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In this work, we studied the mantle flow around cratonic keels using numerical models to simulate the thermochemical convection in the terrestrial mantle taking into account the relative displacement between the lithosphere and asthenosphere. The numerical simulations were performed using the finite element code developed by Sacek (2017) to solve the Stokes Flow for an incompressible Newtonian fluid. Several synthetic models in 2D and 3D were constructed considering different keel geometries and different regimes of relative displacement between the lithosphere and asthenosphere. In the present numerical experiments, we adopted a rheology in which the viscosity of the mantle is controlled by temperature, pressure and composition, assuming that the cratonic keel is compositionally more viscous than the surrounding asthenosphere, using a factor f to rescale the lithospheric viscosity compared to the asthenospheric one. We tested different f values, reference viscosity for the asthenosphere, and relative velocity between the lithosphere and the base of the upper mantle, quantifying the amount of deformation of the cratonic keel in each scenario. In general, we conclude that for a relatively low compositional factor (f < 20), the lithospheric keel can be significantly deformed in a time interval of few tens of million years when the lithosphere is moving horizontally relative to the base of the upper mantle, does not preserving its initial geometry. The synthetic models can be helpful for a better understanding of the interaction in the lithosphere-asthenosphere interface such as the deformation and flow patterns in the mantle around the keels, the rate of erosion of the root of the continental lithosphere due to the convection in the upper mantle and how it affects the thermal flow to the surface.Sacek, V. (2017). Post-rift influence of small-scale convection on the landscape evolution at divergent continental margins. Earth and Planetary Science Letters, 459, 48-57.

From a government perspective, shared-use or open-access infrastructure arrangements can provide significant prospects for sustainable development. The shared use of infrastructure built by mining companies can spur and support additional mining projects and other economic activities and services to the benefit of surrounding communities and other third-party beneficiaries. From the viewpoint of a mining company, however, such arrangements pose risks to profitability and may, in some instances, benefit competitors. This study uses lessons learned from the shared-use arrangements along the Carajás railway corridor in Brazil to shed light on how to strike a balance between divergent private and public interests, and how countries may learn from this approach in order to increase the benefits of existing and future shared-use projects.

This work aims to evaluate the carbon footprint (CF) of microalgae production in a closed pilot-scale multi-tubular photobioreactor (PBR), on a gate-to-gate approach. Primary data from real production conditions complemented with data from the literature and life cycle inventory databases was used. The carbon embedded in the PBR’s construction materials and nutrients necessary for the microalgae growth were considered. A global CF of 68.34 kg CO2-eq/kg dry biomass was obtained. A CF of 1.72 kg CO2-eq/kg dry biomass was calculated for the PBR construction stage, contributing to 3 % of the overall value. For 74 kg of dry biomass/year produced with this PBR, the CF for this stage was 66.62 kg CO2-eq/kg dry biomass, corresponding to 97 % of the total global CF. In this study, electricity production for the reactor operation is the major contributor (79 %) to the overall CF, followed by the production of nutrients used to prepare the culture medium (21 %). CO2 fixation by microalgae reduces the global value by 3 %.

Sampling inspection plans are used in the food industry to determine whether a batch of food is contaminated or not. Testing for pathogens is mandatory in several foodstuffs because some bacteria pose a significant risk to human health, even when these are consumed in minute quantity. Test performance measures such as sensitivity and specificity are generally ignored in microbiological risk assessment and food quality assurance. In this research, we examine the impact of imperfect analytical tests on sampling inspection plans for presence-absence characteristics. We discuss several plausible scenarios and assess the risk for the consumers. The method is illustrated using data collected over 2 years for Cronobacter spp (formerly Enterobacter sakazakii) in skimmed milk powder. The probability of contamination and the test sensitivity and specificity are estimated using Bayesian methods. We examine the sampling plans proposed by the Codex Alimentarius and by the New Zealand's Ministry of Primary Industries for this pathogen. A cost analysis is performed to show the economic loss due to measurement errors. We describe the strengths and limitations of these plans under different conditions and propose a plan that could provide better protection to the consumers as well as to the producers.

Microbiological testing represents a significant expenditure for producers. Two new double sampling plans employing a compressed limit in the first stage of inspection were proposed to reduce the testing costs. These plans were designed for sanitary characteristics where the bacterial count generally fits a Poisson or a mixed-Poisson distribution. Both plans showed improved consumer protection with substantially smaller average sample size. The application of the new plans was validated using an empirical dataset of aerobic plate counts observed in milk powder samples. The new plans enabled a sample size reduction of between 20 and 75% compared to the actual sampling procedures.

In the recently published article, “Heterogeneous incidence and propagation of spreading depolarizations,” it is shown, in vivo and in vitro, how KCl-induced spreading depolarizations in mouse and rat brains can be highly variable, and that they are not limited, as once thought, to a concentric, isotropic, or homogenous depolarization wave in space or in time. The reported results serve as a link between the different species, and this paper contributes to changing the way in which SD expansion is viewed in the lissencephalic brain. Here, we discuss their results with our previous observations made in the gyrencephalic swine brain, in computer simulations, and in the human brain.

Background Multiple aspects of nurses’ rosters interact to affect the quality of patient care they can provide and their own health, safety and wellbeing. Objectives (1) Develop and test a matrix incorporating multiple aspects of rosters and recovery sleep that are individually associated with three fatigue-related outcomes - fatigue-related clinical errors, excessive sleepiness and sleepy driving; and (2) evaluate whether the matrix also predicts nurses’ ratings of the effects of rosters on aspects of life outside work. Design Develop and test the matrix using data from a national survey of nurses’ fatigue and work patterns in six hospital-based practice areas with high fatigue risk. Methods Survey data included demographics, work patterns (previous 14 days), choice about shifts, and the extent to which work patterns cause problems with social life, home life, personal relationships, and other commitments (rated 1 = not at all to 5 = very much). Matrix variables were selected based on univariate associations with the fatigue-related outcomes, limits in the collective employment contract, and previous research. Each variable was categorised as lower (score 0), significant (score 1), or higher risk (score 2). Logistic multiple regression modelling tested the independent predictive power of matrix scores against models including all the (uncategorised) work pattern and recovery sleep variables with significant univariate associations with each outcome variable. Model fit was measured using Akaike and Bayesian Information Criterion statistics. Results Data were included from 2358 nurses who averaged at least 30 h/week in the previous fortnight in one of the target practice areas. Final matrix variables were: total hours worked; number of shift extensions >30 min, night shifts; breaks After controlling for gender, ethnicity, years of nursing experience, and the extent of shift choice, the matrix score was a significant independent predictor of each of the three fatigue-related outcomes, and for all four aspects of life outside work. For all outcome variables, the model including the matrix score was a better fit to the data than the equivalent model including all the (uncategorised) work pattern variables. Conclusions A matrix that predicts the likelihood of nurses reporting fatigue-related safety outcomes can be used to compare the impact of rosters both at work and outside work. It can be used for roster design and management, and to guide nurses’ choices about the shifts they work.

A techno-economic assessment for the direct production of ethanol using a genetically-modified microalgae has been studied. It was considered two main scenarios for process modelling: i) bioenergy-driven microalgae plant, i.e., focused on the production of fuel-grade ethanol and biogas for CHP and, ii) biorefinery-driven microalgae plant, focused on the recovery of added-value bioproducts (zeaxanthin and phycocyanin) along with ethanol and CHP production. These main scenarios and several variants were modelled and optimized for a small-scale demo plant of 1000 Lethanol/day and extrapolated for larger production capacities. Results showed that despite the innovative approach of direct production of ethanol by microalgae, the bioenergy-driven scenario is non-feasible under the studied conditions. Conversely, ethanol production becomes economically feasible as co-product in the biorefinery-driven scenario although having payback periods>10 years. Furthermore, if only bio-based products are produced the NPV and the payback are even more positive, 104.8 M€ and ca. 5 years, respectively. info:eu-repo/semantics/publishedVersion

The main objective of this study was to generate a hemodynamically stable swine model to detect spreading depolarizations (SDs) using electrocorticography (ECoG) and intrinsic optical signal (IOS) imaging and laser speckle flowmetry (LSF) after a 30-h middle cerebral artery (MCA) occlusion (MCAo) in German Landrace Swine. A total of 21 swine were used. The study comprised a training group (group 1, n = 7), a group that underwent bilateral craniectomy and MCAo (group 2, n = 10) and a group used for 2,3,5-triphenyltetrazolium (TTC) staining (group 3, n = 5). In group 2, nine animals that underwent MCAo survived for 30 h, and one animal survived for 12 h. We detected MCA variants with 2 to 4 vessels. In all cases, all of the MCAs were occluded. The intensity changes exhibited by IOS and LSF after clipping were closely correlated and indicated a lower blood volume and reduced blood flow in the middle cerebral artery territory. Using IOS, we detected a mean of 2.37 ± (STD) 2.35 SDs/h. Using ECoG, we detected a mean of 0.29 ± (STD) 0.53 SDs/h. Infarctions were diagnosed using histological analysis. TTC staining in group 3 confirmed that the MCA territory was compromised and that the anterior and posterior cerebral arteries were preserved. We confirm the reliability of performing live monitoring of cerebral infarctions using our MCAo protocol to detect SDs.

Spreading Depolarization (SD) is a phenomenon in the brain related to the abrupt depolarization of neurons in gray matter which results from a break-down of ion gradients across the neuron membrane and propagates like a wave of ischemia. While modulating the hemodynamic response of the SDs is a therapeutic target, the lack of imaging methods that allow for monitoring SDs with high spatiotemporal resolution hinder progress in the field. In this work, we address this bottleneck with a new method for brain imaging based on multispectral imaging (MSI).

Spreading depolarization (SD) is a self-propagating wave of near-complete neuronal depolarization that is abundant in a wide range of neurological conditions, including stroke. SD was only recently documented in humans and is now considered a therapeutic target for brain injury, but the mechanisms related to SD in complex brains are not well understood. While there are numerous approaches to interventional imaging of SD on the exposed brain surface, measuring SD deep in brain is so far only possible with low spatiotemporal resolution and poor contrast. Here, we show that photoacoustic imaging enables the study of SD and its hemodynamics deep in the gyrencephalic brain with high spatiotemporal resolution. As rapid neuronal depolarization causes tissue hypoxia, we achieve this by continuously estimating blood oxygenation with an intraoperative hybrid photoacoustic and ultrasonic imaging system. Due to its high resolution, promising imaging depth and high contrast, this novel approach to SD imaging can yield new insights into SD and thereby lead to advances in stroke, and brain injury research.

State-of-the-art concepts in the field of computer assisted medical interventions are typically based on registering pre-operative imaging data to the patient. While this approach has many relevant clinical applications, it suffers from one core bottleneck: it cannot account for tissue dynamics because it works with “offline” data. To overcome this issue, we propose a new approach to surgical imaging that combines the power of multispectral imaging with the speed and robustness of deep learning based image analysis. Core innovation is an end-to-end deep learning architecture that integrates all preprocessing steps as well as the actual regression task in a single network. According to a quantitative in silico validation, our approach is well-suited for solving the inverse problem of relating multispectral image pixels to underlying functional tissue properties in real time. A porcine study further suggests that our method is capable of monitoring haemodynamic changes in vivo. Deep learning based multispectral imaging could thus become a valuable tool for imaging tissue dynamics.

Contains fulltext : 206372.pdf (Publisher’s version ) (Closed access) Observer variability in local radiological reading is a major concern in large-scale multi-center traumatic brain injury (TBI) studies. A central review process has been advocated to minimize this variability. The aim of this study is to compare central with local reading of TBI imaging datasets and to investigate the added value of central review. A total of 2050 admission computed tomography (CT) scans from subjects enrolled in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study were analyzed for seven main CT characteristics. Kappa statistics were used to calculate agreement between central and local evaluations and a center-specific analysis was performed. The McNemar test was used to detect whether discordances were significant. Central interobserver and intra-observer agreement was calculated in a subset of patients. Good agreement was found between central and local assessment for the presence or absence of structural pathology (CT+, CT-, kappa = 0.73) and most CT characteristics (kappa = 0.62 to 0.71), except for traumatic axonal injury lesions (kappa = 0.37). Despite good kappa values, discordances were significant in four of seven CT characteristics (i.e., midline shift, contusion, traumatic subarachnoid hemorrhage, and cisternal compression; p = 0.0005). Central reviewers showed substantial to excellent interobserver and intra-observer agreement (kappa = 0.73 to kappa = 0.96), contrasted by considerable variability in local radiological reading. Compared with local evaluation, a central review process offers a more consistent radiological reading of acute CT characteristics in TBI. It generates reliable, reproducible data and should be recommended for use in multi-center TBI studies.

Virtual reality (VR) technology is an emerging tool that is supporting the connection between conservation research and public engagement with environmental issues. The use of VR in ecology consists of interviewing diverse groups of people while they are immersed within a virtual ecosystem to produce better information than more traditional surveys. However, at present, the relatively high level of expertise in specific programming languages and disjoint pathways required to run VR experiments hinder their wider application in ecology and other sciences. We present R2VR, a package for implementing and performing VR experiments in R with the aim of easing the learning curve for applied scientists including ecologists. The package provides functions for rendering VR scenes on web browsers with A-Frame that can be viewed by multiple users on smartphones, laptops, and VR headsets. It also provides instructions on how to retrieve answers from an online database in R. Three published ecological case studies are used to illustrate the R2VR workflow, and show how to run a VR experiments and collect the resulting datasets. By tapping into the popularity of R among ecologists, the R2VR package creates new opportunities to address the complex challenges associated with conservation, improve scientific knowledge, and promote new ways to share better understanding of environmental issues. The package could also be used in other fields outside of ecology.

Haemodynamic responses to spreading depolarizations (SDs) have an important role during the development of secondary brain damage. Characterization of the haemodynamic responses in larger brains, however, is difficult due to movement artefacts. Intrinsic optical signal (IOS) imaging, laser speckle flowmetry (LSF) and electrocorticography were performed in different configurations in three groups of in total 18 swine. SDs were elicited by topical application of KCl or occurred spontaneously after middle cerebral artery occlusion. Movement artefacts in IOS were compensated by an elastic registration algorithm during post-processing. Using movement-compensated IOS, we were able to differentiate between four components of optical changes, corresponding closely with haemodynamic variations measured by LSF. Compared with ECoG and LSF, our setup provides higher spatial and temporal resolution, as well as a better signal-to-noise ratio. Using IOS alone, we could identify the different zones of infarction in a large gyrencephalic middle cerebral artery occlusion pig model. We strongly suggest movement-compensated IOS for the investigation of the role of haemodynamic responses to SDs during the development of secondary brain damage and in particular to examine the effect of potential therapeutic interventions in gyrencephalic brains.

The aim was to characterize the effects of magnesium sulfate, using i.v. bolus and local administration, using intrinsic signal imaging, and on electrocorticographic activity during the induction and propagation of spreading depolarizations in the gyrencephalic porcine brain. Local application of magnesium sulfate led to a complete inhibition of spreading depolarizations. One hour after washing out the topical magnesium sulfate, re-incidence of the spreading depolarizations was observed in 50% of the hemispheres. Those spreading depolarizations showed attenuation in hemodynamic characteristics and speed in intrinsic optical signal imaging. The electrical amplitude decreased through electrocorticographic activity. Intravenous magnesium therapy showed no significant effects on spreading depolarization incidence and characteristics.

A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão’s historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum of spreading mass depolarizations, a concept that is central to understanding their pathologic effects. Within minutes of acute severe ischemia, the onset of persistent depolarization triggers the breakdown of ion homeostasis and development of cytotoxic edema. These persistent changes are diagnosed as diffusion restriction in magnetic resonance imaging and define the ischemic core. In delayed lesion growth, transient spreading depolarizations arise spontaneously in the ischemic penumbra and induce further persistent depolarization and excitotoxic damage, progressively expanding the ischemic core. The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion development. These pathophysiologic concepts establish a working hypothesis for translation to human disease, where complex patterns of depolarizations are observed in acute brain injury and appear to mediate and signal ongoing secondary damage.

Spreading depolarization (SD) generates significant alterations in cerebral haemodynamics, which can have detrimental consequences on brain function and integrity. Ketamine has shown an important capacity to modulate SD; however, its impact on SD haemodynamic response is incompletely understood. We investigated the effect of two therapeutic ketamine dosages, a low-dose of 2 mg/kg/h and a high-dose of 4 mg/kg/h, on the haemodynamic response to SD in the gyrencephalic swine brain. Cerebral blood volume, pial arterial diameter and cerebral blood flow were assessed through intrinsic optical signal imaging and laser-Doppler flowmetry. Our findings indicate that frequent SDs caused a persistent increase in the baseline pial arterial diameter, which can lead to a diminished capacity to further dilate. Ketamine infused at a low-dose reduced the hyperemic/vasodilative response to SD; however, it did not alter the subsequent oligemic/vasoconstrictive response. This low-dose did not prevent the baseline diameter increase and the diminished dilative capacity. Only infusion of ketamine at a high-dose suppressed SD and the coupled haemodynamic response. Therefore, the haemodynamic response to SD can be modulated by continuous infusion of ketamine. However, its use in pathological models needs to be explored to corroborate its possible clinical benefit.

Objective Spreading depolarization (SD) occurs after traumatic brain injury, subarachnoid hemorrhage, malignant hemispheric stroke and intracranial hemorrhage. SD has been associated with secondary brain injury, which can be reduced by ketamine. In this present study frequency bands of electrocorticographic (ECoG) recordings were investigated with regards to SDs. Methods A total of 43 patients after acute brain injury were included in this retrospective and explorative study. Relative delta 0.5–4Hz, theta 4–8Hz, alpha 8–13Hz and beta 13–40Hz bands were analyzed with regards to SD occurrence and analgesic and sedative administration. Higher frequencies, including gamma 40–70Hz, fast gamma 70–100Hz and high frequency oscillations 100–200Hz were analyzed in a subset of patients with a sampling rate of up to 400Hz. Results A close association of relative beta frequency and SD was found. Relative beta frequency was suppressed up to two hours prior to SD when compared to hours with no SD. This finding was partially explained by administration of ketamine. Even after removal of all patient data during administration of ketamine, SDs occurred predominantly during times with low relative beta frequency in a patient-independent analysis. Conclusion Suppression of beta frequency by ketamine or without ketamine is associated with low SD counts. Significance Alteration of beta frequency might help to predict occurrence of SDs in acutely brain injured patients.

Sampling inspection plans are principally used to determine whether a batch of food is contaminated or not. In this theoretical research, we study the effect of increasing the analytical unit amount on the performance of microbiological sampling plans, and on the resulting quality after inspection. We discuss several scenarios of homogeneous and inhomogeneous contamination for assessing the consumer's risk. Several statistical approaches to describe the effect of an increase in analytical amount are studied. We provided a procedure for designing of the sampling plan for a given consumer's risk and according to different dispersion parameters and contamination levels.

The design of attribute sampling inspection plans based on compressed or narrow limits for food safety applications is covered. Artificially compressed limits allow a significant reduction in the number of analytical tests to be carried out while maintaining the risks at predefined levels. The design of optimal sampling plans is discussed for two given points on the operating characteristic curve and especially for the zero acceptance number case. Compressed limit plans matching the attribute plans of the International Commission on Microbiological Specifications for Foods are also given. The case of unknown batch standard deviation is also discussed. Three-class attribute plans with optimal positions for given microbiological limit M and good manufacturing practices limit m are derived. The proposed plans are illustrated through examples. R software codes to obtain sampling plans are also given. Copyright © 2016 John Wiley & Sons, Ltd.

Numerous organisations collect data in the Great Barrier Reef (GBR), but they are rarely analysed together due to different program objectives, methods, and data quality. We developed a weighted spatio-temporal Bayesian model and used it to integrate image-based hard-coral data collected by professional and citizen scientists, who captured and/or classified underwater images. We used the model to predict coral cover across the GBR with estimates of uncertainty; thus filling gaps in space and time where no data exist. Additional data increased the model's predictive ability by 43%, but did not affect model inferences about pressures (e.g. bleaching and cyclone damage). Thus, effective integration of professional and high-volume citizen data could enhance the capacity and cost-efficiency of monitoring programs. This general approach is equally viable for other variables collected in the marine environment or other ecosystems; opening up new opportunities to integrate data and provide pathways for community engagement/stewardship.

This work aims to evaluate the water footprint of microalgae cultivation in a closed pilot-scale multi-tubular photobioreactor, taking into account the life cycle stages of reactor construction and its operation for microalgae cultivation, on a gate-to-gate approach. The data was obtained from real production conditions complemented with data from the literature and life cycle inventory databases. Results indicate that the total water footprint lies in the range of 2.4-6.8 m3/kg dry biomass, being the PBR operation stage responsible for the largest contribution (> 60 %), mainly due to water consumption associated to electricity and nutrients production for the PBR operation.

BACKGROUND: Disease progression and delayed neurological complications are common after aneurysmal subarachnoid hemorrhage (aSAH). We explored the potential of quantitative blood-brain barrier (BBB) imaging to predict disease progression and neurological outcome. METHODS: Data were collected as part of the Co-Operative Studies of Brain Injury Depolarizations (COSBID). We analyzed retrospectively, blinded and semi-automatically magnetic resonance images from 124 aSAH patients scanned at 4 time points (24–48 h, 6–8 days, 12–15 days and 6–12 months) after the initial hemorrhage. Volume of brain with apparent pathology and/or BBB dysfunction (BBBD), subarachnoid space and lateral ventricles were measured. Neurological status on admission was assessed using the World Federation of Neurosurgical Societies and Rosen-Macdonald scores. Outcome at ≥6 months was assessed using the extended Glasgow outcome scale and disease course (progressive or non-progressive based on imaging-detected loss of normal brain tissue in consecutive scans). Logistic regression was used to define biomarkers that best predict outcomes. Receiver operating characteristic analysis was performed to assess accuracy of outcome prediction models. FINDINGS: In the present cohort, 63% of patients had progressive and 37% non-progressive disease course. Progressive course was associated with worse outcome at ≥6 months (sensitivity of 98% and specificity of 97%). Brain volume with BBBD was significantly larger in patients with progressive course already 24–48 h after admission (2.23 (1.23–3.17) folds, median with 95%CI), and persisted at all time points. The highest probability of a BBB-disrupted voxel to become pathological was found at a distance of ≤1 cm from the brain with apparent pathology (0·284 (0·122–0·594), p

Introduction Airlines are required to monitor the effectiveness of their pilot fatigue risk management. The present survey sought the views of all pilots at Delta Air Lines on fatigue-related issues raised by their colleagues participating in regular airline safety audits. Methods All 13,217 pilots from 9 aircraft fleets were invited to participate in an anonymous online survey. Questions related to aspects of scheduling, fatigue mitigations, and fatigue safety culture. Results There were 1108 pilots who completed the survey (response rate = 8.4%). On 7/9 fleets, most pilots thought 5- to 7-d rotations were too long (exceptions: B747, median = 14 d; A330 median = 8.5 d). In the previous year, on average across all fleets, 60.6% of pilots had worked up to or beyond their personal rotation limit (minimum, B747 = 6.3%; maximum, MD88/90 = 75.9%). Rotations where duty periods start progressively earlier were considered highly fatiguing by 73.8% of pilots, compared to 14.7% for rotations where duty periods started progressively later and 1.6% for rotations with successive duty periods starting at the same time. The median optimum break length between rotations was 3-4 d. On 7/9 fleets, fewer than 20% of pilots tried to build their monthly schedules with back-to-back rotations (exceptions: B747, 43.8%; A330, 34.3%). Awareness of fatigue and perceptions of company fatigue risk management activities varied widely among fleets. Discussion The findings identify possible improvements in fatigue risk management and highlight that care is needed when extrapolating from one operational context to another. As a safety assurance exercise, we recommend repeating the survey biannually, or sooner if warranted by specific circumstances.Gander P, Mangie J, Phillips A, Santos-Fernandez E, Wu LJ. Monitoring the effectiveness of fatigue risk management: a survey of pilots' concerns. Aerosp Med Hum Perform. 2018; 89(10):889-895.

Spreading depolarization (SD) occurs alongside brain injuries and it can lead to neuronal damage. Therefore, pharmacological modulation of SD can constitute a therapeutic approach to reduce its detrimental effects and to improve the clinical outcome of patients. The major objective of this article was to produce a systematic review of all the drugs that have been tested against SD. Of the substances that have been examined, most have been shown to modulate certain SD characteristics. Only a few have succeeded in significantly inhibiting SD. We present a variety of strategies that have been proposed to overcome the notorious harmfulness and pharmacoresistance of SD. Information on clinically used anesthetic, sedative, hypnotic agents, anti-migraine drugs, anticonvulsants and various other substances have been compiled and reviewed with respect to the efficacy against SD, in order to answer the question of whether a drug at safe doses could be of therapeutic use against SD in humans.

ObjectiveTo investigate whether spreading depolarization (SD)-related variables at 2 different time windows (days 1–4 and 5–8) after aneurysmal subarachnoid hemorrhage (aSAH) correlate with the stereologically determined volume of early focal brain injury on the preinterventional CT scan.MethodsIn this observational multicenter study of 54 patients, volumes of unaffected brain tissue, ventricles, cerebellum, aSAH, intracerebral hemorrhage, and focal parenchymal hypodensity were stereologically estimated. Patients were electrocorticographically monitored using subdural electrodes for 81.8 hours (median) (interquartile range: 70.6–90.5) during days 1–4 (n = 54) and for 75.9 (59.5–88.7) hours during days 5–8 (n = 51). Peak total SD-induced depression duration of a recording day (PTDDD) and peak numbers of (1) SDs, (2) isoelectric SDs, and (3) spreading depressions of a recording day were determined following the recommendations of the Co-Operative Studies on Brain Injury Depolarizations.ResultsThirty-three of 37 patients with early focal brain injury (intracerebral hemorrhage and/or hypodensity) in contrast to 7 of 17 without displayed SDs during days 1–4 (sensitivity: 89% [95% confidence interval, CI: 75%–97%], specificity: 59% [CI: 33%–82%], positive predictive value: 83% [CI: 67%–93%], negative predictive value: 71% [CI: 42%–92%], Fisher exact test, p < 0.001). All 4 SD-related variables during days 1–4 significantly correlated with the volume of early focal brain injury (Spearman rank order correlations). A multiple ordinal regression analysis identified the PTDDD as the most important predictor.ConclusionsOur findings suggest that early focal brain injury after aSAH is associated with early SDs and further support the notion that SDs are a biomarker of focal brain lesions.

Background General supportive and preventive measures in the intensive care management of traumatic brain injury (TBI) aim to prevent or limit secondary brain injury and optimize recovery. The aim of this survey was to assess and quantify variation in perceptions on intensive care unit (ICU) management of patients with TBI in European neurotrauma centers. Methods We performed a survey as part of the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. We analyzed 23 questions focused on: 1) circulatory and respiratory management; 2) fever control; 3) use of corticosteroids; 4) nutrition and glucose management; and 5) seizure prophylaxis and treatment. Results The survey was completed predominantly by intensivists (n = 33, 50%) and neurosurgeons (n = 23, 35%) from 66 centers (97% response rate). The most common cerebral perfusion pressure (CPP) target was > 60 mmHg (n = 39, 60%) and/or an individualized target (n = 25, 38%). To support CPP, crystalloid fluid loading (n = 60, 91%) was generally preferred over albumin (n = 15, 23%), and vasopressors (n = 63, 96%) over inotropes (n = 29, 44%). The most commonly reported target of partial pressure of carbon dioxide in arterial blood (PaCO2) was 36–40 mmHg (4.8–5.3 kPa) in case of controlled intracranial pressure (ICP)

Background: Disease progression and delayed neurological complications are common after aneurysmal subarachnoid hemorrhage (aSAH). We explored the potential of quantitative blood-brain barrier (BBB) imaging to predict disease progression and neurological outcome. Methods: Data were collected as part of the Co-Operative Studies of Brain Injury Depolarizations (COSBID). We analyzed retrospectively, blindly and semi-automatically magnetic resonance images from 124 aSAH patients scanned at 4 time points (24-48 h, 6-8 days, 12-15 days and 6-12 months) after the initial hemorrhage. Volume of brain with apparent pathology and BBB dysfunction (BBBD), subarachnoid space and lateral ventricles were measured. Neurological status on admission was assessed using the Fisher grades, World Federation of Neurosurgical Societies and Rosen-Macdonald (RMS) scores. Clinical outcome at 6 months or later was assessed using the extended Glasgow outcome scale. Findings: Based on repeated volumetric measures of pathological brain tissue and CSF, patients were categorized as having either progressive (increased pathology; 64%) or nonprogressive (36%) disease course. No differences were found between the two groups in aneurysm locations, neurological status on admission, initial brain pathology or treatment (coiling or clipping). Females were older and more likely to have a non-progressive course compared to males (p=0·01). Progressive course was associated with worse outcome at ≥6 months. A substantial brain volume with BBBD was found already 24-48 h after admission, and persisted at all time points. Brain volume with BBBD was significantly larger in patients with progressive course. BBBD increased the likelihood of a normal brain tissue to become pathological (p

Testing composite samples is a useful strategy to achieve sampling economy. Several studies have shown the effectiveness of this technique under the assumption of perfect mixing of primary samples. This paper investigates the effect of imperfect composite sample preparation on the performance of two and three-class variables sampling inspection plans, and identifies scenarios in which testing composite samples is not advantageous. The design of sampling plans using composite samples is discussed and an implementation guide based on two points of the OC curve for perfect and imperfect mixing is provided.

OBJECT The pressure reactivity index (PRx) correlates with outcome after traumatic brain injury (TBI) and is used to calculate optimal cerebral perfusion pressure (CPPopt). The PRx is a correlation coefficient between slow, spontaneous changes (0.003–0.05 Hz) in intracranial pressure (ICP) and arterial blood pressure (ABP). A novel index—the so-called long PRx (L-PRx)—that considers ABP and ICP changes (0.0008–0.008 Hz) was proposed. METHODS The authors compared PRx and L-PRx for 6-month outcome prediction and CPPopt calculation in 307 patients with TBI. The PRx- and L-PRx–based CPPopt were determined and the predictive power and discriminant abilities were compared. RESULTS The PRx and L-PRx correlation was good (R = 0.7, p < 0.00001; Spearman test). The PRx, age, CPP, and Glasgow Coma Scale score but not L-PRx were significant fatal outcome predictors (death and persistent vegetative state). There was a significant difference between the areas under the receiver operating characteristic curves calculated for PRx and L-PRx (0.61 ± 0.04 vs 0.51 ± 0.04; z-statistic = −3.26, p = 0.011), which indicates a better ability by PRx than L-PRx to predict fatal outcome. The CPPopt was higher for L-PRx than for PRx, without a statistical difference (median CPPopt for L-PRx: 76.9 mm Hg, interquartile range [IQR] ± 10.1 mm Hg; median CPPopt for PRx: 74.7 mm Hg, IQR ± 8.2 mm Hg). Death was associated with CPP below CPPopt for PRx (χ2 = 30.6, p < 0.00001), and severe disability was associated with CPP above CPPopt for PRx (χ2 = 7.8, p = 0.005). These relationships were not statistically significant for CPPopt for L-PRx. CONCLUSIONS The PRx is superior to the L-PRx for TBI outcome prediction. Individual CPPopt for L-PRx and PRx are not statistically different. Deviations between CPP and CPPopt for PRx are relevant for outcome prediction; those between CPP and CPPopt for L-PRx are not. The PRx uses the entire B-wave spectrum for index calculation, whereas the L-PRX covers only one-third of it. This may explain the performance discrepancy.

Large-scale cultivation of Chlorella vulgaris is of great interest given the extent of products and potential applications that can derive from its biomass. From an industrial point of view it is imperative to consistently obtain high productivities and high quality biomass at the lowest production costs. The mass balance of critical nutrients such as carbon and nitrogen is therefore necessary to quantify its recovery and consumption yields, the efficiency of the biomass production system and to identify operational optimization opportunities. The mass balance of C. vulgaris mixotrophic growth throughout scale-up from 10 m 3 to 100 m 3 on acetate and urea as carbon and nitrogen sources was calculated using a black-box model developed to illustrate the inputs and outputs of the system in quasi - real time and resulted on recovery factors of 0.99 ± 0.08 and 0.99 ± 0.25, respectively. Under these conditions C. vulgaris cultivation yielded a maximal productivity of 0.14 g L − 1 d − 1 and maximal growth rate of 0.38 d − 1 . Both parameters decreased throughout scale up reaching an average productivity of 0.09 g L − 1 d − 1 with an average growth rate of 0.13 d − 1 for the whole process. Global carbon and nitrogen yields measured were 0.76 mol C-X mol C − 1 and 0.72 mol N-X mol N − 1 . The mass balance determination indicates the incorporation of both acetate and urea carbon atoms into the biomass. Therefore, external inorganic carbon from CO 2 was concluded to have little influence on microalgae growth in the conditions studied apart from pH control. Urea and ammonium were found to be effectively used by C. vulgaris cells. However, despite the satisfactory yield obtained for nitrogen, the metabolism of urea resulted in ammonium build-up in the culture medium. To our knowledge this is the first report of growth parameters and mass balance analysis of a Chlorella sp. culture in industrial scale closed tubular photobioreactors.

Objectives The detection of the hemodynamic and propagation patterns of spreading depolarizations (SDs) in the gyrencephalic brain using intrinsic optical signal imaging (IOS). Methods The convexity of the brain surface was surgically exposed in fourteen male swine. Within the boundaries of this window, brains were immersed and preconditioned with an elevated K+ concentration (7 mmol/l) in the standard Ringer lactate solution for 30–40 min. SDs were triggered using 3–5 μl of 1 mol/l KCl solution. Changes in tissue absorbency or reflection were registered with a CCD camera at a wavelength of 564 nm (14 nm FWHM), which was mounted 25 cm above the exposed cortex. Additional monitoring by electrocorticography and laser-Doppler was used in a subset of animals (n = 7) to validate the detection of SD. Results Of 198 SDs quantified in all of the experiments, 187 SDs appeared as radial waves that developed semi-planar fronts. The morphology was affected by the surface of the gyri, the sulci and the pial vessels. Other SD patterns such as spirals and reverberating waves, which have not been described before in gyrencephalic brains, were also observed. Diffusion gradients created in the cortex surface (i.e., KCl concentrations), sulci, vessels and SD–SD interactions make the gyrencephalic brain prone to the appearance of irregular SD waves. Conclusion The gyrencephalic brain is capable of irregular SD propagation patterns. The irregularities of the gyrencephalic brain cortex may promote the presence of re-entrance waves, such as spirals and reverberating waves.

Variables sampling plans for microbial safety are usually based on the log transformation of the observed counts. We propose a new variables plan for lognormal data using the angular transformation. In a comparison with the classic approach, this new method shows more stringency and allows the use of smaller sample sizes to obtain the same level of consumer protection. This transformation is robust when the underlying distribution departs from the lognormal distribution as well as in the presence of contamination. A description of the new plan and the software codes are provided.

La despolarizacion cortical extendida (cortical spreading depolarization en ingles) es una onda de despolarizacion casi completa de las celulas neuronales y de la glia acoplada a una respuesta de vasoconstriccion y dilatacion vascular que ocurre en la migrana con aura, la hemorragia subaracnoidea, la hemorragia intracerebral, el traumatismo craneoencefalico y el ictus isquemico. Estas ondas de despolarizacion se caracterizan por un cambio de potencial negativo con una amplitud de entre -10 a -30 mV, una duracion de ~1 min y cambios en la homeostasis ionica cerebral intracelular y extracelular. Bajo situaciones patologicas de hipoperfusion estas ondas despolarizantes pueden conducir a estres oxidativo, agravamiento de estados hipoxicos y muerte neuronal debido a vasoconstriccion arterial intensa causada por una repuesta hemodinamica inversa, fenomeno denominado isquemia extendida (spreading ischemia). En los ultimos anos se ha podido confirmar electrofisiologicamente la presencia de estas ondas despolarizantes propagandose en el cerebro humano y se ha visto una asociacion entre su incidencia y el deterioro neurologico. Actualmente se esta recogiendo evidencia clinica que apoya no solo su coexistencia con el dano neuronal, sino su causalidad. Existen medidas terapeuticas probadas en laboratorio que podrian reducir los efectos de este elemento fisiopatologico en el dano cerebral

To evaluate an intraparenchymal probe for intracranial pressure (ICP) and temperature (TEMP) monitoring as well as determination of cerebral hemodynamics using a near-infrared spectroscopy (NIRS) and indocyanine green (ICG) dye dilution method (NIRS-ICP probe).The NIRS-ICP probe was applied after aneurysmal subarachnoid hemorrhage if multimodal monitoring was established due to poor neurological condition. ICP and TEMP values were obtained from ventricular catheters and systemic temperature sensors. Repeated NIRS-ICG measurements (2 injections within 30 min) were performed daily for determination of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time of ICG (mttICG). Secondary neurologic dysfunction was defined as brain tissue oxygen tension20 mmHg and/or lactate/pyruvate ratio35 obtained from cerebral probing.A total of 128 NIRS-ICG measurements were performed in ten patients. The correlation coefficients between ICP and TEMP values obtained with the NIRS-ICP probe and values from routine monitoring were r = 0.72 and r = 0.96, respectively. The mean values were 30.3 ± 13.6 ml/100 g/min for CBF, 3.3 ± 1.2 ml/100 g for CBV, and 6.8 ± 1.6 s for mttICG. The coefficients of variation from repeated NIRS-ICG measurements were 10.9 % for CBF, 11.7 % for CBV, and 3.8 % for mttICG. The sensitivity for detection of secondary neurologic dysfunction was 85 % and the specificity 83 % using a CBF-threshold of 25 ml/100 g/min.Multimodal monitoring using the NIRS-ICP probe is feasible with high reproducibility of measurement values and the ability to detect secondary neurologic dysfunction. No safety concerns exist for the routine clinical use of the NIRS-ICP probe.

ALGAFARM is an industrial-scale microalgae production facility for the production of Chlorella biomass for food and feed applications. ALGAFARM integrates the entire production process, from small-volume production at a lab scale to final product packaging. It uses a combination of closed photobioreactor (PBR) technologies comprising mainly of large modular arrays of tubular PBRs (Figure 13.1) to cultivate the microalgae. The closed modular PBRs are based on transparent plastic

Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy supply-demand mismatch in viable tissue. Spreading depolarizations exacerbate neuronal injury through prolonged ionic breakdown and spreading depolarization-related hypoperfusion (spreading ischemia). Local duration of the depolarization indicates local tissue energy status and risk of injury. Regional electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can be recognized and quantified. Here, we describe the experimental basis for interpreting these patterns and illustrate their translation to human disease. We further provide consensus recommendations for electrocorticographic methods to record, classify, and score spreading depolarizations and associated spreading depressions. These methods offer distinct advantages over other neuromonitoring modalities and allow for future refinement through less invasive and more automated approaches.

This study investigates the outcome prediction and calculation of optimal cerebral perfusion pressure (CPPopt) in 307 patients after severe traumatic brain injury (TBI) based on cerebrovascular reactivity calculation of a moving correlation correlation coefficient, named PRx, between mean arterial pressure (ABP) and intracranial pressure (ICP). The correlation coefficient was calculated from simultaneously recorded data using different frequencies. PRx was calculated from oscillations between 0.008 and 0.05Hz and the longPRx (L-PRx) was calculated from oscillations between 0.0008 and 0.016 Hz. PRx was a significant mortality predictor, whereas L-PRx was not. CPPopt for pooled data was higher for L-PRx than for PRx, with no statistical difference. Mortality was associated with mean CPP below CPPopt. Severe disability was associated with CPP above CPPopt (PRx). These relationships were not statistically significant for CPPopt (L-PRx). We conclude that PRx and L-PRx cannot be used interchangeably.

Cerebral autoregulation and, consequently, cerebrovascular pressure reactivity, can be disturbed after traumatic brain injury (TBI). Continuous monitoring of autoregulation has shown its clinical importance as an independent predictor of neurological outcome. The cerebral pressure reactivity index (PRx) reflects that changes in seconds of cerebrovascular reactivity have prognostic significance. Using an alternative algorithm similar to PRx, we investigate whether the utilization of lower-frequency changes of the order of minutes of mean arterial blood pressure (MAP) and intracranial pressure (ICP) could have a prognostic value in TBI patients.Head-injured patients requiring continued advanced multimodal monitoring, including hemodynamic, ICP and microdialysis (MD) monitoring, were analyzed retrospectively. A low-frequency sample pressure reactivity index (L-PRx) was calculated, using 20-min averages of MAP and ICP data as a linear Pearson's correlation. The mean values per patient were correlated to outcome at 6 months after injury. Differences of monitoring parameters between non-survivors and survivors were compared.A total of 29 patients (mean age 37.2 years, 26 males) suffering from TBI were monitored for a mean of 109.6 h (16-236 h, SD ± 60.4). Mean L-PRx was found to be of 0.1 (-0.2 to 0.6, SD ± 0.20), six patients presented impaired (0.2) values. The averaged L-PRx correlated significantly with ICP (r = 0.467, p = 0.011) and 6-month outcome (r = -0.556, p = 0.002). Significant statistical differences were found in L-PRx, cerebral perfusion pressure (CPP), lactate, and lactate-pyruvate ratio when comparing patients who died (n = 5) and patients who survived.L-PRx correlates with the 6-month outcome in TBI patients. Very slow changes of MAP and ICP may contain important autoregulation information. L-PRx may be an alternative algorithm for the estimation of cerebral autoregulation and clinical prognosis.

Introduction Cortical spreading depressions (CSDs) are waves of near-complete cellular depolarization that spread slowly across the cortical surface (2–5 mm/min) and result in transient loss of cell signaling capabilities. CSDs is a biomarker of neuronal damage described in several clinical hypoxic-ischemic conditions However, only has been found in one patient operated for Giant pituitary adenoma. Methods This is a prospective study that included adult patients undergoing elective craniotomy for epileptogenic supratentorial lesions lasting >2 h. Electrocorticographic recordings were obtained from time of dural opening through the time of dural closure, using a standard 1 × 8 silver electrode coupled with a full-spectrum DC amplifier (0–45 Hz, Notch: 60 Hz). We analyzed the clinical and socio-demographic characteristics. The data were processed using the COSBID research group methodology to evaluate for slow potential changes coupled with suppression of high-frequency ECoG propagating across the electrodes. Describe statistics were used. Results We included 16 patients, mean age 37 (19–75) years-old, 50% male, underwent 4 callosotomies and 12 temporal lesionectomies (3 cortical dysplasia, 2 cavernomas, 5 gliomas and 2 dermoid cystic). All the patients had history of symptomatic epilepsy and none had postsurgical complications and only 2 patients post-callosotomy continued with seizures at 6 months of follow-up. We didn’t find any CSD during these neurosurgeries. Conclusion CSDs were absent during lesional epilepsy surgery. Future studies are needed to confirm these findings.

PurposeThe paper aims to study the friction behaviour of alumina and zirconia against steel DIN‐Ck45K under water lubricated conditions.Design/methodology/approachThe tests were performed with a contact stress of 3.5 MPa and a constant sliding velocity of 0.5 m/s for 5.35 km of sliding distance, using a pin‐on‐disk tribometer.FindingsThe friction coefficient and the energy dissipated in the contact were considered in this comparative study. The zirconia ceramic present less friction coefficient and contact temperature than alumina ceramic. The zirconia present about 70 per cent of the energy dissipated against when compared with the alumina. Abrasive scars of the surface ploughing were observed on every wear track for two pairs in contact.Research limitations/implicationsThis research used only one test condition.Originality/valueThe paper describes the tribological conditions used and a new methodology based on the energy dissipated in the contact is proposed.