425 research outputs found
An Allometric Approach to Evaluate Physiological and Production Efficiencies in Tree Size for Tart Cherry and Apple Orchard Systems
Improving production efficiency is a major challenge for modern orchard systems. The primary response in horticulture is to develop high-density orchard systems that use dwarfing rootstocks and intense management strategies to maintain small tree size. As development and evaluation of novel orchard systems may help improve understanding of plant physiology for the development of high-density systems. The effect of tree size and architecture on physiological and production efficiency was evaluated for tart cherry (Prunus cerasus, P. mahaleb) and apple (Malus spp.) orchard systems using a physiologically driven modeling approach, called allometry. Branch dimensions, canopy dimensions and biomass were measured for 24-year-old tart cherry individuals and 10-year-old \u27Golden Delicious\u27 apple individuals on various rootstocks in experimental blocks at the Kaysville Research Farm in Davis Co., Utah. Tree size was related to annual fruit biomass that had been collected over the duration of the apple trial. Branch dimensions, canopy dimensions, yield, and fruit quality were collected in commercial tart cherry orchards of Utah Co.
Tree size, architecture, and biomass of tart cherry and apple expressed strong allometric relationships that were broadly consistent among the two orchard tree species and the theoretical expectations derived from wild plants. The most consistent relationship was the trunk diameter (or trunk cross sectional area) - stem biomass relationship, which broadly followed the 8/3-power law. Branch and canopy dimensions that include a measure of length, such as branch length and canopy height, demonstrated architecture indicative of high water efficiency and metabolic activity that is relieved from biomechanical constrains of weight bearing. The apple rootstocks differed from each other in production efficiency with individuals that express smaller branch and canopy dimensions producing a higher proportion of fruit relative to tree size. In the commercial tart cherry orchards, smaller individuals with relatively higher canopy height and spread expressed higher yield and fruit quality.
Overall, this research supported the continued development of training systems that maintain small trees to improve physiological and production efficiency. Further research must reconcile other consequences of intense management and overproduction that arise with the increased efficiency facilitated by small tree size and high-density orchard systems to maintain sustainable fruit production
Genetic variability and population structure of eastern white pine in a two hectare stand, Durham, New Hampshire
The genetic structure of a two hectare stand of eastern white pine (Pinus strobus L.) was studied by relating foliar allozyme composition of individual trees to tree location and age. Using starch gel electrophoresis, the trees were found to have variants for six of the seven enzymes analyzed. Trees of similar age and with common allozymes were found in clusters, suggesting that genetic structure existed in the stand. The genetic structure may have originated during establishment of several seedlings from common parents when openings were created in the canopy. Knowing that a genetic structure, such as that observed in this study, may exist in natural forests is important to foresters who are concerned with maintaining current levels of genetic variability in those forests.
Evaluation of sampling strategies revealed that at least 50 randomly sampled trees would be required to correctly estimate allele frequencies, the number of alleles per locus, and heterozygosity in this stand. Smaller samples were likely to yield incorrect estimates by chance. To estimate polymorphism, between 100 and 250 trees would be needed. Reliable detection of deviations from allelic frequencies expected under the Hardy-Weinberg equilibrium required 25 to 425 randomly chosen trees, depending on allozyme frequencies for the enzyme in question. Differences in estimates for larger samples compared to smaller ones were due mainly to detection of additional low frequency alleles in the larger samples. These results indicate that cost and labor can be saved by selecting approximately ten percent of trees in a stand such as the one used in this study to obtain estimates for the first three measures, but more extensive and costly samples must be taken when estimating polymorphism and testing for deviation from the Hardy-Weinberg Equilibrium
Jewish Religious Intermarriage in Canada
Drawing on secondary literature, this paper first identifies trends in Jewish religious intermarriage in Canadaâincluding variation over time, gender, age and community size. It then critically examines results from the 2018 Survey of Jews in Canada to explore factors associated with intermarriage. Binary logistic regression demonstrates that intermarriage is significantly and independently associated with residing in cities other than Montreal and Toronto, relative youth, male gender, having little Jewish secondary socialization outside the family and having both parents born in Canada. The statistically positive effect of having intermarried parents on childrenâs likelihood of intermarriage falls if children attend full-time Jewish school and summer camp with Jewish content. The effect disappears if at least one parent is an immigrant. These findings imply that the rising rate of intermarriage can be significantly mitigated if the Jewish community finds the means to increase the proportion of children who undergo intensive Jewish secondary socialization and the proportion of immigrants in the Jewish community. The paper concludes by discussing policies that could facilitate this outcome.
En sâappuyant sur la littĂ©rature secondaire, cet article identifie dâabord les tendances des mariages interreligieux juifs au Canada, y compris les variations dans le temps, le sexe, lâĂąge et la taille des communautĂ©s. Il examine ensuite de maniĂšre critique les rĂ©sultats de lâenquĂȘte de 2018 sur les Juifs au Canada afin dâĂ©tudier les facteurs associĂ©s aux mariages mixtes. La rĂ©gression logistique binaire dĂ©montre que les mariages mixtes sont associĂ©s de maniĂšre significative et indĂ©pendante Ă la rĂ©sidence dans des villes autres que MontrĂ©al et Toronto, Ă la jeunesse relative, au sexe masculin, Ă une faible socialisation secondaire juive en dehors de la famille et au fait que les deux parents sont nĂ©s au Canada. Lâeffet statistiquement positif du fait dâavoir des parents mariĂ©s Ă des non-Juifs sur la probabilitĂ© de mariage mixte diminue si les enfants frĂ©quentent une Ă©cole juive Ă temps plein et un camp dâĂ©tĂ© Ă contenu juif. Lâeffet disparait si au moins un des parents est un immigrant. Ces rĂ©sultats impliquent que le taux croissant de mariages mixtes peut ĂȘtre considĂ©rablement attĂ©nuĂ© si la communautĂ© juive trouve les moyens dâaugmenter la proportion dâenfants qui poursuivent une socialisation secondaire juive intensive et la proportion dâimmigrants dans la communautĂ© juive. Lâarticle conclut en discutant des politiques qui pourraient faciliter ce rĂ©sultat
Isolation of total ribonucleic acid from fresh and frozen-thawed boar semen and its relevance in transcriptome studies
The main objective of this study was to isolate high-quality total ribonucleic acid (RNA) from raw fresh semen and frozen-thawed boar semen, using a protocol comprising the conventional TRIzol assay and a membrane-based technique, the PureLink RNA mini kit. Bioanalyzer profile revealed that the sperm RNA size distributions comprised mainly intact RNA ranging from 1500 to 1800 bp, without any detectable residual genomic deoxyribonucleic acid (DNA) or 28S ribosomal RNA (rRNA). Spectrophotometric quantifications of the total RNA yielded 1.64 to 2.44 ÎŒg/106 spermatozoa, irrespective of the sperm source. The TRIzol/PureLink protocol allowed the isolation of high-quality intact RNA from boar spermatozoa, which is required for transcriptome analysis on high-throughput RNA-sequencing (RNA-Seq) data. Such an approach is relevant to identifying sperm messenger RNA (mRNA transcripts) that are associated with boar semen freezability.Keywords: cryopreservation, RNA-Seq, semen qualit
Visible, Indigenous, and Gender Minorities among Canadian Jews, 2021
This paper focuses on Canadian Jewish minorities that have attracted little scholarly attention. It does so mainly by reviewing data from the 2021 Canadian census on Jews who identify as members of visible, Indigenous, and gender minorities. This discussion points to several areas in need of further academic research, and concludes by claiming that, ironically, understudied Canadian Jewish minorities (including but not restricted to those discussed here) may form a majority of Canadaâs Jewish population, making their inclusion in community affairs a necessity for the continued social cohesion of the countryâs Jewish community
New aspects of low co-ordination phosphorus chemistry
Chapter six describes miscellaneous results obtained during these investigations; some revolve around several iridium compounds, e.g. ortho-metallated Vaska's compound, [IrHC1(CO)(PPh3){eta2-PPh 2(C6H4)}], others around group 15 formamidinate and phenolate compounds, and others around ruthenium phosphaalkenyl chemistry
Assessment of the Impact of Planning on Land Prices in a Selected Area within the District of ĆœÄĂĄr nad SĂĄzavou
DiplomovĂĄ prĂĄce se zabĂœvĂĄ posuzovĂĄnĂm vlivu ĂșzemnĂho plĂĄnovĂĄnĂ na ceny pozemkĆŻ dle oceĆovacĂch pĆedpisĆŻ a ceny obvyklĂ© v okrese ĆœÄĂĄr nad SĂĄzavou. PrĂĄce zkoumĂĄ pozemky nestavebnĂ â zemÄdÄlskĂ©, pozemky urÄenĂ© pro vĂœstavbu a pozemky stavebnĂ. DĂĄle cenu a atraktivitu pozemkĆŻ nestavebnĂch, fĂĄmu o pĆechodu pozemku nestavebnĂho na stavebnĂ a cenu stavebnĂho pozemku.This thesis deals with the assessment of the impact of spatial planning on land prices according to valuation rules and prices usual in the district of the town. The work examines the non-construction land - agricultural, land for construction of building and land. In addition, the price of land and the attractiveness of non-construction, the rumor about the transition than construction land and construction cost of building land.
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