultrafast timescales.Comment: 12 pages, 4 figure
Anti-tumor activity of CpG-ODN aerosol in mouse lung metastases
Studies in preclinical models have demonstrated the superior anti-tumor effect of CpG oligodeoxynucleotides (CpG-ODN) when administered at the tumor site rather than systemically. We evaluated the effect of aerosolized CpG-ODN on lung metastases in mice injected with immunogenic N202.1A mammary carcinoma cells or weakly immunogenic B16 melanoma cells. Upon reaching the bronchoalveolar space, aerosolized CpG-ODN activated a local immune response, as indicated by production of IL-12p40, IFN-γ and IL-1β and by recruitment and maturation of DC cells in bronchoalveolar lavage fluid of mice. Treatment with aerosolized CpG-ODN induced an expansion of CD4+ cells in lung and was more efficacious than systemic i.p. administration against experimental lung metastases of immunogenic N202.1A mammary carcinoma cells, whereas only i.p. delivery of CpG-ODN provided anti-tumor activity, which correlated with NK cell expansion in the lung, against lung metastases of the poorly immunogenic B16 melanoma. The inefficacy of aerosol therapy to induce NK expansion was related to the presence of immunosuppressive macrophages in B16 tumor-bearing lungs, as mice depleted of these cells by clodronate treatment responded to aerosol CpG-ODN through expansion of the NK cell population and significantly reduced numbers of lung metastases. Our results indicate that tumor immunogenicity and the tumor-induced immunosuppressive environment are critical factors to the success of CpG therapy in the lung, and point to the value of routine sampling of the lung immune environment in defining an optimal immunotherapeutic strategy
Clostridium difficile infection in children: epidemiology and risk of recurrence in a low-prevalence country
Clostridium difficile infection (CDI) is increasingly found in children worldwide, but limited data are available from children living in southern Europe. A 6-year retrospective study was performed to investigate the epidemiology, clinical features, treatment, and risk of recurrence in Italy. Data of children with community- and hospital-acquired CDI (CA-CDI and HA-CDI, respectively) seen at seven pediatric referral centers in Italy were recorded retrospectively. Annual infection rates/10,000 hospital admissions were calculated. Logistic regression was used to investigate risk factors for recurrence. A total of 177 CDI episodes was reported in 148 children (83 males, median age 55.3 months), with a cumulative infection rate of 2.25/10,000 admissions, with no significant variability over time. The majority of children (60.8 %) had CA-CDI. Children with HA-CDI (39.2 %) had a longer duration of symptoms and hospitalization (p = 0.003) and a more common previous use of antibiotics (p = 0.0001). Metronidazole was used in 70.7 % of cases (87/123) and vancomycin in 29.3 % (36/123), with similar success rates. Recurrence occurred in 16 children (10.8 %), and 3 (2 %) of them presented a further treatment failure. The use of metronidazole was associated with a 5-fold increase in the risk of recurrence [odds ratio (OR) 5.18, 95 % confidence interval (CI) 1.1-23.8, p = 0.03]. Short bowel syndrome was the only underlying condition associated with treatment failure (OR 5.29, 95 % CI 1.17-23.8, p = 0.03). The incidence of pediatric CDI in Italy is low and substantially stable. In this setting, there is a limited risk of recurrence, which mainly concerns children treated with oral metronidazole and those with short bowel syndrome
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