Contrasting litter effects on old field tree germination and emergence

Because the fate of seeds is critical to understanding the invasion of old fields by trees, and plant litter is an important component defining the old field microsite of dispersed seeds, I investigated the effects of litter type (Solidago spp./goldenrod,Quercus spp./oak, mixed) and litter amount (100–800 g/m²) on tree seed germination and seedling emergence. I found that at all densities bothSolidago andQuercus litter greatly reduced emergence of the small-seeded, bird-dispersed species,Juniperus virginiana andCornus florida. For one of the large-seeded, mammal-dispersed species,Carya tomentosa, high densitySolidago litter and high density mixed litter treatments reduced emergence. For the other large-seeded species,Quercus rubra, the high density mixed litter treatment and all levels ofSolidago litter reduced emergence.Quercus seedlings emerged twice as often as the other three species in control pots without litter.Carya emerged before the other species but the high density oak treatment delayed the expansion of its cotyledons. My results suggest that litter may contribute to the slow rate of tree invasion and the low probability of tree establishment in old fields. However, old field litter studies taken together point to the difficulty in drawing general conclusions about any net effect of litter on old field tree establishment.     

Lumi-mestranol and epi-lumi-mestranol.

Treatment of lumi-estrone 3-methyl ether (I) with acetylene gave the C-17-epimeric compounds lumi-mestranol (3-methoxy-17 alpha-ethynyl-13 alpha-estra-1,3,5(10)-trien-17 beta-ol, III ) and epi-lumi-mestranol (3-methoxy-17 beta-ethynyl-13 alpha-estra-1,3,5(10)-trien-17 alpha-ol, IV). The structures of the two isomers were assigned on the basis of their molecular rotations and shift-reagent experiments in the NMR. The irradiation of estrone 3-methyl ether (II) to provide compound I was investigated in two solvent systems. Minor products of these reactions were the seco-steroids VII, VIII and X.     

Quantitative trait loci for organ weights and adipose fat composition in Jersey and Limousin back‐cross cattle finished on pasture or feedlot

A QTL study of live animal and carcass traits in beef cattle was carried out in New Zealand and Australia. Back‐cross calves (385 heifers and 398 steers) were generated, with Jersey and Limousin backgrounds. This paper reports on weights of eight organs (heart, liver, lungs, kidneys, spleen, gastro‐intestinal tract, fat, and rumen contents) and 12 fat composition traits (fatty acid (FA) percentages, saturated and monounsaturated FA subtotals, and fat melting point). The New Zealand cattle were reared and finished on pasture, whilst Australian cattle were reared on grass and finished on grain for at least 180 days. For organ weights and fat composition traits, 10 and 12 significant QTL locations (P < 0.05), respectively, were detected on a genome‐wide basis, in combined‐sire or within‐sire analyses. Seven QTL significant for organ weights were found at the proximal end of chromosome 2. This chromosome carries a variant myostatin allele (F94L), segregating from the Limousin ancestry, and this is a positional candidate for the QTL. Ten significant QTL for fat composition were found on chromosomes 19 and 26. Fatty acid synthase and stearoyl‐CoA desaturase (SCD1), respectively, are positional candidate genes for these QTL. Two FA QTL found to be common to sire groups in both populations were for percentages of C14:0 and C14:1 (relative to all FAs) on chromosome 26, near the SCD1 candidate gene.     

Akkermansia与高原牛肺水肿病相关性研究

【目的】本文通过对高原牛胃肠道菌群结构组成的分析,从微生物学角度探讨Akkermansia与高原牛肺水肿病的关系。【方法】本研究以沈阳地区健康娟姗牛为对照,以引进入拉萨半年的健康娟姗牛、拉萨本地健康黄牛以及引进入拉萨半年患肺水肿病的娟姗牛的粪便作为分析样本,采用Illumina MiSeq高通量测序技术测定样本中微生物16S rRNA基因V3–V4区序列,通过比较4种粪便样本菌群组成及丰度的差异,探讨Akkermansia与高原牛肺水肿病的相关性。【结果】Verrucomicrobia中Akkermansia在拉萨本地健康黄牛的胃肠道中的含量显著高于引进入拉萨半年的健康娟姗牛,在引进入拉萨半年患肺水肿病的娟姗牛胃肠道中的含量显著高于引进入拉萨半年的健康娟姗牛。在属水平上,沈阳地区健康娟姗牛胃肠道菌群中Akkermansia丰度占比为0.07%;引进入拉萨半年的健康娟姗牛胃肠道菌群中Akkermansia丰度占比为0.09%;拉萨本地黄牛胃肠道菌群中Akkermansia丰度占比为6.62%,是优势菌属;引进入拉萨半年的患肺水肿病的娟姗牛胃肠道菌群中Akkermansia丰度占比为11.85%,且是第一优势菌属。【结论】首次从微生物学角度探讨Akkermansia与高原牛肺水肿病的关系,为将Akkermansia丰度作为诊断肺水肿病的监测指标提供参考,但具体丰度值还有待进一步研究。     

Recent artificial selection in U.S. Jersey cattle impacts autozygosity levels of specific genomic regions

Background

Genome signatures of artificial selection in U.S. Jersey cattle were identified by examining changes in haplotype homozygosity for a resource population of animals born between 1953 and 2007. Genetic merit of this population changed dramatically during this period for a number of traits, especially milk yield. The intense selection underlying these changes was achieved through extensive use of artificial insemination (AI), which also increased consanguinity of the population to a few superior Jersey bulls. As a result, allele frequencies are shifted for many contemporary animals, and in numerous cases to a homozygous state for specific genomic regions. The goal of this study was to identify those selection signatures that occurred after extensive use of AI since the 1960, using analyses of shared haplotype segments or Runs of Homozygosity. When combined with animal birth year information, signatures of selection associated with economically important traits were identified and compared to results from an extended haplotype homozygosity analysis.

Results

Overall, our results reveal that more recent selection increased autozygosity across the entire genome, but some specific regions increased more than others. A genome-wide scan identified more than 15 regions with a substantial change in autozygosity. Haplotypes found to be associated with increased milk, fat and protein yield in U.S. Jersey cattle also consistently increased in frequency.

Conclusions

The analyses used in this study was able to detect directional selection over the last few decades when individual production records for Jersey animals were available.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1500-x) contains supplementary material, which is available to authorized users.     

Sharing reference data and including cows in the reference population improve genomic predictions in Danish Jersey

Small reference populations limit the accuracy of genomic prediction in numerically small breeds, such like Danish Jersey. The objective of this study was to investigate two approaches to improve genomic prediction by increasing size of reference population in Danish Jersey. The first approach was to include North American Jersey bulls in Danish Jersey reference population. The second was to genotype cows and use them as reference animals. The validation of genomic prediction was carried out on bulls and cows, respectively. In validation on bulls, about 300 Danish bulls (depending on traits) born in 2005 and later were used as validation data, and the reference populations were: (1) about 1050 Danish bulls, (2) about 1050 Danish bulls and about 1150 US bulls. In validation on cows, about 3000 Danish cows from 87 young half-sib families were used as validation data, and the reference populations were: (1) about 1250 Danish bulls, (2) about 1250 Danish bulls and about 1150 US bulls, (3) about 1250 Danish bulls and about 4800 cows, (4) about 1250 Danish bulls, 1150 US bulls and 4800 Danish cows. Genomic best linear unbiased prediction model was used to predict breeding values. De-regressed proofs were used as response variables. In the validation on bulls for eight traits, the joint DK-US bull reference population led to higher reliability of genomic prediction than the DK bull reference population for six traits, but not for fertility and longevity. Averaged over the eight traits, the gain was 3 percentage points. In the validation on cows for six traits (fertility and longevity were not available), the gain from inclusion of US bull in reference population was 6.6 percentage points in average over the six traits, and the gain from inclusion of cows was 8.2 percentage points. However, the gains from cows and US bulls were not accumulative. The total gain of including both US bulls and Danish cows was 10.5 percentage points. The results indicate that sharing reference data and including cows in reference population are efficient approaches to increase reliability of genomic prediction. Therefore, genomic selection is promising for numerically small population.     

‘We eat meat every day’: ecology and economy of dietary change among Oaxacan migrants from Mexico to New Jersey

Abstract

In the late twentieth and early twenty-first centuries, the USA has experienced large-scale and continuing immigration from around the world, especially Latin America and, within Latin America, from Mexico. One dimension of these transnational processes is dietary change. In this paper, we qualitatively assess the effects of migration from Oaxaca, Mexico to central New Jersey on the ecology and economy of dietary patterns. We explore multiple factors at the micro and macro levels. Data come from focus groups held among Mexican migrants in New Jersey, and in Oaxaca among people from their sending communities. Economic constraints and lack of culturally appropriate foods are larger barriers to healthy eating than lack of knowledge about appropriate diets. We end with recommendations for nutrition education and interventions.     

The ontogeny of maternal responsiveness in female Rockland-Swiss albino mice

Twenty-two-day-old female Rockland-Swiss albino mice ignored 1-day-old young. As age increased there was a decrease in the percentage of animals that ignored pups. Pup-killing, exhibited by a significant number of 32- and 42-day olds, declined as age increased. Furthermore, the number of females exhibiting maternal behavior increased with advancing age. Olfactory bulb removal and testosterone propionate treatment, each of which elicit pup-killing in adult females, did not induce killing behavior in 22-day olds. Finally, ovariectomy performed on Day 18 reduced the number of animals that displayed maternal behavior on Day 62.     

Integrating Comparative Risk Assessment with Multi-Criteria Decision Analysis to Manage Contaminated Sediments: An Example for the New York/New Jersey Harbor

Current environmental challenges involve complex assessment and analysis of tradeoffs among differing criteria, expectations, and levels of certainty. Using multi-criteria decision analysis in combination with comparative risk assessment, a systematic and transparent framework can be created to integrate different types and sources of decision-relevant information. Although examples of decision analysis abound in the literature and academic efforts, its use within the practice of risk assessment and environmental management is still being established. This article provides an example of the use of decision analysis study that builds on a previous screening-level, comparative risk assessment of contaminated sediment from the New York/New Jersey harbor area. Using multi-criteria decision analysis, we explored the effect of different criteria weights, utility functions, and cost estimates on the ranking of seven contaminated sediment management alternatives. Values used in weighting decision criteria were surveyed from two interaction sessions with sediment management professionals.