3,510 research outputs found
Chemical trends in the Galactic halo from APOGEE data
Indexación: Web of Science; Scopus.The galaxy formation process in the A cold dark matter scenario can be constrained from the analysis of stars in the Milky Way's halo system. We examine the variation of chemical abundances in distant halo stars observed by the Apache Point Observatory Galactic Evolution Experiment ( APOGEE), as a function of distance from the Galactic Centre ( r) and iron abundance ([M/H]), in the range 5 less than or similar to r less than or similar to 30 kpc and - 2.5 15 kpc and [M/H] > - 1.1 (larger in the case of O, Mg, and S) with respect to the nearest halo stars. This result confirms previous claims for low-alpha stars found at larger distances. Chemical differences in elements with other nucleosynthetic origins (Ni, K, Na, and Al) are also detected. C and N do not provide reliable information about the interstellar medium from which stars formed because our sample comprises red giant branch and asymptotic giant branch stars and can experience mixing of material to their surfaces.https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stw286
The Impact of a Simple Representation of Non-Structural Carbohydrates on the Simulated Response of Tropical Forests to Drought
This is the final version. Available on open access from European Geosciences Union via the DOI in this recordCode availability.
A model example of SUGAR for a single site and set-up to run at Caxiuanã using output from JULES is available at https://doi.org/10.5281/zenodo.3547613 (Jones, 2019). For further information or code please contact [email protected] representing the response of ecosystems to environmental change in land surface models (LSMs) is crucial to making accurate predictions of future climate. Many LSMs do not correctly capture plant respiration and growth fluxes, particularly in response to extreme climatic events. This is in part due to the unrealistic assumption that total plant carbon expenditure (PCE) is always equal to gross carbon accumulation by photosynthesis. We present and evaluate a simple model of labile carbon storage and utilisation (SUGAR) designed to be integrated into an LSM, which allows simulated plant respiration and growth to vary independent of photosynthesis. SUGAR buffers simulated PCE against seasonal variation in photosynthesis, producing more constant (less variable) predictions of plant growth and respiration relative to an LSM that does not represent labile carbon storage. This allows the model to more accurately capture observed carbon fluxes at a large-scale drought experiment in a tropical moist forest in the Amazon, relative to the Joint UK Land Environment Simulator LSM (JULES). SUGAR is designed to improve the representation of carbon storage in LSMs and provides a simple framework that allows new processes to be integrated as the empirical understanding of carbon storage in plants improves. The study highlights the need for future research into carbon storage and allocation in plants, particularly in response to extreme climate events such as drought.Natural Environment Research Council (NERC)Newton FundAustralian Research Council (ARC)Spanish Ministry of Economy and Competitiveness (MINECO)Engineering and Physical Sciences Research Council (EPSRC)JPL-Caltech President's and Director's Research & Development FundMet Office Hadley Centre Climate ProgrammeEuropean Union Horizon 202
Achieving excellence in lean implementation at construction companies - A case study from Brazil
Lean Construction has become a popular concept to improve performance and reduce costs in construction projects. Assessment tools and implementation strategies that focus on lean practices such as the Last Planner System, the use of Kanbans, the routine of Kaizens and, recently, the integration with information technology are also common. However, barriers to the wide adoption of lean principles remain and implementation challenges continue to intrigue scholars. Previous studies suggest that barriers to the successful implementation can be either political, economical, social and/or technical, with the focus on lack of knowledge about lean concepts, resistance to the required organisational culture change, and lack of support from top management. Few studies present the lean implementation process from the practitioners’ perspective. Using the narrative enquiry methodology, the authors aim to describe how a construction company from Brazil matured from the implementation of lean operational tools to achieve excellence in the lean culture and mindset. Key themes that emerge from this study for a successful lean construction journey are; effort to stabilise the environment, knowledge creation and management, transparency in the process to enable simplicity and shared understanding, and building trust for further growth.
Sex differences in axial spondyloarthritis: data from a Portuguese spondyloarthritis cohort
Background: Axial spondyloarthritis (axSpA), particularly ankylosing spondylitis was historically considered a
male’s disease and has been under-recognized in women.
Emerging evidence reveals sex differences in pathophysiology, disease presentation and therapeutic efficacy.
Objective: To identify differences between sexes in a Portuguese cohort of patients with axSpA regarding clinical
manifestations, disease activity, functional capacity, patient related outcomes and presence of sacroiliitis on x-ray or
magnetic resonance imaging.
Methods: Patients with ≥18 years fulfilling the ASAS- Assessment of Spondyloarthritis International Society
classification criteria for axSpA registered in the electronic Rheumatic Diseases Portuguese Register (Reuma.pt)
were included in this multicentric cross-sectional study. Sociodemographic data, clinical features and imaging were
collected from the first record in Reuma.pt. These variables were compared between sexes using Mann-Whitney
test and Chi-Square test. Variables with a significant association with variable sex were considered in the multiple
variable analysis to adjust the sex effect on the outcome variables. Statistical analysis was performed with R version
4.0.2 and p<0.05 was considered statistically significant.
Results: A total of 1995 patients were included, 1114 (55.9%) men and 881 (44.1%) women. Men had an earlier
disease onset (25.1 vs 28.4, p<0.001), were younger at diagnosis (26.9 vs 30.4, p<0.001) and were more frequently
smokers (32.1% vs 15.7%, p<0.001). Comparing to women, men had worse Bath Ankylosing Spondylitis
Metrological Index scores (4.0 vs 3.4, p<0.001), higher levels of C-Reactive Protein (10.5 vs 6.9 mg/L, p<0.001)
and were more often Human Leukocyte Antigen-B27 positive (67.8% vs 54%, p<0.001).
In contrast, women more frequently had inflammatory bowel disease (8.8% vs 4.9%, p=0.004), higher levels of
erythrocyte sedimentation rate (25.0 vs 21.0mm/h, p=0.003) and worse patient-related outcomes- Bath Ankylosing
Spondylitis Disease Activity Index (5.7 vs 4.5, p<0.001), Patient Global Assessment (60.0 vs 50.0, p<0.001) and
fatigue (6.2 vs 5.0, p<0.001).
Discussion: In this large multicentric study from a Portuguese axSpA cohort, we confirmed sex differences in patients
with axSpA. This work brings awareness to these differences, resulting in less underdiagnosis and misdiagnosis,
optimizing treatment strategies, and improving outcomes in axSpA.publishe
Minor psychiatric disorders among Brazilian ragpickers: a cross-sectional study
BACKGROUND: Ragpickers are informal workers who collect recyclable materials to earn a small wage. Their life and working conditions are extremely difficult. We examined minor psychiatric disorders (MPD) among a cohort of ragpickers in Pelotas, a city in southern Brazil. METHODS: Ragpickers were matched by sex, age, and years of schooling with a sample of non-ragpickers from the same poor neighborhoods. The cross-sectional study gathered data by interview on 990 individuals in 2004. MPD were assessed using a standard self-reporting questionnaire, the SRQ-20. RESULTS: The prevalence of MPD among ragpickers was 44.7%, higher than reported by neighborhood controls (33.6%; p < 0.001). MPD were more common among females, those of lower economic level, smokers and alcoholics. Among occupational characteristics, MPD prevalence was associated with frequent static postures, low job satisfaction and recent work accidents. CONCLUSION: Ragpickers more frequently report MPD than other poor workers living in the same neighborhoods, with many of the same life conditions. Improving the work lives of these precarious workers should address not only the physical hazards of their jobs but their mental and emotional health as well
Microinvasive carcinoma of the uterine cervix in a 14-year-old adolescent: case report and literature review
Targeting miR-423-5p reverses exercise training–induced HCN4 channel remodeling and sinus bradycardia
Rationale: Downregulation of the pacemaking ion channel, HCN4 (hyperpolarization-activated cyclic nucleotide gated channel 4), and the corresponding ionic current, If, underlies exercise training–induced sinus bradycardia in rodents. If this occurs in humans, it could explain the increased incidence of bradyarrhythmias in veteran athletes, and it will be important to understand the underlying processes.
Objective: To test the role of HCN4 in the training-induced bradycardia in human athletes and investigate the role of microRNAs (miRs) in the repression of HCN4.
Methods and Results: As in rodents, the intrinsic heart rate was significantly lower in human athletes than in nonathletes, and in all subjects, the rate-lowering effect of the HCN selective blocker, ivabradine, was significantly correlated with the intrinsic heart rate, consistent with HCN repression in athletes. Next-generation sequencing and quantitative real-time reverse transcription polymerase chain reaction showed remodeling of miRs in the sinus node of swim-trained mice. Computational predictions highlighted a prominent role for miR-423-5p. Interaction between miR-423-5p and HCN4 was confirmed by a dose-dependent reduction in HCN4 3′-untranslated region luciferase reporter activity on cotransfection with precursor miR-423-5p (abolished by mutation of predicted recognition elements). Knockdown of miR-423-5p with anti-miR-423-5p reversed training-induced bradycardia via rescue of HCN4 and If. Further experiments showed that in the sinus node of swim-trained mice, upregulation of miR-423-5p (intronic miR) and its host gene, NSRP1, is driven by an upregulation of the transcription factor Nkx2.5.
Conclusions: HCN remodeling likely occurs in human athletes, as well as in rodent models. miR-423-5p contributes to training-induced bradycardia by targeting HCN4. This work presents the first evidence of miR control of HCN4 and heart rate. miR-423-5p could be a therapeutic target for pathological sinus node dysfunction in veteran athletes
Fast and Slow Effects of Medial Olivocochlear Efferent Activity in Humans
Background: The medial olivocochlear (MOC) pathway modulates basilar membrane motion and auditory nerve activity on both a fast (10–100 ms) and a slow (10–100 s) time scale in guinea pigs. The slow MOC modulation of cochlear activity is postulated to aide in protection against acoustic trauma. However in humans, the existence and functional roles of slow MOC effects remain unexplored. Methodology/Principal Findings: By employing contralateral noise at moderate to high levels (68 and 83 dB SPL) as an MOC reflex elicitor, and spontaneous otoacoustic emissions (SOAEs) as a non-invasive probe of the cochlea, we demonstrated MOC modulation of human cochlear output both on a fast and a slow time scale, analogous to the fast and slow MOC efferent effects observed on basilar membrane vibration and auditory nerve activity in guinea pigs. The magnitude of slow effects was minimal compared with that of fast effects. Consistent with basilar membrane and auditory nerve activity data, SOAE level was reduced by both fast and slow MOC effects, whereas SOAE frequency was elevated by fast and reduced by slow MOC effects. The magnitudes of fast and slow effects on SOAE level were positively correlated. Conclusions/Significance: Contralateral noise up to 83 dB SPL elicited minimal yet significant changes in both SOAE leve
- …