1,384 research outputs found
(In)Consistencies in responses to sodium bicarbonate supplementation: a randomised, repeated measures, counterbalanced and double-blind study
Objectives:
Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB).
Design and Methods:
15 physically active males (age 25 ± 4 y; body mass 76.0 ± 7.3 kg; height 1.77 ± 0.05 m) completed six cycling capacity tests at 110% of maximum power output (CCT 110% ) following ingestion of either 0.3 g.kg -1 BM of SB (4 trials) or placebo (PL, 2 trials). Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD) was recorded as the exercise outcome.
Results:
SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05). Blood lactate was elevated following exercise in all trials (p ≤ 0.001), and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05), although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none.
Conclusions:
The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation.
Trial Registration:
ClinicalTrials.gov NCT0247462
Electrochemical performances of vitreous materials in the system Li2O–V2O5–P2O5 as electrode for lithium batteries
International audienceGlass composition 25Li2O–50V2O5–25P2O5 has been investigated as a potential material for electrode. Electrical properties as well as electrochemical performances of this glass composition have been characterized and results show a capacity less than 80mAhg−1 when tested in the [3–4.5V] potential window. To the best of our knowledge, this is the first lithiated amorphous material reported as a potential positive electrode material. Glasses, due to their wide available compositions in a given system and their easy processing, pave the way to new type of electrode material
Embryo transfer from seropositive goats for caprine arthritis-encephalitis virus (CAEV) with birth of seronegative kid.
Abstract: The aim of this study was to determine whether recipient goats would seroconvert following transfer of embryos collected from donor goats seropositive for CAEV and if kids produced would be clinically normal and seronegative for CAEV. Four does (Saanen and Alpine), seropositive for CAEV, were used as donors, receiving superovulation treatment consisting of progestagen, cloprostenol and FSH. During estrus the donors were mated with seropositive bucks. Seven days after estrus, embryo recovery was performed by surgery. The embryos were then frozen according to the protocol of the International Embryo Transfer Society (IETS). Twelve seronegative does were used as recipients and received an estrus synchronization treatment consisting of progestagen, cloprostenol and eCG. Embryo transfer was performed seven days after synchronized estrus using the semilaparoscopy technique. Pregnancy was verified in one of twelve recipients, that remained seronegative until six months after giving birth and the kid until six months of age. The preliminary success in producing CAEV negative kids and failure of seroconversion in previously seronegative recipients in this study suggests that embryo transfer technology may offer an alternative in the prevention of CAEV transmission in goat herds as well for the utilization of genetic patrimony of seropositive goats. [Transferência de embriões de cabras soropositivas para artrite-encefalite caprina a vírus (CAEV) com nascimento de cria soronegativa]. Resumo: O objetivo deste estudo foi verificar se cabras receptoras sofreriam soroconversão após a transferência de embriões colhidos de cabras soropositivas e se as crias nascidas seriam clinicamente normais e soronegativas para CAEV. Foram utilizadas quatro cabras (Saanen e Alpina), todas soropositivas para CAEV e que receberam um tratamento superovulatório que consistiu no uso de progestágeno, cloprostenol e FSH. Durante o estro, as doadoras foram cobertas por bodes soropositivos. Sete dias após o estro, a colheita de embriões foi realizada utilizando a técnica cirúrgica. Os embriões colhidos foram congelados de acordo com o protocolo da Sociedade Internacional de Transferência de Embriões (IETS). Doze cabras soronegativas foram utilizadas como receptoras e receberam um tratamento de sincronização do estro consistindo de progestágeno, cloprostenol e eCG. A transferência de embriões foi realizada sete dias após o estro sincronizado usando a técnica de semi-laparoscopia. A gestação foi confirmada em uma das doze receptoras, a qual permaneceu soronegativa até seis meses após o parto e sua cria até os seis meses de idade. O sucesso preliminar na produção de crias soronegativas para CAEV e a não soroconversão em receptoras soronegativas sugere que a tecnologia de transferência de embriões pode oferecer uma alternativa para a profilaxia da CAEV em rebanhos caprinos, bem como para o aproveitamento do patrimônio genético de animais soropositivos
Varroa destructor infestation in pre-pupae and pupae of Apis mellifera in Pantanal, Brazil, 2018-2021.
The Varroa destructor mite is an ectoparasite that feeds by sucking the hemolymph from pupae, pre-pupae and adults of Africanized bees (Apis mellifera). The process of parasitism exerted by V. destructor results in various damages to affected individuals, ranging from malformation, reduced longevity, possible transmission of viruses and, in cases of greater infestation, death. With this study, we sought to determine the infestation rate in capped broods (pre-pupae and pupae) during the seasons of the year in the two castes of adult bees: workers and drones in five colonies in an apiary of Embrapa Pantanal located in the Nhumirim ranch (18°59'15.70”S, 56°37'09.30”W), sub-region of Nhecolândia of Pantanal, in Corumbá-MS, Brazil.Ref. PP-282
Varroa destructor infestation in adult bees of Apis mellifera in Pantanal, Brazil, 2018-2021.
Brazil has a high potential for beekeeping production and is considered one of the exporters of high-quality honey. However, it ranked eleventh in world honey production and had only 4.8% of global export capacity in 2019. In addition, parasitism caused by the mite Varroa destructor, a virus vector and ectoparasite of larvae and adult bees of Apis mellifera still lacks further studies in the country. This work aimed to determine the infestation rate of this ectoparasite in the two castes of adult bees: workers and drones.Ref. PP-285
Electronic neuron within a ganglion of a leech (Hirudo medicinalis)
Fil:Aliaga, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Busca, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Salles, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Influence of the disorder on tracer dispersion in a flow channel
Tracer dispersion is studied experimentally in periodic or disordered arrays
of beads in a capillary tube. Dispersion is measured from light absorption
variations near the outlet following a steplike injection of dye at the inlet.
Visualizations using dye and pure glycerol are also performed in similar
geometries. Taylor dispersion is dominant both in an empty tube and for a
periodic array of beads: the dispersivity increases with the P\'eclet
number respectively as and and is larger by a factor of 8
in the second case. In a disordered packing of smaller beads (1/3 of the tube
diameter) geometrical dispersion associated to the disorder of the flow field
is dominant with a constant value of reached at high P\'eclet numbers.
The minimum dispersivity is slightly higher than in homogeneous nonconsolidated
packings of small grains, likely due heterogeneities resulting from wall
effects. In a disordered packing with the same beads as in the periodic
configuration, is up to 20 times lower than in the latter and varies as
with or (depending on the fluid viscosity).
A simple model accounting for this latter result is suggested.Comment: available online at
http://www.edpsciences.org/journal/index.cfm?edpsname=epjap&niv1=contents&niv2=archive
Comprehensive Overview on HVDC Converter Transformer Design: Additional Discussions to the IEC/IEEE 60076-57-129 Standard
HVDC has been chosen as an economical and technical solution for power transmission through long distances, asynchronous interconnections and long submarine cables crossing. Despite DC transmission benefits to power systems, the converters non-linearity produces undesirable effects to the converter transformer in service, mainly listed in the technical standard IEC/IEEE 60076-57-129. However, additional discussions and complementary information can be found in a plurality of references, which are brought in the article under a comprehensive overview perspective. Some design solutions deal with these effects increasing the technical margins, which have direct influence on manufacturing costs and transformer reliability and availability levels. This article goes through the main topics pointed by the standard and the references, investigating their consequences in the converter transformer operation, in order to provide a comprehensive tutorial on design solutions and considerations to deal with those undesirable effects
Бедий эсер талилининъ принциплери ве усуллары меселесине даир
В предложенной статье представлен теоретический материал, который раскрывает вопросы, связанные с принципами и методами анализа художественного произведения, подкреплённый необходимым материалом из крымскотатарской литературы.У запропонованій статті представлений теоретичний матеріал, що розкриває питання, пов'язані із принципами й методами аналізу художнього твору, підкріплений необхідним матеріалом із кримськотатарської літератури.In offered(suggested) clause(article) the theoretical material which opens the questions connected to principles and methods of the analysis of a work of art, supported by a necessary material from крымскотатарской literatures is submitted
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