bluuebunny/crossref_metadata_2025_split huggingface dataset:
High ultrasonic and tremulation signals in neotropical katydids (Orthoptera: Tettigoniidae)
Authors: Morris G. K. , Mason A. C. , Wall P. , Belwood J. J. 
Published: May 2009

Myopophyllum speciosum is a pseudophylline katydid (Tettigoniidae) from the neotropics that generates unusually high ultrasonic frequencies as the dominant carrier in its calling song. Male calls average only 148 ms duration and are given at long intervals: 8.7 s. Pairing is completed with vibrational signals, generated at closer range by body oscillation (tremulation). Two distinctive vibrational motor patterns, short and long, are produced by both sexes. Physical parameters of the sound and vibratory signals of this species are described. The relatively high‐Q carrier frequency (mean = 81 kHz) varies between males over a range of 20 kHz but does not predict a singer's body size. Short tremulations are much more intense than long as measured by acceleration. Descriptions of the songs of three other pseudophylline species with unusually high principal carriers (65–105 kHz) are also presented.Eavesdropping by predatory bats offers the most plausible selective explanation for the features of M. speciosum's signal system. This hypothesis is supported by the species' sexually dimorphic defensive spination: males, the sound‐signalling sex, have metafemoral spines of greater size and distinctive orientation. Evidence for eavesdropping and for alternative hypotheses is assessed. Other neotropical tettigoniids in rainforest understorey also employ elaborate vibratory signals (species of Choeroparnops, Schedocentrus, Docidocercus, Copiphora) and some show a trend to reduce or even to eliminate their use of airborne sound. Some rainforest tettigoniids may have replaced acoustic with vibrational signalling as a response to bat eavesdropping.
Photoperiod control of birth timing in the harbour seal (Phoca vitulina)
Authors: Temte Jonathan L. 
Published: May 2009

The harbour seal (Phoca vitulina) has delayed implantation, precise annual birth timing, and significant latitudinal variation in birth timing. The birth timing patterns of four distinct groups of seals, including colonies ofP. v. vitulinaand colonies and captive individuals of P.v. richardsi, were examined using population‐based photoperiod analysis to assess the role of photoperiod in setting annual birth timing. This analysis simultaneously determined the time, relative to birth, at which photoperiod response was likely to occur and the critical photoperiod.Despite marked differences in birth timing patterns, a high level of agreement was found among groups for the timing of photoperiod response. The two subspecies, however, demonstrated significantly divergent critical photoperiods. Eastern Atlantic harbour seals were exposed to a common critical photoperiod of 11.7 h/day on the 268th pre‐partum day. Wild Pacific harbour seals were exposed to 14.3 h/day on the 283rd pre‐partum day. These times corresponded to the estimated occurrence of blastocyst implantation.Using the above information, three small captive populations were subjected to artificially prolonged photoperiods during the period of embryonic diapause to test whether subsequent birth timing could be delayed. Technical difficulties invalidated results at two sites. At the third and largest colony, the mean pupping date of six individuals was significantly delayed by 10.7days.The precision and latitudinal variation of annual birth timing in the harbour seal are due to a response to photoperiod which occurs immediately prior to blastocyst implantation. The critical photoperiod, however, is divergent among subspecies and, thus, has probably evolved allowing seasonal adaptation. Similar environmental signalling has been described for California sea lions and northern fur seals and represents the likely timing mechanism for most pinniped species.
Dental morphology and diet in anuran amphibians from south India
Authors: Das I. , Coe M. 
Published: May 2009

The morphology of the jaw and palatine surfaces of eight species of metamorphosed anuran amphibians (Microhyla ornata, M. rubra, Uperodon systoma, Tomopterna rolandae, Polypedates maculatus, Rana cyanophlycris, R. crassaandR. hexadactyla) from a locality in south India, were examined by scanning electron microscopy. A relationship was observed between dentition (or its absence) and diet. In large prey feeders, there is a strong tendency towards the development of large secondary (or even tertiary) cusps, while myrmecophagous and termitophagous species lack teeth.In the largely folivorous adults ofRana hexadactyla, secondary cusps are reduced to faint ridges and the tooth is cylindro‐conical (as opposed to the recurved teeth with apices oriented lingually or distally in the insectivorous species). Although the phylogenetic relationships within members of the community are largely unknown, the oral armature is reflective of diet, and may represent adaptive suites.
Taxonomy and natural history of the Australian bandy‐bandy snakes (Elapidae: Vermicella) with a description of two new species
Authors: Keogh J. Sott , Smith Sarah A. 
Published: May 2009

The Australian elapid snake genus Vermicella has traditionally included three taxa: annulata, multifasciata, and snelli. These animals have a history of unstable taxonomy and nomenclature, with rearrangements based mainly on subjective evaluations by different authorities rather than on acquisition of new data. We have quantified characters of external morphology to examine patterns of phenotypic variation in 425 museum specimens of Vermicella. Our aims were to understand better the nature of morphological variation in the genus, and the taxonomic implications of this variation, using univariate and multivariate statistical techniques. Based on our results, we recognize each of the three currently described taxa as separate species, and describe two additional species. Vermicella multifasciata is restricted to those specimens from the Darwin area that display exceptionally high numbers of, and very thin, body bands, and is sympatric with a new species described in this paper. Vermicella snelli is restricted to northern Western Australia and a second species from the Alice Springs area of the Northern Territory that displays fewer body bands is described.Males have fewer ventral scales and more subcaudal scales than females in the four species, with sample sizes large enough for meaningful statistical analyses, and V. annulata females have more body and tail bands than conspecific males. In conjunction with the taxonomic study, we also examined reproductive biology and diet of Vermicella. Females reach larger adult body sizes than males in V. annulata, V. intermedia, and probably the other species as well. Gut contents of four species suggest that they feed solely on blind snakes of the genus Ramphotyphlops. Clutch sizes for the smaller species of Vermicella are low, ranging from one to four, while published data for the larger V. annulata shows clutch size to vary from two to 13. Based on published work, it appears that the affinities of Vermicella may lie with Simoselaps in Australia and/or some Melanesian elapids.
The biology and functional morphology of Minnivola pyxidatus (Bivalvia: Pectinoidea)
Authors: Morton Brian 
Published: May 2009

The shallow subtidal scallopMinnivola pyxidutusoccurs in the relatively clean oceanic, southern, and south‐eastern waters of Hong Kong and elsewhere in the Western Pacific and is highly polymorphic in terms of shell patterning of the left, upper valve. Locally, because of sea‐bed perturbations, numbers are declining. The species can probably live for ∼ 3 years, with reproduction occurring in winter.M. pyxidatusis monoecious.Shell form and anatomy are described. Normally, the species lives attached by a fragile byssus to sand grains or stones, but can swim, albeit weakly, in response to predation risks.In most respects,Minnivola pyxidatusis a typical scallop, with a bowl‐shaped, right lower valve and a concave, disc‐like, left upper valve. The mantle has pallial eyes and a complex array of tentacles which possess small, ciliary‐based sensory cells. There is also a cleansing tract on the outer surface of the middle mantle fold and a muscular velum formed from the inner fold. The latter is developed into a simple exhalant aperture posteriorly. Both mantle lobes possess extensive posterior pallial glands and an abdominal sense organ on the right lobe only, anterior to the single posterior adductor muscle. Ciliary currents of the mantle cavity are for cleansing and are powerful, particularly on the visceral mass and right mantle lobe but not the left.The ctenidia and their ciliary currents are typical of the Pectinidae except that the ascending lamellae of all demibranchs are greatly reduced and, it is suggested, previse the situation seen in the Propeamussiidae where they are lost and the ventral margins of the inner and outer descending lamellae fuse to create an ‘inside out’ gill. Unusually, the labial palps ofMinnivola pyxidatusare fused to the mantle and visceral mass, preventing their collapse in the mantle cavity and thus maintaining particle selection efficiency. The gut is simple. Left and right statocysts are unusually equal and the pericardium is located dorsal to the adductor muscle.Minnivola pyxidatusis adapted to an epibenthic life on subtidal sands and muds. Powerful cleansing currents and an ability to swim have allowed this species to survive in dredged and trawled waters with high levels of settling and resuspended silt.
Duration of the oestrous cycle and changes in plasma hormone concentrations measured after an induced ovulation in scimitar‐horned oryx (Oryx dammah)
Authors: Bowen J. M. , Barrell G. K. 
Published: May 2009

To determine the duration and hormonal characteristics of the oestrous cycle in scimitar‐horned oryx, ovulation was synchronized in 11 females using exogenous progesterone and a prostaglandin analogue. Daily blood samples were taken from six animals during 46 days (with a 7‐day hiatus). The remaining five animals were blood sampled every 30 min for 6 h on three occassions druing 22 days, then resynchronized with prostaglandin analogue and pregnant mare's serum gonadotrophin and blood sampled daily for another 21 days (with a 7‐day hiatus). Behavioural observations were made on days 1 through 3 and 24 through 28 to determine the occurrence of oestrus.Only animals > 2 years old (n= 7) had plasma progesterone concentrations indicative of luteal function, with a mean luteal phase progesterone concentration of 13.6 ± 3.3 (S.E.) nmol.l−1 and a mean follicular phase concentration of < 3.2 nmol.l−1. Mean duration of the oestrous cycle estimated from plasma progesterone profiles and behavioural data 22.7 ± 1.1 (S.E.; n= 7) days, range 17‐25 days. When estimated from behavioural data alone, mean duration of the oestrous cycle was 22.3 ± 0.3 (S.E.; n= 3) days, range 22‐23 days. Mean length of the luteal phase was 17.3 ± 0.6 (S.E.; n= 8) days, range 14‐19 days, and mean length of the follucular phase was 5.6 ± 0.5 (S.E.; n= 5) days, range 3‐7 days. Pulses in plasma LH concentration detected by Cluster analysis ranged from 0.34‐1.55ng.ml−1 in animals ≷ 2 years old (n= 3), and from 0.17‐0.29ng.ml−1 in animals < 2 years old (n= 2), the difference in mean pulse height being significant (P < 0.01). No difference in mean plasma LH concentration was detected due to stage of cycle. Elevations in plasma oestradiol‐17β concentration were observed at or preceding oestrus in three animals and during the mid‐luteal phase in three animals.A significant decrease in haematocrit with time was recorded for blood samples from the third serial bleed. This was greater (P > 0.01) in animals > 2 years of age (n= 3), suggesting that these older animals adapted better to the stress of repeated sampling. Plasma cortisol concentrations also declined throughout the serial bleed but there was no difference in this decline between the two age groups.Results of this study define the duration of the oestrous cycle in scimitar‐horned oryx and show that its hormonal components are similar to the well‐characterized patterns of other species, especially cattle.
Ultrastructural study of the myocardium of the sinus venosus and sinoatrial valve in the dogfish (Scyliorhinus canicula)
Authors: Ramos C. , Mungoz‐Chaapuli R. , Navarro P. 
Published: May 2009

The myocardium of the sinus venosus of the dogfish (Scyliorhinus canicula) is located between a thick subepicardial collagen‐rich layer and a subendocardial network of nerve fibres and ganglion cells. The sinoatrial valve consists of two transversal folds of the cardiac wall which are separated by connective tissue, except in their free margins.The myocardium of the sinus venosus and the sinusal face of the sinoatrial valve is arranged in bundles which are surrounded by a 40 nm‐thick basal lamina. The myocardial cells measure about 7‐9 μm in diameter at the nuclear level. Nerve terminals are frequent in the centre of the bundles. Most of the sinusal myocardiocytes have a scarce amount of myofibrils which are randomly orientated. The sarcoplasmic reticulum is relatively well developed and consists of peripheral couplings, subsarcolemmal vesicles, circular and longitudinal tubules. The scarce intercalated discs show only fasciae adhaerentes. Gap junctions, desmosomes or specific granules are not observed in the sinusal myocardiocytes of the dogfish. In contrast, the atrial myocardiocytes are smaller, about 5‐6 μm in diameter at the nuclear level. The cytoplasm is denser and the myofibrils are abundant and orientated in parallel directions. Specific granules are present. although scarce. Subsarcolemmal vesicles are less frequent, while the atrial intercalated discs are larger and more abundant than those of the sinus venosus. Neural elements are scarce in the atrium.The differences observed between sinus venosus and atrium might be related to the morphological criteria to distinguish between the nodal tissue and the working myocardiocytes of higher vertebrates. On the other hand, we think that the connective tissue placed between sinus venom and atrium means that the contraction impulse generated in the sinus venosus must reach the atrium through the free margin of the valve. It might play a role in the sinoatrial valve function.
Folivory and seasonal changes in diet in Rana hexadactyla (Anura: Ranidae)
Authors: Das I. 
Published: May 2009

The autecology of Rana hexadactyla (Lesson) was studied at a seasonal locality in south India. The herbivorous larva transforms into an insectivorous frog, and a second dietary switch from insectivory to folivory occurs in adults, with plants constituting 79.5% of the diet, by volume. A variety of invertebrates and small vertebrates is consumed, especially by the adult females before the reproductive season. Larger frogs take larger animal prey and more prey types. Monthly figures of prey diversity generally show high values during the wet months.In Rana hexadactyla, the utilization of permanent waterbodies may help buffer the impact of the long dry seasons and, together with a supply of abundant food in the form of aquatic macrophytes, is thought to be linked to the capacity of the species to spawn three times a year.
Patterns of intestinal parasitism in the mountain gorillaGorilla gorillain the Bwindi‐Impenetrable Forest, Uganda
Authors: Ashford R. W. , Lawson H. , Butynski T. M. , Reid G. D. F. 
Published: May 2009

The intestinal parasite fauna of the mountain gorillas of Bwindi—Impenetrable Forest, Uganda was studied by means of faecal examination and a single post‐mortem. The fauna was remarkably uniform between social groups and individuals, showing only slight differences between age groups; there is no evidence of any interaction between the parasites observed. The only protozoa were entodiniomorph ciliates; amoebae and flagellates were absent. Helminths included a single host‐specific cestode species and at least five nematodes, three of which are hostspecific. The closest relatives of the host‐specific parasites are found in ungulates and paenungulates, not in hosts phylogenetically related to the gorilla.This unique and specialized parasite fauna deserves to be monitored so that any effects of the habituation of the gorillas for tourism can be assessed.
Spacing patterns within populations of a tropical forest rodent, Proechimys semispinosus, on five Panamanian islands
Authors: Adler G. H. , Endries M. , Piotter S. 
Published: May 2009

Spacing patterns of adult Proechimys semispinosus (Central American spiny rat) within five island populations in central Panamá were determined by live‐trapping over a one‐year period. Home ranges were described by minimum convex polygons for each individual that had a sufficient number of captures to allow accurate description. Home‐range size was calculated as the area of an individual's polygon. The total area of overlap of each individual's home range with every other consexual's home range was also calculated. Mean home‐range size and overlap were compared among islands and between sexes with two‐way analysis of variance and were related to mean density of adult males and females and island size with linear regression analysis. Home‐range size and overlap were also compared while controlling for density using analysis of covariance.Home‐range size varied between the sexes but not among islands, with males generally having larger home ranges than females. Home‐range size showed a negative relationship to density, and the difference in home‐range size between the sexes prevailed even after controlling for density. Home‐range overlap varied among islands but not between the sexes. There was no linear relationship between overlap and density, although individuals within two low‐density populations had nearly exclusive home ranges. The high degree of overlap among home ranges within some populations suggests that P. semispinosus do not maintain large exclusive territories. Such territories may be economically indefensible because of the spatial and temporal distribution of resources (i.e. primarily falling fruit). Although theory predicts that spatially patchy and poorly renewable resources promote territoriality, resources in tropical forests of the study area may be randomly or too patchily distributed or ephemeral to permit maintenance of territories that span a large portion of an animal's home range. More detailed study is necessary to reveal finer‐scale patterns of territoriality (e.g. defence of burrows or concentrations of fallen fruit).
Spatial ecology of the European wildcat in a Mediterranean ecosystem: dealing with small radio‐tracking datasets in species conservation
Authors: Monterroso P. , Brito J. C. , Ferreras P. , Alves P. C. 
Published: May 2009

AbstractDespite some populations of European wildcat Felis silvestris in central Europe are stable or increasing, the Iberian subpopulation is in decline and is listed as ‘vulnerable’. In Portugal, little is known about wildcat populations, making conservation policies extremely difficult to define. Furthermore, the secretive behaviour of these mammals, along with low population densities, make data collection complicated. Thus, it is crucial to develop efficient analytical tools to interpret existing data for this species. In this study, we determine the home‐range size and environmental factors related to wildcat spatial ecology in a Mediterranean ecosystem using a combined analysis of habitat selection and maximum entropy (Maxent) modelling. Simultaneously, we test the feasibility of using radio‐tracking locations to construct an ecologically meaningful distribution model. Six wildcats were captured and tracked. The average home‐range size (MCP95) was 2.28 km2 for females and 13.71 km2 for one male. The Maxent model built from radio‐tracking locations indicated that the abundance of the European rabbit Oryctolagus cuniculus and limited human disturbance were the most important correlates of wildcat presence. Habitat selection analysis revealed that wildcats tend to use scrubland areas significantly more than expected by chance. A mosaic of scrublands and agricultural areas, with a higher proportion of the former, benefits wildcat presence in the study area; however, species distribution is mainly constrained by availability of prey and resting sites. The Maxent model validation with camera‐trapping data indicated that highly adequate model performance. This technique may prove useful for recovering small radio‐tracking datasets as it provides a new alternative for handling data and maximizing the ecological information on a target population, which can then be used for conservation planning.
The Parkinson disease‐associated A30P mutation stabilizes α‐synuclein against proteasomal degradation triggered by heme oxygenase‐1 over‐expression in human neuroblastoma cells
Authors: Song Wei , Patel Amar , Qureshi Hamid Y. , Han Dong , Schipper Hyman M. , Paudel Hemant K. 
Published: May 2009

AbstractProteosomal degradation of proteins is one of the major mechanisms of intracellular protein turnover. Failure of the proteosome to degrade misfolded protein is implicated in the accumulation of α‐synuclein in Parkinson’s disease (PD). Heme oxygenase‐1 (HO‐1), an enzyme that converts heme to free iron, carbon monoxide (CO) and biliverdin (bilirubin precursor) is expressed in response to various stressors. HO‐1 is up‐regulated in PD‐ and Alzheimer’s disease‐affected neural tissues. In this study, we found that HO‐1 over‐expression engenders dose‐dependent decreases in α‐synuclein protein levels in human neuroblastoma M17 cells. When over‐expression of HO‐1 was silenced in HO‐1 transfected cells, level of α‐synuclein was restored. Likewise, treatment of HO‐1 over‐expressing cells with the HO‐1 inhibitor, tin mesoporphyrin, the iron chelator deferoxamine or antagonist of CO‐dependent cGMP activation, methylene blue, mitigated the HO‐1‐induced reduction in α‐synuclein levels. Furthermore, when HO‐1 over‐expressing cells were treated with the proteosome inhibitors, lactacystin and MG132, level of α‐synuclein was almost completely restored. In contrast to the effect on α‐synuclein [wild‐type (WT)] levels, HO‐1 over‐expression did not significantly impact PD‐associated α‐synuclein (A30P) levels in these cells. HO‐1 also significantly reduced aggregation of α‐synuclein (WT) but not that of A30P. Our results suggest that HO‐1, which is expressed when neurons are exposed to toxic stimuli capable of inducing protein misfolding, triggers proteosomal degradation of proteins and prevents intracellular accumulation of protein aggregates and inclusions. Resistance to HO‐1 induced proteosomal degradation may render the familial PD‐associated A30P mutation prone to toxic intracellular aggregation.