37 research outputs found
Assessment of a Side-Row Continuous Canopy Shaking Harvester and Its Adaptability to the Portuguese Cobrançosa Variety in High-Density Olive Orchards
The olive tree is an important crop in Portugal, where different levels of intensification coexist. The traditional olive orchards present profitability problems, mainly due to harvesting, so there has been a drastic reconversion towards high-density or super-high-density olive orchards. The latter present major constraints due to very specific needs for their use, being practically destined for new orchards. Consequently, the possibility of using systems based on canopy shakers in high-density olive orchards with local varieties is promising. The objective of this work is to evaluate a prototype canopy shaker for the harvesting of high-density olive orchards of the Portuguese variety ‘Cobrançosa’. The evaluation is based on the study of canopy shaking in order to adapt canopy training and the adaptability of the machine. For this purpose, the vibration of 72 points of the tree canopy was recorded and a qualitative assessment of the harvest was carried out. Differences were found between the different zones according to the direction of the forward movement of the harvester and the distance to the trunk. These differences were associated with the values obtained for fruit detachment, and a greater quantity of fruit was harvested in the areas of the canopy in contact with the rods
Development and Validity Assessment of a Chronic Obstructive Pulmonary Disease Knowledge Questionnaire in Low- and Middle-Income Countries
Rationale: The majority of the morbidity and mortality related to chronic obstructive pulmonary disease (COPD) occurs in low- and middle-income countries (LMICs). Despite the increasing burden of COPD, disease-specific knowledge among healthcare workers (HCWs) and patients in LMICs remains limited. COPD knowledge questionnaires are valid and reliable tools to assess COPD knowledge and can be employed in settings with limited health literacy. Objective: To develop and assess validity and reliability of a COPD knowledge questionnaire among individuals with COPD in three LMIC settings. Methods: Twelve questions were generated by an expert team of sixteen researchers, physicians, and public health professionals to create an LMIC-specific COPD knowledge questionnaire. Content was based on previous instruments, clinical guidelines, focus group discussions, and questionnaire piloting. Participants with COPD completed the questionnaire across three diverse LMIC settings before and three months after delivery of a standardized COPD specific education package by a local community health worker (CHW) trained to deliver the education to an appropriate standard. We utilized paired t-tests to assess improvement in knowledge post-intervention. Results: Questionnaire development initially yielded 52 items. Based on community feedback and expertise, items were eliminated and added yielding a final 12-item questionnaire, with a maximum total score of 12. A total of 196 participants with COPD were included this study in Nepal (n=86), Peru (n=35) and Uganda (n=75). Mean (± SD) baseline score was 8.0 ± 2.5 and 3-months post-education the mean score was 10.2 ± 1.7 among participants. The CHW-led COPD educational intervention improved COPD knowledge among community members by 2.2 points (95% CI 1.8 to 2.6, t=10.9, p<0.001). Internal consistency using Cronbach’s alpha was 0.75. Conclusion: The LMIC COPD-KQ demonstrates face and content validity and acceptable internal consistency through development phases, suggesting a reliable and valid COPD education instrument that can be utilized to assess educational interventions across LMIC settings. Clinical trial registered with ClinicalTrials.gov (NCT03365713
Morris-Thorne wormholes with a cosmological constant
First, the ideas introduced in the wormhole research field since the work of
Morris and Thorne are briefly reviewed, namely, the issues of energy
conditions, wormhole construction, stability, time machines and astrophysical
signatures. Then, spherically symmetric and static traversable Morris-Thorne
wormholes in the presence of a generic cosmological constant are analyzed. A
matching of an interior solution to the unique exterior vacuum solution is done
using directly the Einstein equations. The structure as well as several
physical properties and characteristics of traversable wormholes due to the
effects of the cosmological term are studied. Interesting equations appear in
the process of matching. For instance, one finds that for asymptotically flat
and anti-de Sitter spacetimes the surface tangential pressure of the
thin-shell, at the boundary of the interior and exterior solutions, is always
strictly positive, whereas for de Sitter spacetime it can take either sign as
one could expect, being negative (tension) for relatively high cosmological
constant and high wormhole radius, positive for relatively high mass and small
wormhole radius, and zero in-between. Finally, some specific solutions with
generic cosmological constant, based on the Morris-Thorne solutions, are
provided.Comment: latex, 49 pages, 8 figures. Expanded version of the paper published
in Physical Review
American tripanosomiasis: a study on the prevalence of Trypanosoma cruzi and Trypanosoma cruzi-like organisms in wild rodents in San Luis province, Argentina
Present and future tradeoffs between biodiversity, ecosystem services and human well-being in tropical Latin America.
Effect of thinning on flower and fruit and of edible coatings on postharvest quality of jaboticaba fruit stored at low temperature
Paleobiology of titanosaurs: reproduction, development, histology, pneumaticity, locomotion and neuroanatomy from the South American fossil record
Fil: García, Rodolfo A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Salgado, Leonardo. Instituto de Investigación en Paleobiología y Geología. General Roca. Río Negro; ArgentinaFil: Fernández, Mariela. Inibioma-Centro Regional Universitario Bariloche. Bariloche. Río Negro; ArgentinaFil: Cerda, Ignacio A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Carabajal, Ariana Paulina. Museo Carmen Funes. Plaza Huincul. Neuquén; ArgentinaFil: Otero, Alejandro. Museo de La Plata. Universidad Nacional de La Plata; ArgentinaFil: Coria, Rodolfo A.. Instituto de Paleobiología y Geología. Universidad Nacional de Río Negro. Neuquén; ArgentinaFil: Fiorelli, Lucas E.. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica. Anillaco. La Rioja; Argentin
Properties of OB star−black hole systems derived from detailed binary evolution models
Context. The recent gravitational wave measurements have demonstrated the existence of stellar mass black hole binaries. It is essential for our understanding of massive star evolution to identify the contribution of binary evolution to the formation of double black holes.
Aims. A promising way to progress is investigating the progenitors of double black hole systems and comparing predictions with local massive star samples, such as the population in 30 Doradus in the Large Magellanic Cloud (LMC).
Methods. With this purpose in mind, we analysed a large grid of detailed binary evolution models at LMC metallicity with initial primary masses between 10 and 40 M⊙, and identified the model systems that potentially evolve into a binary consisting of a black hole and a massive main-sequence star. We then derived the observable properties of such systems, as well as peculiarities of the OB star component.
Results. We find that ∼3% of the LMC late-O and early-B stars in binaries are expected to possess a black hole companion when stars with a final helium core mass above 6.6 M⊙ are assumed to form black holes. While the vast majority of them may be X-ray quiet, our models suggest that these black holes may be identified in spectroscopic binaries, either by large amplitude radial velocity variations (≳50 km s−1) and simultaneous nitrogen surface enrichment, or through a moderate radial velocity (≳10 km s−1) and simultaneous rapid rotation of the OB star. The predicted mass ratios are such that main-sequence companions can be excluded in most cases. A comparison to the observed OB+WR binaries in the LMC, Be and X-ray binaries, and known massive black hole binaries supports our conclusion.
Conclusions. We expect spectroscopic observations to be able to test key assumptions in our models, with important implications for massive star evolution in general and for the formation of double black hole mergers in particular