Loss of buoyancy control in the copepod Calanus finmarchicus

A mechanism is demonstrated that could explain large-scale aggregations of lipid-rich copepods in the surface waters of marine environments. Laboratory experiments establish that changes in salinity and temperature induce lipid-mediated buoyancy instability that entrains copepods in surface waters. Reduced hydrostatic pressure associated with forced ascent of copepods at fjordic sills, shelf breaks and seamounts would also reduce the density of the lipid reserves, forcing copepods and particularly those in diapause to the surface. We propose that salinity, temperature and hydrodynamics of the physical environment, in conjunction with the biophysical properties of lipids, explain periodic high abundances of lipid-rich copepods in surface waters

Circadian Clock Involvement in Zooplankton Diel Vertical Migration

Biological clocks are a ubiquitous ancient and adaptive mechanism enabling organisms to anticipate environmental cycles and to regulate behavioral and physiological processes accordingly [1]. Although terrestrial circadian clocks are well understood, knowledge of clocks in marine organisms is still very limited [2, 3, 4, 5]. This is particularly true for abundant species displaying large-scale rhythms like diel vertical migration (DVM) that contribute significantly to shaping their respective ecosystems [6]. Here we describe exogenous cycles and endogenous rhythms associated with DVM of the ecologically important and highly abundant planktic copepod Calanus finmarchicus. In the laboratory, C. finmarchicus shows circadian rhythms of DVM, metabolism, and most core circadian clock genes (clock, period1, period2, timeless, cryptochrome2, and clockwork orange). Most of these genes also cycle in animals assessed in the wild, though expression is less rhythmic at depth (50–140 m) relative to shallow-caught animals (0–50 m). Further, peak expressions of clock genes generally occurred at either sunset or sunrise, coinciding with peak migration times. Including one of the first field investigations of clock genes in a marine species [5, 7], this study couples clock gene measurements with laboratory and field data on DVM. While the mechanistic connection remains elusive, our results imply a high degree of causality between clock gene expression and one of the planet’s largest daily migrations of biomass. We thus suggest that circadian clocks increase zooplankton fitness by optimizing the temporal trade-off between feeding and predator avoidance, especially when environmental drivers are weak or absent [8]

Calanus finmarchicus seasonal cycle and diapause in relation to gene expression, physiology, and endogenous clocks: Calanus finmarchicus seasonal rhythmicity

The copepod Calanus finmarchicus plays a crucial role in the north Atlantic food web. Its seasonal life cycle involves reproduction and development in surface waters before overwintering in diapause at depth. Although diapause has been studied for more than a century, the factors responsible for the initiation and termination of it are still unclear. Endogenous clocks have been identified as potent tools for photoperiod measurement and seasonal rhythmicity in many terrestrial species, but knowledge of these remains scarce in the marine realm. Focusing on the dominant CV copepodid stage, we sampled a population of C. finmarchicus from a Scottish sea loch to characterize population dynamics, several physiological parameters, and diel and seasonal expression rhythms of 35 genes representing different metabolic pathways, including the circadian clock machinery. This generated a detailed overview of the seasonal cycle of C. finmarchicus including the most extensive field dataset on circadian clock gene expression in a marine species to date. Gene expression patterns revealed distinct gene clusters upregulated at different phases of the copepod's seasonal cycle. While diel clock cycling was restricted to the active spring/summer phase, many clock genes exhibited the highest expression during diapause. Our results provide new insights into diapause on physiological and genetic levels. We suggest that photoperiod, in interaction with internal and external factors (lipid content, temperature, food availability) and the endogenous clock mechanism, plays an important role in the timing of diapause in C. finmarchicus

Dynamical ionization ignition of clusters in intense and short laser pulses

The electron dynamics of rare gas clusters in laser fields is investigated quantum mechanically by means of time-dependent density functional theory. The mechanism of early inner and outer ionization is revealed. The formation of an electron wave packet inside the cluster shortly after the first removal of a small amount of electron density is observed. By collisions with the cluster boundary the wave packet oscillation is driven into resonance with the laser field, hence leading to higher absorption of laser energy. Inner ionization is increased because the electric field of the bouncing electron wave packet adds up constructively to the laser field. The fastest electrons in the wave packet escape from the cluster as a whole so that outer ionization is increased as well.Comment: 8 pages, revtex4, PDF-file with high resolution figures is available from http://mitarbeiter.mbi-berlin.de/bauer/publist.html, publication no. 24. Accepted for publication in Phys. Rev.

Evaluation of wet-cupping therapy for persistent non-specific low back pain: a randomised, waiting-list controlled, open-label, parallel-group pilot trial

<p>Abstract</p> <p>Background</p> <p>Persistent non-specific low back pain (PNSLBP) is one of the most frequently experienced types of back pain around the world. Wet-cupping is a common intervention for various pain conditions, especially in Korea. In this context, we conducted a pilot study to determine the effectiveness and safety of wet-cupping treatment for PNSLBP.</p> <p>Methods</p> <p>We recruited 32 participants (21 in the wet-cupping group and 11 in the waiting-list group) who had been having PNSLBP for at least 3 months. The participants were recruited at the clinical research centre of the Korea Institute of Oriental Medicine, Korea. Eligible participants were randomly allocated to wet-cupping and waiting-list groups. Following the practice of traditional Korean medicine, the treatment group was provided with wet-cupping treatment at two acupuncture points among the BL23, BL24 and BL25 6 times within 2 weeks. Usual care, including providing brochures for exercise, general advice for PNSLBP and acetaminophen, was allowed in both groups. Separate assessors participated in the outcome assessment. We used the 0 to100 numerical rating scale (NRS) for pain, the McGill Pain Questionnaire for pain intensity (PPI) and the Oswestry Disability Questionnaire (ODQ), and we assessed acetaminophen use and safety issues.</p> <p>Results</p> <p>The results showed that the NRS score for pain decreased (-16.0 [95% CI: -24.4 to -7.7] in the wet-cupping group and -9.1 [-18.1 to -0.1] in the waiting-list group), but there was no statistical difference between the groups (p = 0.52). However, the PPI scores showed significant differences between the two groups (-1.2 [-1.6 to -0.8] for the wet-cupping group and -0.2 [-0.8 to 0.4] for the waiting-list group, p < 0.01). In addition, less acetaminophen was used in the wet-cupping group during 4 weeks (p = 0.09). The ODQ score did not show significant differences between the two groups (-5.60 [-8.90 to -2.30] in the wet-cupping group and -1.8 [-5.8 to 2.2] in the waiting-list group, p = 0.14). There was no report of adverse events due to wet-cupping.</p> <p>Conclusion</p> <p>This pilot study may provide preliminary data on the effectiveness and safety of wet-cupping treatments for PNSLBP. Future full-scale randomised controlled trials will be needed to provide firm evidence of the effectiveness of this intervention.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: (Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00925951">NCT00925951</a>)</p> <p>Date of trial registration: June 19th, 2009</p> <p>The date when the first patient was randomised: July 15th, 2009</p> <p>The date when the study was completed: November 27th, 2009</p

Family treatment of child anxiety: outcomes, limitations and future directions

Anxiety of childhood is a common and serious condition. The past decade has seen an increase in treatment-focussed research, with recent trials tending to give greater attention to parents in the treatment process. This review examines the efficacy of family-based cognitive behaviour therapy and attempts to delineate some of the factors that might have an impact on its efficacy. The choice and timing of outcome measure, age and gender of the child, level of parental anxiety, severity and type of child anxiety and treatment format and content are scrutinised. The main conclusions are necessarily tentative, but it seems likely that Family Cognitive Behaviour Therapy (FCBT) is superior to no treatment, and, for some outcome measures, also superior to Child Cognitive Behaviour Therapy (CCBT). Where FCBT is successful, the results are consistently maintained at follow-up. It appears that where a parent is anxious, and this is not addressed, outcomes are less good. However, for children of anxious parents, FCBT is probably more effective than CCBT. What is most clear is that large, well-designed studies, examining these factors alone and in combination, are now needed

Deciphering mollusc shell production: the roles of genetic mechanisms through to ecology, aquaculture and biomimetics

Most molluscs possess shells, constructed from a vast array of microstructures and architectures. The fully formed shell is composed of calcite or aragonite. These CaCO3 crystals form complex biocomposites with proteins, which although typically less than 5% of total shell mass, play significant roles in determining shell microstructure. Despite much research effort, large knowledge gaps remain in how molluscs construct and maintain their shells, and how they produce such a great diversity of forms. Here we synthesize results on how shell shape, microstructure, composition and organic content vary among, and within, species in response to numerous biotic and abiotic factors. At the local level, temperature, food supply and predation cues significantly affect shell morphology, whilst salinity has a much stronger influence across latitudes. Moreover, we emphasize how advances in genomic technologies [e.g. restriction site-associated DNA sequencing (RAD-Seq) and epigenetics] allow detailed examinations of whether morphological changes result from phenotypic plasticity or genetic adaptation, or a combination of these. RAD-Seq has already identified single nucleotide polymorphisms associated with temperature and aquaculture practices, whilst epigenetic processes have been shown significantly to modify shell construction to local conditions in, for example, Antarctica and New Zealand. We also synthesize results on the costs of shell construction and explore how these affect energetic trade-offs in animal metabolism. The cellular costs are still debated, with CaCO3 precipitation estimates ranging from 1-2 J/mg to 17-55 J/mg depending on experimental and environmental conditions. However, organic components are more expensive (~29 J/mg) and recent data indicate transmembrane calcium ion transporters can involve considerable costs. This review emphasizes the role that molecular analyses have played in demonstrating multiple evolutionary origins of biomineralization genes. Although these are characterized by lineage-specific proteins and unique combinations of co-opted genes, a small set of protein domains have been identified as a conserved biomineralization tool box. We further highlight the use of sequence data sets in providing candidate genes for in situ localization and protein function studies. The former has elucidated gene expression modularity in mantle tissue, improving understanding of the diversity of shell morphology synthesis. RNA interference (RNAi) and clustered regularly interspersed short palindromic repeats - CRISPR-associated protein 9 (CRISPR-Cas9) experiments have provided proof of concept for use in the functional investigation of mollusc gene sequences, showing for example that Pif (aragonite-binding) protein plays a significant role in structured nacre crystal growth and that the Lsdia1 gene sets shell chirality in Lymnaea stagnalis. Much research has focused on the impacts of ocean acidification on molluscs. Initial studies were predominantly pessimistic for future molluscan biodiversity. However, more sophisticated experiments incorporating selective breeding and multiple generations are identifying subtle effects and that variability within mollusc genomes has potential for adaption to future conditions. Furthermore, we highlight recent historical studies based on museum collections that demonstrate a greater resilience of molluscs to climate change compared with experimental data. The future of mollusc research lies not solely with ecological investigations into biodiversity, and this review synthesizes knowledge across disciplines to understand biomineralization. It spans research ranging from evolution and development, through predictions of biodiversity prospects and future-proofing of aquaculture to identifying new biomimetic opportunities and societal benefits from recycling shell products.FCT: UID/Multi/04326/2019; European Marine Biological Research Infrastructure Cluster-EMBRIC (EU H2020 research and innovation program) 654008; European Union Seventh Framework Programme [FP7] ITN project 'CACHE: Calcium in a Changing Environment' under REA 60505; NERC Natural Environment Research Council NE/J500173/1info:eu-repo/semantics/publishedVersio

A gap analysis on modelling of sea lice infection pressure from salmonid farms. I. A structured knowledge review

Sustainability of aquaculture, an important component of the blue economy, relies in part on ensuring assessment of environmental impact and interactions relating to sea lice dispersing from open pen salmon and trout farms. We review research underpinning the key stages in the sea lice infection process to support modelling of lice on wild salmon in relation to those on farms. The review is split into 5 stages: larval production; larval transport and survival; exposure and infestation of new hosts; development and survival of the attached stages; and impact on host populations. This modular structure allows the existing published data to be reviewed and assessed to identify data gaps in modelling sea lice impacts in a systematic way. Model parameterisation and parameter variation is discussed for each stage, providing an overview of knowledge strength and gaps. We conclude that a combination of literature review, empirical data collection and modelling studies are required on an iterative basis to ensure best practice is applied for sustainable aquaculture. The knowledge gained can then be optimised and applied at regional scales, with the most suitable modelling frameworks applied for the system, given regional limitations

A gap analysis on modelling of sea lice infection pressure from salmonid farms. II. Identifying and ranking knowledge gaps: output of an international workshop

Sea lice are a major health hazard for farmed Atlantic salmon in Europe, and their impact is felt globally. Given the breadth of ongoing research in sea lice dispersal and population modelling, and focus on research-led adaptive management, we brought experts together to discuss research knowledge gaps. Gaps for salmon lice infection pressure from fish farms were identified and scored by experts in sea lice-aquaculture-environment interactions, at an international workshop in 2021. The contributors included experts based in Scotland, Norway, Ireland, Iceland, Canada, the Faroe Islands, England and Australia, employed by governments, industry, universities and non-government organisations. The workshop focused on knowledge gaps underpinning 5 key stages in salmon lice infection pressure from fish farms: larval production; larval transport and survival; exposure and infestation of new hosts; development and survival of the attached stages; and impact on host populations. A total of 47 research gaps were identified; 5 broad themes emerged with 13 priority research gaps highlighted as important across multiple sectors. The highest-ranking gap called for higher quality and frequency of on-farm lice count data, along with better sharing of information across sectors. We highlight the need for synergistic international collaboration to maximise transferable knowledge. Round table discussions through collaborative workshops provide an important forum for experts to discuss and agree research priorities