Orca

Carbon is one of the most important chemical elements, forming a wide range of important allotropes, ranging from diamond over graphite to nanostructural materials such as graphene, fullerenes, and carbon nanotubes (CNTs). Especially these nanomaterials play an important role in technology and are commonly formed in laborious synthetic processes that often are of high energy demand. Recently, fullerenes and their building blocks (buckybowls) have been found in natural fossil materials formed under geological conditions...

The Northern California Current is a highly productive marine upwelling ecosystem that is economically and ecologically important. It is home to both commercially harvested species and those that are federally listed under the U.S. Endangered Species Act. Recently, there has been a global shift from single-species fisheries management to ecosystem-based fisheries management, which acknowledges that more complex dynamics can reverberate through a food web. Here, we have integrated new research into an end-to-end ecosystem model (i...

Ionic liquids have gained attention as 'designer solvents' since they offer a broad spectrum of properties that can be tuned by altering the constituent ions. In this work, 1-alkyl-2-methyl imidazolium-based ionic liquids with two different alkyl chains (alkyl = hexyl and octyl) have been synthesized and characterized. Since the binary mixture of ionic liquids with molecular solvents can give rise to striking physicochemical properties, the interaction of the synthesized room temperature ionic liquids, 1-hexyl-2-methyl imidazolium bromide [HMIM][Br]/1-octyl-2-methyl imidazolium bromide [OMIM][Br] with DMSO has been examined through density and specific conductance at T = (303...

Killer whales are apex predators with temporally and spatially varying distributions throughout the world's oceans. Their ecology and behaviour are poorly understood in most regions due to limited research, often because of logistical challenges. Here, we used a passive acoustic monitoring device to investigate the seasonal acoustic occurrence and diel vocalizing behaviour of killer whales around the remote sub-Antarctic Prince Edward Islands (PEIs), Southern Ocean. Killer whales showed diel vocalizing patterns that varied seasonally in relation to their prey abundance and social activities...

CONTEXT: It is well known that antibiotic resistance is a major health hazard. To eradicate antibiotic-resistant bacterial infections, it is essential to find a novel antibacterial agent. Hence, in this study, a quantitative structure-activity relationship (QSAR) model was developed using 43 DNA gyrase inhibitors, and 700 natural compounds were screened for their antibacterial properties. Based on molecular docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies, the top three leads viz...

Phthalates are used in plastics, found throughout the marine environment and have the potential to cause adverse health effects. In the present study, we quantified blubber concentrations of 11 phthalates in 16 samples from stranded and/or free-living marine mammals from the Norwegian coast: the killer whale (Orcinus orca), sperm whale (Physeter macrocephalus), long-finned pilot whale (Globicephala melas), white-beaked dolphin (Lagenorhynchus albirostris), harbour porpoise (Phocoena phocoena), and harbour seal (Phoca vitulina)...

Cetaceans are well known for their unique behavioral habits, such as calls and tactics. The possibility that these are acquired through social learning continues to be explored. This study investigates the ability of a young beluga whale to imitate novel behaviors. Using a do-as-other-does paradigm, the subject observed the performance of a conspecific demonstrator involving familiar and novel behaviors. The subject: (1) learned a specific 'copy' command; (2) copied 100% of the demonstrator's familiar behaviors and accurately reproduced two out of three novel actions; (3) achieved full matches on the first trial for a subset of familiar behaviors; and (4) demonstrated proficiency in coping with each familiar behavior as well as the two novel behaviors...

Killer whales (Orcinus orca) historically restricted to certain Arctic regions due to extensive sea ice have recently been documented farther north and for longer durations in the Canadian Arctic. These apex predators accumulate high levels of persistent organic pollutants (POPs). The objective of this study was to evaluate the concentration and profile of POPs in killer whales of the Canadian Arctic, thus determining potential risks for Inuit communities if consumed. Biopsies were collected from 33 killer whales across areas of the Canadian Arctic between 2009 and 2021...

A psychophysical procedure was used to measure pure-tone detection thresholds for a killer whale (Orcinus orca) as a function of both signal frequency and signal duration. Frequencies ranged between 1 and 100 kHz and signal durations ranged from 50 μs to 2 s, depending on the frequency. Detection thresholds decreased with an increase in signal duration up to a critical duration, which represents the auditory integration time. Integration times ranged from 4 ms at 100 kHz and increased up to 241 ms at 1 kHz...

The northeastern Pacific (NEP) Ocean spans the coast of British Columbia (Canada) and is impacted by anthropogenic activities including oil pipeline developments, maritime fossil fuel tanker traffic, industrial chemical effluents, agricultural and urban emissions in tandem with stormwater and wastewater discharges, and forest wildfires. Such events may expose surrounding marine environments to toxic polycyclic aromatic hydrocarbons (PAHs) and impact critical habitats of threatened killer whales (Orcinus orca)...

Accurate assignment of 19 F NMR has long been a challenge, and quantum chemical methods are possible solutions. Herein we reported a scaling method for the prediction of 19 F NMR chemical shift with freely available ORCA program package. Performance of 31 DFT functionals coupled with 11 basis sets were evaluated and influence of geometry optimization was also studied with five functionals coupled with three basis sets. The significance of geometry was further examined through the execution of relaxed surface scans of seven flexible compounds, and averaged shieldings of obtained conformers yielded notable improvement of the correlation between calculated isotropic shielidings and experimental chemical shifts...

CONTEXT: Area-selective atomic layer deposition (AS-ALD) is a thin film deposition technique developed using conventional ALD by considering the surface chemical nature of the substrate. Selecting appropriate precursors is a critical step in developing an efficient AS-ALD process with high deposition selectivity. However, the current efficiency of research on viable AS-ALD precursors is limited because of the absence of theoretical design rules for precursor chemical structures. In this study, our objective is to propose molecular design principle for precursors for AS-ALD, particularly focusing on achieving high deposition selectivity of oxides on diverse substrates...

AIM: The epidemiological relationship between periodontitis and caries remains controversial, and evidence synthesis is currently lacking. Therefore, this systematic review was designed to answer the following PECO question: 'In human adults (P), do subjects suffering from periodontitis (E) have higher presence/number of untreated carious lesions and caries experience (O) than subjects not suffering from periodontitis (C)?'. MATERIALS AND METHODS: Observational studies that met specific inclusion criteria established to answer to the PECO question were included...

Acoustic sequences have been described in a range of species and in varying complexity. Cetaceans are known to produce complex song displays but these are generally limited to mysticetes; little is known about call combinations in odontocetes. Here we investigate call combinations produced by killer whales (Orcinus orca), a highly social and vocal species. Using acoustic recordings from 22 multisensor tags, we use a first order Markov model to show that transitions between call types or subtypes were significantly different from random, with repetitions and specific call combinations occurring more often than expected by chance...

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The aim of this paper was to present a summary of the process of developing and preparing the final documents of the national consensus for teaching undergraduate Brazilian dental students the dental caries curriculum in the Portuguese language. The final document was developed in three steps: a) The ABENO and LAOHA cariology group invited experts from all five regions of Brazil to participate in the discussion. The theoretical support for crafting the first draft of the consensus was based on two publications: National Curriculum Guidelines of the Dentistry graduation in Brazil, Ministry of Education (2021) and the competences described in the European Core Curriculum for Cariology (ORCA-ADEE, 2011); b) The group of experts was divided into 5 working groups: G1-Domain, Main and Specific Competences, G2-Essential knowledge, G3-Life course perspective, G4-Social determinants and dental caries, G5- Glossary...

We describe a non-invasive method for profiling selected hormones, pharmaceuticals and personal care products (PPCPs) in killer whales ( Orcinus orca ) based on analysis of faecal samples by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method targets 21 compounds of interest including glucocorticoids, mineralocorticoids, androgens, estrogens, progestogens, selective serotonin uptake inhibitors and an antibacterial/antifungal agent. This method is suitable for routine simultaneous determination of target compounds in killer whale faecal samples as well as validation of immunoassays for the detection and measurement of steroid hormones in faeces...

Understanding the interaction of ligands with biomolecules is an integral component of drug discovery and development. Challenges for computing thermodynamic and kinetic quantities for pharmaceutically relevant receptor-ligand complexes include the size and flexibility of the ligands, large-scale conformational rearrangements of the receptor, accurate force field parameters, simulation efficiency, and sufficient sampling associated with rare events. Our recently developed multiscale milestoning simulation approach, SEEKR2 (Simulation Enabled Estimation of Kinetic Rates v...

Despite their ban and restriction under the 2001 Stockholm Convention, persistent organic pollutants (POPs) are still widespread and pervasive in the environment. Releases of these toxic and bioaccumulative chemicals are ongoing, and their contribution to population declines of marine mammals is of global concern. To safeguard their survival, it is of paramount importance to understand the effectiveness of mitigation measures. Using one of the world's largest marine mammals strandings data sets, we combine published and unpublished data to examine pollutant concentrations in 11 species that stranded along the coast of Great Britain to quantify spatiotemporal trends over three decades and identify species and regions where pollutants pose the greatest threat...

BACKGROUND: The use of research tools developed and validated in one cultural and linguistic context to another often faces challenges. One major challenge is poor performance of the tool in the new context. This potentially impact the legitimacy of health policy research conducted with informal adaptations of existing tools which have not been subjected to formal validation. Best practices exist to guide researchers in adapting and validating research tools effectively. We present here, as an extended example, our validation of the SHEMESH questionnaire ('Organizational Readiness to Change Assessment'; In Hebrew: 'SHE'elon Muchanut Ergunit le'SHinuy'), a Hebrew-language version of the Organizational Readiness to Change Assessment (ORCA)...