Juvenile Greylag Geese (Anser anser) Discriminate between Individual Siblings

Social species that maintain individualised relationships with certain others despite continuous changes in age, reproductive status and dominance rank between group members ought to be capable of individual recognition. Tests of “true” individual recognition, where an individual recognises unique features of another, are rare, however. Often kinship and/or familiarity suffice to explain dyadic interactions. The complex relationships within a greylag goose flock suggest that they should be able to recognise individuals irrespective of familiarity or kinship. We tested whether six-week-old hand-raised greylags can discriminate between two of their siblings. We developed a new experimental protocol, in which geese were trained to associate social siblings with geometrical symbols. Subsequently, focals were presented with two geometrical symbols in the presence of a sibling associated with one of the symbols. Significant choice of the geometrical symbol associated with the target present indicated that focals were able to distinguish between individual targets. Greylag goslings successfully learned this association-discrimination task, regardless of genetic relatedness or sex of the sibling targets. Social relationships within a goose flock thus may indeed be based on recognition of unique features of individual conspecifics

High source levels and small active space of high-pitched song in bowhead whales (Balaena mysticetus)

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Public Library of Science, doi:10.1371/journal.pone.0052072.The low-frequency, powerful vocalizations of blue and fin whales may potentially be detected by conspecifics across entire ocean basins. In contrast, humpback and bowhead whales produce equally powerful, but more complex broadband vocalizations composed of higher frequencies that suffer from higher attenuation. Here we evaluate the active space of high frequency song notes of bowhead whales (Balaena mysticetus) in Western Greenland using measurements of song source levels and ambient noise. Four independent, GPS-synchronized hydrophones were deployed through holes in the ice to localize vocalizing bowhead whales, estimate source levels and measure ambient noise. The song had a mean apparent source level of 185±2 dB rms re 1 µPa @ 1 m and a high mean centroid frequency of 444±48 Hz. Using measured ambient noise levels in the area and Arctic sound spreading models, the estimated active space of these song notes is between 40 and 130 km, an order of magnitude smaller than the estimated active space of low frequency blue and fin whale songs produced at similar source levels and for similar noise conditions. We propose that bowhead whales spatially compensate for their smaller communication range through mating aggregations that co-evolved with broadband song to form a complex and dynamic acoustically mediated sexual display.This work was funded by the Oticon Foundation (grant # 08-3469 to Arctic Station, OT). OT and MC were additionally funded by AP Møller og Hustru Chastine Mc-Kinney Møllers Fond til almene Formaal, MS by a PhD scholarship from the Oticon Foundation, FHJ by a Danish Council for Independent Research, Natural Sciences post-doctoral grant, SEP by a grant from the U.S. Office of Naval Research, and PTM by frame grants from the Danish Natural Science Research Council

The importance of the altricial – precocial spectrum for social complexity in mammals and birds:A review

Various types of long-term stable relationships that individuals uphold, including cooperation and competition between group members, define social complexity in vertebrates. Numerous life history, physiological and cognitive traits have been shown to affect, or to be affected by, such social relationships. As such, differences in developmental modes, i.e. the ‘altricial-precocial’ spectrum, may play an important role in understanding the interspecific variation in occurrence of social interactions, but to what extent this is the case is unclear because the role of the developmental mode has not been studied directly in across-species studies of sociality. In other words, although there are studies on the effects of developmental mode on brain size, on the effects of brain size on cognition, and on the effects of cognition on social complexity, there are no studies directly investigating the link between developmental mode and social complexity. This is surprising because developmental differences play a significant role in the evolution of, for example, brain size, which is in turn considered an essential building block with respect to social complexity. Here, we compiled an overview of studies on various aspects of the complexity of social systems in altricial and precocial mammals and birds. Although systematic studies are scarce and do not allow for a quantitative comparison, we show that several forms of social relationships and cognitive abilities occur in species along the entire developmental spectrum. Based on the existing evidence it seems that differences in developmental modes play a minor role in whether or not individuals or species are able to meet the cognitive capabilities and requirements for maintaining complex social relationships. Given the scarcity of comparative studies and potential subtle differences, however, we suggest that future studies should consider developmental differences to determine whether our finding is general or whether some of the vast variation in social complexity across species can be explained by developmental mode. This would allow a more detailed assessment of the relative importance of developmental mode in the evolution of vertebrate social systems

Processability of Extended-release Tablets Containing Carbopol® 971P NY Polymer by Roller-compaction

Purpose To determine the processability of formulations containing Carbopol® 971P NF polymer via roller compaction and study the influence of formulation and process variables on the properties of granules and tablets. Methods Two theophylline (50% w/w) formulations containing Carbopol® 971P NF polymer (10 or 20% w/w) and one guaifenesin (25% w/w) formulation containing Carbopol® 971P NF polymer (10% w/w) were dry-granulated at varying process parameters i.e. roll speed (6-12 rpm) and roll pressure (80-100 bars). The granules were blended with lubricant and compressed into tablets (800 mg) on a rotary tablet press. The granules were evaluated for density, particle size and flow characteristics. The tablets were evaluated for weight variation, breaking force, friability and dissolution properties. Reproducibility studies were carried out to ascertain the robustness of the formulations. Results Successful tablet formulations were prepared using theophylline as a model drug, Carbopol® 971P NF polymer (10% and 20% w/w) as a release rate-controlling matrix former via roller compaction. At both polymer levels, the tablets showed acceptable weight, thickness, breaking force and friability values across the process variables tested. The release of theophylline was inversely proportional to the incorporated polymer level i.e. for formulations containing 10% w/w Carbopol® 971P NF polymer complete dissolution was observed after 16 hours while for formulations containing 20% w/w Carbopol® 971P NF polymer complete dissolution was observed after 24 hours. The roller-compaction parameters studied did not appear to have a significant influence on the dissolution performance of the tablets. Guaifenesin tablets containing 10% w/w Carbopol® 971P NF polymer showed consistent and acceptable weight, thickness, breaking force and friability across the process parameters evaluated. The drug release showed low intra-batch variability and complete dissolution was observed after 16 hours. The overall performance of the tablets was found to be reproducible at all the roller compaction process parameters evaluated. Conclusion Theophylline formulations containing Carbopol® 971P NF polymer (10 or 20% w/w) and guaifenesin formulation containing Carbopol® 971P NF polymer (10% w/w) could be successfully processed by roller-compaction for preparing extended-release matrix tablets

Processability of Extended-release Tablets Containing Carbopol® 971P NY Polymer by Roller-compaction

Purpose To determine the processability of formulations containing Carbopol® 971P NF polymer via roller compaction and study the influence of formulation and process variables on the properties of granules and tablets. Methods Two theophylline (50% w/w) formulations containing Carbopol® 971P NF polymer (10 or 20% w/w) and one guaifenesin (25% w/w) formulation containing Carbopol® 971P NF polymer (10% w/w) were dry-granulated at varying process parameters i.e. roll speed (6-12 rpm) and roll pressure (80-100 bars). The granules were blended with lubricant and compressed into tablets (800 mg) on a rotary tablet press. The granules were evaluated for density, particle size and flow characteristics. The tablets were evaluated for weight variation, breaking force, friability and dissolution properties. Reproducibility studies were carried out to ascertain the robustness of the formulations. Results Successful tablet formulations were prepared using theophylline as a model drug, Carbopol® 971P NF polymer (10% and 20% w/w) as a release rate-controlling matrix former via roller compaction. At both polymer levels, the tablets showed acceptable weight, thickness, breaking force and friability values across the process variables tested. The release of theophylline was inversely proportional to the incorporated polymer level i.e. for formulations containing 10% w/w Carbopol® 971P NF polymer complete dissolution was observed after 16 hours while for formulations containing 20% w/w Carbopol® 971P NF polymer complete dissolution was observed after 24 hours. The roller-compaction parameters studied did not appear to have a significant influence on the dissolution performance of the tablets. Guaifenesin tablets containing 10% w/w Carbopol® 971P NF polymer showed consistent and acceptable weight, thickness, breaking force and friability across the process parameters evaluated. The drug release showed low intra-batch variability and complete dissolution was observed after 16 hours. The overall performance of the tablets was found to be reproducible at all the roller compaction process parameters evaluated. Conclusion Theophylline formulations containing Carbopol® 971P NF polymer (10 or 20% w/w) and guaifenesin formulation containing Carbopol® 971P NF polymer (10% w/w) could be successfully processed by roller-compaction for preparing extended-release matrix tablets

Preparation and In-vivo Pharmacokinetic Study of a Novel Extended Release Compression Coated Tablets of Fenoterol Hydrobromide

The aim of this study was to formulate extended release compression coated core tablets of fenoterol hydrobromide, a selective β2 adrenergic receptor agonist, in an attempt to prevent nocturnal asthma. Two hydrophilic polymers viz Kollidon® SR, Polyox® WSR 303 and a hydrophobic one (Precirol® ATO5) were employed. Compression coated tablets were formulated by preparing a core tablet containing 7.5 mg drug and various amounts of polymer and Emcompress® then compressed coated with the same polymeric materials. For comparison purpose different matrix tablets were also prepared employing the same polymers. In-vitro release studies were carried out at different pH (1.2 and 6.8). Pharmacokinetics of extended release tablets as well as commercially available immediate release tablets (Berotec®) were studied after oral administration to beagle dogs using a new developed LC-MS/MS method with a lower limit of quantification of 1 ng/ml. Fenoterol release from compression coated tablets was significantly lower than matrix tablets. The mechanism of release was changed with the nature and content of polymer. The release pattern of drug from F16 containing 40 mg Kollidon® SR divided in the core tablet (15 mg) and the rest in the compressed coat (25 mg) showed a typical zero order release kinetic that could extend drug release >10 h and reasonable time for 75% to be released (t75) (8.92 h). When compared to immediate release Berotec® tablet the MRT was significantly extended from 7.03 ± 0.76 to 10.93 ± 1.25 h (P < 0.001) and HVDt 50%Cmax was also significantly extended from 2.71 ± 0.68 to 6.81 ± 0.67 h with expected prevention of nocturnal asthma

Estimating the complexity of bird song by using capture-recapture approaches from community ecology

Repertoire size, the number of unique song or syllable types in the repertoire, is a widely used measure of song complexity in birds, but it is difficult to calculate this exactly in species with large repertoires. A new method of repertoire size estimation applies species richness estimation procedures from community ecology, but such capture-recapture approaches have not been much tested. Here, we establish standardized sampling schemes and estimation procedures using capture-recapture models for syllable repertoires from 18 bird species, and suggest how these may be used to tackle problems of repertoire estimation. Different models, with different assumptions regarding the heterogeneity of the use of syllable types, performed best for different species with different song organizations. For most species, models assuming heterogeneous probability of occurrence of syllables (so-called detection probability) were selected due to the presence of both rare and frequent syllables. Capture-recapture estimates of syllable repertoire size from our small sample did not differ significantly from previous estimates using larger samples of count data. However, the enumeration of syllables in 15 songs yielded significantly lower estimates than previous reports. Hence, heterogeneity in detection probability of syllables should be addressed when estimating repertoire size. This is neglected using simple enumeration procedures, but is taken into account when repertoire size is estimated by appropriate capture-recapture models adjusted for species-specific song organization characteristics. We suggest that such approaches, in combination with standardized sampling, should be applied in species with potentially large repertoire size. On the other hand, in species with small repertoire size and homogenous syllable usage, enumerations may be satisfactory. Although researchers often use repertoire size as a measure of song complexity, listeners to songs are unlikely to count entire repertoires and they may rely on other cues, such as syllable detection probability