Face-off Droop: A Case Report of Pediatric Stroke.

Introduction: Cerebrovascular accidents rarely occur in children; the incidence of ischemic stroke in patients <16 years of age is between 0.6-7.9/100,000. However, they are the fourth most common cause of acute neurological deficits in the pediatric population, and possible cases should be evaluated with a high index of suspicion to ensure timely intervention. Case Report: We describe a previously healthy 17-year-old male who presented to the pediatric emergency department with a left facial droop and hemiparesis consistent with a stroke. The patient's age and lack of comorbidities made this an extremely uncommon presentation. Our patient's neurologic symptoms were believed to have been caused by a recent traumatic clavicular injury sustained two weeks prior, which subsequently led to vascular insult. Conclusion: Cerebrovascular accidents are an important cause of morbidity and mortality in pediatric patients. Cerebrovascular accidents in children are most often secondary to congenital causes; however, care should be taken to assess for acquired causes, such as trauma to major blood vessels. While rarely implicated in traumatic injuries, arterial structures posterior to the medial clavicle can result in severe complications.

A novel experimental chamber for the characterization of free-falling particles in volcanic plumes.

Volcanic plumes pose a hazard to health and society and a particular risk for aviation. Hazard mitigation relies on forecasting plume dispersion within the atmosphere over time. The accuracy of forecasts depends on our understanding of particle dispersion and sedimentation processes, as well as on the accuracy of model input parameters, such as the initial particle size distribution and concentrations of volcanic particles (i.e., volcanic ash) in the atmosphere. However, our understating of these processes and the accurate quantification of input parameters remain the main sources of uncertainty in plume dispersion modeling. It is usually impractical to sample volcanic plumes directly, but particle sedimentation can be constrained in the laboratory. Here, we describe the design of a new experimental apparatus for investigating the dynamics of free-falling volcanic particles. The apparatus can produce a sustained column of falling particles with variable particle concentrations appropriate to a volcanic plume. Controllable experimental parameters include particle size distributions, types, and release rates. A laser-illuminated macrophotography system allows imaging of in-flight particles and their interactions. The mass of landing particles is logged to inform deposition rates. Quantitative measurements include particle morphology characterization, settling velocities, flow rates, and estimation of concentrations. Simultaneous observations of particle interaction processes and settling dynamics through direct control over a wide range of parameters will improve our parameterization of volcanic plume dynamics. Although the apparatus has been specifically designed for volcanological investigations, it can also be used to explore the characteristics of free-falling particle columns occurring in both environmental and industrial settings.

Supporting wild pollinators in agricultural landscapes through targeted legume mixtures.

Insect-pollinated legumes are rich in plant-based proteins making them a vital constituent of sustainable healthy diets for people and livestock. Furthermore, they deliver or support a range of ecosystem services that underpin agricultural production and their prevalence in agricultural landscapes is likely to increase. Under typical implementation and management, the value of legumes to pollinators has, however, been questioned. Through exploring a range of legume crops, grown as monocultures and mixtures, this study aims to identify multifunctional legume cropping systems that optimise forage availability for a diversity of wild pollinators whilst delivering a wide range of agronomic and environmental benefits. This study innovatively explores legume mixtures concurrently with monocultures of the component species using replicated small-plot field trials established in two geographical locations. Observational plots assessed the richness and abundance of floral resources, and wild pollinators (i.e. bumblebees and hoverflies) throughout the peak flowering period. Densely flowering, highly profitable legumes (e.g. Trifolium incarnatum and Trifolium mixes) supported abundant and rich pollinator assemblages. The functional makeup of floral visitors was strongly influenced by flower structure and hoverflies, with their shorter proboscises, were largely constrained to legumes with shallower corolla and open weed species. Floral richness was not a key driver of pollinator assemblages; however, clear intra-specific differences were observed in flowering phenology. Combining functionally distinct legumes with respect to flower structure and phenology, will support a wider suite of pollinating insects and help stabilise the temporal availability of forage. For highly competitive legumes (e.g. Vicia faba and Vicia sativa), planting in discrete patches is recommended to reduce the risk of less competitive species failing in mixtures. Legumes can provide valuable forage for pollinators; however, they fail to meet all resource requirements. They should therefore be used in combination with agri-environmental measures targeted to promote early-season forage (e.g. hedgerows and farm woodlands), open flowers for hoverflies, saprophytic hoverfly larval resources (e.g. ditches and ponds) and nesting habitats (e.g. undisturbed field margins).

Challenges on the interaction of models and policy for pandemic control.

The COVID-19 pandemic has seen infectious disease modelling at the forefront of government decision-making. Models have been widely used throughout the pandemic to estimate pathogen spread and explore the potential impact of different intervention strategies. Infectious disease modellers and policymakers have worked effectively together, but there are many avenues for progress on this interface. In this paper, we identify and discuss seven broad challenges on the interaction of models and policy for pandemic control. We then conclude with suggestions and recommendations for the future.

Alternatives to direct emergency department conveyance of ambulance patients: a scoping review of the evidence.

BACKGROUND: The role of ambulance services is shifting, due in part to more intermediate, non-urgent patients who do not require direct emergency department conveyance, yet who cannot be safely left at home alone. Evidence surrounding the safety, effectiveness and efficiency of alternate care routes is not well known. METHODS: This scoping review sought to identify all studies that examined alternate routes of care for the non-urgent "intermediate" patient, as triaged on scene. Search terms for the sample (ambulances, paramedics, etc.) and intervention (e.g. referrals, alternate care route, non-conveyance) were combined. Articles were systematically searched using four databases and grey literature sources (February 2020). Independent researchers screened title-abstract and full text stages. RESULTS: Of 16,037 records, 41 examined alternate routes of care after triage by the on-scene paramedic. Eighteen articles considered quantitative patient data, 12 studies provided qualitative perspectives while 11 were consensus or opinion-based articles. The benefits of alternative schemes are well-recognised by patients, paramedics and stakeholders and there is supporting evidence for a positive impact on patient-centered care and operational efficiency. Challenges to successful use of schemes included: patient safety resulting from incorrect triage decisions, inadequate training, lack of formal partnerships between ambulance and supporting services, and insufficient evidence to support safe implementation or continued use. Studies often inaccurately defined success using proxies for patient safety (e.g. decision comparisons, rates of secondary contact). Finally, patients expressed willingness for such schemes but their preference must be better understood. CONCLUSIONS: This broad summary offers initial support for alternate routes of care for intermediate, non-urgent patients. Even so, most studies lacked methodologically rigorous evidence and failed to evaluate safe patient outcomes. Some remedies appear to be available such as formal triage pathways, targeted training and organisational support, however there is an urgent need for more research and dissemination in this area.

Piloting data linkage in a prospective cohort study of a GP referral scheme to avoid unnecessary emergency department conveyance.

BACKGROUND: UK Ambulance services are under pressure to safely stream appropriate patients away from the Emergency Department (ED). Even so, there has been little evaluation of patient outcomes. We investigated differences between patients who are conveyed directly to ED after calling 999 and those referred by an ambulance crew to a novel GP referral scheme. METHODS: This was a prospective study comparing patients from two cohorts, one conveyed directly to the ED (n = 4219) and the other referred to a GP by the on-scene paramedic (n = 321). To compare differences in patient outcomes, we include follow-up data of a smaller subset of each cohort (up to n = 150 in each) including hospital admission, history of long-term illness, previous ED attendance, length of stay, hospital investigations, internal transfers, 30-day re-admission and 10-month mortality. RESULTS: Older individuals, females, and those with minor incidents were more likely to be referred to a GP than conveyed directly to ED. Of those patients referred to the GP, only 22.4% presented at ED within 30 days. These patients were more likely to be admitted then than were those initially conveyed directly to ED (59% vs 31%). Those conveyed to ED had a higher risk of death compared to those who were referred to the GP (HR: 2.59; 95% CI 1.14-5.89), however when analyses were restricted to those who presented at ED within 30 days, there was no difference in mortality risk (HR: 1.45; 95% CI 0.58-3.65). CONCLUSIONS: Despite limited data and a small sample size, there were differences between patients conveyed directly to ED and those who were referred into GP care. Initial evidence suggests that referring individuals to a GP may provide an appropriate and safe alternative path of care. This pilot study demonstrated a need for larger scale, methodologically rigorous study to demonstrate the benefits of alternative conveyance schemes and recommend changes to the current system of urgent and emergency care.

Advance decisions to refuse treatment and suicidal behaviour in emergency care: 'it's very much a step into the unknown'.

BACKGROUND: Complex challenges may arise when patients present to emergency services with an advance decision to refuse life-saving treatment following suicidal behaviour. AIMS: To investigate the use of advance decisions to refuse treatment in the context of suicidal behaviour from the perspective of clinicians and people with lived experience of self-harm and/or psychiatric services. METHOD: Forty-one participants aged 18 or over from hospital services (emergency departments, liaison psychiatry and ambulance services) and groups of individuals with experience of psychiatric services and/or self-harm were recruited to six focus groups in a multisite study in England. Data were collected in 2016 using a structured topic guide and included a fictional vignette. They were analysed using thematic framework analysis. RESULTS: Advance decisions to refuse treatment for suicidal behaviour were contentious across groups. Three main themes emerged from the data: (a) they may enhance patient autonomy and aid clarity in acute emergencies, but also create legal and ethical uncertainty over treatment following self-harm; (b) they are anxiety provoking for clinicians; and (c) in practice, there are challenges in validation (for example, validating the patient's mental capacity at the time of writing), time constraints and significant legal/ethical complexities. CONCLUSIONS: The potential for patients to refuse life-saving treatment following suicidal behaviour in a legal document was challenging and anxiety provoking for participants. Clinicians should act with caution given the potential for recovery and fluctuations in suicidal ideation. Currently, advance decisions to refuse treatment have questionable use in the context of suicidal behaviour given the challenges in validation. Discussion and further patient research are needed in this area. DECLARATION OF INTEREST: D.G., K.H. and N.K. are members of the Department of Health's (England) National Suicide Prevention Advisory Group. N.K. chaired the National Institute for Health and Care Excellence (NICE) guideline development group for the longer-term management of self-harm and the NICE Topic Expert Group (which developed the quality standards for self-harm services). He is currently chair of the updated NICE guideline for Depression. K.H. and D.G. are NIHR Senior Investigators. K.H. is also supported by the Oxford Health NHS Foundation Trust and N.K. by the Greater Manchester Mental Health NHS Foundation Trust.

Spatial Transmission Models: A Taxonomy and Framework.

Within risk analysis and, more broadly, the decision behind the choice of which modeling technique to use to study the spread of disease, epidemics, fires, technology, rumors, or, more generally, spatial dynamics, is not well documented. While individual models are well defined and the modeling techniques are well understood by practitioners, there is little deliberate choice made as to the type of model to be used, with modelers using techniques that are well accepted in the field, sometimes with little thought as to whether alternative modeling techniques could or should be used. In this article, we divide modeling techniques for spatial transmission into four main categories: population-level models, where a macro-level estimate of the infected population is required; cellular models, where the transmission takes place between connected domains, but is restricted to a fixed topology of neighboring cells; network models, where host-to-host transmission routes are modeled, either as planar spatial graphs or where shortcuts can take place as in social networks; and, finally, agent-based models that model the local transmission between agents, either as host-to-host geographical contacts, or by modeling the movement of the disease vector, with dynamic movement of hosts and vectors possible, on a Euclidian space or a more complex space deformed by the existence of information about the topology of the landscape. We summarize these techniques by introducing a taxonomy classifying these modeling approaches. Finally, we present a framework for choosing the most appropriate spatial modeling method, highlighting the links between seemingly disparate methodologies, bearing in mind that the choice of technique rests with the subject expert.

Radar micro-Doppler signatures of drones and birds at K-band and W-band.

Due to the substantial increase in the number of affordable drones in the consumer market and their regrettable misuse, there is a need for efficient technology to detect drones in airspace. This paper presents the characteristic radar micro-Doppler properties of drones and birds. Drones and birds both induce micro-Doppler signatures due to their propeller blade rotation and wingbeats, respectively. These distinctive signatures can then be used to differentiate a drone from a bird, along with studying them separately. Here, experimental measurements of micro-Doppler signatures of different types of drones and birds are presented and discussed. The data have been collected using two radars operating at different frequencies; K-band (24 GHz) and W-band (94 GHz). Three different models of drones and four species of birds of varying sizes have been used for data collection. The results clearly demonstrate that a phase coherent radar system can retrieve highly reliable and distinctive micro-Doppler signatures of these flying targets, both at K-band and W-band. Comparison of the signatures obtained at the two frequencies indicates that the micro-Doppler return from the W-band radar has higher SNR. However, micro-Doppler features in the K-band radar returns also reveal the micro-motion characteristics of drones and birds very effectively.

Effective use of the built environment to manage behavioural and psychological symptoms of dementia: a systematic review.

OBJECTIVE: To determine the effectiveness of built environment interventions in managing behavioural and psychological symptoms of dementia (BPSD) among residents in long-term care settings. METHODS: Systematic review of literature published from 1995-2013. Studies were included if they: were randomized controlled trials, quasi-experimental trials, or comparative cohort studies; were in long-term or specialized dementia care; included residents with dementia and BPSD; and examined effectiveness of a built environment intervention on frequency and/or severity of BPSD. Quality of included studies was assessed using the Downs and Black Checklist. Study design, patient population, intervention, and outcomes were extracted and narratively synthesized. RESULTS: Five low to moderate quality studies were included. Three categories of interventions were identified: change/redesign of existing physical space, addition of physical objects to environment, and type of living environment. One of the two studies that examined change/redesign of physical spaces reported improvements in BPSD. The addition of physical objects to an existing environment (n = 1) resulted in no difference in BPSD between treatment and control groups. The two studies that examined relocation to a novel living environment reported decreased or no difference in the severity and/or frequency of BPSD post-intervention. No studies reported worsening of BPSD following a built environment intervention. CONCLUSIONS: The range of built environment interventions is broad, as is the complex and multi-dimensional nature of BPSD. There is inconclusive evidence to suggest a built environment intervention which is clinically superior in long-term care settings. Further high-quality methodological and experimental studies are required to demonstrate the feasibility and effectiveness of such interventions.

Improving the farmland biodiversity value of riparian buffer strips: conflicts and compromises.

The intensity of management of lowland grassland fields in the United Kingdom, coupled with the fact that such grasslands dominate much of the lowland landscape, means that there are now few opportunities for many plants, invertebrates, birds, or mammals to survive. The Scottish Agricultural College (SAC) has investigated whether fencing off the margins of such fields next to watercourses to control diffuse pollution has any positive impacts on biodiversity, based on assessments of vegetation composition and condition and structure of assemblages of invertebrates of importance as foodstuffs to farmland birds. Fencing watercourses increased the abundance of key groups of invertebrates. However, the invertebrate species diversity was not increased unless the margins were ≥ 5.4 m in width. Margins established in the study area to prevent access by livestock to watercourses or to enhance biodiversity are generally ≤ 2.6 m wide and are therefore unlikely to provide conditions for additional invertebrate species to use. The dense, tall swards within such margins are also unlikely to provide foraging opportunities for farmland birds. Management (such as low-intensity grazing by livestock in the margins) is essential to provide the conditions required for these groups, but this could conflict with the diffuse pollution mitigation aims. A compromise is proposed whereby limited autumn/winter grazing by livestock could be used to open the vegetation structure in the margins. Grazing by livestock at that time may be acceptable since it is not occurring in the period of main diffuse pollution concern (i.e., the fecal contamination of watercourses and bathing waters in the spring and summer). It is also essential that a landscape-scale approach is taken, driven by knowledge of the full needs of the species concerned, when deciding where best to target agri-environmental actions aimed at farmland bird conservation.

Topological isomorphisms of human brain and financial market networks.

Although metaphorical and conceptual connections between the human brain and the financial markets have often been drawn, rigorous physical or mathematical underpinnings of this analogy remain largely unexplored. Here, we apply a statistical and graph theoretic approach to the study of two datasets - the time series of 90 stocks from the New York stock exchange over a 3-year period, and the fMRI-derived time series acquired from 90 brain regions over the course of a 10-min-long functional MRI scan of resting brain function in healthy volunteers. Despite the many obvious substantive differences between these two datasets, graphical analysis demonstrated striking commonalities in terms of global network topological properties. Both the human brain and the market networks were non-random, small-world, modular, hierarchical systems with fat-tailed degree distributions indicating the presence of highly connected hubs. These properties could not be trivially explained by the univariate time series statistics of stock price returns. This degree of topological isomorphism suggests that brains and markets can be regarded broadly as members of the same family of networks. The two systems, however, were not topologically identical. The financial market was more efficient and more modular - more highly optimized for information processing - than the brain networks; but also less robust to systemic disintegration as a result of hub deletion. We conclude that the conceptual connections between brains and markets are not merely metaphorical; rather these two information processing systems can be rigorously compared in the same mathematical language and turn out often to share important topological properties in common to some degree. There will be interesting scientific arbitrage opportunities in further work at the graph-theoretically mediated interface between systems neuroscience and the statistical physics of financial markets.

Quantifying transient psychological stress using a novel technique: changes to PMA-induced leukocyte production of ROS in vitro.

Although much work has been conducted to quantify the long-term physiological effects of psychological stress, measures of short-term, low-level stress have been more elusive. This study assessed the effect of exposure of volunteers to a mild, brief, psychologically stressful event, on the functional ability of leukocytes in whole blood to respond to phorbol 12-myristate 13-acetate (PMA) in vitro. Volunteers operated a car electric window and adjusted it to 4 pre-determined positions. Between each operation the mechanism's polarity was covertly altered (group B) or remained unaltered (group A). For each treatment group 10 different subjects provided capillary blood samples pre- and post-stressor. Using a chemiluminescent technique termed leukocyte coping capacity, the ability of leukocytes to produce reactive oxygen species (ROS) in vitro was assessed. ROS release differed significantly at 10 min post-stressor between treatment groups, suggesting exposure to acute psychological stress leads to a reduced ability to respond to bacterial challenge.

Roborovskin, a lipocalin in the urine of the Roborovski hamster, Phodopus roborovskii.

Many rodents are now known to exhibit an obligate proteinuria that delivers urine-mediated chemosignals. In this paper, we explore the urinary proteins of the Roborovski hamster (Phodopus roborovskii). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of urine from individual male and female Roborovski hamsters revealed 2 proteins, with approximate masses of 6 and 17 kDa, the expression pattern of which showed little variation between individuals or between sexes. Peptide mass fingerprints obtained from these 2 proteins revealed a number of features: 1) the proteins of a given mass were the same in all individuals regardless of sex, 2) the 6 kDa protein was not a fragment of the 21 kDa protein, and 3) neither protein was a fragment of a larger, conserved protein such as serum albumin. Electrospray mass spectrometry of purified protein preparations established the mass of the larger protein as invariant, at 17144 ± 2 Da in all samples. This protein has been termed roborovskin. The primary structure of roborovskin was determined by tandem mass spectrometry of peptides derived from independent and overlapping digestion with 3 proteases, supported by Edman degradation of the protein N-terminus. Roborovskin shared significant homology with olfactory-binding proteins from Myodes glareolus (bank vole) and with aphrodisin and submandibular protein from the golden hamster Mesocricetus auratus, all of which belong to the lipocalin superfamily. Lower levels of homology were also indicated between a variety of other lipocalins including the major urinary proteins from house mice and Norway rats. A model of the tertiary structure of roborovskin was constructed from the primary sequence by homology modeling. This model structure resembled other 8-stranded beta barrel lipocalins. Thus, the Roborovski hamster may demonstrate another variant of urinary lipocalin expression, as for the animals studied here, there appears to be no polymorphism in expression either between sexes or individuals.

Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male's odour.

BACKGROUND: Among invertebrates, specific pheromones elicit inherent (fixed) behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing for individual-specific choice? We hypothesized that male mouse urine contains a specific pheromonal component that invokes inherent sexual attraction to the scent and which also stimulates female memory and conditions sexual attraction to the airborne odours of an individual scent owner associated with this pheromone. RESULTS: Using wild-stock house mice to ensure natural responses that generalize across individual genomes, we identify a single atypical male-specific major urinary protein (MUP) of mass 18893Da that invokes a female's inherent sexual attraction to male compared to female urinary scent. Attraction to this protein pheromone, which we named darcin, was as strong as the attraction to intact male urine. Importantly, contact with darcin also stimulated a strong learned attraction to the associated airborne urinary odour of an individual male, such that, subsequently, females were attracted to the airborne scent of that specific individual but not to that of other males. CONCLUSIONS: This involatile protein is a mammalian male sex pheromone that stimulates a flexible response to individual-specific odours through associative learning and memory, allowing female sexual attraction to be inherent but selective towards particular males. This 'darcin effect' offers a new system to investigate the neural basis of individual-specific memories in the brain and give new insights into the regulation of behaviour in complex social mammals.See associated Commentary http://www.biomedcentral.com/1741-7007/8/71.

A kilowatt pulsed 94 GHz electron paramagnetic resonance spectrometer with high concentration sensitivity, high instantaneous bandwidth, and low dead time.

We describe a quasioptical 94 GHz kW pulsed electron paramagnetic resonance spectrometer featuring pi/2 pulses as short as 5 ns and an instantaneous bandwidth of 1 GHz in nonresonant sample holders operating in induction mode and at low temperatures. Low power pulses can be as short as 200 ps and kilowatt pulses as short as 1.5 ns with timing resolution of a few hundred picoseconds. Phase and frequency can be changed on nanosecond time scales and complex high power pulse sequences can be run at repetition rates up to 80 kHz with low dead time. We demonstrate that the combination of high power pulses at high frequencies and nonresonant cavities can offer excellent concentration sensitivity for orientation selective pulsed electron double resonance (double electron-electron resonance), where we demonstrate measurements at 1 microM concentration levels.

Dynamic instability of the major urinary protein gene family revealed by genomic and phenotypic comparisons between C57 and 129 strain mice.

BACKGROUND: The major urinary proteins (MUPs) of Mus musculus domesticus are deposited in urine in large quantities, where they bind and release pheromones and also provide an individual 'recognition signal' via their phenotypic polymorphism. Whilst important information about MUP functionality has been gained in recent years, the gene cluster is poorly studied in terms of structure, genic polymorphism and evolution. RESULTS: We combine targeted sequencing, manual genome annotation and phylogenetic analysis to compare the Mup clusters of C57BL/6J and 129 strains of mice. We describe organizational heterogeneity within both clusters: a central array of cassettes containing Mup genes highly similar at the protein level, flanked by regions containing Mup genes displaying significantly elevated divergence. Observed genomic rearrangements in all regions have likely been mediated by endogenous retroviral elements. Mup loci with coding sequences that differ between the strains are identified--including a gene/pseudogene pair--suggesting that these inbred lineages exhibit variation that exists in wild populations. We have characterized the distinct MUP profiles in the urine of both strains by mass spectrometry. The total MUP phenotype data is reconciled with our genomic sequence data, matching all proteins identified in urine to annotated genes. CONCLUSION: Our observations indicate that the MUP phenotypic polymorphism observed in wild populations results from a combination of Mup gene turnover coupled with currently unidentified mechanisms regulating gene expression patterns. We propose that the structural heterogeneity described within the cluster reflects functional divergence within the Mup gene family.

Observation of heterogeneous gene products by FT-ICR MS.

The ability of FT-ICR MS to resolve isotopic variants of intact proteins for each of the charge states formed by electrospray ionization offers a sensitive, rapid method for detecting "low mass" heterogeneity, where this is defined as the presence of structural variants differing in mass by 2 Da or less. Such heterogeneity may reflect biological or chemical modifications of structure or may result from the coexpression of related proteins from a multi-gene family. In the analytical approach described here, comparisons are made between observed isotopic distributions and those expected for predicted protein sequences. Close agreement is demonstrated for a homogeneous model protein, and the utility of the method has been evaluated in the study of mouse major urinary proteins (MUPs), a group of closely related sequences. Divergence of the experimental isotopic distribution from distributions predicted for known MUP sequences can be explained, in quantitative terms, by the coexpression of closely related sequences. This approach provides a facile method for the assessment of protein homogeneity and for the detection of structural variants, without recourse to proteolytic digestion and analysis of the resulting products.

Global cooling: cold acclimation and the expression of soluble proteins in carp skeletal muscle.

The common carp (Cyprinus carpio) has a well-developed capacity to modify muscle properties in response to changes in temperature. Understanding the mechanisms underpinning this phenotypic response at the protein level may provide fundamental insights into the molecular basis of adaptive processes in skeletal muscle. In this study, common carp were subjected to a cooling regimen and soluble extracts of muscle homogenates were separated by 1-D SDS-PAGE and 2-DE. Proteins were identified using MALDI-TOF-MS and de novo peptide sequencing using LC-MS/MS. The 2-D gel was populated with numerous protein spots that were fragments of all three muscle isoforms (M1, M2 and M3) of carp creatine kinase (CK). The accumulation of the CK fragments was enhanced when the carp were cooled to 10 degrees C. The protein changes observed in the skeletal muscle of carp subjected to cold acclimation were compared to changes described in a previous transcript analysis study. Genes encoding CK isoforms were downregulated and the genes encoding key proteins of the ubiquitin-proteasome pathway were upregulated. These findings are consistent with a specific cold-induced enhancement of proteolysis of CK.