Individual vocal production in a sperm whale (Physeter macrocephalus) social unit

The vocal repertoires of group‐living animals may communicate individual or group identity. Female and juvenile sperm whales live in long‐term social units that can be assigned to vocal clans based on the pattern of clicks in coda vocalizations. An unusual set of circumstances allowed us to record the vocalizations of photo‐identified individuals within a single social unit over a 41 d period. Using click interpulse intervals, we were able to assign codas to individuals and investigate coda production at the individual level within a social unit for the first time. Adult females in the unit vocalized at approximately equal rates. A calf and juvenile, both male, vocalized less often than the adult females. Repertoires were indistinguishable for all unit members apart from a mother and her calf, which possessed significantly different repertoires—even from one another. We suggest that similarity among the coda repertoires of most unit members indicates a function in advertising unit identity. In contrast, the distinctive repertoires of the calf and its mother may facilitate reunions between these whales. We hypothesize that sperm whales may be able to vary their vocal repertoires as their reproductive status alters the trade‐off between the benefits of individual and group identification.     

关于健康成人左右运动神经传导参数的比较

目的:研究正常人左、右侧的末梢神经传导特点及易损伤性,探讨生活习惯与末梢神经潜在性损伤的内在关联,提高电生理诊断准确率。方法:100名志愿者为对象,检测正中、尺、胫和腓神经的复合肌肉动作电位(CMAP)、F波,观察左、右侧的神经传导参数及左右差值与生活习惯之间的联系。结果:左侧尺、胫运动神经传导速度(MCV)慢于右侧(P值各为0.013、0.011)。MCV≤X-1S尺神经组的远端潜伏期(D Lat)、F波最短潜伏期(F-Lat)延长于MCV>X-1S组(P值均为0.000)。MCV≤X-1S胫神经组的近端波幅(P Amp)低于MCV>X-1S组(P=0.000)。右侧腓神经D Lat延长于左侧(P=0.007),D Lat≥X+1S腓神经组的MCV、F-Lat平均值慢或延长于D Lat相似文献   

改良Nikaidoh 手术治疗合并肺动脉瓣狭窄的右室双出口

目的:总结改良Nikaidoh手术治疗右心室双出口(DORV)患者的临床经验,以提高手术疗效。方法:2例先天性心脏病右心室双出口伴肺动脉瓣狭窄行改良Nikaidoh手术,游离主动脉根部及冠状动脉,重建左心室流出道,以带单瓣牛心包片补片重建肺动脉及右心室流出道。结果:术后患者紫绀消失,复查心脏彩超仅有轻度肺动脉瓣关闭不全,未发现左、右心室流出道梗阻,康复出院。结论:采用改良Nikaidoh手术治疗伴肺动脉瓣狭窄的右室双出口,术后可获得良好的血流动力学效果,早期临床结果满意。     

Confirmation of right whales near a nineteenth-century whaling ground east of southern Greenland

North Atlantic right whales (Eubalaena glacialis) were found in an important nineteenth century whaling area east of southern Greenland, from which they were once thought to have been extirpated. In 2007-2008, a 1-year passive acoustic survey was conducted at five sites in and near the 'Cape Farewell Ground', the former whaling ground. Over 2000 right whale calls were recorded at these sites, primarily during July-November. Most calls were northwest of the historic ground, suggesting a broader range in this region than previously known. Geographical and temporal separation of calls confirms use of this area by multiple animals.     

A quarter of a world away: female humpback whale moves 10,000 km between breeding areas

Fidelity of individual animals to breeding sites is a primary determinant of population structure. The degree and scale of philopatry in a population reflect the fitness effects of social facilitation, ecological adaptation and optimal inbreeding. Patterns of breeding-site movement and fidelity are functions of social structure and are frequently sex biased. We report on a female humpback whale (Megaptera novaeangliae) first identified by natural markings off Brazil that subsequently was photographed off Madagascar. The minimum travel distance between these locations is greater than 9800 km, approximately 4000 km longer than any previously reported movement between breeding grounds, more than twice the species' typical seasonal migratory distance and the longest documented movement by a mammal. It is unexpected to find this exceptional long-distance movement between breeding groups by a female, as models of philopatry suggest that male mammals move more frequently or over longer distances in search of mating opportunities. While such movement may be advantageous, especially in changeable or unpredictable circumstances, it is not possible to unambiguously ascribe causality to this rare observation. This finding illustrates the behavioural flexibility in movement patterns that may be demonstrated within a typically philopatric species.     

Altered microtubule dynamics by expression of modified alpha-tubulin protein causes right-handed helical growth in transgenic Arabidopsis plants

The proper organization of cortical microtubule arrays is essential for anisotropic growth in plants but how distinct array patterns are formed is not understood. Here, we report a relationship between microtubule dynamics and array organization using transgenic plants expressing modified tubulins. When green fluorescent protein (GFP) or a hemaglutinin epitope tag was fused to the N-terminus of tubulins and expressed in Arabidopsis plants, these tubulins were incorporated into microtubules along with endogenous tubulins. Plants expressing the modified beta-tubulins were phenotypically normal and possessed transversely oriented cortical arrays in the epidermal cells of the root elongation zone; however, the expression of modified alpha-tubulins caused right-handed helical growth, increased trichome branching, and a shallow left-handed (S-form) helical array organization. In cells expressing the modified alpha-tubulins, microtubule dynamicity was suppressed and polymerization was promoted, and GFP-EB1 (End Binding 1) labeled larger regions of the microtubule end more frequently, when compared with control cells. We propose that the N-terminal appendage introduced into alpha-tubulin inhibits GTP hydrolysis, thus producing polymerization-prone microtubules with an extended GTP cap. Consistent with this interpretation, plants expressing an alpha-tubulin mutated in the GTPase-activating domain exhibited similar microtubule properties, with regard to dynamics and the localization of GFP-EB1, and showed right-handed helical growth.     

Beaked whale auditory evoked potential hearing measurements

Several mass strandings of beaked whales have recently been correlated with military exercises involving mid-frequency sonar highlighting unknowns regarding hearing sensitivity in these species. We report the hearing abilities of a stranded juvenile beaked whale (Mesoplodon europaeus) measured with auditory evoked potentials. The beaked whale’s modulation rate transfer function (MRTF) measured with a 40-kHz carrier showed responses up to an 1,800 Hz amplitude modulation (AM) rate. The MRTF was strongest at the 1,000 and 1,200 Hz AM rates. The envelope following response (EFR) input–output functions were non-linear. The beaked whale was most sensitive to high frequency signals between 40 and 80 kHz, but produced smaller evoked potentials to 5 kHz, the lowest frequency tested. The beaked whale hearing range and sensitivity are similar to other odontocetes that have been measured.     

The systematics of right whales (Mysticeti: Balaenidae)

Balaenidae (right whales) are large, critically endangered baleen whales represented by four living species. The evolutionary relationships of balaenids are poorly known, with the number of genera, relationships to fossil taxa, and position within Mysticeti in contention. This study employs a comprehensive set of morphological characters to address aspects of balaenid phylogeny. A sister‐group relationship between neobalaenids and balaenids is strongly supported, although this conflicts with molecular evidence, which may be an artifact of long‐branch attraction (LBA). Monophyly of Balaenidae is supported, and three major clades are recognized: (1) extinct genus Balaenula, (2) extant and extinct species of the genus Eubalaena, and (3) extant and extinct species of the genus Balaena plus the extinct taxon, Balaenella. The relationships of these clades to one another, as well as to the early Miocene stem balaenid, Morenocetus parvus, remain unresolved. Pliocene taxa, Balaenula astensis and Balaenula balaenopsis, form a clade that is the sister group to the Japanese Pliocene Balaenula sp. Eubalaena glacialis and Pliocene Eubalaena belgica, are in an unresolved polytomy with a clade including E. japonica and E. australis. Extant and fossil species of Balaena form a monophyletic group that is sister group to the Dutch Pliocene Balaenella, although phylogenetic relationships within Balaena remain unresolved.     

Assessing changes in numbers and distribution of large whale entanglements in Newfoundland and Labrador,Canada1

Entanglements of large whales in commercial fisheries in Newfoundland and Labrador, Canada, have been consistently recorded since 1979, as part of a program aimed at releasing captured animals and reducing costs to fishermen. This data set represented an opportunity to identify fisheries posing particular entanglement risks to local whale populations. Data were assessed over the periods 1979–1992 and 1993–2008, corresponding to distinct phases in fisheries distribution and intensity. Between 1979 and 2008, 1,209 large whale entanglements were recorded in Newfoundland and Labrador. These were mostly humpback whales (Megaptera novaeangliae; 80%) and minke whales (Balaenoptera acutorostrata; 15%). Dramatic declines in reported inshore whale entanglement rates were observed following the 1992 moratorium on Atlantic cod (Gadus morhua) fisheries. Recently, more entanglements have been reported further offshore, largely due to expansion of fisheries targeting snow crab (Chionoecetes opilio). For all whale species, entanglement rates and associated mortality rates varied considerably in different fishing gear. Fractions of humpback and minke whales found dead in different fishing gear differed substantially, with minke whales far more likely to be found dead than humpback whales.