bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass transfer during lactation of an ice‐breeding pinniped, the grey seal (Halichoerus grypus), in Nova Scotia, Canada
Authors: Baker S. R. , Barrette C. , Hammill M. O. 
Published: March 2009

Mass transfer during lactation was examined by serial weighing of mother‐pup pairs in an ice‐breeding population of grey seals, in the southern Gulf of St. Lawrence (c. 46° N‐c. 63° W), Canada.Male pups (171 ± 1–3kg, n= 4) were significantly heavier at birth (P= 001) than females (14.6 ± 1.4 kg, n= 9), and grew significantly faster until weaning (males: 2.7 ± 0.6kg/d, n= 45; females: 2.4 ± 0–5kg/d, n= 63, P= 004). At weaning, males (56.2 ± 6.7 kg, n= 24) were significantly heavier (P= 0‐01) than females (51.6 ± 53kg, n= 25). Lactation for both sexes lasted 14.9 ± 1.4 days (n= 13).At parturition, adult females weighed 227 ± 26 kg (n= 26). During lactation they lost 5.6 ± 1.lkg/d (n= 35). An analysis of carcass composition of six females collected during different stages of lactation showed that they utilized 61% of their fat reserves during lactation.Efficiency of mass transfer varied from 25–3% to 70–4% (49.3 ± 10.8%, n= 35). Examination of stomach contents indicated that some ice‐breeding females consumed food during lactation.Our results in this ice‐breeding population show that females invest more in sons than in daughters.
Variability in the distribution and composition of adipose tissue in wild arctic foxes (Alopex lagopus) on Svalbard
Authors: Pond Caroline M. , Mattacks Christine A. , Prestrud P. 
Published: March 2009

Adipose tissue was dissected completely from 35 adult and subadult arctic foxes collected between November 1991 and March 1992 in four different areas of Svalbard (latitude 78°5′ to 79° 50′ N). The gross mass, lipid, protein and collagen content and mean adipocyte volume were measured in adipose tissue from six superficial, four intra‐abdominal, three intermuscular and two cardiac depots homologous to those of other terrestrial mammals. The total adipocyte complement was calculated from the mass of each depot and its site‐specific adipocyte volume. The mean fatness was 14.81 ± 1.3% and sex differences were not significant. All depots except the epicardial enlarged with increasing fatness, but the superficial depots expanded more than the internal depots. The average partitioning of adipose tissue between intra‐abdominal and superficial depots was consistent with predictions from allometric equations fitted to data from other Carnivora, but there was much unexplainable variation between individuals. The relative masses of the four intra‐abdominal depots were also variable. The mean adipocyte complement was low compared to other continually or seasonally obese arctic mammals, only slightly larger than that predicted from allometric equations relating adipocyte complement to body mass in other carnivorous mammals, but there were large differences between specimens, with some having more than four times the expected number and others only half the expected number. The size of the adipocyte complement was unrelated to age, sex or fatness. Because of such variation in number and size of adipocytes, measurements of adipocyte volume from biopsies of adipose tissue would not provide an accurate estimate of fatness.Almost all the adipose depots found in other terrestrial mammals were present. Site‐specific differences in adipocyte volume and the lipid and protein content of adipose tissue were similar to those of other wild mammals and did not change with fatness. The collagen content was highest in superficial and lowest in intra‐abdominal adipose depots. The differences of up to 60% in the collagen content of homologous depots of different foxes could not be explained by age or cytologically visible blood vessels and fascia but correlated with adipocyte complement.
Egg‐morphs and host preference in the common cuckoo (Cuculus canorus): an analysis of cuckoo and host eggs from European museum collections
Authors: Moksnes Arne , ØSkaft Eivin r. 
Published: March 2009

An examination of about 12000 clutches of European passerines that contained eggs of the common cuckoo (Cuculus canorus), held in museum egg‐collections, revealed statistically significant correlations between the cuckoo and the host eggs within a clutch in volume, ground colour, and size and percentage coverage of the spots. Although most cuckoo eggs were yellowish, the range in coloration and the percentage coverage of spots indicate that in these respects the cuckoo eggs are distributed along a continuum. However, a similar distribution was also found among the pooled host eggs. These results provide some support for the ‘host preference hypothesis’, which states that each cuckoo female specializes on one particular host species.By using a subjective classification, we found that there are at least 15 different cuckoo egg‐morphs in Europe, but only 44% of the clutches contained cuckoo eggs of the egg‐morph corresponding to the host eggs. The ‘host preference hypothesis’ therefore cannot provide a satisfactory explanation for the variation found among cuckoo eggs in Europe. However, 77% of the cuckoo eggs had been laid in nests of hosts with nesting sites similar to those of the main host of the egg‐morph. This indicates that cuckoos also parasitize several species whose nest sites are similar to those of their main host. These results therefore provide support for the ‘nest site hypothesis’ which states that each cuckoo female parasitizes a group of host species with similar eggs or nest sites. The ‘natal philopatry hypothesis’ which states that female cuckoos may search for nests completely at random in their natal habitat is only weakly supported and can probably be rejected.Most of the hosts, main and secondary, nest among low vegetation or on the ground, whereas tree‐nesting species are seldom parasitized. The most frequently used hosts in the egg collections we examined were species of the Acrocephalus and Sylvia genera of warblers, all species that breed in low vegetation.
The evolution of viviparity within the Australian scincid lizardLerista bougainvillii
Authors: Qualla Carl P. , Shine Richard , Donnellan Steve , Hutchinsonm Mark 
Published: March 2009

The semi‐fossorial scincid lizard, Lerista bougainvillii, is oviparous throughout its extensive range in south‐eastern mainland Australia. However, two widely separated (by approximately 1000 km) island populations are viviparous; in these populations the eggshell is lost and females retain their offspring in utero until embryogenesis complete. One mainland population in south‐eastern Victoria shows an intermediate condition, in which the eggshells are incomplete and uterine embryogenesis is prolonged.Morphological and electrophoretic analyses confirm a high degree of morphological and genetic similarity between populations (i.e. there is no evidence for the presence of more than one species), and phenetic analyses of these data show that each of the two disjunct viviparous populations more closely resembles adjacent oviparous populations than the other viviparous group. Hence, we infer that viviparity may have arisen twice within L. bougainvillii, in both cases on offshore islands with a cold climate.
Spatial organization in the Ethiopian wolf Canis simensis: large packs and small stable home ranges
Authors: Zubiri C. Sillero , Gottelli D. 
Published: March 2009

The spatial organization of the rare Ethiopian wolf (Canis simensis) was studied in the Afroalpine heathlands of Bale Mountains National Park, southern Ethiopia, between 1988 and 1992. Nineteen animals were radio‐tracked, 48 ear‐tagged and 64 others recognized by coat patterns and observed directly. Dry season (October—March) home ranges of resident wolves covered between 2 and 15 km2. The ranges of adult males were slightly larger than those of females, and subadults' home ranges were slightly smaller than those of adults. The population density of the wolves was correlated with prey biomass. In optimal habitat, wolves lived in packs of 3—13 adults (mean 5.9 wolves > 1year old) containing several close‐kin males; adult sex ratio favoured males 1.88: 1 and combined pack home ranges averaged 6.0km2. In an area of lower prey productivity, wolves lived in pairs or small groups (mean 2.7), adult sex ratio was 1:1 and home ranges averaged 13.4 km2.Home ranges overlapped extensively (mean 85%) between members of the same pack. Four to seven percent of the population was additionally composed of non‐resident females, inhabiting larger ranges (mean 11.1 km2). Home ranges of neighbouring packs were largely discrete, forming a tessellating mosaic of packs occupying all available habitat. Pack home ranges were stable in time, drifting only during major pack readjustment after the disappearance of a pack or significant demographic changes. Ethiopian wolf home ranges were smaller than would be expected for a carnivore of its size and sociality, presumably as a result of the high rodent productivity of the Afroalpine ecosystem.
Cephalopods in the diet of the striped dolphin Stenella coeruleoalba from the western Mediterranean during an epizootic in 1990
Authors: Blanco C. , Aznar J. , Raga J.A. 
Published: March 2009

Fifteen cephalopod species from 28 stomach contents of striped dolphins, Stenella coeruleoalba (Meyen, 1833), stranded during an epizootic on the western Mediterranean coast in summer 1990, were analysed. Albraliopsis pfefferi, Onychoteuthis banksii, Todarodes sagittatus and Brachioteuthis riisei are species showing higher relative importance indices. Composition and characteristics of cephalopod preys were discussed and compared to the scarce literature for this cetacean. The data showed a mixed diet of muscular and gelatinous body squids, mainly consisting of oceanic and pelagic or bathypelagic species.
Feeding behaviour in Cylindrophis and its bearing on the evolution of alethinophidian snakes
Authors: Cundall David 
Published: March 2009

Cylindrophis ruffus ingests prey using two distinct mechanisms. During initial phases of prey transport, lateral movements of the rear of the braincase combine with small unilateral movements of the toothed bones of each side; prey is usually constricted during this phase to permit the snake to push its head over the prey. Once transport has carried the leading part of the prey into the anterior oesophagus, Cylindrophis begins to use bilaterally synchronized movements of the jaw apparatus combined with low‐amplitude, short wave‐length flexions of the anterior vertebral column. Transport of prey is many times faster during the bilateral phase than during the unilateral phase.Radiographic and cinematographic evidence indicates that the mandibular tips of Cylindrophis do not separate more than 1.5–2.0 times the resting distance between the dentary tips. Although this limits potential gape size, the intramandibular joint is highly mobile, allowing the mandibles to conform to a variety of prey shapes. Manipulations of anaesthetized and fresh, dead specimens revealed that the palatomaxillary arches are tightly attached to the ventral bones of the snout, movements of each arch being reflected in equivalent movements of the ipsilateral elements of the snout. Cylindrophis represents a functional stage intermediate between most lizards with limited palatomaxillary kinesis and advanced snakes with considerable palatomaxillary mobility. Contrary to previous hypotheses, however, upper jaw liberation in Cylindrophis is due to liberation of the ventral snout, not to reduction of attachments to the braincase and snout. This suggests that the nose played a crucial role in the evolution of the feeding apparatus in alethinophidian snakes.
The ecology and functional morphology ofTrigonothracia jinxingae(Bivalvia: Anomalodesmata: Thracioidea) from Xiamen, China
Authors: Morton Brian 
Published: March 2009

All anomalodesmatans are ‘rare’ butTrigonothrucia jinxingaeis relatively common in Xiamen Harbour, Fujian Province, China. This is because the species has a life span of approximately one year and is a simultaneous hermaphrodite, probably with either a short or absent planktonic larval stage. That is, success results from rapid maturation, self‐fertilization, direct development and within‐habitat recruitment over an extended period in early summer.Trigonothracia jinxingaeis interesting in another way, however. The Thraciidae is the Mesozoic stem group of the Thracioidea which also contains the more modern (Caenozoic) Laternulidae and Periplomatidae. Features of the anatomy ofT. jinxingae, such as the method of hydraulically moving the foot by the pumping of blood into a capacious pallial haemocoel, and the structure of the stomach, are reminiscent of the earliest (Palaeozoic) anomalodesmat́ans, i.e. the Pholadomyoidea, represented today byPholadomya candida.The thraciidAsthenothaerussp. (Pelseneer, 1911) even has, likeP. cundida, an opisthopodium on its visceral mass.P. candida, however, fed on sub‐surface deposits using its foot.T. jinxingaeis also a deposit feeder, but on surface deposits using the inhalant siphon.Modern periplomatids resemble thraciids in their separate siphons, but both representatives of this family and the Laternulidae are suspension feeders with extensive sorting areas on the wall of the stomach to process such material. The Thraciidae thus form a link between the oldest, pedal feeding, pholadomyoidean anomalodesmatan and the most advanced, suspension feeding, laternulids and periplomatids.
The biology and functional morphology of Pteria brevialata (Bivalvia: Pterioidea), epizoic on gorgonians in Hong Kong
Authors: Morton Brian 
Published: March 2009

Pteria brevialata characteristically attaches to Hicksonella princeps (Cnidaria: Gorgonoidea) at depths > 10 m in Hong Kong and the South China Sea. Attachment is by a stout byssus to the basal regions of the gorgonian colonies. The shell appears typical of the Pteriidae, but closer inspection shows that the antero‐ventral margin, in particular, moulds itself to the form of the cylindrical gorgonian, which also changes its growth form, so that securer attachment is achieved. The margin of the right valve is not nacred so that the flexible outer prismatic layer adpresses firmly against the more extensively nacred left valve when they close; mantle and ctenidia also being withdrawn deeply. This is probably an anti‐predation device. There are no mantle fusions, even between posterior inhalant and exhalant streams. The mantle margin is, however, complexly tentaculate. Pteria brevialata is monomyarian with reduced anterior byssal retractor muscles. The anterior face of the shell is thus greatly reduced whereas the posterior is inflated and postero‐dorsally ’winged’.Other features of the anatomy are described, including the ctenidial eyespot and simple photoreceptors in the inner component of the duplicated outer mantle folds, under the periostracum. Similar structures in other pterioideans and arcoideans suggest a close relationship between their respective orders.It is concluded that gorgonian‐associated pterioids can be derived from an epibyssate, crevice‐dwelling ancestor, exploiting, as solitary individuals, the currents and clean oceanic waters above the substratum. This has three important advantages: (a) removal from surface‐roving predators (the gorgonian providing additional protection); (b) exploitation of a niche hitherto unoccupied by bivalves and (c) removal of the animal from the sea‐bed and exclusive exploitation of potential food held in suspension. Current stresses to attachment are avoided by modifications to the shell.
Differentiating neural responses to emotional pictures: Evidence from temporal‐spatial PCA
Authors: Foti Dan , Hajcak Greg , Dien Joseph 
Published: March 2009

AbstractConsistent with the notion that emotional stimuli receive preferential attention and perceptual processing, many event‐related potential (ERP) components appear sensitive to emotional stimuli. In an effort to differentiate components that are sensitive to emotional versus neutral stimuli, the current study utilized temporospatial principal components analysis to analyze ERPs from a large sample (N=82) while pleasant, neutral, and unpleasant images were passively viewed. Several factors sensitive to emotional stimuli were identified—corresponding to the N1, early posterior negativity (EPN), and P3; multiple factors resembling the late positive potential (LPP) emerged. Results indicate that the N1 represents the earliest component modulated by emotional stimuli; the EPN and the LPP represent unique components; the scalp‐recorded LPP appears to include a P3‐like positivity as well as additional positivities at occipital and central recording sites.
Measuring appetitive responding with the postauricular reflex
Authors: Sandt Arthur R. , Sloan Denise M. , Johnson Kareem J. 
Published: March 2009

AbstractRecent research has provided evidence that the postauricular reflex (PAR) is potentiated while people view pleasant images relative to unpleasant and neutral images. The present study sought to extend these findings by investigating whether the PAR is more robustly modulated by the appetitive salience of the stimuli. Eyeblink startle and PAR responses of 51 participants were recorded while they viewed images that varied in valence and thematic content. Participants displayed significantly greater mean PAR magnitude during appetitive‐related images (e.g., food, erotica, families) compared with non‐appetitive‐related pleasant images. These findings support the contention that the PAR is a useful tool for measuring appetitive responding in humans.
Distraction by color and its electrophysiological correlates
Authors: Vierck Esther , Miller Jeff 
Published: March 2009

AbstractWe used the effects of colored distractors on ERPs to assess the psychophysiological consequences of selection by color. In Experiment 1 participants searched a rapid serial visual presentation (RSVP) sequence for a prespecified target letter that usually appeared in a cued color. ERPs elicited by cued‐color distractors were similar to those elicited by targets, indicating relatively complete distractor processing. In Experiment 2 one letter in the RSVP sequence was framed by an irrelevant distractor probe in either the cued color or an uncued color. Such distractor probes elicited a P1, N1, or P2 sequence that depended on their color. In addition, probes presented shortly before the target tended to suppress the ERP components associated with target processing, especially for probes in the cued color. These observed variations in ERPs depending on the distractor's type and its distance from the target help to reveal the time course and mechanisms of selection by color.
Planning of rapid aiming movements and the contingent negative variation: Are movement duration and extent specified independently?
Authors: Leuthold Hartmut , Jentzsch Ines 
Published: March 2009

AbstractIn the present study we investigated motor programming constraints implied by the Generalized Motor Program (GMP) view. A response precuing task was used in which participants performed aiming movements of either short or long duration to either a near or a far target position. Precues provided either no advance information or partial information about extent or duration or fully specified the aiming movement. Reaction time (RT) decreased and late Contingent Negative Variation (CNV) amplitude increased with the amount of advance information. In contrast to predictions of the GMP view, the extent precue led to faster responses and larger CNV amplitude than the duration precue. We conclude that late CNV amplitude reflects independent parameter specification processes at an abstract level at which GMP's motor programming constraints do not apply.
The instructed context of a motor task modulates covert response preparation and shifts of spatial attention
Authors: Gherri Elena , Van Velzen José , Eimer Martin 
Published: March 2009

AbstractWe investigated how covert response preparation is modulated by the instructed cognitive context of a motor task. Participants prepared left‐hand or right‐hand movements toward or away from the body midline, as indicated by a response cue (S1) presented prior to a go/no‐go stimulus (S2). Different participants were instructed that response cues specified the response hand or movement direction, respectively. This emphasis on effector versus movement direction selection modulated lateralized ERP components triggered during the S1–S2 interval. Attention shifts during movement preparation were assessed by measuring ERPs to irrelevant visual probes. Enhanced N1 components were found for probes near the effector when effector selection was emphasized, but for probes near the movement target location when movement direction selection was emphasized. Results demonstrate strong top‐down contextual biases on motor control and on the locus of spatial attention during response preparation.
Distraction of task‐relevant information processing by irrelevant changes in auditory, visual, and bimodal stimulus features: A behavioral and event‐related potential study
Authors: Boll Sabrina , Berti Stefan 
Published: March 2009

AbstractDistractibility with auditory, visual, and bimodal stimulus changes was investigated using an audio‐visual distraction paradigm. Participants were asked to discriminate between equiprobable short and long audio‐visual stimuli. Infrequently, the auditory, the visual, or both parts of the stimuli changed. These rare deviations (deviants) were irrelevant for the actual task. The influence of the three types of deviant stimuli on the processing of task‐relevant information was assessed with behavioral and event‐related potential (ERP) measures assuming that bimodal deviants would lead to an increase in distraction. Behavioral and ERP results did not support this assumption, as reaction time (RT) prolongation and components amplitudes did not differ significantly for auditory and bimodal deviants. It is suggested that a maximal threshold of distraction accounts for these results. In addition, the processing of bimodal deviations was assessed. Audio‐visual interactions were found following modality‐specific deviance detection suggesting that integration only occurs with involuntary attention switching to task‐irrelevant changes.
Silencing DJ‐1 reveals its contribution in paraquat‐induced autophagy
Authors: González‐Polo Rosa A. , Niso‐Santano Mireia , Morán José M. , Ortiz‐Ortiz Miguel A. , Bravo‐San Pedro José M. , Soler Germán , Fuentes José M. 
Published: March 2009

J. Neurochem. (2009) 109, 889–898.AbstractThe role of autophagy as a survival strategy of cells constitutes an emerging topic in the study of the pathogenesis of several diseases with autophagic changes being described in a number of age‐related neurodegenerative disorders, including Parkinson’s disease (PD). Although the etiology of PD is still unknown, both environmental (for example, paraquat exposure) and genetic factors have been investigated as putative causes of the disease. In the latter case, mutations or changes in the protein DJ‐1 have been reported to be associated with autosomal recessive, early‐onset parkinsonism. In this paper we established a model system to study the involvement of the DJ‐1 protein in paraquat‐induced autophagy. When human neuroblastoma SH‐SY5Y cells were transfected with DJ‐1‐specific small interfering RNAs and exposed to paraquat, we observed (i) sensitization additive with paraquat‐induced apoptotic cell death, (ii) inhibition of the cytoplasmic accumulation of autophagic vacuoles as well as the recruitment of LC3 fusion protein to the vacuoles, (iii) exacerbation of apoptotic cell death in the presence of the autophagy inhibitor 3‐methyladenine, and (iv) an increase in mammalian target of rapamycin phosphorylation. Taken together, these findings suggest an active role for DJ‐1 in the autophagic response produced by paraquat, providing evidence for the role of PD‐related proteins in the autophagic degradation pathway, a factor that should be considered in the design of potential therapies for the treatment of the disease.