Do Zebra Finch Parents Fail to Recognise Their Own Offspring?

Individual recognition systems require the sender to be individually distinctive and the receiver to be able to perceive differences between individuals and react accordingly. Many studies have demonstrated that acoustic signals of almost any species contain individualized information. However, fewer studies have tested experimentally if those signals are used for individual recognition by potential receivers. While laboratory studies using zebra finches have shown that fledglings recognize their parents by their “distance call”, mutual recognition using the same call type has not been demonstrated yet. In a laboratory study with zebra finches, we first quantified between-individual acoustic variation in distance calls of fledglings. In a second step, we tested recognition of fledgling calls by parents using playback experiments. With a discriminant function analysis, we show that individuals are highly distinctive and most measured parameters show very high potential to encode for individuality. The response pattern of zebra finch parents shows that they do react to calls of fledglings, however they do not distinguish between own and unfamiliar offspring, despite individual distinctiveness. This finding is interesting in light of the observation of a high percentage of misdirected feedings in our communal breeding aviaries. Our results demonstrate the importance of adopting a receiver's perspective and suggest that variation in fledgling contact calls might not be used in individual recognition of offspring

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

Are acoustical parameters of begging call elements of thin-billed prions related to chick condition?

Chicks of burrowing petrels use begging calls to advertise their hunger levels when parents arrived at the nest. In a previous study, adult thin-billed prions Pachyptila belcheri responded to higher begging call rates of their single chick by regurgitating larger meals. We tested whether acoustic parameters of begging call elements may also be involved in signalling. To describe variation in begging, we determined begging session parameters, namely the duration, number of calls and the mean and maximum rate of calling. We then digitised calls and carried out a semi-automatic extraction of six acoustic parameters of call elements, including mean and maximum acoustic frequency, the length of call elements and the location of the maximum frequency and amplitude within calls. Chicks showed strong individual differences in all parameters. While the session parameters were correlated with body condition and with the meal size the chick received, none of the acoustic parameters were related to body condition and provisioning. A cross-fostering experiment showed the same pattern, as only session parameters changed related to an experimentally altered body condition, while acoustical cues appear to play no role in signalling hunger levels. We suggest that this may be explained by the absence of sibling competition in these birds. As parents do not need to decide which chick to feed, immediate information on condition at the time of adult arrival may not be required

Use of hydrophilic and hydrophobic polymers for the development of controlled release tizanidine matrix tablets

The aim of the present study was to develop tizanidine controlled release matrix. Formulations were designed using central composite method with the help of design expert version 7.0 software. Avicel pH 101 in the range of 14-50% was used as a filler, while HPMC K4M and K100M in the range of 25-55%, Ethylcellulose 10 ST and 10FP in the range of 15 - 45% and Kollidon SR in the range of 25-60% were used as controlled release agents in designing different formulations. Various physical parameters including powder flow for blends and weight variation, thickness, hardness, friability, disintegration time and in-vitro release were tested for tablets. Assay of tablets were also performed as specified in USP 35 NF 32. Physical parameters of both powder blend and compressed tablets such as compressibility index, angle of repose, weight variation, thickness, hardness, friability, disintegration time and assay were evaluated and found to be satisfactory for formulations K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 & KSR9. In vitro dissolution study was conducted in 900 ml of 0.1N HCl, phosphate buffer pH 4.5 and 6.8 medium using USP Apparatus II. In vitro release profiles indicated that formulations prepared with Ethocel 10 standard were unable to control the release of drug while formulations K4M2, K100M9, E10FP2 & KSR2 having polymer content ranging from 40-55% showed a controlled drug release pattern in the above mentioned medium. Zero-order drug release kinetics was observed for formulations K4M2, K100M9, E10FP2 & KSR2. Similarity test (f2) results for K4M2, E10FP2 & KSR2 were found to be comparable with reference formulation K100M9. Response Surface plots were also prepared for evaluating the effect of independent variable on the responses. Stability study was performed as per ICH guidelines and the calculated shelf life was 24-30 months for formulation K4M2, K100M9 and E10FP2

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

A dataset of acoustic measurements from soundscapes collected worldwide during the COVID-19 pandemic

Political responses to the COVID-19 pandemic led to changes in city soundscapes around the globe. From March to October 2020, a consortium of 261 contributors from 35 countries brought together by the Silent Cities project built a unique soundscape recordings collection to report on local acoustic changes in urban areas. We present this collection here, along with metadata including observational descriptions of the local areas from the contributors, open-source environmental data, open-source confinement levels and calculation of acoustic descriptors. We performed a technical validation of the dataset using statistical models run on a subset of manually annotated soundscapes. Results confirmed the large-scale usability of ecoacoustic indices and automatic sound event recognition in the Silent Cities soundscape collection. We expect this dataset to be useful for research in the multidisciplinary field of environmental sciences

Measuring the Impact of Social Media on Brand Trust A Case Study of Virgin Media

With scant literature on Social Media and brand trust influenced through the online environment, I have decided to conduct a research based on this theme. Although ethnography would have been a more appropriate methodology, because of certain limitations, two methods of research will be used: semi structured interviews with key employees from Virgin Media and an online survey ran through the customers of Virgin Media. The interviews have given a better understanding of the company’s culture and how they view and use Social Media. Several themes were identified through the interviews and then, with the help of the survey, i could see if the strategy Virgin Media is implementing is actually reaching the customers and having the desired result. With the help of the survey, a brand trust scale will also be developed and several items from it will be crucial in its development. The Online Marketing sector from Virgin Media is strictly connected with the Customer Service one, thus giving them a better coverage of the customer feedback and a better understanding of what impact Social Media has on them. Although some of the channels Virgin Media are using (e.g. Facebook) have been recently set up, customers seem pleased with their management and feel they can trust Virgin Media through these channels

Measuring the Impact of Social Media on Brand Trust A Case Study of Virgin Media

With scant literature on Social Media and brand trust influenced through the online environment, I have decided to conduct a research based on this theme. Although ethnography would have been a more appropriate methodology, because of certain limitations, two methods of research will be used: semi structured interviews with key employees from Virgin Media and an online survey ran through the customers of Virgin Media. The interviews have given a better understanding of the company’s culture and how they view and use Social Media. Several themes were identified through the interviews and then, with the help of the survey, i could see if the strategy Virgin Media is implementing is actually reaching the customers and having the desired result. With the help of the survey, a brand trust scale will also be developed and several items from it will be crucial in its development. The Online Marketing sector from Virgin Media is strictly connected with the Customer Service one, thus giving them a better coverage of the customer feedback and a better understanding of what impact Social Media has on them. Although some of the channels Virgin Media are using (e.g. Facebook) have been recently set up, customers seem pleased with their management and feel they can trust Virgin Media through these channels

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