21 research outputs found

    The marine soundscape off Elephant Island: A Southern Ocean coastal habitat

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    Here we present a comprehensive description of the acoustic environment approximately 31 km west-northwest of Minstrel Point, Elephant Island, Antarctica at 210 m water depth based on three years (Jan 2013 – Feb 2016) of subsampled (5 min per hour) passive acoustic recordings. Long-term spectrograms reveal a notable recurrence of acoustic environments between years. Fin and Antarctic blue whale calls dominate the low (< 100 Hz) part of the biophonic spectrum energetically from end of January to late July/early August. November through early January are dominated by leopard seal vocalizations at around 300 Hz. Concurrently, the geophonic spectrum exhibits strong fluctuations between days, both due to storm and tidal influences, causing flow and shackle noise from the instrumentation itself. Manual analysis of every second day of the subsampled data by visual and aural screening (employing short term spectrograms) was used to examine the data in greater detail for additional acoustic contributions and to assign the various acoustic signatures to their sources. Six cetacean and two pinniped species were identified based on their acoustic signatures and analysed for seasonal and diel patterns in occurrence. Anthrophonic signatures were attributed to air guns on 3 % of the analysed days. Vessel noise was noted between 10 and 12% of days on annual averages, occurring mainly in austral summer and fall with sporadic events throughout the remainder of the year

    Fin whale (Balaenoptera physalus) acoustic presence off Elephant Island, Antarctica

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    Recent visual observations suggest that the region around Elephant Island serves as an important feeding area for fin whales. Passive acoustic recordings collected northwest of Elephant Island (61°0.88’S, 55°58.53’W) from January 2013 to February 2016 were analysed manually for seasonal and diel patterns of fin whale 20 Hz calls. Overall, calls were detected year-round, although in some years calls were not present during all months. For all years, fin whale calls were consistently present from February to July for more than 90% of days per month. From August to January, percentage of days with calls varied between years, with presence exceeding 75% of days per month throughout 2014, whereas in 2015 calls were absent in October and November. In 2013, fin whale calling dropped in August and increased again towards November (present 80% of days per month). Diel patterns in call activity were analysed for a 10-month subset of the data from 2013. Fluctuations in call rates did not follow a diel pattern nor correspond to local insolation. During peak calling period, maximum calls amounted approximately to 80 per 10-minute file. Fluctuations in call presence outside the peak calling period may be explained by variation in local ice conditions as drift may temporally force the animals away to areas with reduced ice concentrations. Furthermore, delays in the timing of migration between age groups, sexes and/or reproductive classes may also affect temporal patterns in the clustering of calls. The observed peaks in fin whale call activity correspond to the periods during which fin whale super groups have been repeatedly observed visually in this region. Our year-round acoustic analysis indicates that the Elephant Island region is likely to play an important role for fin whales throughout the remainder of the year

    Fin whale (Balaenoptera physalus) acoustic presence off Elephant Island (South Shetland Islands), Antarctica

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    Summertime visual observations suggest that the region around Elephant Island may serve as an important feeding area for fin whales. To explore its year-round relevance, passive acoustic recordings collected northwest of Elephant Island (61°0.88’S, 55°58.53’W) from January 2013 to February 2016 were analysed for seasonal and diel patterns of fin whale 20 Hz calls. Calls were detected year-round, although in some years calls were not present during all months. For all years, fin whale calls were consistently present from March to July for more than 90% of days per month. From August to January, percentage of days with calls varied between years, with presence exceeding 75% of days per month throughout 2014, whereas in 2015 calls were absent in October and November. In 2013, fin whale calling dropped in August and increased again towards October and November. Quantitative analyses of power spectral density for the 20-Hz and 89-Hz fin whale bands, showed that fin whale acoustic power in both frequency bands followed a Gaussian-like temporal pattern, increasing in late January, peaking during April-May and decreasing in late August for all years. A second shoulder peak in PSD seemed to occur during the second part of July showing strongest for the upper fin whale band, followed by a rapid decrease, after which SNR for both bands dropped to zero. Diel patterns in call activity were analysed for a 10-month subset of the data from 2013. Fluctuations in call rates did not follow a diel pattern nor correspond to local insolation. The observed peaks in fin whale call activity correspond to the periods during which fin whale super groups have been observed visually in this region. Our year-round acoustic analysis indicates that the Elephant Island region likely carries an important role for fin whales throughout the entire year

    How often do general practitioners use placebos and non-specific interventions? Systematic review and meta-analysis of surveys

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    Background In a systematic review and meta-analysis we summarize the available evidence on how frequently general practitioners/family physicians (GPs) use pure placebos (e.g., placebo pills) and non-specific therapies (sometimes referred to as impure placebos;e.g., antibiotics for common cold). Methods We searched Medline, PubMed and SCOPUS up to July 2018 to identify cross-sectional quantitative surveys among GPs. Outcomes of primary interest were the percentages of GPs having used any placebo, pure placebos or non-specific therapies at least once in their career, at least once in the last year, at least monthly or at least weekly. Outcomes were described as proportions and pooled with random-effects meta-analysis. Results Of 674 publications, 16 studies from 13 countries with a total of 2.981 participating GPs (range 27 to 783) met the inclusion criteria. The percentage of GPs having used any form of placebo at least once in their career ranged from 29% to 97%, in the last year at least once from 46% to 95%, at least monthly from 15% to 89%, and at least weekly from 1% to 75%. The use of non-specific therapies by far outnumbered the use of pure placebo. For example, the proportion of GPs using pure placebos at least monthly varied between 2% and 15% compared to 53% and 89% for non-specific therapies;use at least weekly varied between 1% and 3% for pure placebos and between 16% and 75% for non-specific therapies. Besides eliciting placebos effects, many other reasons related to patient expectations, demands and medical problems were reported as reasons for applying placebo interventions. Conclusion High prevalence estimates of placebo use among GPs are mainly driven by the frequent use of non-specific therapies;pure placebos are used rarely. The interpretation of our quantitative findings is complicated by the diversity of definitions and survey methods

    Continuation and maintenance treatments for persistent depressive disorder

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    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of pharmacological and psychological continuation and maintenance treatments for persistent depressive disorder, in comparison with each other; placebo (drug/attention placebo/non‐specific treatment control); and treatment as usual (TAU). In addition, to assess the effects of combined psychological and pharmacological continuation and maintenance treatments, in comparison with either of these treatments alone

    Passive acoustic monitoring data recorded by recorder SV1009 at mooring AWI208-08 in the Weddell Sea, Southern Ocean, in 2017/2018

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    Passive acoustic monitoring (PAM) data were collected by recorder SV1009 of type Sono.Vault (manufactured by develogic GmbH, Hamburg, Germany) at 65°41.79' S, 36°41.012' W, mooring AWI208-08, in Weddell Sea, Atlantic sector of the Southern Ocean. During a deployment period from January 2017 to January 2019, passive acoustic data were collected from January 2017 to May 2018 (recording period) by SV1009 as part of the Hybrid Antarctic Float Observing System (HAFOS) in the Weddell Sea. The recorder was moored at 1032 m depth and scheduled to record continuously at a sample rate of 6,857 Hz. Further details about the data acquisition and processing of this data set can be found in the accompanying metadata file (see Additional metadata) as well as the data processing report (see Data Processing Report). Passive acoustic data archived here represent data processing Level 1+, according to the standards defined in the associated Standard Operation Procedure (SOP) Glossary (Thomisch et al. 2023a). Further information on data processing with regard to data preparation and standardization can be found in the associated SOP Part 1: Data preparation and standardization (Thomisch et al. 2023b)

    Comparative Safety of Pharmacologic Treatments for Persistent Depressive Disorder: A Systematic Review and Network Meta-Analysis.

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    We aimed to compare the safety of antidepressants for the treatment of persistent depressive disorder (PDD) with each other and with placebo. We conducted a systematic electronic search and included randomized controlled trials that investigated antidepressants for the treatment of PDD in adults. Outcomes were the incidence of experiencing any adverse event, specific adverse events and related treatment discontinuations. We analyzed the data using traditional and network meta-analyses. Thirty-four studies that comprised 4,769 patients and examined 20 individual agents in nine substance classes were included. Almost all analyzed substance classes were associated with higher discontinuation rates than placebo including tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAOIs), antipsychotics, and the serotonin antagonist and reuptake inhibitor (SARI) trazodone. The odds of experiencing any adverse event were significantly higher for TCAs and serotonin noradrenaline reuptake inhibitors (SNRIs) compared to placebo. Pairwise comparisons among the substance classes revealed that more patients receiving TCAs or SNRIs experienced any adverse event and that more patients receiving TCAs or the SARI trazodone discontinued treatment. The complementary treatment with acetyl-l-carnitine showed lower rates of experiencing any adverse event and related discontinuations than all other comparators. TCAs were primarily associated with (anti-)cholinergic and sedating adverse events. SSRIs primarily showed gastrointestinal adverse events. Patients treated with the antipsychotic amisulpride were more likely to manifest weight gain and endocrine adverse events. The comparative evidence for further agents was insufficient or lacking. The identified safety differences may be used to inform the selection among the antidepressants

    Seasonal and diel cycles of fin whale acoustic occurrence near Elephant Island, Antarctica

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    This study investigates the relevance of the Elephant Island (EI) region for Southern Hemisphere fin whales (Balaenoptera physalus) in their annual life cycle. We collected 3 years of passive acoustic recordings (January 2013 to February 2016) northwest of EI to calculate time series of fin whale acoustic indices, daily acoustic occurrence, spectrograms, as well as the abundance of their 20-Hz pulses. Acoustic backscatter strength, sea ice concentration and chlorophyll-a composites provided concurrent environmental information for graphic comparisons. Acoustic interannual, seasonal and diel patterns together with visual information and literature resources were used to define the period of occupancy and to infer potential drivers for their behaviour. Spectral results suggest that these fin whales migrate annually to and from offshore central Chile. Acoustic data and visual information reveal their arrival at EI in December to feed without producing their typical 20-Hz pulse. For all 3 years, acoustic activity commences in February, peaks in May and decreases in August, in phase with the onset of their breeding season. Our results emphasize the importance of EI for fin whales throughout most of the year. Our recommendation is to consider EI for establishing a marine protected area to expedite the recovery of this vulnerable species
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