317 research outputs found
Fitting Time Series Models to Fisheries Data to Ascertain Age
The ability of government agencies to assign accurate ages of fish is important to fisheries management. Accurate ageing allows for most reliable age-based models to be used to support sustainability and maximize economic benefit. Assigning age relies on validating putative annual marks by evaluating accretional material laid down in patterns in fish ear bones, typically by marginal increment analysis. These patterns often take the shape of a sawtooth wave with an abrupt drop in accretion yearly to form an annual band and are typically validated qualitatively. Researchers have shown key interest in modeling marginal increments to verify the marks do, in fact, occur yearly. However, it has been challenging in finding the best model to predict this sawtooth wave pattern. We propose three new applications of time series models to validate the existence of the yearly sawtooth wave patterned data: autoregressive integrated moving average (ARIMA), unobserved component, and copula. These methods are expected to enable the identification of yearly patterns in accretion. ARIMA and unobserved components account for the dependence of observations and error, while copula incorporates a variety of marginal distributions and dependence structures. The unobserved component model produced the best results (AIC: -123.7, MSE 0.00626), followed by the time series model (AIC: -117.292, MSE: 0.0081), and then the copula model (AIC: -96.62, Kendall\u27s tau: -0.5503). The unobserved component model performed best due to the completeness of the dataset. In conclusion, all three models are effective tools to validate yearly accretional patterns in fish ear bones despite their differences in constraints and assumptions
Palliative care and prehospital emergency medicine: analysis of a case series.
Palliative care, which is intended to keep patients at home as long as possible, is increasingly proposed for patients who live at home, with their family, or in retirement homes. Although their condition is expected to have a lethal evolution, the patients-or more often their families or entourages-are sometimes confronted with sudden situations of respiratory distress, convulsions, hemorrhage, coma, anxiety, or pain. Prehospital emergency services are therefore often confronted with palliative care situations, situations in which medical teams are not skilled and therefore frequently feel awkward.We conducted a retrospective study about cases of palliative care situations that were managed by prehospital emergency physicians (EPs) over a period of 8 months in 2012, in the urban region of Lausanne in the State of Vaud, Switzerland.The prehospital EPs managed 1586 prehospital emergencies during the study period. We report 4 situations of respiratory distress or neurological disorders in advanced cancer patients, highlighting end-of-life and palliative care situations that may be encountered by prehospital emergency services.The similarity of the cases, the reasons leading to the involvement of prehospital EPs, and the ethical dilemma illustrated by these situations are discussed. These situations highlight the need for more formal education in palliative care for EPs and prehospital emergency teams, and the need to fully communicate the planning and implementation of palliative care with patients and patients' family members
Perspectives in restoration: storage and pretreatments of seeds for better germination of Sudanian savanna-woodland species
Insufficient knowledge of the germination ecology of local species is one of the main constraints to restoration of degraded rural lands. We tested seeds from fourteen Sudanian savanna species targeted for restoration for their response to two different pretreatments (conventional and prolonged acid pretreatments) and two different storage conditions (ambient room conditions and refrigerator at 4 °C). For 6 of the studied species, longer soaking in sulphuric acid significantly improved germination rates and also reduced the germination time of some species. Storage condition, in general did not affect germination rates except for two species where cool storage depressed germination. The practical implication is that, for the species tested, when mature seeds are collected for plantation in the upcoming rainy season, there is no need to invest in infrastructure and energy for storing in cold conditions. The study also revealed that in general when seeds are stored in ambient conditions from the time of collection up to seeding time, although germination rate does not increase, germination time is shortened and this could be of great interest in synchronizing germination in real field conditions
Volatile compounds of maari, a fermented product from baobab (Adansonia digitata L.) seeds
The volatile compounds associated with baobab seeds fermentation for Maari production were extracted and analysed by Likens-Nickerson simultaneous steam distillation-extraction method and gas chromatography-mass spectrometry (GC-MS), respectively. Furthermore, the titratable acidity, tannin content and proximate composition were evaluated. A total of 96 compounds were identified with esters, acids, alcohols and ketones being quantitatively the major groups. Fermentation led to an increase in the concentration of total volatile compounds from 121.6 in unfermented cooked seeds to 809.1 mg kg-1 in the fermented product. Drying resulted in a significant loss of up to 80.7% of the total volatiles.Key words: Volatile compounds, maari, baobab, fermentation
Etude Comparative Des Produits Issus De La Transformation En Filature Des Fibres De Trois Nouvelles Variétés De Cotonnier
Résumé - Au Mali, comme ailleurs en Afrique, la sélection variétale est à la base du succès de la culture cotonnière. Le coton du Mali est presqu’entièrement exporté ; les fibres issues des variétés cultivées doivent répondre aux exigences du marché en termes de caractéristiques technologiques des fibres, facteurs clés du fonctionnement de la filature. Cette étude comparative a été réalisée sur trois nouvelles variétés de cotonniers A, B et C, issues d’un point d'expérimentation. L'objectif de l'étude est d’identifier les variétés ayant les meilleures performances variétales et industrielles pour la vulgarisation en production commerciale par les sociétés cotonnières. 1 échantillon représentatif de 100g de coton fibre, 20 échantillons de 5 m de rubans de carde, d’étirage et de 10 m de mèches, 30 échantillons de 100 m de fil et 40 échantillons de 500 mm de fil ont été respectivement prélevés par balle de chaque variété et à différentes étapes du processus de transformation par variété. Ces échantillons ont été testés sur des appareils de mesure dans les conditions requises au laboratoire de métrologie textile du CERFITEX, Ségou - Mali.L’analyse de variance (ANOVA) des données relatives aux fibres, rubans, mèches et fils et la comparaison de leurs principales caractéristiques de qualité à celle de la production mondiale avec l’application des USTER STATISTICS 2018 ont montré que les variétés de cotonnier A et B sont nettement meilleures que celle de C. Les performances variétales et industrielles de A et B, meilleures que celles de C sont recommandées à la vulgarisation Mots clés : Coton, caractéristiques technologiques, qualité, fibres, fils. [Comparative Study Of The Products Resulting From The Transformation Into Spinning Of The Fibers Of Three New Varieties Of Cotton]Abstract - In Mali, as elsewhere in Africa, varietal selection is the basis of the success of cotton growing. Cotton from Mali is almost entirely exported; fibers from cultivated varieties must meet market requirements in terms of the technological characteristics of fibers, key factors in the operation of the spinning mill. This comparative study was carried out on three new varieties of cotton A, B and C, from an experimental point. The objective of the study is to identify the varieties with the best varietal and industrial performance for popularization in commercial production by cotton companies. 1 representative sample of 100g of cotton fiber, 20 samples of 5m of carding and drawing slivers and 10m of rovings, 30 samples of 100m of yarn and 40 samples of 500mm of yarn were respectively taken per bale of each variety and at different stages of the transformation process by variety. These samples were tested on measuring devices under the required conditions at the CERFITEX textile metrology laboratory, Ségou - Mali.The analysis of variance (ANOVA) of fiber, sliver, roving and yarn data and the comparison of their main quality characteristics to that of world production with the application of USTER STATISTICS 2018 showed that cotton varieties A and B are clearly better than those of C. The varietal and industrial performances of A and B, better than that of C are recommended for popularisation Keywords : Cotton, technological characteristics, quality, fibres, yarns
Sensitivity study of the regional climate model RegCM4 to different convective schemes over West Africa
Abstract. The latest version of RegCM4 with CLM4.5 as a land surface scheme was used to
assess the performance and sensitivity of the simulated West African
climate system to different convection schemes. The sensitivity studies were
performed over the West African domain from November 2002 to December 2004 at
a spatial resolution of 50 km × 50 km and involved five
convective schemes: (i) Emanuel; (ii) Grell; (iii) Emanuel over land and
Grell over ocean (Mix1); (iv) Grell over land and Emanuel over ocean (Mix2);
and (v) Tiedtke. All simulations were forced with ERA-Interim data.
Validation of surface temperature at 2 m and precipitation were conducted
using data from the Climate Research Unit (CRU), Global
Precipitation Climatology Project (GPCP) and the Tropical Rainfall Measurement
Mission (TRMM) during June to September (rainy season), while the simulated
atmospheric dynamic was compared to ERA-Interim data. It is worth noting that
the few previous similar sensitivity studies conducted in the region were
performed using BATS as a land surface scheme and involved less convective
schemes. Compared with the previous version of RegCM, RegCM4-CLM also shows a
general cold bias over West Africa whatever the convective scheme used. This
cold bias is more reduced when using the Emanuel convective scheme. In terms of
precipitation, the dominant feature in model simulations is a dry bias that
is
better reduced when using the Emanuel convective scheme. Considering the good
performance with respect to a quantitative evaluation of the temperature and
precipitation simulations over the entire West African domain and its
subregions, the Emanuel convective scheme is recommended for the study of the
West African climate system
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