Behavioural responses in a congested sea: an observational study on a coastal nest-guarding fish

The deleterious effects of anthropogenic noise on animal communication are nowadays recognised, not only in urban environments but also in terrestrial habitats and along coasts and in open waters. Yet, the assessment of short- and long-term exposure consequences of anthropogenic noise in marine organisms remains challenging, especially in fish and invertebrates. Males of the Mediterranean damselfish Chromis chromis vocalise and perform visual displays (multimodal communication) to attract mates. The frequency-range of courtship vocalisations overlaps with low-frequency noise generated by maritime activities, resulting in a reduced detection distance among conspecifics. We quantified the number of courtship-related visual displays performed by males living in areas with different levels of maritime traffic. We also tried to manipulate ambient noise in the field to test male short-term response to increased noise levels. Males living in busier areas (near to a harbour) performed significantly more visual displays than those living in less congested areas. When exposed to artificially-increased ambient noise level (playback of boat noise), males did not adjust the number of visual displays accordingly. Yet, we note how assessing the actual effect of maritime traffic in marine populations in their natural environments is particularly difficult, as the effects of boat noise cannot be easily disentangled from a variety of other intrinsic or environmental factors, discussed in the paper. We thus present suggestions to obtain more robust analyses of variations of courtship behaviours in territorial fishes. We hope this will facilitate a further understanding of the potential long-term effects of anthropogenic noise, whose analyses should be prioritised in the context of environmental impact assessment, resource management and biodiversity conservation

Representation of complex vocalizations in the Lusitanian toadfish auditory system: evidence of fine temporal, frequency and amplitude discrimination

Many fishes rely on their auditory skills to interpret crucial information about predators and prey, and to communicate intraspecifically. Few studies, however, have examined how complex natural sounds are perceived in fishes. We investigated the representation of conspecific mating and agonistic calls in the auditory system of the Lusitanian toadfish Halobatrachus didactylus, and analysed auditory responses to heterospecific signals from ecologically relevant species: a sympatric vocal fish (meagre Argyrosomus regius) and a potential predator (dolphin Tursiops truncatus). Using auditory evoked potential (AEP) recordings, we showed that both sexes can resolve fine features of conspecific calls. The toadfish auditory system was most sensitive to frequencies well represented in the conspecific vocalizations (namely the mating boatwhistle), and revealed a fine representation of duration and pulsed structure of agonistic and mating calls. Stimuli and corresponding AEP amplitudes were highly correlated, indicating an accurate encoding of amplitude modulation. Moreover, Lusitanian toadfish were able to detect T. truncatus foraging sounds and A. regius calls, although at higher amplitudes. We provide strong evidence that the auditory system of a vocal fish, lacking accessory hearing structures, is capable of resolving fine features of complex vocalizations that are probably important for intraspecific communication and other relevant stimuli from the auditory scene

Progress in physical oceanography of the Baltic Sea during the 2003-2014 period

We review progress in Baltic Sea physical oceanography (including sea ice and atmosphere-land interactions) and Baltic Sea modelling, focusing on research related to BALTEX Phase II and other relevant work during the 2003-2014 period. The major advances achieved in this period are: Meteorological databases are now available to the research community, partly as station data, with a growing number of freely available gridded datasets on decadal and centennial time scales. The free availability of meteorological datasets supports the development of more accurate forcing functions for Baltic Sea models. In the last decade, oceanographic data have become much more accessible and new important measurement platforms, such as FerryBoxes and satellites, have provided better temporally and spatially resolved observations. Our understanding of how large-scale atmospheric circulation affects the Baltic Sea climate, particularly in winter, has improved. Internal variability is strong illustrating the dominant stochastic behaviour of the atmosphere. The heat and water cycles of the Baltic Sea are better understood. The importance of surface waves in air-sea interaction is better understood, and Stokes drift and Langmuir circulation have been identified as likely playing an important role in surface water mixing in sea water. We better understand sea ice dynamics and thermodynamics in the coastal zone where sea ice interaction between land and sea is crucial. The Baltic Sea's various straits and sills are of increasing interest in seeking to understand water exchange and mixing. There has been increased research into the Baltic Sea coastal zone, particularly into upwelling, in the past decade. Modelling of the Baltic Sea-North Sea system, including the development of coupled land-sea-atmosphere models, has improved. Despite marked progress in Baltic Sea research over the last decade, several gaps remain in our knowledge and understanding. The current understanding of salinity changes is limited, and future projections of salinity evolution are uncertain. In addition, modelling of the hydrological cycle in atmospheric climate models is severely biased. More detailed investigations of regional precipitation and evaporation patterns (including runoff), atmospheric variability, highly saline water inflows, exchange between sub-basins, circulation, and especially turbulent mixing are still needed. Furthermore, more highly resolved oceanographic models are necessary. In addition, models that incorporate more advanced carbon cycle and ecosystem descriptions and improved description of water-sediment interactions are needed. There is also a need for new climate projections and simulations with improved atmospheric and oceanographic coupled model systems. These and other research challenges are addressed by the recently formed Baltic Earth research programme, the successor of the BALTEX programme, which ended in 2013. Baltic Earth will treat anthropogenic changes and impacts together with their natural drivers. Baltic Earth will serve as a network for earth system sciences in the region, following in the BALTEX tradition but in a wider context. (C) 2014 The Authors. Published by Elsevier Ltd.Peer reviewe

Direct and indirect effects of interspecific competition in a highly partitioned guild of reef fishes

Competitive interactions and resource partitioning facilitate species coexistence in complex ecosystems. However, while pairwise interactions between ecologically similar species have been well studied, multi‐species competitive networks have received less attention. When interference competition between two species results in partitioning of resources, this may have indirect consequences for other species distributed along the same resource gradient. Here, we tested whether interference competition between two territorial damselfish influenced the fine‐scale species distributions of five other territorial damselfish in Kimbe Bay, Papua New Guinea. These species partition habitat across three reef zones—the flat, crest, and slope, with distinct patterns of distribution within these zones. We predicted the two species with similar distributions and microhabitat use, Pomacentrus adelus and Pomacentrus bankanensis, would display the greatest level of aggression toward one another. This was tested through an intruder experiment where stimulus fish were introduced into a resident's territory, which confirmed disproportionately high levels of interspecific aggression between these two species. We also predicted that the fine‐scale differences in the distribution of each species were maintained through multi‐species interference competition among neighboring species, with further indirect effects on species that did not directly interact. To test this, we conducted a large‐scale (22 × 10 m) experimental removal of the most abundant species, Po. adelus, and quantified the abundance and distribution of all territorial damselfish species for 6 months to a 25 cm resolution. The main direct competitor, Po. bankanensis, exhibited a marked increase in abundance and expanded its distribution (+1.33 m) to acquire the space previously occupied by Po. adelus. This competitive release triggered indirect effects on the distribution of other neighboring species further back on the reef flat, with Chrysiptera unimaculata moving into the zone formerly occupied by Po. bankanensis. This study indicates that the distinct distribution patterns among the reef crest species are linked to levels of interspecific agonistic behavior. We argue that the competitive release following the removal of a superior competitor resulted in both direct and indirect effects, with the immediate neighbor shifting into the newly available space, followed by successive shifts in species responding to the change in the distributions of their immediate neighbors

Upwelling events, coastal offshore exchange, links to biogeochemical processes - Highlights from the Baltic Sea Sciences Congress at Rostock University, Germany, 19-22 March 2007

The Baltic Sea Science Congress was held at Rostock University, Germany, from 19 to 22 March 2007. In the session entitled"Upwelling events, coastal offshore exchange, links to biogeochemical processes" 20 presentations were given,including 7 talks and 13 posters related to the theme of the session.This paper summarises new findings of the upwelling-related studies reported in the session. It deals with investigationsbased on the use of in situ and remote sensing measurements as well as numerical modelling tools. The biogeochemicalimplications of upwelling are also discussed.Our knowledge of the fine structure and dynamic considerations of upwelling has increased in recent decades with the advent ofhigh-resolution modern measurement techniques and modelling studies. The forcing and the overall structure, duration and intensity ofupwelling events are understood quite well. However, the quantification of related transports and the contribution to the overall mixingof upwelling requires further research. Furthermore, our knowledge of the links between upwelling and biogeochemical processes is stillincomplete. Numerical modelling has advanced to the extent that horizontal resolutions of c. 0.5 nautical miles can now be applied,which allows the complete spectrum of meso-scale features to be described. Even the development of filaments can be describedrealistically in comparison with high-resolution satellite data.But the effect of upwelling at a basin scale and possible changes under changing climatic conditions remain open questions

On a hyperconvex manifold without non-constant bounded holomorphic functions

An example is given of a hyperconvex manifold without non-constant bounded holomorphic functions, which is realized as a domain with real-analytic Levi-flat boundary in a projective surface.Comment: 10 pages, final version, to appear in "Geometric Complex Analysis", Springer Proceedings in Mathematics & Statistic

Acute central nervous system toxicity during treatment of pediatric acute lymphoblastic leukemia : phenotypes, risk factors and genotypes

Publisher Copyright: © 2022 Ferrata Storti Foundation Published under a CC BY-NC license.Central nervous system (CNS) toxicity is common at diagnosis and during treatment of pediatric acute lymphoblastic leukemia (ALL). We studied CNS toxicity in 1, 464 children aged 1.0-17.9 years, diagnosed with ALL and treated according to the Nordic Society of Pediatric Hematology and Oncology ALL2008 protocol. Genome-wide association studies, and a candidate single-nucleotide polymorphism (SNP; n=19) study were performed in 1, 166 patients. Findings were validated in an independent Australian cohort of children with ALL (n=797) in whom two phenotypes were evaluated: diverse CNS toxicities (n=103) and methotrexate-related CNS toxicity (n=48). In total, 135/1, 464 (9.2%) patients experienced CNS toxicity for a cumulative incidence of 8.7% (95% confidence interval: 7.31-10.20) at 12 months from diagnosis. Patients aged ≥10 years had a higher risk of CNS toxicity than had younger patients (16.3% vs. 7.4%; P<0.001). The most common CNS toxicities were posterior reversible encephalopathy syndrome (n=52, 43 with seizures), sinus venous thrombosis (n=28, 9 with seizures), and isolated seizures (n=16). The most significant SNP identified by the genome-wide association studies did not reach genomic significance (lowest P-value: 1.11x10-6), but several were annotated in genes regulating neuronal functions. In candidate SNP analysis, ATXN1 rs68082256, related to epilepsy, was associated with seizures in patients <10 years (P=0.01). ATXN1 rs68082256 was validated in the Australian cohort with diverse CNS toxicities (P=0.04). The role of ATXN1 as well as the novel SNP in neurotoxicity in pediatric ALL should be further explored.Peer reviewe

Auditory temporal resolution of a wild white-beaked dolphin (Lagenorhynchus albirostris)

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology 195 (2009): 375-384, doi:10.1007/s00359-009-0415-x.Adequate temporal resolution is required across taxa to properly utilize amplitude modulated acoustic signals. Among mammals, odontocete marine mammals are considered to have relatively high temporal resolution, which is a selective advantage when processing fast traveling underwater sound. However, multiple methods used to estimate auditory temporal resolution have left comparisons among odontocetes and other mammals somewhat vague. Here we present the estimated auditory temporal resolution of an adult male white-beaked dolphin, (Lagenorhynchus albirostris), using auditory evoked potentials and click stimuli. Ours is the first of such studies performed on a wild dolphin in a capture-and-release scenario. The white-beaked dolphin followed rhythmic clicks up to a rate of approximately 1125-1250 Hz, after which the modulation rate transfer function (MRTF) cut-off steeply. However, 10% of the maximum response was still found at 1450 Hz indicating high temporal resolution. The MRTF was similar in shape and bandwidth to that of other odontocetes. The estimated maximal temporal resolution of white-beaked dolphins and other odontocetes was approximately twice that of pinnipeds and manatees, and more than ten-times faster than humans and gerbils. The exceptionally high temporal resolution abilities of odontocetes are likely due primarily to echolocation capabilities that require rapid processing of acoustic cues.We wish to thank the Danish Natural Science Research Council for major financial support (grant no. 272-05-0395)