نتایج جستجو برای: حداکثر محصول قابل برداشت msy
تعداد نتایج: 150164 فیلتر نتایج به سال:
Although more than thirty mammalian genomes have been sequenced to draft quality, very few of these include the Y chromosome. This has limited our understanding of the evolutionary dynamics of gene persistence and loss, our ability to identify conserved regulatory elements, as well our knowledge of the extent to which different types of selection act to maintain genes within this unique genomic...
The distribution of genetic diversity in great ape species is likely to have been affected by patterns of dispersal and mating. This has previously been investigated by sequencing autosomal and mitochondrial DNA (mtDNA), but large-scale sequence analysis of the male-specific region of the Y Chromosome (MSY) has not yet been undertaken. Here, we use the human MSY reference sequence as a basis fo...
Stock-recruitment models have been used for decades in fisheries management as a means of formalizing the expected number of offspring that recruit to a fishery based on the number of parents. In particular, Ricker's stock recruitment model is widely used due to its flexibility and ease with which the parameters can be estimated. After model fitting, the spawning stock size that produces the ma...
برداشت کلزا به دو روش مستقیم و غیر مستقیم(دو مرحله ای) انجام می شود. از عوامل اصلی موثر بر تلفات برداشت می توان به روش و زمان برداشت اشاره نمود. هدف اصلی این تحقیق، ارزیابی و مقایسه روش های مختلف برداشت کلزاست. آزمون ها با استفاده از سه روش برداشت و هر کدام در سه سطح رطوبتی انجام گرفت. کمباین مجهز به هد متداول غلات و هد مخصوص کلزا در رطوبت های 15،12 و 9 درصد در برداشت مستقیم، و دروگر شاسی بلند ...
It has been generally accepted for more than half a century that the fishing sector stood to gain from managing fisheries at the effort level producing maximum economic yield (MEY) rather than at the higher effort level producing maximum sustainable yield (MSY). However, the acceptance is built on evaluating only the revenue and cost structure for the fishing fleet, not for the overall fishing ...
This article investigates the effects of reaching the maximum sustainable yield (MSY) in prey–predator systems where the prey population follows logistic law of growth. Two different models are proposed: (i) first model involves linear prey–predator interaction and intraspecific competition among predator populations, and (ii) the second one is a ratio-dependent prey–predator system. In the fir...
نگهداری سیبزمینی پس از برداشت با مشکلات عمدهای همراه است. تقریباً 30 درصد محصول تولیدی کشور طی چند ماه نگهداری از بین میرود. استفاده از نگهدارندههای شیمیایی نه تنها به نگهداری مناسب محصول در انبار کمک نمیکند، بلکه اثراتجانبی نامطلوبی را نیز بهدنبال دارند. در این مطالعه اثر پرتو بتا بر نگهداری غدههای سیبزمینی بررسی شده است. غدههای سیب زمینی رقم آگریا با دوزهای 30 تا150 گری تیمار و هم...
10 Further research is needed to reduce the existing uncertainties on the effect that specific aerosol particle sources have on light extinction and consequently on climate. This study presents a new approach aiming at quantifying the mass scattering and absorption efficiencies (MSE and MAE) of different aerosol sources at urban (Barcelona-BCN), regional (Montseny-MSY) and remote (Montsec-MSA) ...
The proportion of Europeans descending from Neolithic farmers ∼ 10 thousand years ago (KYA) or Palaeolithic hunter-gatherers has been much debated. The male-specific region of the Y chromosome (MSY) has been widely applied to this question, but unbiased estimates of diversity and time depth have been lacking. Here we show that European patrilineages underwent a recent continent-wide expansion. ...
The trawl fishery of the Mediterranean coast of Israel was analyzed vis á vis catch and fishing effort for the years 1949-2010. The Maximum Sustainable Yield (MSY) was calculated using the Fox surplus-yield model and was found to be 1,413 ton per annum using 1,415 units of effort (fishing days X engine power divided by 1000). Only during nine years (1997-2005) did fishing effort exceed the valu...
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