scholarly journals Effects of Certain Environmental Factors and Sex on Poult Growth with Reference to Future Experimental Design

1958 ◽  
Vol 37 (5) ◽  
pp. 1051-1054 ◽  
Author(s):  
J.C. Atkinson ◽  
K.R. Bennett ◽  
E.W. Callenbach
2019 ◽  
Vol 40 ◽  
pp. 11
Author(s):  
Alicia Baumhardt Dorneles ◽  
Eduardo Leonel Bottega ◽  
Zanandra Boff de Oliveira ◽  
Alberto Eduardo Knies ◽  
Clarissa Moraes da Silva ◽  
...  

Unstable environmental factors contribute to the incidence of diseases and pests, causing reduced yield and grain contamination, especially the attack by Giberela (Fusarium graminerum). In this scenario, appropriate management techniques are needed. Strategies such as choosing the suitability of the spray tip for chemical control are indispensable. The aim of this study was to use four spray tips: CVI 11002, ADI ISO 11002, TVI ISO 8002 and ATR 8002. The experiment was conducted in the experimental area of The State University of Rio Grande do Sul, in the district of Três Vendas, in Cachoeira do Sul-RS. The cultivar used was TBIO SELETO. The fungicide used was Nativo®. A completely randomized experimental design with 4 replicates and a control plot was adopted. The following parameters were evaluated: weight of one thousand grains (PMG, %), hectoliter weight (PH; kg hL-1) and yield (PRD; kg ha-1). The variance was tested by applying the Snedcor F test (p<0.05) and the means were compared by the Tukey's test (p<0.05). The weight of one thousand grains, hectoliter weight and yield were not influenced by the use of different spray tips adopted in the wheat phytosanitary control.


2018 ◽  
Author(s):  
Charlotte Depeux ◽  
Ascel Samba-Louaka ◽  
Christine Braquart-Varnier ◽  
Jérôme Moreau ◽  
Jean-François Lemaître ◽  
...  

AbstractMost living organisms display a decline in physiological performances when ageing, a process called senescence that is most often associated with increased mortality risk. Previous researches have shown that both the timing and the intensity of senescence vary a lot within and among species, but the role of environmental factors in this variation is still poorly understood. To fill this knowledge gap, we investigated the impact of environmental conditions on the strength of senescence using an experimental design applied to a population of common woodlouse Armadillidium vulgare intensively monitored in the lab. Cellular senescence biomarkers are available in woodlouse and are age-related. These biomarkers provide relevant biomarkers to test the impact of environmental conditions, through changes in temperature and photoperiod, on individuals of the same age maintained in different environmental conditions. We found different effects of the environmental changing: the increasing of day light modification leaded the same effect as age on our senescence biomarkers while temperature modifications leaded the opposite effect as age on the β-galactosidase activity and cell size. We also demonstrated the existence of sex-specific responses to changes in environmental conditions. By using an experimental approach and biomarkers of senescence in woodlouse, we show that environmental conditions and sex both shape the diversity observed in senescence patterns of woodlouse and underline the importance of identifying senescence biomarkers to understand how environmental conditions influence the evolution of senescence.


2018 ◽  
Vol 24 (11) ◽  
pp. 1419-1420 ◽  
Author(s):  
Sergio E Baranzini

Conducting a robust experiment is not trivial in microbiome research, and as with any study, experimental methods, environmental factors, and analysis methods can affect results. Standards for data collection and analysis are still emerging in the field, and notably, many of the most fundamental issues that concern microbiome studies arise from statistical and experimental design issues. The most important challenge for the field is to integrate new approaches that are unique to microbiome studies, while remembering standard practices that are broadly applicable to all scientific studies. In this section, attention is focused on sample collection, storage and shipping of microbiome-related samples, and how careful, purposeful design can increase the statistical power of these studies.


2009 ◽  
Vol 9 (2) ◽  
pp. 37
Author(s):  
Ángela Liliana Rivera Calderón ◽  
Raúl Iván Valbuena Benavides ◽  
Rigoberto Hidalgo Hidalgo ◽  
José Dílmer Moreno Mendoza

<p class="Corpoica"><span lang="ES-CO">En la Corporación de Investigación Agropecuaria Corpoica, C.I. Tibaitatá, se evaluó la crioconservación de yemas de microtubérculos en dos accesiones de papa Solanum tuberosum ssp. andigena de la Colección Central Colombiana: C.C.C. 4318 (carriza) y C.C.C. 4981 (guata negra) mediante la metodología del desecado de yemas. Esta metodología tuvo dos etapas: la preliminar o de ajuste y la principal. En la principal, el secado se hizo con flujo de aire estéril durante 30 minutos, crioconservación en nitrógeno líquido a -196°C durante un día, descongelamiento en baño maría a 37°C durante 3 minutos y recuperación en medio de cultivo (100% MS + 8% sacarosa + 2 g/L carbón activado) durante siete días en oscuridad; luego, el medio de cultivo se cambió (100% MS + 0,04 mg/L kinetina + 0,1mg/L ácido giberélico). El diseño experimental fue al azar: dos accesiones, cuatro tratamientos, diez repeticiones y diez yemas. </span>Se evaluó sobrevivencia a 7, 14 y 30 días. <span lang="ES-CO">Paralelamente se adaptó la prueba de tetrazolio en semillas al 0,5% a 25°C durante 24 horas, y se evaluó a los 14 y 30 días; en esta prueba se dificultó la evaluación de la sobrevivencia de las yemas posiblemente por efecto del medio de cultivo y los factores ambientales; el resultado final fue pérdida de sobrevivencia a los 30 días, posiblemente porque las condiciones de recuperación no fueron aptas. </span></p><p class="Corpoica"><span lang="ES-CO"> </span></p><p class="Corpoica"><strong><span lang="EN-US">Cryoconservation of buds of potato’s microtubers Solanum tuberosum ssp. andigena by means of drying tissues</span></strong></p><p class="Corpoica">At the Corporación de Investigación Agropecuaria Corpoica, C.I. Tibaitatá, the cryoconservation of microtubers buds was evaluated in two potato accessions of Solanum tuberosum ssp. andigena, C.C.C. 4318 (carriza) and C.C.C. 4981 (guata negra), from the Colombian Central Collection by using the dried bud methodology. This methodology had two steps, the preliminary one or adjustment and the main one. In the main step, the tissue drying was made with sterile air flow for 30 minutes, cryoconservation in liquid nitrogen at -196°C during 1 day, water bath thawing at 37°C for 3 minutes and recuperation culture medium (100% MS + 8% sucrose + 2 g/L activated charcoal) during 7 days in dark, then the cultured medium was changed (100% MS + 0.04 mg/L kinetin + 0.1mg/L gibberellic acid). A completely randomized experimental design with 2 accessions, 4 treatments, 10 replications and 10 buds, was used. The survival was evaluated at 7, 14 and 30 days. At the same time, the tetrazolium test on seeds was adapted at 0.5% a 25°C for 24 hours, and evaluated after 14 and 30 days. In this bioassay, the survival evaluation of the buds was difficult possibly due to the effect of culture medium and environmental factors. The final result was loss of survival at 30 days, probably because the recovery conditions were not suitable. </p>


1994 ◽  
Vol 59 (1) ◽  
pp. 61-70 ◽  
Author(s):  
G. Wiener ◽  
G. J. Lee ◽  
J. A. Woolliams

AbstractFleece weight and shedding score, a measure of premature fleece loss, were examined at first shearing and in older female sheep of three hilt breeds and their reciprocal crosses. Starting from a non-inbred base, the sheep were mated, mostly by younger-parent × offspring, for four generations, to produce inbreeding coefficients from 0·25 to 0·59. Crosses of inbred lines were also produced within breed type. The experimental design allowed the effects of inbreeding of the individual to be separated from the effects of maternal inbreeding.Inbreeding of the individual significantly and linearly reduced fleece weight. This effect was still apparent after adjustment for body weight. Maternal inbreeding significantly reduced only the weight of first fleeces, but the trends were similar at the later ages, especially among the purebreds. There was no significant interaction of purebred/crossbred status with level of inbreeding. Inbreeding did not significantly affect shedding score. The pure breeds and the crosses did not differ, on average, in fleece weights or shedding scores, but within the purebred and within the crossbred classes breed variation was significant. Fleece weight declined and the incidence of shedding increased with increasing age. The larger the number of lambs born in the year of shearing the lower the fleece weight and the greater the extent of fleece shedding.The effects of inbreeding could not be fully explained, statistically, in terms of dominance alone. Therefore, it seems probable that epistasis also plays a role in producing the observed changes with inbreeding in these traits.


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