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We perform two-way coupled direct numerical simulation of particle-laden flow in an open channel at a friction Reynolds number ($Re_{\tau }$) of 5186, which exhibits many characteristics of high-Reynolds-number wall-bounded turbulence, such as the distinct separation of scales in the inner and outer layers. Three representative cases, an unladen case and low- and high-Stokes-number particle-laden cases, are performed to investigate the turbulent modification by particles. To this end, we compare several statistical quantities to understand the particle effect on momentum exchange and interphasial energy transfer. The modulation of large-scale motions (LSMs) and very-large-scale motions (VLSMs) are analysed using spectral information, and we find that the LSMs and VLSMs are generally weakened in the inner and outer layers, which is qualitatively different from similar simulations at lower Reynolds numbers ($Re_{\tau } \approx 500$). The spatial structures are investigated with correlation analysis, and inclined VLSMs are observed in the near-wall region, with decreased inclination angles by particles. The particles tend to widen and shorten the spanwise and streamwise extent of coherent structures, respectively. Furthermore, we find that the vorticity vector displays a preferential alignment with the eigenvector corresponding to the intermediate eigenvalue of the strain-rate tensor, independent of the particle Stokes number.
What is the most robust way to communicate flow trajectories? To answer this question, we employ two neural networks to respectively deconstruct (the encoder) and reconstruct (the decoder) trajectories, where information is passed between the two networks through a low-dimensional latent space in a set-up known as an autoencoder. To ensure that their communications are robust, we add noise to the coded information passed through this latent space. In the low-noise limit the latent space structures are non-spatial in nature, resembling modes of a principle component analysis (PCA). However, as the signal-to-noise ratio is decreased, we uncover Lagrangian coherent structures (LCS) as the most compact representations which still allow the decoder to accurately reconstruct trajectories. This relationship offers increased interpretability to both PCA and LCS analysis, and helps to bridge the gap between two methods of flow analysis.
Basal melt of ice shelves is not only an important part of Antarctica's ice sheet mass budget, but it is also the origin of platelet ice, one of the most distinctive types of sea ice. In many coastal Antarctic regions, ice crystals form and grow in supercooled plumes of Ice Shelf Water. They usually rise towards the surface, becoming trapped under an ice shelf as marine ice or forming a semi-consolidated layer, known as the sub-ice platelet layer, below an overlying sea ice cover. In the latter, sea ice growth consolidates loose crystals to form incorporated platelet ice. These phenomena have numerous and profound impacts on the physical properties, biological processes and biogeochemical cycles associated with Antarctic fast ice: platelet ice contributes to sea ice mass balance and may indicate the extent of ice-shelf basal melting. It can also host a highly productive and uniquely adapted ecosystem. This paper clarifies the terminology and reviews platelet ice formation, observational methods as well as the geographical and seasonal occurrence of this ice type. The physical properties and ecological implications are presented in a way understandable for physicists and biologists alike, thereby providing the background for much needed interdisciplinary research on this topic.
Positive symptoms are a useful predictor of aggression in schizophrenia. Although a similar pattern of abnormal brain structures related to both positive symptoms and aggression has been reported, this observation has not yet been confirmed in a single sample.
Method
To study the association between positive symptoms and aggression in schizophrenia on a neurobiological level, a prospective meta-analytic approach was employed to analyze harmonized structural neuroimaging data from 10 research centers worldwide. We analyzed brain MRI scans from 902 individuals with a primary diagnosis of schizophrenia and 952 healthy controls.
Results
The result identified a widespread cortical thickness reduction in schizophrenia compared to their controls. Two separate meta-regression analyses revealed that a common pattern of reduced cortical gray matter thickness within the left lateral temporal lobe and right midcingulate cortex was significantly associated with both positive symptoms and aggression.
Conclusion
These findings suggested that positive symptoms such as formal thought disorder and auditory misperception, combined with cognitive impairments reflecting difficulties in deploying an adaptive control toward perceived threats, could escalate the likelihood of aggression in schizophrenia.
In the intensive care setting, delirium is a common occurrence; however, the impact of the level of alertness has never been evaluated. Therefore, this study aimed to assess the delirium characteristics in the drowsy, as well as the alert and calm patient.
Method
In this prospective cohort study, 225 intensive care patients with Richmond Agitation and Sedation Scale (RASS) scores of −1 — drowsy and 0 — alert and calm were evaluated with the Delirium Rating Scale-Revised-1998 (DRS-R-98) and the Diagnostic and Statistical Manual 4th edition text revision (DSM-IV-TR)-determined diagnosis of delirium.
Results
In total, 85 drowsy and 140 alert and calm patients were included. Crucial items for the correct identification of delirium were sleep–wake cycle disturbances, language abnormalities, thought process alterations, psychomotor retardation, disorientation, inattention, short- and long-term memory, as well as visuo-spatial impairment, and the temporal onset. Conversely, perceptual disturbances, delusions, affective lability, psychomotor agitation, or fluctuations were items, which identified delirium less correctly. Further, the severities of inattentiveness and visuo-spatial impairment were indicative of delirium in both alert- or calmness and drowsiness.
Significance of results
The impairment in the cognitive domain, psychomotor retardation, and sleep–wake cycle disturbances correctly identified delirium irrespective of the level alertness. Further, inattentiveness and — to a lesser degree — visuo-spatial impairment could represent a specific marker for delirium in the intensive care setting meriting further evaluation.
The biggest advantage of Additive Manufacturing is the individualization of products. Mass Customization is well known as a promising future application. The use of Additive Manufacturing for assembly groups is mostly not reasonable, however combining it with conventional manufacturing processes can lead to new opportunities.
This paper works out concepts to join, by using similar material combinations, an injection molded part with an additive deposited geometry by the Fused-Deposition-Modeling (FDM) process. Therefore, two of the main industrially used polymers, acrylonitrile butadiene styrene (ABS) and polypropylene (PP), are selected for further study. In particular, this investigation focuses on the procedural potentials and surface preparation of the injection molded part. By the variation of adhesive bonding, the fusion of similar materials can be identified and tested in several series of testing.
First in general a direct joining function by the FLM process will be tested. After proving this hypothesis, the results will be summarised in a recommendation of joining similar materials, which are manufactured in different ways.
The importance of the proper identification of delirium, with its high incidence and adversities in the intensive care setting, has been widely recognized. One common screening instrument is the Intensive Care Delirium Screening Checklist (ICDSC); however, the symptom profile and key features of delirium dependent on the level of sedation have not yet been evaluated.
Method
In this prospective cohort study, the ICDSC was evaluated versus the Diagnostic and Statistical Manual, 4th edition, text revision, diagnosis of delirium set as standard with respect to the symptom profile, and correct identification of delirium. The aim of this study was to identify key features of delirium in the intensive care setting dependent on the Richmond Agitation and Sedation Scale levels of sedation: drowsiness versus alert and calmness.
Result
The 88 delirious patients of 225 were older, had more severe disease, and prolonged hospitalization. Irrespective of the level of sedation, delirium was correctly classified by items related to inattention, disorientation, psychomotor alterations, inappropriate speech or mood, and symptom fluctuation. In the drowsy patients, inattention reached substantial sensitivity and specificity, whereas psychomotor alterations and sleep-wake cycle disturbances were sensitive lacked specificity. The positive prediction was substantial across items, whereas the negative prediction was only moderate. In the alert and calm patient, the sensitivities were substantial for psychomotor alterations, sleep-wake cycle disturbances, and symptom fluctuations; however, these fluctuations were not specific. The positive prediction was moderate and the negative prediction substantial. Between the nondelirious drowsy and alert, the symptom profile was similar; however, drowsiness was associated with alterations in consciousness.
Significance of results
In the clinical routine, irrespective of the level of sedation, delirium was characterized by the ICDSC items for inattention, disorientation, psychomotor alterations, inappropriate speech or mood and symptom fluctuation. Further, drowsiness caused altered levels of consciousness.
Similar to delirium, its subsyndromal form has been recognized as the cause of diverse adverse outcomes. Nonetheless, the nature of this subsyndromal delirium remains vastly understudied. Therefore, in the following, we evaluate the phenomenological characteristics of this syndrome versus no and full-syndromal delirium.
Method:
In this prospective cohort study, we evaluated the Delirium Rating Scale–Revised, 1998 (DRS–R–98) versus the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM–IV–TR) diagnostic criteria and examined the diagnosis of delirium with respect to phenomenological distinctions in the intensive care setting.
Results:
Out of 289 patients, 36 with subsyndromal delirium versus 86 with full-syndromal and 167 without delirium were identified. Agreement with respect to the DSM–IV–TR diagnosis of delirium was perfect. The most common subtype in those with subsyndromal delirium was hypoactive, in contrast to mixed subtype in those with full-syndromal delirium versus no motor alterations in those without delirium. By presence and severity of delirium symptoms, subsyndromal delirium was intermediate. The ability of the DRS–R–98 items to discriminate between either form of delirium was substantial. Between subsyndromal and no delirium, the cognitive domain and sleep–wake cycle were more impaired and allowed a distinction with no delirium. Further, between full- and subsyndromal delirium, the prevalence and severity of individual DRS–R–98 items were greater. Although the differences between these two forms of delirium was substantial, the items were not very specific, indicating that the phenomenology of subsyndromal delirium is closer to full-syndromal delirium.
Significance of results:
Phenomenologically, subsyndromal delirium was found to be distinct from and intermediate between no delirium and full-syndromal delirium. Moreover, the greater proximity to full-syndromal delirium indicated that subsyndromal delirium represents an identifiable subform of full-syndromal delirium.
In the intensive care setting, delirium is a common occurrence that comes with subsequent adversities. Therefore, several instruments have been developed to screen for and detect delirium. Their validity and psychometric properties, however, remain controversial.
Method:
In this prospective cohort study, the Confusion Assessment Method for the Intensive Care Unit (CAM–ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) were evaluated versus the DSM–IV–TR in the diagnosis of delirium with respect to their validity and psychometric properties.
Results:
Out of some 289 patients, 210 with matching CAM–ICU, ICDSC, and DSM–IV–TR diagnoses were included. Between the scales, the prevalence of delirium ranged from 23.3% with the CAM–ICU, to 30.5% with the ICDSC, to 43.8% with the DSM–IV–TR criteria. The CAM–ICU showed only moderate concurrent validity (Cohen's κ = 0.44) and sensitivity (50%), but high specificity (95%). The ICDSC also reached moderate agreement (Cohen's κ = 0.60) and sensitivity (63%) while being very specific (95%). Between the CAM–ICU and the ICDSC, the concurrent validity was again only moderate (Cohen's κ = 0.56); however, the ICDSC yielded higher sensitivity and specificity (78 and 83%, respectively).
Significance of Results:
In the daily clinical routine, neither the CAM–ICU nor the ICDSC, common tools used in screening and detecting delirium in the intensive care setting, reached sufficient concurrent validity; nor did they outperform the DSM–IV–TR diagnostic criteria with respect to sensitivity or positive prediction, but they were very specific. Thus, the non-prediction by the CAM–ICU or ICDSC did not refute the presence of delirium. Between the CAM–ICU and ICDSC, the ICDSC proved to be the more accurate instrument.
The management of and prognosis for delirium are affected by its subtype: hypoactive, hyperactive, mixed, and none. The DMSS–4, an abbreviated version of the Delirium Motor Symptom Scale, is a brief instrument for the assessment of delirium subtypes. However, it has not yet been evaluated in an intensive care setting.
Method:
We performed a prospective/descriptive cohort study in order to determine the internal consistency, reliability, and validity of the relevant items of the DMSS–4 versus the Delirium Rating Scale–Revised-98 (DRS–R-98) and the original DMSS in a surgical intensive care setting.
Results:
A total of 289 elderly, predominantly male patients were screened for delirium, and 122 were included in our sample. The internal consistency of the DMSS–4 items was excellent (Cronbach's α = 0.92), and between the DMSS–4 and DRS–R-98 the overall concurrent validity was substantial (Cramer's V = 0.67). Within individual motor subtypes, concurrent validity remained at least substantial (Cohen's κ = 0.65–0.81) and sensitivity high (69.8 to 82.2%), in contrast to those of the no-motor subtype, with less validity and sensitivity (κ = 0.28, 22%). Similarly, total concurrent validity between the DMSS–4 and the original DMSS reached perfection (Cramer's V = 0.83), as did agreement between the subtypes (κ = 0.83–0.92), while sensitivity remained high (88.2–100%). Only in those with delirium with no-motor subtype was agreement moderate (κ = 0.56) and sensitivity lower (67%). Specificity was high across all subtypes (91.2–99.1%). The DMSS–4 yielded very sensitive ratings, particularly for hypoactive and hyperactive motor symptoms, and interrater agreement was excellent (Fleiss's κ = 0.83).
Significance of Results:
We found the DMSS–4 to be a most reliable and valid brief assessment of delirium in characterizing the subtypes of delirium in an intensive care setting, with increased sensitivity to hypoactive and hyperactive motor alterations.
Inpatients with blood cultures positive for Staphylococcus aureus, Enterococcus faecalis, E. faecium, Streptococcus pneumoniae, S. pyogenes, S. agalactiae, S. anginosus, Streptococcus spp., and Listeria monocytogenes during the 6 months before and after implementation of Verigene Gram-positive blood culture microarray (BC-GP) with an antimicrobial stewardship intervention.
METHODS
Before the intervention, no rapid diagnostic technology was used or antimicrobial stewardship intervention was undertaken, except for the use of peptide nucleic acid fluorescent in situ hybridization and MRSA agar to identify staphylococcal isolates. After the intervention, all Gram-positive blood cultures underwent BC-GP microarray and the antimicrobial stewardship intervention consisting of real-time notification and pharmacist review.
RESULTS
In total, 513 patients with bacteremia were included in this study: 280 patients with S. aureus, 150 patients with enterococci, 82 patients with stretococci, and 1 patient with L. monocytogenes. The number of antimicrobial switches was similar in the pre–BC-GP (52%; 155 of 300) and post–BC-GP (50%; 107 of 213) periods. The time to antimicrobial switch was significantly shorter in the post–BC-GP group than in the pre–BC-GP group: 48±41 hours versus 75±46 hours, respectively (P<.001). The most common antimicrobial switch was de-escalation and time to de-escalation, was significantly shorter in the post-BC-GP group than in the pre–BC-GP group: 53±41 hours versus 82±48 hours, respectively (P<.001). There was no difference in mortality or hospital length of stay as a result of the intervention.
CONCLUSIONS
The combination of a rapid microarray diagnostic test with an antimicrobial stewardship intervention improved time to antimicrobial switch, especially time to de-escalation to optimal therapy, in patients with Gram-positive blood cultures.
Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated (“CRKP readmission”) potentially contribute to transmission of CRKP.
OBJECTIVE
To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe).
DESIGN
Cohort study from December 24, 2011, through July 1, 2013.
SETTING
Multicenter consortium of acute care hospitals in the Great Lakes region.
PATIENTS
All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture.
METHODS
All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models.
RESULTS
Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32–6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72–17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission.
CONCLUSION
Hospitalized patients with CRKP—specifically those with a history of malignancy—are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.
Infect. Control Hosp. Epidemiol. 2016;37(3):281–288
We report on localised patches of cellular hexagons observed on the surface of a magnetic fluid in a vertical magnetic field. These patches are spontaneously generated by jumping into the neighbourhood of the unstable branch of the domain-covering hexagons of the Rosensweig instability upon which the patches equilibrate and stabilise. They are found to coexist in intervals of the applied magnetic field strength parameter around this branch. We formulate a general energy functional for the system and a corresponding Hamiltonian that provide a pattern selection principle allowing us to compute Maxwell points (where the energy of a single hexagon cell lies in the same Hamiltonian level set as the flat state) for general magnetic permeabilities. Using numerical continuation techniques, we investigate the existence of localised hexagons in the Young–Laplace equation coupled to the Maxwell equations. We find that cellular hexagons possess a Maxwell point, providing an energetic explanation for the multitude of measured hexagon patches. Furthermore, it is found that planar hexagon fronts and hexagon patches undergo homoclinic snaking, corroborating the experimentally detected intervals. Besides making a contribution to the specific area of ferrofluids, our work paves the ground for a deeper understanding of homoclinic snaking of two-dimensional localised patches of cellular patterns in many physical systems.
The activities and some research progress of IAU Commission 19 (C19) - Rotation of the Earth - in the past triennial term (2012-2015) is reported in this paper, including the scientific session and business meeting of C19, as well as a business meeting of the IAU/IAG Joint Working Group of “Theory of Earth Rotation” (JWG_ThER) during the XXIX IAU General Assembly in Hawaii, USA. Three reports of JWG_ThER progress, IERS and IAG, eleven reports of national projects and individual institutions, a short summary of the history and heritage of C19, and an Overview of the status and outlook of new Commission A2 are also presented.
To determine the rates of and risk factors for tigecycline nonsusceptibility among carbapenem-resistant Klebsiella pneumoniae (CRKPs) isolated from hospitalized patients
DESIGN
Multicenter prospective observational study
SETTING
Acute care hospitals participating in the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRaCKle)
PATIENTS
A cohort of 287 patients who had CRKPs isolated from clinical cultures during hospitalization
METHODS
For the period from December 24, 2011 to October 1, 2013, the first hospitalization of each patient with a CRKP during which tigecycline susceptibility for the CRKP isolate was determined was included. Clinical data were entered into a centralized database, including data regarding pre-hospital origin. Breakpoints established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) were used to interpret tigecycline susceptibility testing.
RESULTS
Of 287 patients included in the final cohort, 155 (54%) had tigecycline-susceptible CRKPs. Of all index isolates, 81 (28%) were tigecycline-intermediate and 51 (18%) were tigecycline resistant. In multivariate modeling, independent risk factors for tigecycline nonsusceptibility were (1) admission from a skilled nursing facility (OR, 2.51; 95% CI, 1.51–4.21; P=.0004), (2) positive culture within 2 days of admission (OR, 1.82; 95% CI, 1.06–3.15; P=.03), and (3) receipt of tigecycline within 14 days (OR, 4.38, 95% CI, 1.37–17.01, P=.02).
CONCLUSIONS
In hospitalized patients with CRKPs, tigecycline nonsusceptibility was more frequently observed in those admitted from skilled nursing facilities and occurred earlier during hospitalization. Skilled nursing facilities are an important target for interventions to decrease antibacterial resistance to antibiotics of last resort for treatment of CRKPs.
Recently it has been demonstrated that there are differences between sheep and goats in respect to adaptation to a calcium-restricted diet. It was the aim of the present study to evaluate whether species-specific peculiarities also occur when calcium homoeostasis is challenged by lactation. Therefore, we investigated the time courses of plasma parameters related to calcium homoeostasis (calcium, phosphate, calcitriol, the bone resorption marker CrossLaps® and the bone formation marker osteocalcin) during the transition period in multiparous animals of both species and compared the results to data from a former study carried out with dairy cows. As in cows, plasma calcium and the ratio of bone formation to bone resorption decreased at parturition in goats while plasma calcitriol increased. On day 10 post partum the bone parameters of goats reached prepartum values again, which was not the case in cows. Sheep were found to experience a challenge of calcium homoeostasis already 10 d before parturition, reflected by a very low ratio of bone formation to bone resorption, which was not accompanied by an increase in plasma calcitriol. Additionally, sheep and goats which had been in milk for 3 months were sampled, dried-off and sampled again 6 weeks later. In dried-off animals there were no detectable differences in parameters of bone metabolism. In conclusion we could show that the contribution of bone mobilisation to the compensation for the enhanced calcium demand due to lactation differs between the three ruminant species.
During the XXVIII IAU General Assembly in Beijing IAU Commission 19 - Rotation of the Earth - held a business meeting and a scientific meeting. The business meeting was held on Wednesday, 29 August 2012 during session 1 (08:30-10:00). It was attended by about 35 participants, and six reports were given. First the activities of IAU Commission 19 during the past triennium (2009–2012) were highlighted by the Commission president. Afterwards, the Commission secretary presented the results of the elections for the next triennium (2012–2015) and a list of new members of the Commission. The designated Commission president provided an outlook into the next triennium, before the representatives of the international bodies and services IAG (International Association of Geodesy), IVS (International VLBI Service for Geodesy and Astrometry), and IERS (International Earth Rotation and Reference Systems Service) gave reports about recent activities. A summary of the business meeting is given below in Section 2. The scientific meeting was held on Thursday, 20 August 2012 during sessions 1 and 2 (08:30-12:30). Eleven presentations were given, and about 40 participants attended the sessions. Summaries of the presentations are provided below in Section 3.
An overview about the German cluster project Cool Silicon aiming at increasing the energy efficiency for semiconductors, communications, sensors and software is presented. Examples for achievements are: 1000 times reduced gate leakage in transistors using high-fc (HKMG) materials compared to conventional poly-gate (SiON) devices at the same technology node; 700 V transistors integrated in standard 0.35 μm CMOS; solar cell efficiencies above 19% at < 200 W/m2 irradiation; 0.99 power factor, 87% efficiency and 0.088 distortion factor for dc supplies; 1 ns synchronization resolution via Ethernet; database accelerators allowing 85% energy savings for servers; adaptive software yielding energy reduction of 73% for e-Commerce applications; processors and corresponding data links with 40% and 70% energy savings, respectively, by adaption of clock frequency and supply voltage in less than 20 ns; clock generator chip with tunable frequency from 83-666 MHz and 0.62-1.6 mW dc power; 90 Gb/s on-chip link over 6 mm and efficiency of 174 fJ/mm; dynamic biasing system doubling efficiency in power amplifiers; 60 GHz BiCMOS frontends with dc power to bandwidth ratio of 0.17 mW/MHz; driver assistance systems reducing energy consumption by 10% in cars
At , Newtonian flow past a circular cylinder exhibits a wake and detached shear layers which have transitioned to turbulence. It is the goal of the present study to investigate the effects which viscoelasticity has on this state and to identify the mechanisms responsible for wake stabilization. It is found through numerical simulations (employing the FENE-P rheological model) that viscoelasticity greatly reduces the amount of turbulence in the wake, reverting it back to a state which qualitatively appears similar to the Newtonian mode B instability which occurs at lower . By focusing on the separated shear layers, it is found that viscoelasticity suppresses the formation of the Kelvin–Helmholtz instability which dominates for Newtonian flows, consistent with previous studies of viscoelastic free shear layers. Through this shear layer stabilization, the viscoelastic far wake is then subject to the same instability mechanisms which dominate for Newtonian flows, but at far lower Reynolds numbers.