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1.
Denise Risch Nicholas J. Gales Jason Gedamke Lars Kindermann Douglas P. Nowacek Andrew J. Read Ursula Siebert Ilse C. Van Opzeeland Sofie M. Van Parijs Ari S. Friedlaender 《Biology letters》2014,10(4)
For decades, the bio-duck sound has been recorded in the Southern Ocean, but the animal producing it has remained a mystery. Heard mainly during austral winter in the Southern Ocean, this ubiquitous sound has been recorded in Antarctic waters and contemporaneously off the Australian west coast. Here, we present conclusive evidence that the bio-duck sound is produced by Antarctic minke whales (Balaenoptera bonaerensis). We analysed data from multi-sensor acoustic recording tags that included intense bio-duck sounds as well as singular downsweeps that have previously been attributed to this species. This finding allows the interpretation of a wealth of long-term acoustic recordings for this previously acoustically concealed species, which will improve our understanding of the distribution, abundance and behaviour of Antarctic minke whales. This is critical information for a species that inhabits a difficult to access sea-ice environment that is changing rapidly in some regions and has been the subject of contentious lethal sampling efforts and ongoing international legal action. 相似文献
2.
T. R. FRASIER T. RASTOGI M. W. BROWN P. K. HAMILTON S. D. KRAUS B. N. WHITE 《Molecular ecology resources》2006,6(4):1025-1029
A North Atlantic right whale (Eubalaena glacialis) genomic library was developed and screened with a (GATA)8 probe to identify tetranucleotide microsatellite loci. Sixteen characterized loci were polymorphic in North Atlantic and/or South Atlantic (Eubalaena australis) right whales, 12 being polymorphic in E. glacialis, and 15 in E. australis. Fourteen of these were combined with 21 other previously identified loci for a suite of 35 loci which can be used to increase resolution of genetic analyses of these species. Multiplex reactions were developed for genotyping samples at these loci, providing a method that is rapid, reliable and cost‐effective. 相似文献
3.
Summary A single scan method for the suppression of signals arising from zero-quantum coherences (ZQC) is analysed with respect to its application to NMR experiments on proteins. The ZQC are dephased during a spinlock period due to the natural RF inhomogeneity of a commercial probe. A quantitative analysis of a ZQC-compensated NOESY experiment is given. Although the build-up curve for the cross peaks in ZQC-compensated NOESY experiments differ from those in uncompensated experiments, interproton distances in medium-sized proteins can be evaluated with high accuracy. The proposed method is compared with other techniques for ZQC suppression. 相似文献
4.
Modulation of ζ-Protein Kinase C by Cyclic AMP in PC12 Cells Occurs Through Phosphorylation by Protein Kinase A 总被引:1,自引:1,他引:0
Marie W. Wooten M. Lamar Seibenhener Laura H. Matthews Guisheng Zhou Elaine S. Coleman 《Journal of neurochemistry》1996,67(3):1023-1031
Abstract: Although cyclic AMP (cAMP) has been reported to cross talk with the protein kinase C (PKC) system, effects of elevated intracellular cAMP on the activities of specific PKC isoforms have not been studied. We report findings from a permeabilized cell assay that was used to examine changes in the activity of the atypical PKC isoforms brought about by exposure of PC12 cells to agents that elevate intracellular cAMP. We found that increases in intracellular cAMP led to rapid stimulation of atypical PKC activity, 40–70% above control, for a sustained period of time, a response that occurred independent of the phorbol 12-myristate 13-acetate (PMA)-sensitive PKC isoforms. Changes in intracellular cAMP levels resulted in a dose-dependent redistribution of ζ-PKC to the cytoplasm with a concomitant increase in the phosphorylation state of the enzyme. Incubation of purified ζ-PKC with increasing concentrations of PKA likewise caused a twofold increase in the phosphorylation state of ζ-PKC. In contrast to the positive effect that PKA-mediated phosphorylation had on the activity of ζ-PKC, the enzyme displayed reduced binding to ras when phosphorylated. Taken together, these findings are consistent with the hypothesis that protein phosphorylation of PKC acts as a positive effector of its enzyme activity and may serve as a negative modulator for interaction with other proteins. 相似文献
5.
大豆灰斑病抗性遗传的三点测交分析 总被引:1,自引:0,他引:1
本实验利用三点测交分析的方法, 对3个组合在人工接种大豆灰斑病菌的条件下的抗性表现进行基因效应分析,各组合均存在加性,组合1存在显性,组合2、3存在上位性。
Abstract:In this paper,Triple Test Cross Design was used in studing the resistance of soybean to 10 physiological race of Cercospora Sojina Haraby inoculation.Results o analysis of gene effects of resistance indicated that additive effect is significant in all the three crosses,dominant effect exsists only in the cross 1 and epistatic effect remains in the cross 2 and cross 3. 相似文献
6.
Y. Fukui T. Mogoe Y. G. Jung Y. Terawaki A. Miyamoto H. Ishikawa Y. Fujise S. Ohsumi 《Marine Mammal Science》1996,12(1):28-37
Spermatozoa from 21 mature minke whales ( Balaenoptera acutorostrata ) taken in the Antarctic Ocean for Japanese research were recovered from vasa deferentia, diluted 1:9 in a Tris-based diluent, and frozen at - 80°C on board the vessel. After a period ranging from 45 to 125 d, the samples were transferred to liquid nitrogen and transported to the laboratory. After thawing at 37°C the motility (percentage of motile spermatozoa), vitality (proportion of live spermatozoa), and sperm concentration were determined for each sample. These values were tested for correlations with morphological measurements (body size, body weight, testis weight) and serum concentrations of progesterone (Pd), estradiol-17β (E2), and testosterone (T). Ten of 21 samples had motile spermatozoa (2%-40%). Although no motile spermatozoa were observed in 1.1 samples, all sperm samples were examined by eosinnigrosin staining and showed vitality levels of 3%44%. It was found that the motility (Y = 0.54) and vitality (r = 0.53) of the spermatozoa were significantly (P < 0.01) correlated with the E2 levels (8.50 ± 1.80 pg/ml). Serum T levels (0.07 ± 0.02 ngml) were significantly correlated with the E2 levels (r = 0.58, P < 0.01>, but sperm concentrations were not correlated with either Ea or T levels. The present study demonstrates that spermatozoa of minke whales can be successfully cryopreserved. 相似文献
7.
三系和二系籼粳交杂种F1农艺性状遗传表现的比较 总被引:3,自引:0,他引:3
通过6个籼型三系不育系(A)和3个籼型光温敏核不育系(S)分别与7个粳型广亲和系(W)的不完全双列杂交试验,对两类不同配组模式(即AW和SW)的杂种优势的表现、农艺性状遗传特点及参试亲本基因效应值的差异进行了比较,结果表明,在多数性状上,AW比SW型具有更强的群体平均优势和群体超亲优势;而两者农艺性状遗传方差分量除主穗总粒数等外,在抽穗期、着粒密度和剑叶长的遗传分量则较为一致;参试亲本的加性效应预测值,是D汕A具有降低株高的效应,红突A、W6llls和浙南1号A具有明显地缩短生育期的效应,红突A、D汕A和协青早A有显著地增加每株穗数的效应,而02428、T984和轮回422则有增加主穗总粒数的效应. 相似文献
8.
G. Ferretti M. V. Narici T. Binzoni L. Gariod J. F. Le Bas H. Reutenauer P. Cerretelli 《European journal of applied physiology and occupational physiology》1994,68(2):111-115
The relationships between absolute peak muscle power (W
peak), muscle cross sectional area (CSAtot, i.e. the sum of both thigh and calf CSA) and muscle high energy phosphate concentration (adenosine 5-triphosphate [ATP] and phosphocreatine concentrations [PC]) were studied in 47 subjects classified into five groups: A, 10 sedentary (S) subjects aged 20–35 years; B, 9 S aged 35–50 years; C, 9 S aged more than 50 years; D, 13 children aged 8–13 years; and E, 6 athletes (top level volleyball players) aged 24 (SD 3) years. The W
peak was measured during a maximal vertical high jump off both feet on a force platform. The CSAtot was measured anthropometrically. The [ATP] and [PC] were determined by 31Phosphorus nuclear magnetic resonance spectroscopy. The W
peak decreased with age, was 65% lower in D than in A, and 43% higher in E than in A. The CSAtot did not vary with age, was 45% smaller in D than in A, and 15% greater in E than in A. The [ATP] and [PC] were essentially the same in all groups. The changes observed in W
peak were only partially accounted for by changes in CSAtot. Therefore, in addition to the variables investigated, other factors appear to have been involved in the determination of W
peak with increasing age and training. An important role may be played by hormonal, particularly at puberty, and neural factors. 相似文献
9.
H. -P. Piepho 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(5):647-654
Multilocation trials are often used to analyse the adaptability of genotypes in different environments and to find for each environment the genotype that is best adapted; i.e. that is highest yielding in that environment. For this purpose, it is of interest to obtain a reliable estimate of the mean yield of a cultivar in a given environment. This article compares two different statistical estimation procedures for this task: the Additive Main Effects and Multiplicative Interaction (AMMI) analysis and Best Linear Unbiased Prediction (BLUP). A modification of a cross validation procedure commonly used with AMMI is suggested for trials that are laid out as a randomized complete block design. The use of these procedure is exemplified using five faba bean datasets from German registration trails. BLUP was found to outperform AMMI in four of five faba bean datasets. 相似文献
10.
Logan J. Pallin Nick M. Kellar Debbie Steel Natalia Botero-Acosta C. Scott Baker Jack A. Conroy Daniel P. Costa Chris M. Johnson David W. Johnston Ross C. Nichols Doug P. Nowacek Andrew J. Read Oksana Savenko Oscar M. Schofield Sharon E. Stammerjohn Deborah K. Steinberg Ari S. Friedlaender 《Global Change Biology》2023,29(8):2108-2121
The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human-induced changes. Understanding how climate-mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8-year dataset (2013–2020), we show that inter-annual humpback whale pregnancy rates, as determined from skin-blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter-annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region. 相似文献