190 research outputs found
Managers' cultural origin and corporate response to an economic shock
We exploit the exogenous Covid-19 shock in a bicultural area of Italy to identify cultural differences in the way companies respond to economic shocks. Firms with managers of diverse cultural backgrounds resort to different forms of government aid, diverge in their investment decisions, and have different growth rates. These findings are consistent with cultural differences in time preferences and debt aversion. Specifically, we find that the response of managers belonging to a more long-term oriented culture is characterized by a lower recourse to debt, more investments and higher growth rates. Overall, our results show that the cultural origin of managers significantly affects firms’ reaction to economic shocks and real economic outcome
High resolution computed tomography quantitation of emphysema is correlated with selected lung function values in stable COPD.
BACKGROUND:
The literature shows conflicting results when high-resolution computed tomography (HRCT) scores of emphysema were correlated with different indices of airflow obstruction.
OBJECTIVES:
We correlated HRCT scores of emphysema with different indices of airflow obstruction.
METHODS:
We performed HRCT of the chest in 59 patients, all smokers or ex-smokers, with stable chronic obstructive pulmonary disease of different severity [GOLD stages I-IV; mean age \ub1 SD 67.8 \ub1 7.3 years; pack/years 51.0 \ub1 34.6; percent predicted forced expiratory volume in 1 s (FEV(1)% predicted) 52.3 \ub1 17.6; post-bronchodilator FEV(1)% predicted 56.5 \ub1 19.1; FEV(1)/forced vital capacity (FVC) ratio 50.8 \ub1 10.2; post-bronchodilator FEV(1)/FVC ratio 51.6 \ub1 11.0; percent diffusion lung capacity for carbon monoxide (DLCO%) 59.2 \ub1 21.1; DLCO/percent alveolar volume (VA%) 54.5 \ub1 18.2; percent residual volume 163.0 \ub1 35.6; percent total lung capacity (TLC%) 113.2 \ub1 15; residual volume/TLC 1.44 \ub1 0.2]. All patients were in stable phase.
RESULTS:
The mean \ub1 SD visual emphysema score in all patients was 25.6 \ub1 25.4%. There was a weak but significant correlation between the percentage of pulmonary emphysema and numbers of pack/years (R = +0.31, p = 0.024). The percentage of emphysema was inversely correlated with the FEV(1)/FVC ratio before and after bronchodilator use (R = -0.44, p = 0.002, and R = -0.39, p = 0.005), DLCO% (R = -0.64, p = 0.0003) and DLCO/VA% (R = -0.68, p < 0.0001). A weak positive correlation was also found with TLC% (R = +0.28, p = 0.048). When patients with documented emphysema were considered separately, the best significant correlation observed was between DLCO/VA% and HRCT scan score (p = 0.007).
CONCLUSIONS:
These data suggest that in patients with stable chronic obstructive pulmonary disease of varying severity, the presence of pulmonary emphysema is best represented by the impaired gas exchange capability of the respiratory system
Global ocean wave fields show consistent regional trends between 1980 and 2014 in a multi-product ensemble
Historical trends in the direction and magnitude of ocean surface wave height, period, or direction are debated due to diverse data, time-periods, or methodologies. Using a consistent community-driven ensemble of global wave products, we quantify and establish regions with robust trends in global multivariate wave fields between 1980 and 2014. We find that about 30-40% of the global ocean experienced robust seasonal trends in mean and extreme wave height, period, and direction. Most of the Southern Hemisphere exhibited strong upward-trending wave heights (1-2 cm per year) and periods during winter and summer. Ocean basins with robust positive trends are far larger than those with negative trends. Historical trends calculated over shorter periods generally agree with satellite records but vary from product to product, with some showing a consistently negative bias. Variability in trends across products and time-periods highlights the importance of considering multiple sources when seeking robust change analyses
Global ocean wave fields show consistent regional trends between 1980 and 2014 in a multi-product ensemble
Historical trends in the direction and magnitude of ocean surface wave height, period, or direction are debated due to diverse data, time-periods, or methodologies. Using a consistent community-driven ensemble of global wave products, we quantify and establish regions with robust trends in global multivariate wave fields between 1980 and 2014. We find that about 30–40% of the global ocean experienced robust seasonal trends in mean and extreme wave height, period, and direction. Most of the Southern Hemisphere exhibited strong upward-trending wave heights (1–2 cm per year) and periods during winter and summer. Ocean basins with robust positive trends are far larger than those with negative trends. Historical trends calculated over shorter periods generally agree with satellite records but vary from product to product, with some showing a consistently negative bias. Variability in trends across products and time-periods highlights the importance of considering multiple sources when seeking robust change analyses.publishedVersio
Monitoring of total positive end-expiratory pressure during mechanical ventilation by artificial neural networks
Ventilation treatment of acute lung injury (ALI) requires the application of positive airway pressure at the end of expiration (PEEPapp) to avoid lung collapse. However, the total pressure exerted on the alveolar walls (PEEPtot) is the sum of PEEPapp and intrinsic PEEP (PEEPi), a hidden component. To measure PEEPtot, ventilation must be discontinued with an end-expiratory hold maneuver (EEHM). We hypothesized that artificial neural networks (ANN) could estimate the PEEPtot from flow and pressure tracings during ongoing mechanical ventilation. Ten pigs were mechanically ventilated, and the time constant of their respiratory system (τRS) was measured. We shortened their expiratory time (TE) according to multiples of τRS, obtaining different respiratory patterns (Rpat). Pressure (PAW) and flow (V′AW) at the airway opening during ongoing mechanical ventilation were simultaneously recorded, with and without the addition of external resistance. The last breath of each Rpat included an EEHM, which was used to compute the reference PEEPtot. The entire protocol was repeated after the induction of ALI with i.v. injection of oleic acid, and 382 tracings were obtained. The ANN had to extract the PEEPtot, from the tracings without an EEHM. ANN agreement with reference PEEPtot was assessed with the Bland–Altman method. Bland Altman analysis of estimation error by ANN showed −0.40 ± 2.84 (expressed as bias ± precision) and ±5.58 as limits of agreement (data expressed as cmH2O). The ANNs estimated the PEEPtot well at different levels of PEEPapp under dynamic conditions, opening up new possibilities in monitoring PEEPi in critically ill patients who require ventilator treatment
Antimicrobial functionalized genetically engineered spider silk
Genetically engineered fusion proteins offer potential as multifunctional biomaterials for medical use.
Fusion or chimeric proteins can be formed using recombinant DNA technology by combining nucleotide
sequences encoding different peptides or proteins that are otherwise not found together in nature. In the
present study, three new fusion proteins were designed, cloned and expressed and assessed for function,
by combining the consensus sequence of dragline spider silk with three different antimicrobial peptides.
The human antimicrobial peptides human neutrophil defensin 2 (HNP-2), human neutrophil defensins 4
(HNP-4) and hepcidin were fused to spider silk through bioengineering. The spider silk domain maintained
its self-assembly features, a key aspect of these new polymeric protein biomaterials, allowing the
formation of b-sheets to lock in structures via physical interactions without the need for chemical crosslinking.
These new functional silk proteins were assessed for antimicrobial activity against Gram e
Escherichia coli and Gram þ Staphylococcus aureus and microbicidal activity was demonstrated. Dynamic
light scattering was used to assess protein aggregation to clarify the antimicrobial patterns observed.
Attenuated-total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and circular dichroism
(CD) were used to assess the secondary structure of the new recombinant proteins. In vitro cell studies
with a human osteosarcoma cell line (SaOs-2) demonstrated the compatibility of these new proteins
with mammalian cells.Fundação para a Ciência e a Tecnologia (FCT) - Bolsa de doutoramento (SFRH/BD/28603/2006); Chimera project (PTDC/EBB-EBI/109093/2008); NIH and Tissue Engineering Resource Center EB003210, P41
EB002520, DE017207
Land conflict in peri-urban areas: Exploring the effects of land reform on informal settlement in Mexico
Peri-urban areas are often subject to intensive construction, through both formal and informal processes. As land transitions from rural to urban status, different land tenure and administration systems may come into conflict, leading to disputes, contestation and, in some cases, violence. However, little is known about the precise causes of peri-urban land conflict. In Mexico, peri-urban growth has historically proceeded peacefully, owing to the control exerted by a corporatist system of government, and the political use of land tenure regularisation. However, the effects of land reforms on transactions at the peri-urban fringe, in the context of wider processes of liberalisation, may be increasing vulnerability to conflict over land. This paper explores these issues through a case study of an irregular settlement on the peri-urban fringe of the provincial Mexican city of Xalapa, where contestations over informally developed land have escalated into violent encounters between groups of settlers and the state. The findings show that vulnerability to conflict in peri-urban areas can be attributed to the interaction of macro-level processes with local-level factors, including diverse claims, overlapping legal and governance frameworks and, critically, local power relations
Poly(Ethylene Oxide) Functionalized Polyimide-Based Microporous Films to Prevent Bacterial Adhesion
Plasmonic Nanoparticle/Polymer Nanocomposites with Enhanced Photocatalytic Antimicrobial Properties
Active Packaging Technologies with an Emphasis on Antimicrobial Packaging and its Applications
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