Enteric-coated sodium bicarbonate supplementation improves high-intensity cycling performance in trained cyclists

Purpose: Enteric-coated sodium bicarbonate (NaHCO3) can attenuate gastrointestinal (GI) symptoms following acute bicarbonate loading, although the subsequent effects on exercise performance have not been investigated. The purpose of this study was to examine the effects of enteric-coated NaHCO3 supplementation on high-intensity exercise performance and GI symptoms. Methods: Eleven trained male cyclists completed three 4 km time trials after consuming; a placebo or 0.3 g∙kg–1 body mass NaHCO3 in enteric-coated or gelatin capsules. Exercise trials were timed with individual peak blood bicarbonate ion concentration ([HCO3–]). Blood acid–base balance was measured pre-ingestion, pre-exercise, and post-exercise, whereas GI symptoms were recorded pre-ingestion and immediately pre-exercise. Results: Pre-exercise blood [HCO3−] and potential hydrogen (pH) were greater for both NaHCO3 conditions (P &lt; 0.0005) when compared to placebo. Performance time was faster with enteric-coated (− 8.5 ± 9.6 s, P = 0.044) and gelatin (− 9.6 ± 7.2 s, P = 0.004) NaHCO3 compared to placebo, with no significant difference between conditions (mean difference = 1.1 ± 5.3 s, P = 1.000). Physiological responses were similar between conditions, although blood lactate ion concentration was higher with gelatin NaHCO3 (2.4 ± 1.7 mmol∙L–1, P = 0.003) compared with placebo. Furthermore, fewer participants experienced GI symptoms with enteric-coated (n = 3) compared to gelatin (n = 7) NaHCO3. Discussion: Acute enteric-coated NaHCO3 consumption mitigates GI symptoms at the onset of exercise and improves subsequent 4 km cycling TT performance. Athletes who experience GI side-effects after acute bicarbonate loading may, therefore, benefit from enteric-coated NaHCO3 supplementation prior to exercise performance.</p

Paving (through) Amazonia: Neoliberal Urbanism and the Reperipheralization of Roraima

This paper examines the neoliberal reshaping of infrastructure provision in Brazil's extreme north since the mid-1990s, when roadway investments resulted in unprecedented regional connectivity. The BR-174 upgrade, the era's most important project, marked a transition from resource-based developmentalism to free-market transnationalism. Primarily concerned with urban competitiveness, the federal government funded the trunk roadway's paving to facilitate manufacturing exports from Manaus. While an effort was made to minimize deforestation, planners sidelined development implications in adjacent Roraima. The state's urban system has thus experienced reperipheralization and intensified primacy. Market-led growth now compounds the inheritance of hierarchical centralism and ongoing governmental neglect. Our study shows a vast territory dependent on primate cities for basic goods and services. Travelling with Roraimans from bypassed towns, we detected long-distance passenger transportation and surface logistics with selective routes. Heterogeneous Roraiman (im)mobilities comprise middle-class tourism and heightened consumerism as well as informal mobility tactics and transnational circulations of precarious labor. The paper exhorts neoliberal urbanism research to look beyond both Euro America's metropoles and their Global South counterparts. Urbanization dynamics in Brazil's extreme north demonstrate that market-disciplined investments to globalize cities produce far-reaching spatial effects. These are felt even by functionally-articulated-yet-marginalized peripheries in ostensibly remote locations

Transformative Agroecology Learning in Europe: Building Consciousness, Skills and Collective Capacity for Food Sovereignty

Agroecology has been proposed as a key building block for food sovereignty. This article examines the meaning, practices and potentials of ‘transformative agroecology learning’ as a collective strategy for food system transformation. Our study is based on our qualitative and action research with the European Coordination of Via Campesina to develop the European Agroecology Knowledge Exchange Network (EAKEN). This network is linked to the global network of La Via Campesina and builds on the strong experiences and traditions of popular education in Latin American peasant movements. Rather than focusing on agroecology education as a process of individual learning, we analyse how a transformative agroecology education can be strengthened as a critical repertoire of action used by social movements to advance food sovereignty. Our analysis contributes a new theory of transformative agroecology learning based on four key characteristics or qualities: horizontalism; diálogo de saberes (wisdom dialogues); combining practical and political knowledge; and building social movement networks. While these different elements of transformative agroecology learning were present across EAKEN, they were unevenly developed and, in many cases, not systematized. The framework can help to strategically and reflexively systematize and strengthen a transformative agroecology learning approach as a key building block for food sovereignty

Height-diameter allometry of tropical forest trees

Copyright © 2011 European Geosciences Union. This is the published version available at http://www.biogeosciences.net/8/1081/2011/bg-8-1081-2011.html doi:10.5194/bg-8-1081-2011Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were: 1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap). 2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A). 3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass. Annual precipitation coefficient of variation (PV), dry season length (SD), and mean annual air temperature (TA) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account

Influence of Immobilization Strategies on the Antibacterial Properties of Antimicrobial Peptide-Chitosan Coatings

It is key to fight bacterial adhesion to prevent biofilm establishment on biomaterials. Surface immobilization of antimicrobial peptides (AMP) is a promising strategy to avoid bacterial colonization. This work aimed to investigate whether the direct surface immobilization of Dhvar5, an AMP with head-to-tail amphipathicity, would improve the antimicrobial activity of chitosan ultrathin coatings. The peptide was grafted by copper-catalyzed azide-alkyne cycloaddition (CuAAC) chemistry by either its C- or N- terminus to assess the influence of peptide orientation on surface properties and antimicrobial activity. These features were compared with those of coatings fabricated using previously described Dhvar5-chitosan conjugates (immobilized in bulk). The peptide was chemoselectively immobilized onto the coating by both termini. Moreover, the covalent immobilization of Dhvar5 by either terminus enhanced the antimicrobial effect of the chitosan coating by decreasing colonization by both Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. Relevantly, the antimicrobial performance of the surface on Gram-positive bacteria depended on how Dhvar5-chitosan coatings were produced. An antiadhesive effect was observed when the peptide was grafted onto prefabricated chitosan coatings (film), and a bactericidal effect was exhibited when coatings were prepared from Dhvar5-chitosan conjugates (bulk). This antiadhesive effect was not due to changes in surface wettability or protein adsorption but rather depended on variations in peptide concentration, exposure, and surface roughness. Results reported in this study show that the antibacterial potency and effect of immobilized AMP vary greatly with the immobilization procedure. Overall, independently of the fabrication protocol and mechanism of action, Dhvar5-chitosan coatings are a promising strategy for the development of antimicrobial medical devices, either as an antiadhesive or contact-killing surface.This work was financed by the FCT- Fundação para a Ciência e a Tecnologia through projects POCI-01-0145-FEDER-031781 (AntINFECT), UIB/50006/2020 (LAQV-REQUIMTE) and FEDER—Fundo Europeu de Desenvolvimento Regional through NORTE 2020—Programa Operacional Regional do Norte-Bio2Skin Advanced (NORTE-01-0247-FEDER-047225). M Barbosa (SFRH/BD/108966/2015) and Pedro Alves (SFRH/BD/145471/2019) Ph.D. grants were financially supported by national (FCT/Norte 2020 Framework) and European Union funds (ESF—European Social Fund). Paula Parreira (CEECIND/01210/2018) and Maria Cristina L. Martins (LA/P/0070/2020) also thank FCT for funding. Maria Cristina L. Martins also acknowledges the MOBILIsE Project, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 951723

Does Foreign Direct Investment Stimulate New Firm Creation? In Search of Spillovers through Industrial and Geographical Linkages

This paper examines the spillover effects of inward foreign direct investment (FDI) on the entrepreneurial activities of new firm creation through both industrial and geographical linkages. Using a dataset of 44,434 newly created small firms in 234 regions of South Korea in 2000–2004, this study finds that while the spillover impacts of FDI in the low-tech industry are positive and significant across almost all four possible combinations of the intra-/inter-regional and intra-/inter-sectoral channels, the impacts in the high-tech industry are largely intra-sectoral within the host region and across neighboring regions. Moreover, all statistically significant spillover effects follow an inverted ‘U’-shaped curvilinear trend

Corneal Epithelial Thickness Correlation with Dry Eye Symptom Severity: A Cross-Sectional Study

Bruno Barbosa Ribeiro,1 João Heitor Marques,1,2 Pedro Manuel Baptista,1,2 Paulo JM Sousa,1 Saúl Pires,1 Pedro Menéres,1,2 Irene Barbosa1,2 1Department of Ophthalmology, Unidade Local de Saúde Santo António, Porto, Portugal; 2School of Medicine and Biomedical Sciences (ICBAS), University of Porto, Porto, PortugalCorrespondence: Bruno Barbosa Ribeiro, Unidade Local de Saúde Santo António – Department of Ophthalmology, Largo Do Prof. Abel Salazar, Oporto, 4099-001, Portugal, Tel +351  222  077 500, Email [email protected]: To study corneal epithelial thickness in patients with Dry Eye Disease (DED), according to symptomatology.Patients and Methods: Cross-sectional study in the outpatient clinic of the Ophthalmology Department of a tertiary hospital in Oporto, Portugal. Adult patients with a clinical diagnosis of dry eye disease were eligible for participation. Each patient underwent corneal epithelial thickness mapping with swept-source optical coherence tomography (SS-OCT, Heidelberg Anterion®) and automated ocular surface analysis (IDRA® Ocular Surface Analyzer SBM Sistemi, Italy). Schirmer’s test, tear film osmolarity (by TearLab® Osmolarity System) and Dry-Eye Related Questionnaire (OSDI-12) were also evaluated. Patients were classified accordingly the severity of symptoms in the OSDI-12 in group 1 (mild disease) and group 2 (moderate to severe disease).Results: We enrolled 200 eyes (of 100 subjects): 65 in group 1 and 135 in group 2. Median OSDI and Schirmer’s test in group 1 was 7 vs 46 points, p< 0.001 and 15 vs 11 mm, p=0.007 in group 2. Eyes from group 2 showed higher mean epithelial thickness (48.4 vs 47.1 μm, p=0.027) and lower mean stromal thickness (522.0 vs 546.6 μm, p< 0.001) in comparison with group 1. OSDI score was positively correlated with the mean epithelial thickness (r=0.188, p=0.008) and epithelial variability index (r=0.277, p=0.004) and negatively correlated with the mean stromal thickness (r=− 0.313, p< 0.001). Patients in group 2 showed higher epithelial variability index (4.5 vs 3.2, p< 0.001).Conclusion: Our study suggests that patients with more severe DED symptoms have thicker corneal epithelia and thinner stroma, which may act as a compensatory response. Epithelial variability index is positively correlated with the OSDI score and may reflect DED severity. This is the first study to report stromal thinning in patients with DED, thereby proving novel information regarding the matter. More studies are needed to confirm these results.Plain Language Summary: We have conducted original research regarding the effects of Dry Eye Disease on corneal epithelial and stromal thickness, as evaluated by Swept-Source Optical Coherence Tomography (Heidelberg Anterion®). Our study is pioneer in showing that patients with more severe symptoms have thicker epithelia with an apparent compensatory stromal thinning. Besides, corneal epithelium seems to have higher variability index in these patients, which appears to correlate with Dry Eye symptom severity. Our results may be helpful to reveal the role of dry eye disease in corneal structural changes.Keywords: dry eye, cornea, epithelium, thickness, anterio

Antimicrobial resistance (AMR) nanomachines: mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation

In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics—the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex ‘nanomachines’ that drive survival of bacterial cells in antibiotic environments