137 research outputs found
Dense infinite Bh sequences
For h = 3 and h = 4 we prove the existence of infinite Bh sequences B with counting function B(x) = x√(h−1)2+1−(h−1)+o(1). This result extends a construction of I. Ruzsa for B2 sequences
Magma dynamics during the 2007 Stromboli eruption (Aeolian Islands. Italy): mineralogical, geochemical and isotopic data
After the 6 month-long effusive event of 2002-2003, a new lava effusion occurred at Stromboli between 27
February and 2 April 2007. Despite the different durations, approximately the same volume of magma was
emitted in both eruptions, in the order of 107
m3
. A paroxysmal eruption occurred at the summit craters in
both the 2002–2003 and 2007 episodes, during which a significant amount of low porphyritic (LP), volatile-
rich magma was erupted. In both cases, the paroxysm did not interrupt the lava emission. Here, we present
compositional data, including texture, mineralogy, chemistry and Sr and Nd isotope ratios of bulk-rock,
groundmass and separated minerals of lavas erupted in 2007, together with chemistry and Sr and Nd isotope
composition of the pumices emitted during the 15 March paroxysm. As a whole, the lavas have the same
texture and chemistry that characterize the highly porphyritic (HP) products usually erupted at Stromboli
during normal Strombolian activity and effusive events. Compared to the previous HP products, the 2007
lavas show minor but systematic mineralogical and isotopic variations which are consistent with a modest
increase of the magma supply rate of the volcano. Compositional variations during the entire duration of the
event are very modest. Glass chemistry changes in lavas erupted in the second half of March can be explained
by theminormixing between the volatile-rich LPmagma rising through the shallowmagmatic systemduring the
15 March paroxysm and the degassed residing HP magma. A first conclusion of this study is that there is no
compositional evidence supporting major changes in the magma dynamics of the volcano accompanying the
effusive activity, as also suggested for the 2002–2003 event. The activity of Stromboli is controlled by a steady
state feeding system in which refilling, mixing, degassing and crystallization at shallow level continuously
operate,withmodest oscillations in themagma supply rate. Switching between normal Strombolian and effusive
activity is related to periods of relatively more vigorous refilling of the shallow system, leading to progressive
pressure increase in the upper conduits associated with only minor compositional variations in the erupted
products
An Interplay between a Face-Centred Composite Experimental Design and Solid-Phase Microextraction for Wine Aroma GC/MS Analysis
For oenological products, most of the intrinsic and extrinsic drivers of perceived quality are associated with specific aromatic profiles. Aromatic diversity has been recognized as a central element in perceived quality as it is able to transmit the complex interactions between grape variety, geographical characteristics, and viticultural and winemaking practices, including the fermentative process. A comprehensive characterization of flavour compounds by headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to mass spectrometric analysis is often needed in order to ascertain the quality of wine. HS-SPME requires a proper optimization that can be achieved through an adequate experimental design. Here, a HS-SPME/GC-MS based method was developed to investigate the volatile compounds of wine samples obtained by laboratory-scale fermentations. This was performed by inoculating a commercial Saccharomyces cerevisiae strain, which is used both as single starter and as mixed starter, with an indigenous Hanseniaspora osmophila strain. The experimental conditions of HS-SPME (extraction temperature and time) were optimized by applying a face-centred composite experimental design. Up to 95% of the total variance was explained by the proposed model. The optimized method allowed us to confirm the usefulness of combining the inoculation of grapes with selected yeast strains in co-culture situations in order to improve the wine bouquet
Land use change in a pericolonial society: intensification and diversification in Ifugao, Philippines between 1570 and 1800 CE
Land use modelling is increasingly used by archaeologists and palaeoecologists seeking to quantify and compare the changing influence of humans on the environment. In Southeast Asia, the intensification of rice agriculture and the arrival of European colonizers have both been seen as major catalysts for deforestation, soil erosion, and biodiversity change. Here we consider the Tuwali-Ifugao people of the Cordillera Central (Luzon, Philippines), who resisted Spanish colonial subjugation from the 16th to the mid-nineteenth century, in part through the development of a world-renowned system of intensive wet-rice terrace agriculture. To quantify changes in how the Tuwali-Ifugao used their environment, we model land use in Old Kiyyangan Village, a long-inhabited settlement, at two timepoints: circa 1570 CE, prior to the Spanish arrival in Luzon, and circa 1800 CE, before the village was sacked by Spanish military expeditions. Our model demonstrates that between 1570 and 1800 the adoption of rice as a staple and the corresponding expansion in terrace agriculture, along with a general diversification of diet and land use, enabled the village’s population to double without increasing total land use area. Further, this major intensification led to the solidification of social hierarchies and occurred without a proportional increase in deforestation.Introduction Methodology - Models in Ifugao: The History and Socio-Ecology of the Region - The Historical Land Use Model - Model Calculations for OKV - Population and Boble (Settled Area) at OKV - Payo (Terraces) - Uma (Swidden Fields) - Muyong (Private Forests) - Domesticated Animals - Hunting, Foraging, and Fishing - Fuel and Resource Extraction - Commerce - Agricultural Productivity and Nutritional Value - Dietary Proportions Results - 1800 - 1570 - Exploring Social Difference: Kadangyan and Nawotwot Land Use in 1800 Discussio
Development and Validation of a Reversed-Phase HPLC Method with UV Detection for the Determination of L-Dopa in Vicia faba L. Broad Beans
L-Dopa (LD), a substance used medically in the treatment of Parkinson's disease, is found in several natural products, such as Vicia faba L., also known as broad beans. Due to its low chemical stability, LD analysis in plant matrices requires an appropriate optimization of the chosen analytical method to obtain reliable results. This work proposes an HPLC-UV method, validated according to EURACHEM guidelines as regards linearity, limits of detection and quantification, precision, accuracy, and matrix effect. The LD extraction was studied by evaluating its aqueous stability over 3 months. The best chromatographic conditions were found by systematically testing several C-18 stationary phases and acidic mobile phases. In addition, the assessment of the best storage treatment of Vicia faba L. broad beans able to preserve a high LD content was performed. The best LD determination conditions include sun-drying storage, extraction in HCl 0.1 M, chromatographic separation with a Discovery C-18 column, 250 x 4.6 mm, 5 mu m particle size, and 99% formic acid 0.2% v/v and 1% methanol as the mobile phase. The optimized method proposed here overcomes the problems linked to LD stability and separation, thus contributing to the improvement of its analytical determination
β2M Signals Monocytes Through Non-Canonical TGFβ Receptor Signal Transduction.
Rationale: Circulating monocytes can have pro-inflammatory or pro-reparative phenotypes. The
endogenous signaling molecules and pathways that regulate monocyte polarization in vivo are poorly
understood. We have shown that platelet derived beta-2 microglobulin (β2M) and transforming growth
factor beta (TGFβ) have opposing effects on monocytes by inducing inflammatory and reparative
phenotypes respectively, but each bind and signal through the same receptor. We now define the signaling
pathways involved.
Objective: To determine the molecular mechanisms and signal transduction pathways by which β2M and
TGFβ regulate monocyte responses both in vitro and in vivo.
Methods and Results: Wild-type (WT) and platelet specific β2M knockout (Plt-β2M-/-) mice were treated
intravenously with either β2M or TGFβ to increase plasma concentrations to those in cardiovascular
diseases. Elevated plasma β2M increased pro-inflammatory monocytes, while increased plasma TGFβ
increased pro-reparative monocytes. TGFβ receptor (TGFβR) inhibition blunted monocyte responses to
both β2M and TGFβ in vivo. Using imaging flow cytometry, we found that β2M decreased monocyte
SMAD2/3 nuclear localization, while TGFβ promoted SMAD nuclear translocation, but decreased noncanonical/
inflammatory (JNK and NFκB nuclear localization). This was confirmed in vitro using both
imaging flow cytometry and immunoblots. β2M, but not TGFβ, promoted ubiquitination of SMAD3 and
SMAD4, that inhibited their nuclear trafficking. Inhibition of ubiquitin ligase activity blocked noncanonical
SMAD-independent monocyte signaling and skewed monocytes towards a pro-reparative
monocyte response.
Conclusions: Our findings indicate that elevated plasma β2M and TGFβ dichotomously polarize
monocytes. Furthermore, these immune molecules share a common receptor, but induce SMAD-dependent
canonical signaling (TGFβ) versus non-canonical SMAD-independent signaling (β2M) in a ubiquitin ligase
dependent manner. This work has broad implications as β2M is increased in several inflammatory
conditions, while TGFβ is increased in fibrotic diseases.pre-print3451 K
Effect of awake prone position on diaphragmatic thickening fraction in patients assisted by noninvasive ventilation for hypoxemic acute respiratory failure related to novel coronavirus disease
Background: Awake prone position is an emerging rescue therapy applied in patients undergoing noninvasive ventilation (NIV) for acute hypoxemic respiratory failure (ARF) related to novel coronavirus disease (COVID-19). Although applied to stabilize respiratory status, in awake patients, the application of prone position may reduce comfort with a consequent increase in the workload imposed on respiratory muscles. Thus, we primarily ascertained the effect of awake prone position on diaphragmatic thickening fraction, assessed through ultrasound, in COVID-19 patients undergoing NIV. Methods: We enrolled all COVID-19 adult critically ill patients, admitted to intensive care unit (ICU) for hypoxemic ARF and undergoing NIV, deserving of awake prone positioning as a rescue therapy. Exclusion criteria were pregnancy and any contraindication to awake prone position and NIV. On ICU admission, after NIV onset, in supine position, and at 1\ua0h following awake prone position application, diaphragmatic thickening fraction was obtained on the right side. Across all the study phases, NIV was maintained with the same setting present at study entry. Vital signs were monitored throughout the entire study period. Comfort was assessed through numerical rating scale (0 the worst comfort and 10 the highest comfort level). Data were presented in median and 25th\u201375th percentile range. Results: From February to May 2021, 20 patients were enrolled and finally analyzed. Despite peripheral oxygen saturation improvement [96 (94\u201397)% supine vs 98 (96\u201399)% prone, p = 0.008], turning to prone position induced a worsening in comfort score from 7.0 (6.0\u20138.0) to 6.0 (5.0\u20137.0) (p = 0.012) and an increase in diaphragmatic thickening fraction from 33.3 (25.7\u201340.5)% to 41.5 (29.8\u201350.0)% (p = 0.025). Conclusions: In our COVID-19 patients assisted by NIV in ICU, the application of awake prone position improved the oxygenation at the expense of a greater diaphragmatic thickening fraction compared to supine position. Trial registration ClinicalTrials.gov, number NCT04904731. Registered on 05/25/2021, retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT04904731
A Quantitative Estimate of the Expected Shortening of the Median Isolation Period of Patients With COVID-19 After the Adoption of a Symptom-Based Strategy
A long period of isolation was observed in patients hospitalized for COVID-19 in Milan over March-September 2020 (45; IQR: 37–54 days). A significantly shorter period would have been observed by the application of May-WHO (22, IQR: 17–30 days, P < 0.001) and October-Italian (26, IQR: 21–34 days, P < 0.001) Guidelines. The adoption of the new symptom-based criteria is likely to lead to a significant reduction in the length of the isolation period with potential social, economic and psychological benefits, particularly in the younger population with mild/moderate disease and no comorbidities. In our opinion, the release from isolation after 21 days from symptoms onset, even without a PCR diagnostic test, in most cases seems the most adequate strategy that could balance precautions to prevent SARS CoV-2 transmission and unnecessary prolonged isolation or overuse of diagnostic testing
Antimicrobial Prophylaxis in Neonates and Children Undergoing Dental, Maxillo-Facial or Ear-Nose-Throat (ENT) Surgery: A RAND/UCLA Appropriateness Method Consensus Study
Surgical site infections (SSIs) represent a potential complication in surgical procedures, mainly because clean/contaminated surgery involves organs that are normally colonized by bacteria. Dental, maxillo-facial and ear-nose-throat (ENT) surgeries are among those that carry a risk of SSIs because the mouth and the first respiratory tracts are normally colonized by a bacterial flora. The aim of this consensus document was to provide clinicians with recommendations on surgical antimicrobial prophylaxis in neonates (<28 days of chronological age) and pediatric patients (within the age range of 29 days–18 years) undergoing dental, maxillo-facial or ENT surgical procedures. These included: (1) dental surgery; (2) maxilla-facial surgery following trauma with fracture; (3) temporo-mandibular surgery; (4) cleft palate and cleft lip repair; (5) ear surgery; (6) endoscopic paranasal cavity surgery and septoplasty; (7) clean head and neck surgery; (8) clean/contaminated head and neck surgery and (9) tonsillectomy and adenoidectomy. Due to the lack of pediatric data for the majority of dental, maxillo-facial and ENT surgeries and the fact that the recommendations for adults are currently used, there is a need for ad hoc studies to be rapidly planned for the most deficient areas. This seems even more urgent for interventions such as those involving the first airways since the different composition of the respiratory microbiota in children compared to adults implies the possibility that surgical antibiotic prophylaxis schemes that are ideal for adults may not be equally effective in children
e-Work Self-Efficacy digital competence and work engagement of teachers in public secondary schools from two provinces in the Philippines
This descriptive-correlational research design aimed to determine the significant relationships between e-Work SelfEfficacy digital competence, and work engagement of teachers in secondary schools in the Philippines. The respondents of the study were 244 teachers from public secondary from two provinces. They were selected through Simple Random Sampling. The study was conducted via online forms. The gathered data were treated using statistical tools such as Mean, Standard Deviation, Pearson r, Hayes Process, and Multiple Linear Regression. The results of the study suggest that enhancing e-Work Self-Efficacy and digital competence may lead to increased work engagement, which could ultimately lead to better job performance and satisfaction in the context of remote work. The results of moderation analyses revealed that the
respondents’ profile age, length of service, and academic rank significantly moderated the relationship between e-Work Selt-Efficacy and work engagement. Hence, the hypothesis stating that the respondents’ profile variables do not significantly moderate between e-Work Self-Efficacy and work engagement and also the hypothesis stating that the respondents’ profile variables do not significantly moderate between digital competence and work engagement of the respondents were both partly upheld. The result of regression analysis identified that digital competence singly predicted the Work Engagement of the respondents. Moreover, the regression further revealed that digital competence and e-Work Selt-Efficacy, in combination, predict the work engagement of the respondents. Hence, the hypothesis stating that the respondents’ profile, e-Work Self-Efficacy and digital competence do not significantly predict their work engagement was partly upheld
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