Modeling of aging effects on concrete creep / shrinkage behavior : a lattice discrete particle modeling approach

The currently aging and deteriorating infrastructures both in the US and all around the world have been a major cause to extend the current design provisions for concrete structures to 100 years of design lifetime. During such a long period, concrete exhibits a well-known time dependent behavior that is a function of multiple factors including both rheological aspects of the concrete mix as well as the effect of environmental conditions, which contribute to its time dependent aging. While initial conditions (e.g. concrete mix design parameters) can be well controlled, much less knowledge is available on the type and extent of the environmental conditions that will affect the structure

Evaluation of the preoperative administration of sildenafil on operative and early postoperative outcome after mitral valve replacement in patients with pulmonary hypertension

Background: Mitral valve diseases are commonly associated with pulmonary hypertension. The aim of this study was to evaluate the effect of preoperative administration of sildenafil on the outcome after mitral valve replacement in patients with pulmonary hypertension. Methods: This prospective randomized study was carried out on 67 patients who had a mitral valve replacement and associated high systolic pulmonary artery pressure more than 50 mmHg. Patients were randomized into three groups: group A (n= 20) received preoperative sildenafil for one week, group B (n=22) received sildenafil for one month, and group C (n= 25) did not receive sildenafil. All patients had transthoracic echocardiography preoperatively, one week and one month postoperatively. Results: There was no difference in preoperative and operative variables among groups. Dobutamine support was required in 15 patients (60%) in group C vs. 6 patients (30%) in group A and 5 patients (22.5%) in group B (p= 0.012). Duration of mechanical ventilation was significantly longer in group C (389.2 ± 48.79 minutes) compared to group A and B (295.5 ± 17.01 and 281.4 ± 39.44 minutes, respectively, p<0.001). ICU stay was longer in group C (61.72 ± 13.69 hours) compared to groups A and B (53.55 ± 14.49 and 45.64 ± 13.43 hours, respectively, p=0001). The hospital stay was longer in group C (8.0 ± 1.80 days) compared to group A and B (6.05 ± 0.94 and 6.27 ± 1.24 days, respectively; p< 0.001). The transthoracic echocardiographic study one month after the operation showed that pulmonary artery systolic pressure significantly lower in groups A and B (28.30 ± 3.3 and 28.2 ± 4.98 mmHg, respectively) compared to group C (43.12 ± 4.99 mmHg) (p <0.001). There was no statistically significant difference between groups A and B regarding PASP after five days  (p= 0.287) or one month (p= 0.939). Conclusion: We found that preoperative administration of oral sildenafil in patients with pulmonary hypertension undergoing mitral valve replacement may reduce pulmonary hypertension postoperatively. We could not find a difference in the administration of sildenafil for either one week or one month preoperatively

The Breathing Mode in Extended Skyrme Model

We study an extended Skyrme model which includes fourth and sixth-order terms. We explore some static properties like the $\Delta$-nucleon mass splitting and investigate the Skyrmion breathing mode in the framework of the linear response theory. We find that the monopole response function has a pronounced peak located at $\sim$ 400 MeV, which we identify to the Roper resonance $N(1440)$. As compared to the standard one, the extended Skyrme model provides a more accurate description of baryon properties.Comment: 12 pages of plain Latex and 3 figures (available from the authors), preprint IPNO/TH 93-0

Coherent amplification of classical pion fields during the cooling of droplets of quark plasma

In the framework of the linear sigma model, we study the time evolution of a system of classical $\sigma$ and pion fields coupled to quarks. For this purpose we solve numerically the classical transport equation for relativistic quarks coupled to the nonlinear Klein-Gordon equations for the meson fields. We examine evolution starting from variety of initial conditions corresponding to spherical droplets of hot quark matter, which might mimic the behaviour of a quark plasma produced in high-energy nucleus-nucleus collisions. For large droplets we find a strong amplification of the pion field that oscillates in time. This leads to a coherent production of pions with a particular isospin and so would have similar observable effects to a disoriented chiral condensate which various authors have suggested might be a signal of the chiral phase transition. The mechanism for amplification of the pion field found here does not rely on this phase transition and is better thought of as a "pion laser" which is driven by large oscillations of the $\sigma$ field.Comment: 12 TeX pages + 20 postscript figures, psfig styl

Optimization of organic meso-superstructured solar cells for underwater IoT² self-powered sensors

The effectiveness of the mesoporous TiO₂ layer, which acts as an active n-type semiconductor layer in dye-sensitized solar cells (DSSCs), was investigated by varying AgVO₃ doping. To optimize the meso-superstructure, the doping concentration was varied from 0% to 25% using experimentally validated simulations. Moreover, performance comparisons between the experimentally fabricated DSSCs based on natural beetroot dye and the commonly used N719 dye were made. A 15% doping concentration was found optimum for our DSSC, which delivered an output power of 19.24 mW, 6.1% power conversion efficiency, and an open-circuit voltage, Voc , of 0.5 V and a short-circuit current density, Jsc , of 21 mA/cm² in diffused light conditions. Based on these performance results, we integrated our optimized DSSC in an underwater sensing unit as a light harvester

Vascular and root tip GPT2 expression mediates the PGI1-independent response of Arabidopsis to small microbial volatiles

Resumen del trabajo presentado en el XVI Meeting of Plant Molecular Biology, celebrado en Sevilla (España), del 14 al 16 de septiembre de 2022Microorganisms emit a plethora of volatile compounds (VCs) that promote plant growth and photosynthesis as well as strong developmental and metabolic changes. In Arabidopsis, the plastidial isoform of phosphoglucose isomerase PGI1 mediates photosynthesis, metabolism and development, probably due to its involvement in the synthesis of isoprenoid-derived signals in vascular tissues (Bahaji et al., 2015; Bahaji et al., 2018). Like in wild-type (WT) plants, microbial VCs promote growth and photosynthesis as well as starch and CK accumulation in PGI1-lacking pgi1-2 plants (Sánchez-López et al. 2016). A striking alteration in the transcriptome of leaves of small fungal VC-treated plants involves strong up-regulation of levels of transcripts of GPT2 (At1g61800), a gene that codes for a plastidial G6P/Pi transporter. We hypothesized that the PGI1-independent response to microbial volatile emissions involves GPT2 action. To test this hypothesis, we characterized responses of WT, GPT2-null gpt2-1, PGI1-null pgi1-2 and pgi1- 2gpt2-1 plants to small fungal VCs. In addition, we characterized responses of pgi1-2gpt2-1 plants expressing GPT2 under the control of a vascular tissue- and root tip-specific promoter to small fungal VCs. Results presented in this work provide evidence that, under conditions in which PGI1 activity is reduced, long-distance action of GPT2 plays an important role in the response of plants to small VCs through mechanisms involving resetting of the photosynthesis-related proteome in leaves and complex GPT2 regulation.This work was supported by the Ministerio de Ciencia e Innovación (MCIN) and Agencia Estatal de Investigación (AEI) / 10.13039/501100011033/ (grants BIO2016-78747-P, PID2019-104685GB-100 and PID2019-107657RB-C22) and the Ministry of Education, Youth and Sport of the Czech Republic and ERDF project entitled “Plants as a tool for sustainable global development” (No. CZ.02.1.01/0.0/0.0/16_019/0000827)

Isoscalar NN spin-orbit potential from a Skyrme model with scalar mesons

As a first step toward circumventing the difficulty to obtain an attractive isospin-independent NN spin-orbit force from Skyrme-type models involving only pions, we investigate an improved Skyrme Lagrangian that incorporates the scalar-isoscalar meson \epsilon which can be viewed as the cause behind the enhancement of the $\pi \pi S$-wave. We find that at large distances, the main contribution to the spin-orbit potential comes from the scalar Lagrangian and it is found to be attractive. We briefly discuss how to pursue this work to finally obtain a medium-range attractive interaction.Comment: 10 pages (revtex) + 2 figures; use \psfig command. Minor changes in the text and some discussion added in the last section. To be published in Z. Phys.

Infrastructure Robotics Research at the University of Leeds

Increased population growth and continued urbanisation will necessitate novel, bold, and revolutionary approaches to infrastructure inspection, maintenance, and repair. This will likely be done by swarms of autonomous robotic systems. The University of Leeds is quickly establishing itself as a leader in the field by taking part in two ambitious infrastructure robotics projects - Self-Repairing Cities and Pipebots. Here we present an overview of these projects, as well as two outputs from them - an Asphalt 3D Printing drone, and a wirelessly powered pipe inspection robot

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London