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Carbon dioxide rebreathing (CO2 rebreathing) significantly influences respiratory drive and the work of breathing during BiPAP ventilation. We analyzed CO2 movement during BiPAP ventilation to find a method of real time detection of CO2 rebreathing without the need of CO2 concentration measurement sampled from the circuit (method expensive and not routinely used). Observational study during routine care in 15 bed university hospital ICU. At 18 patients who required BiPAP ventilation, intubated or during noninvasive ventilation, during weaning period airflow, pressure and CO2 concentration signals were registered on both sides of venting port and 17 respiratory parameters were measured or calculated for each of 4747 respiratory cycles analyzed. Based on CO2 movement (expiration–inspiration sequences) 3 types of cycle were identified, type I and II do not induce rebreathing but type III does. To test differences between the 3 types ANOVA, t-tests, and canonical discriminant analysis (CDA) were used. Then a multilayer perceptron (MLP) network, a type of artificial neural network, using the above parameters (excluding CO2 concentration) was applied to automatically identify the three types of respiratory cycles. Of the 4747 respiratory cycles, 1849 were type I, 1545 type II, and 1353 type III. ANOVA and t-tests showed significant differences between the types of respiratory cycles. CDA confirmed a correct apportionment of 93.9% of the cycles; notably, of 97.9% of type III. MLP automatically classified the respiratory cycles into the three types with 98.8% accuracy. Three types of respiratory cycles could be distinguished based on CO2 movement during BiPAP ventilation. Artificial neural networks can be used to automatically detect respiratory cycle type III, the only inducing CO2 rebreathing. [ABSTRACT FROM AUTHOR]

Establishing long-term microbiome-based monitoring programs is critical for managing and conserving wild fish populations in response to climate change. In most cases, these studies have been conducted on gut and, to a lesser extent, skin (mucus) microbiomes. Here, we exploited the concept of liquid biopsy to study the circulating bacterial microbiome of two Northern halibut species of economic and ecological importance. Amplification and sequencing of the 16S rRNA gene were achieved using a single drop of blood fixed on FTA cards to identify the core blood microbiome of Atlantic and Greenland halibut populations inhabiting the Gulf of St. Lawrence, Canada. We provide evidence that the circulating microbiome DNA (cmDNA) is driven by genetic and environmental factors. More specifically, we found that the circulating microbiome signatures are species-specific and vary according to sex, size, temperature, condition factor, and geographical localization. Overall, our study provides a novel approach for detecting dysbiosis signatures and the risk of disease in wild fish populations for fisheries management, most notably in the context of climate change. [ABSTRACT FROM AUTHOR]

Despite the particular focus given to influenza since the 2009 influenza A(H1N1) pandemic, true burden of influenza-associated critical illness remains poorly known. The aim of this study was to identify factors influencing influenza burden imposed on intensive care units (ICUs) in a catchment population during recent influenza seasons. From 2008 to 2013, all adult patients admitted with a laboratory-confirmed influenza infection to one of the ICUs in the catchment area were prospectively included. A total of 201 patients (mean age: 63 ± 16, sex-ratio: 1.1) were included. The influenza-related ICU-bed occupancy rate averaged 4.3% over the five influenza seasons, with the highest mean occupancy rate (16.9%) observed during the 2012 winter. In-hospital mortality for the whole cohort was 26%. Influenza A(H1N1)pdm infections (pdm in the mentioned nomenclature refers to Pandemic Disease Mexico 2009), encountered in 51% of cases, were significantly associated with neither longer length of stay nor higher mortality (ICU and hospital) when compared to infections with other virus subtypes. SOFA score (OR, 1.12; 95% CI, 1.04–1.29) was the only independent factor significantly associated with a prolonged hospitalization. These results highlight both the frequency and the severity of influenza-associated critical illness, leading to a sustained activity in ICUs. Severity of the disease, but not A(H1N1)pdm virus, appears to be a major determinant of ICU burden related to influenza. [ABSTRACT FROM AUTHOR]

An increasing number of boreal marine species are expected to invade the warming Arctic Ocean with the potential to displace endemic species. We provide first evidence that Pacific sand lance ( Ammodytes hexapterus) is expanding its range in the Canadian Arctic Archipelago, a region far outside the species temperate-boreal traditional range south of the Bering Strait. To the best of our knowledge, supported by local Inuit knowledge, the species was not present in the area until the present decade. We observed an increasing density of larval Pacific sand lance with time over the 2011-2016 period, suggesting that environmental conditions are becoming increasingly favorable for the species to reproduce in the Central Canadian Arctic. The northward distribution change of Pacific sand lance is occurring earlier than predicted by current models and could trigger abrupt shifts in Arctic marine food webs if the boreal invader displaces polar cod, a key prey species for top predators in Arctic marine ecosystems. [ABSTRACT FROM AUTHOR]

The early life stages of Boreogadus saida and Arctogadus glacialis are morphologically similar, making it difficult to assess differences in their ecological niche. The present study documented for the first time the early life stage ecology of A. glacialis, compared it to that of B. saida, and identified the factors separating the niches of the two sympatric species. The 10,565 larval gadids collected in the Beaufort Sea from April to August of 2004 and 2008 were identified to species either directly by genetics and/or otolith nucleus size, or indirectly with a redistribution procedure. Between 8.0 and 8.7 % of all gadids were assigned to A. glacialis. Larvae of A. glacialis were longer at hatch and experienced lower mortality rates than those of B. saida. The two species shared similar spatiotemporal and vertical distributions, hatching season, and growth rate. Under the ice, feeding incidence of B. saida was low (14 %) relative to A. glacialis (88 %). At lengths <15 mm, both species specialized on different prey. The diet of fish >15 mm overlapped (Schoener's index = 0.7), with Calanus glacialis and C. hyperboreus providing >50 % of the carbon intake of both species. The higher mortality in B. saida may be explained by the smaller size at age from hatching to metamorphosis and a lower under-ice feeding incidence. The early larval stage appears to be the key period of niche divergence between the two species. [ABSTRACT FROM AUTHOR]

Current trends of fish communities in the interior Arctic Ocean are largely unknown, whereas more fishes of boreal origin are reported from the Chukchi and Barents Seas recently. To assess variability in species composition and spatiotemporal occurrence in ichthyoplankton in the southeast Beaufort Sea, we sampled larval and juvenile fish using square-conical nets in the upper water column (<100 m) from June to September between 2002 and 2011. Gadidae consisting of Boreogadus saida and Arctogadus glacialis numerically accounted for >75 % of total catches every month. Cottidae and Liparidae usually followed Gadidae, together representing 9-94 % of non-gadid species in number. The majority of dominant and subdominant species occurred ubiquitously through the sampling area, whereas Gymnocanthus tricuspis (Cottidae), Liparis gibbus (Liparidae), and Leptoclinus maculatus (Stichaeidae) occurred abundantly on the Mackenzie Shelf. In contrast, Triglops nybelini (Cottidae) was frequently found in the Amundsen Gulf, which was characterized by higher salinities (>25). Exceptional species composition was observed in September 2011, when Ammodytes hexapterus (Ammodytidae) numerically accounted for 67 % of non-gadid species. In the southeast Beaufort Sea, summer ichthyoplankton are characterized by the overwhelming dominance of Arctic gadids as well as the frequent occurrence of Arctic cottids and liparids. However, the sudden and frequent occurrence of A. hexapterus may be a first sign of significant changes in fish communities in the interior Arctic Ocean. [ABSTRACT FROM AUTHOR]

Purpose: Physicians play an important role in strategies to control health care spending. Being aware of the cost of prescriptions is surely the first step to incorporating cost-consciousness into medical practice. The aim of this study was to evaluate current intensivists' knowledge of the costs of common prescriptions and to identify factors influencing the accuracy of cost estimations. Methods: Junior and senior physicians in 99 French intensive care units were asked, by questionnaire, to estimate the true hospital costs of 46 selected prescriptions commonly used in critical care practice. Results: With an 83 % response rate, 1092 questionnaires were examined, completed by 575 (53 %) and 517 (47 %) junior and senior intensivists, respectively. Only 315 (29 %) of the overall estimates were within 50 % of the true cost. Response errors included a 14,756 ± 301 € underestimation, i.e., −58 ± 1 % of the total sum (25,595 €). High-cost drugs (>1000 €) were significantly ( p < 0.001) the most underestimated prescriptions (−67 ± 1 %). Junior grade physicians underestimated more costs than senior physicians ( p < 0.001). Using multivariate analysis, junior physicians [odds ratio (OR), 2.1; 95 % confidence interval (95 % CI), 1.43-3.08; p = 0.0002] and female gender (OR, 1.4; 95 % CI, 1.04-1.89; p = 0.02) were both independently associated with incorrect cost estimations. Conclusions: ICU physicians have a poor awareness of prescriptions costs, especially with regards to high-cost drugs. Considerable emphasis and effort are still required to integrate the cost-containment problem into the daily prescriptions in ICUs. [ABSTRACT FROM AUTHOR]

Even more, in the present study the shorter duration of sleep in case of no post extubation respiratory failure (2 h, median) than in case of respiratory failure (3,2 h, median), even if not statistically different, could be explained by the possibility to better resist to sleep pressure and stay awake in order to avoid respiratory failure. In their recent paper, AW Thille et al. look for an association between sleep assessed by polysomnography (PSG) performed in the afternoon and the night after extubation and the occurrence or not of respiratory failure/reintubation. [Extracted from the article]

Polar cod ( Boreogadus saida) and ice cod ( Arctogadus glacialis) are sympatric on continental shelves of the Arctic Ocean. The larvae and early juveniles of the two species are similar, and discrimination based on morphology and pigmentation is uncertain. We present a discrimination criterion based on the difference in lapillus nucleus size between genetically identified B. saida ( n = 441, 4.2-55.0 mm standard length) and A. glacialis ( n = 82, 8.6-45.5 mm). The product of the shortest and longest diameters of the nucleus (SN × LN) was 58 % larger in A. glacialis than in B. saida. The logistic regression (Ln[ p/(1 − p)] = 0.02687SN × LN − 17.5466), where p is the probability that the fish is A. glacialis, correctly reassigned 501 of the 523 fishes (96 %) used to build the model to their genetically determined species (99 % of B. saida and 80 % of A. glacialis). The same regression correctly classified 97 % of 189 fish sampled in 2002 and 2003 and not used in building the model (99 % of B. saida and 89 % of A. glacialis). [ABSTRACT FROM AUTHOR]

The amount of ultraviolet (UV)-B radiation reaching the sea surface has increased due to ozone depletion. Several laboratory studies have highlighted the negative impacts of UV radiation on fish using hatchery-reared specimens. However, potential differences in UV tolerance between wild and hatchery-reared fish have been given little consideration. Wild and reared juveniles of red sea bream and black sea bream were exposed to one of four different UV-B radiation levels (1.8; 1.1; 0.4; 0 W/m) for 4 h. Survival rate was measured every 2 h for a period of 24 h (red sea bream) or 48 h (black sea bream) following exposure. Wild and reared juvenile red sea bream were characterized by similar survival rate, with survival declining to almost 0 % 24 h after exposure at the 1.1 and 1.8 W/m levels. In black sea bream, wild individuals showed significantly higher survival than reared fish in levels 1.1 and 1.8 W/m. Melanophore density was also measured since melanin absorbs UV radiation. Wild black sea bream showed higher melanophore density compared to reared individuals, while no such difference was observed in red sea bream. We conclude that wild black sea bream juveniles acquire higher UV tolerance partly by increasing melanophore density through exposure to UV radiation. Our results indicate that the predicted impacts of UV radiation on fish populations solely based on experimentation with hatchery-reared specimens may be overestimated for some species. [ABSTRACT FROM AUTHOR]

As part of the Canadian contribution to the International Polar Year (IPY), several major international research programs have focused on offshore arctic marine ecosystems. The general goal of these projects was to improve our understanding of how the response of arctic marine ecosystems to climate warming will alter food web structure and ecosystem services provided to Northerners. At least four key findings from these projects relating to arctic heterotrophic food web, pelagic-benthic coupling and biodiversity have emerged: (1) Contrary to a long-standing paradigm of dormant ecosystems during the long arctic winter, major food web components showed relatively high level of winter activity, well before the spring release of ice algae and subsequent phytoplankton bloom. Such phenological plasticity among key secondary producers like zooplankton may thus narrow the risks of extreme mismatch between primary production and secondary production in an increasingly variable arctic environment. (2) Tight pelagic-benthic coupling and consequent recycling of nutrients at the seafloor characterize specific regions of the Canadian Arctic, such as the North Water polynya and Lancaster Sound. The latter constitute hot spots of benthic ecosystem functioning compared to regions where zooplankton-mediated processes weaken the pelagic-benthic coupling. (3) In contrast with another widely shared assumption of lower biodiversity, arctic marine biodiversity is comparable to that reported off Atlantic and Pacific coasts of Canada, albeit threatened by the potential colonization of subarctic species. (4) The rapid decrease of summer sea-ice cover allows increasing numbers of killer whales to use the Canadian High Arctic as a hunting ground. The stronger presence of this species, bound to become a new apex predator of arctic seas, will likely affect populations of endemic arctic marine mammals such as the narwhal, bowhead, and beluga whales. [ABSTRACT FROM AUTHOR]

During the International Polar Year (IPY), large international research programs provided a unique opportunity for assessing the current state and trends in major components of arctic marine ecosystems at an exceptionally wide spatio-temporal scale: sampling covered most regions of the Canadian Arctic (IPY-Canada's Three Oceans project), and the coastal and offshore areas of the southeastern Beaufort Sea were monitored over almost a full year (IPY-Circumpolar Flaw Lead project). The general goal of these projects was to improve our understanding of how the response of arctic marine ecosystems to climate warming will alter the productivity and structure of the food web and the ecosystem services it provides to Northerners. The present paper summarizes and discusses six key findings related to primary production (PP), which determines the amount of food available to consumers. (1) Offshore, the warming and freshening of the surface layer is leading to the displacement of large nanophytoplankton species by small picophytoplankton cells, with potentially profound bottom-up effects within the marine food web. (2) In coastal areas, PP increases as favourable winds and the deeper seaward retreat of ice promote upwelling. (3) Multiple upwelling events repeatedly provide food to herbivores throughout the growth season. (4) A substantial amount of pelagic PP occurs under thinning ice and cannot be detected by orbiting sensors. (5) Early PP in the spring does not imply a trophic mismatch with key herbivores. (6) The epipelagic ecosystem is very efficient at retaining carbon in surface waters and preventing its sedimentation to the benthos. While enhanced PP could result in increased fish and marine mammal harvests for Northerners, it will most likely be insufficient for sustainable large-scale commercial fisheries in the Canadian Arctic. [ABSTRACT FROM AUTHOR]

During the Circumpolar Flaw Lead System Study (CFL, 2007-2008), large aggregations of polar cod were detected in winter in the Amundsen Gulf (Western Canadian Arctic) using the EK60 echosounder of the CCGS Amundsen research icebreaker. Biomass estimated over 10 months reached a maximum of 0.732 kg m in February. Aggregations were encountered only in the presence of an ice cover from December to April. The vertical extent of the aggregations was dictated by temperature and zooplankton prey distribution. In winter, polar cod generally occupied the relatively warm deep Atlantic Layer (>0°C), but a fraction of the densest aggregations occasionally followed zooplankton prey up into the cold Pacific Halocline (−1.6 to 0°C). The diel vertical migration of polar cod was precisely synchronized with the seasonally increasing photoperiod. Throughout winter, polar cod aggregations migrated to progressively deeper regions (from 220 to 550 m bottom depths) in response to increasing light intensity, presumably to avoid predation by visual predators such as the ringed seal. Comparing Amundsen Gulf and Franklin Bay indicates that the entrapment of polar cod in embayments during winter is an important mechanism to provide marine mammal predators with dense concentrations of their main prey within their diving range. [ABSTRACT FROM AUTHOR]

Use of bilevel positive airway pressure (BLPAP) ventilators for noninvasive ventilation (NIV) is an established treatment for both acute and chronic ventilatory failure. Although BLPAP ventilator circuits are simpler than those of conventional ventilators, one drawback to their use is that they allow variable amounts of rebreathing to occur. The aim of this work is to measure the amount of CO2 reinsufflated in relation to the BLPAP ventilator circuit in patients, and to determine predictive factors for rebreathing. Eighteen adult patients were ventilated on pressure support, either by intubation or with mask ventilation, during a weaning period. The mean inspiratory fraction of CO2 (tidal FiCO2) reinsufflated from the circuit between the intentional leak and the ventilator was measured for each breath. The influence of end-tidal CO2 concentration (ETCO2), respiratory rate (RR), percentage of inspiratory time ( Ti/ TTOT), application of expiratory positive airway pressure (EPAP), and inspiratory tidal volume on magnitude of tidal FiCO2, as well as the influence of intubation versus NIV, were studied by univariate comparisons and logistic regression analysis. In a total of 11,107 cycles, tidal FiCO2 was 0.072 ± 0.173%. Of fractions measured, 8,976 (81%) were under 0.10% and 2,131 (19%) were over 0.10%, with mean values of 0.026 ± 0.027% and 0.239 ± 0.326%, respectively. ETCO2, EPAP, NIV versus intubation, and RR had significant predictive value for tidal FiCO2 >0.10%. BLPAP ventilators present a specific rebreathing risk to patients. However, that risk remains modest, even in intubated patients, provided that EPAP is applied. [ABSTRACT FROM AUTHOR]

We tested whether the predation dynamics of chub mackerel Scomber japonicus and spotted mackerel S. australasicus on young anchovy Engraulis japonicus relates to individual growth characteristics of the prey and could account for the growth-selective survival predicted by recruitment hypotheses. Juvenile and adult mackerel were sampled along with their young anchovy prey field in 2004 (juvenile mackerel and larval anchovy) and 2005 (adult mackerel and juvenile anchovy) off the Pacific coast of Honshu, Japan. The recent 5-day mean growth rate of larval and juvenile survivors and prey found in the stomach of mackerel was estimated from the otolith microstructure. No significant difference was found between the recent growth of larval or juvenile survivors and that of preyed individuals. We conclude that despite a relatively small body size, the high activity level and predation skills displayed by mackerel prevent fast-growing larvae and early juveniles from benefitting in terms of the expected survival advantage over slow-growers. Hence, growth-selective predation mortality of larval fish would depend on the feeding ecology of the predator rather than predator size. Selection for fast growth is more likely to occur under predation pressure from invertebrate organisms and small pelagic fish specialized on zooplankton, such as herring and anchovy. [ABSTRACT FROM AUTHOR]

The dawn chorus is a striking feature of spring mornings and a characteristic behaviour of many bird species, particularly the passerines. Dawn singing has been considered a reliable signal of male quality for mate and rival assessment. Singing is presumed to be relatively costly at dawn both because air temperatures are relatively low and because birds have not fed overnight. Models of optimal daily routine predict the existence of a “dusk chorus” in nocturnal birds, although this prediction has received little empirical attention. Nocturnal birds at dusk may be energy-limited because of a lack of daytime feeding, and singing at dusk may thus ensure signal reliability. Here, we used an observational and experimental approach to study vocal behaviour at dusk and dawn in a nocturnal raptor, the little owl Athene noctua. We assess whether male little owls adjust their vocal behaviour according to feeding stage (i.e. period of the night), ambient air temperature and territorial context (i.e. spontaneous calling behaviour vs elicited calling by intrusion). Across different temperatures, we find that both spontaneous vocal activity and inter-individual variability in call duration increased at dusk, clearly indicating a dusk chorus phenomenon. Results from playback presentations suggest that food, rather than air temperature, is likely to be more constraining at dusk. We discuss how comparing dusk and dawn choruses in nocturnal and diurnal species can provide insights into both mechanistic and functional aspects of signalling behaviour. [ABSTRACT FROM AUTHOR]

Objective. To compare the inspiratory volume pressure (VP) curves of the respiratory system (rs) produced by static occlusion (OCC) and dynamic low constant flow inflation (LCFI) methods using a new device in acute respiratory distress syndrome (ARDS) patients. Setting. A multidisciplinary 24-bed ICU in a tertiary university hospital. Patients. Eleven intubated and mechanically ventilated patients with ARDS. Measurements and results. OCC and LCFI methods were performed using the same ventilator, which had been specifically implemented for this purpose. LCFI of 5, 10, and 15 l/min and OCC were applied in a random order at zero end-expiratory positive pressure. Airway pressure was measured both proximal (Pao) and distal (Ptr) to the endotracheal tube. Lower inflection point (LIP) and maximal slope (Cmax,rs) were estimated using unbiased iterative linear regressions. LIPrs was obtained in all patients under LCFI and in nine patients under OCC. With LCFI of 5, 10, 15 l/min and OCC the average LIPrs values were 12.2±3.9, 12.9±4, 14.3±3.4, and 11.9 cm H2O for Pao and 11.9±3.9, 11.5±3.3, 12.5±3.4 and 11.8±4.4 for Ptr, respectively. Only the mean values of LIPrs for Pao with LCFI at 15 l/min were significantly different from those obtained for OCC. The Cmax,rs values found with the two methods were similar. Conclusions. An LCFI less than or equal to 10 l/min seems to be a quick, safe, and reliable method to determine LIPrs and Cmax,rs at the bedside. [ABSTRACT FROM AUTHOR]

A high molecular weight mitochondrial DNA (mtDNA) replication complex, associated with the mitochondrial membrane, was isolated by sucrose gradient centrifugation from purified wheat embryo mitochondria. This complex comprised the mtDNA as well as enzyme activities involved in the replication and transcription of the organelle genome, such as DNA polymerase, RNA polymerase and topoisomerase type I. The isolated complex is active in mtDNA and mtRNA synthesis in vitro. Electron microscopy and lipid analysis confirmed the membrane origin of this complex. Enzyme activities are resistant to physiological ionic strengths, 0.1-0.2 M KCl, while the membrane-mtDNA association is resistant up to 1 M KCl. DNase treatment of the complex released the DNA polymerase activity while protease treatment solubilized mtDNA, suggesting the direct interaction of mtDNA with membrane protein(s). The use of a novel approach to detect mtDNA fragments specifically retained by the mitochondrial membranes after Sal I digestion of the complex suggests that specific mtDNA sequences anchor mtDNA to mitochondrial membranes. [ABSTRACT FROM AUTHOR]

Introduction: Pyogenic ventriculitis is an uncommon but often severe intracranial infection.Methods: Case report with illustrative CT and MRI imaging.Results: A 49-year-old man presented with an intraparenchymal hematoma with extension of blood into the ventricles. The persistence of intraventricular blood necessitated long term placement of an external ventricular drain. On day 23 after admission, a contrast-enhanced CT scan of the brain showed slight hydrocephalus, irregular debris in the dependent part of the occipital horns and periventricular hypodensities. An MRI scan confirmed the characteristic hallmarks of pyogenic ventriculitis on the T2-weighted, Fluid Attenuated Inversion Recovery (FLAIR), and diffusion-weighted and contrast-enhanced T1-weighted images.Conclusion: Neuroimaging is crucial in clearly depicting pyogenic ventriculitis. A contrast-enhanced CT scan, but especially MR imaging, is an ideal tool to reliably diagnose this life-threatening cerebral infection. [ABSTRACT FROM AUTHOR]

The article describes the case of a 61-year-old man with facial cellulitis secondary to chronic non-invasive ventilation. Topics discussed include heart transplantation, obstructive sleep apnea, and continuous positive airway pressure (CPAP). Also mentioned are intensive care units (ICUs), computed tomography scanning, and mechanical invasive ventilation.

A correction to the article "Contrasting the early life histories of sympatric Arctic gadids Boreogadus saida and Arctogadus glacialis in the Canadian Beaufort Sea" by Caroline Bouchard et al. published online on November 29, 2016 is presented.

A correction to the article related to cost awareness of physicians in intensive care units (ICU) that was published in a previous issue is presented.

A letter to the editor is presented in response to the article about inactive tuberculosis cavity which is responsible for fatal cerebral air embolism in the previous issue.

Describes a case of a fulminant hepatitis in a patient with sulfasalazine-induced drug rash with eosinophilia and systemic symptoms syndrome. Development of the patient of generalized maculopapulous rash within 15 days of the administration of sulfasalazine; Detection of massive centrolobular necrosis and dense inflammatory infiltrates containing lymphocytes and eosinophils upon histological examination; Conclusion of the physician for the case to be that of immunoallergic drug-induced hepatitis.