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Recent experimental and computational studies indicate that near-wall turbulent flows can be characterized by universal small-scale autonomous dynamics that is modulated by large-scale structures. We formulate numerical simulations of near-wall turbulence in a small domain localized to the boundary, whose size scales in viscous units. To mimic the environment in which the near-wall turbulence evolves, the formulation accounts for the flux of mean momentum through the upper boundary of the domain. Comparisons of the model's two-dimensional energy spectra and low-order single-point statistics with the corresponding quantities computed from direct numerical simulations indicate that it successfully captures the dynamics of the small-scale near-wall turbulence.
Liquid phase (or liquid cell) transmission electron microscopy (LP-TEM) has been established as a powerful tool for observing dynamic processes in liquids at nanometer to atomic length scales. However, the simple act of observation using electrons irreversibly alters the nature of the sample. A clear understanding of electron-beam-driven processes during LP-TEM is required to interpret in situ observations and utilize the electron beam as a stimulus to drive nanoscale dynamic processes. In this article, we discuss recent advances toward understanding, quantifying, mitigating, and harnessing electron-beam-driven chemical processes occurring during LP-TEM. We highlight progress in several research areas, including modeling electron-beam-induced radiolysis near interfaces, electron-beam-induced nanocrystal formation, and radiation damage of soft materials and biomolecules.
Serotonergic neurotransmission plays a key role in seasonal changes of mood and behaviour. Higher serotonin transporter availability in healthy human subjects in times of lesser light has been reported in recent studies. Furthermore, seasonal alterations of postsynaptic serotonin-1A receptors have been suggested by a recent animal study. Following that, this study aimed at identifying seasonal alterations of serotonin-1A receptor binding in the living human brain.
Thirty-six healthy, drug-naïve subjects were investigated using PET and the specific tracer [carbonyl-11C]WAY-100635. Regional serotonin-1A receptor binding (5-HT1A BPND) was related to the individual exposure to global radiation. Furthermore, the subjects were divided into two groups depending on individual exposure to global radiation, and the group differences in regional 5-HT1A BPND were determined.
Correlation analysis controlled for age and gender revealed highly significant positive correlations between regional postsynaptic 5-HT1A BPND and global radiation accumulated for 5 days (r=.32 to .48, p=.030 to .002). Highly significant differences in 5-HT1A BPND binding between subjects with low compared to high exposure to global radiation were revealed (T=-2.63 to -3.77, p .013 to .001). 20% to 30% lower 5-HT1A BPND was found in the subject group exposed to lower amount of global radiation.
Seasonal factors such as exposure to global radiation influence postsynaptic serotonin-1A receptor binding in various brain regions in healthy human subjects. In combination with seasonal alterations in serotonin turnover and 5-HTT availability revealed in recent studies, our results provide an essential contribution of molecular mechanisms in seasonal changes of human serotonergic neurotransmission.
Regional alterations of serotonergic neurotransmission and functional activation in the amygdalar region of patients with major depression are underpinning its important role in affective disorders. In this study we used fMRI and PET to describe functional and molecular alterations associtated with an astrocytoma in the left amygdalar region in a patient with organic depressive disorder compared to control subjects.
The serotonin-1A (5-HT1A) receptor binding (BPND) was quantified with PET (30 frames, 90 min, 4.4 mm FWHM) in 36 subjects using the radioligand [carbonyl-11C]WAY-100635, and a reference tissue model (MRTM2). In fMRI (3T, EPI inplane resolution 1.6*2.7 mm, 10 AC-PC orientated slices, ST = 3 mm, TE/TR = 31/1000 ms), 32 participants performed emotion discrimination and sensorimotor control tasks. Statistical analysis with SPM5 and unpaired t-tests were performed on molecular and functional data separately.
The astrocytoma was delineated in the serotonin-1A receptor distribution showing (p < 0.01, uncorrected) regional BPND decrease. The ipsilateral thalamus and bilateral habenula regions displayed (p < 0.001; uncorrected) BPND increase. The fMRI data showed significantly (p < 0.05; uncorrected) reduced activation in the affected amygdalar region, ipsilateral fusiform gyrus, bilateral orbitofrontal cortex and temporal regions and increased activation in the contralateral temporal pole.
Lower serotonin-1A receptor binding in the left amydala region reflects the glial provenance of the tumor. The increased receptor binding in the habenulae might be associated with altered monoaminergic neurotransmission and depressive symptoms according to the influence of the habenulae on monoaminergic nuclei. The functional data demonstrate neuroplastic changes beyond affected areas and might indicate compensatory mechanisms.
Dysfunction in the basal ganglia has been related to impaired reward processing and anhedonia, a core symptom of Major Depressive Disorder (MDD). In particular, the ventral striatum including the nucleus accumbens is increasingly implicated in the pathophysiology of MDD, but evidence for a specific role during episodes of full remission is lacking so far.
To investigate functional connectivity patterns of resting-state activity in patients in the remitted phase of MDD (rMDD).
To determine whether rMDD is related to disruptions of functional coupling between the ventral striatum and cortical regions.
Forty-three remitted depressed patients and thirty-five healthy controls were recruited at Medical University of Vienna, Vienna, Austria, and performed a six minute resting-state fMRI scan. Seed time series were extracted from the preprocessed data using individual masks for ventral striatum and correlated with all nodes in a surface based analysis using FreeSurfer, AFNI and SUMA. The resulting correlation coefficients were then Fishertransformed, group results were determined by comparing group mean smoothed z-scores with a two-sample ttest.
Increased resting-state functional connectivity was revealed between ventral striatum (seed region) and anterior cingulate cortex as well as orbitofrontal cortex in the rMDD group compared to healthy controls.
Our preliminary data is in accordance with the idea that increased functional coupling between the ventral striatum and two major emotion processing regions, the anterior cingulate cortex and the orbitofrontal cortex, may represent a neural mechanism contributing to the maintenance of full remission of MDD.
Converging evidence suggests alterations of neural activation in the basal ganglia to represent neural correlates of Major Depressive Disorder (MDD). While a previous study reported increases of functional connectivity in resting state activity between the caudate nuclei and the posterior cingulate cortex in acutely depressed patients, it remains unclear whether this finding persists during full remission once antidepressant treatment has been discontinued.
To investigate patterns of functional coupling between the basal ganglia and cortical regions during resting-state conditions.
To determine whether increases of functional connectivity between caudate nuclei, putamen, and pallidum with cortical regions, in particular the cingulate cortex, pertain during remission of MDD.
Forty-three remitted depressed (rMDD) patients and thirty-five healthy controls were recruited at Medical University of Vienna, Vienna, Austria, and performed a six minute resting-state fMRI scan. Seed time series were extracted from the preprocessed data using individual masks for the basal ganglia and correlated with all nodes in a surface based analysis using FreeSurfer, AFNI and SUMA. The resulting correlation coefficients were then Fisher-transformed, group results were determined by comparing group mean smoothed z-scores with a two-sample t-test.
Increased resting-state functional connectivity was revealed between basal ganglia and cingulate as well as prefrontal cortex in the rMDD group compared to healthy controls.
Our preliminary results revealed increased functional coupling between the basal ganglia and wide parts of the cingulate and prefrontal cortex to possibly represent a specific neural pattern during remission of MDD.
While most neuroimaging studies have investigated acutely depressed patients, neural mechanisms underlying stable remission are rarely examined. Furthermore, the majority of previous functional MRI (fMRI) studies have focused on task-induced neural activity, while resting-state activity may be more reproducible across study centers.
To clarify patterns of functional coupling between subcortical structures and cortical resting state activity.
To determine whether alterations of functional coupling between the amygdala and cortical emotion processing regions characterize patients in the remitted phase of Major Depressive Disorder (rMDD).
Forty-three remitted depressed patients and thirty-five healthy controls were recruited at Medical University of Vienna, Vienna, Austria, and performed a six minute resting-state fMRI scan. The scans were corrected for slice timing and motion, as well as for mean white matter, mean CSF, and median gray matter signals. Seed time series were extracted using individual amygdala masks and correlated with all nodes in a surface based analysis using FreeSurfer, AFNI and SUMA. The resulting correlation coefficients were then Fisher-transformed, group results were determined by comparing group mean smoothed (to 8 mm FWHM) z-scores with a two-sample t-test.
Increased resting-state functional connectivity was revealed between amygdala (seed region) and posterior cingulate cortex as well as orbitofrontal cortex in the rMDD group compared to healthy controls.
Our preliminary results suggest altered functional coupling between amygdala and cortical emotion processing areas during resting state conditions, possibly representing a neural mechanism contributing to the maintenance of stable remission of MDD.
Due to concerns over increasing fluoroquinolone (FQ) resistance among gram-negative organisms, our stewardship program implemented a preauthorization use policy. The goal of this study was to assess the relationship between hospital FQ use and antibiotic resistance.
Large academic medical center.
We performed a retrospective analysis of FQ susceptibility of hospital isolates for 5 common gram-negative bacteria: Acinetobacter spp., Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Primary endpoint was the change of FQ susceptibility. A Poisson regression model was used to calculate the rate of change between the preintervention period (1998–2005) and the postimplementation period (2006–2016).
Large rates of decline of FQ susceptibility began in 1998, particularly among P. aeruginosa, Acinetobacter spp., and E. cloacae. Our FQ restriction policy improved FQ use from 173 days of therapy (DOT) per 1,000 patient days to <60 DOT per 1,000 patient days. Fluoroquinolone susceptibility increased for Acinetobacter spp. (rate ratio [RR], 1.038; 95% confidence interval [CI], 1.005–1.072), E. cloacae (RR, 1.028; 95% CI, 1.013–1.044), and P. aeruginosa (RR, 1.013; 95% CI, 1.006–1.020). No significant change in susceptibility was detected for K. pneumoniae (RR, 1.002; 95% CI, 0.996–1.008), and the susceptibility for E. coli continued to decline, although the decline was not as steep (RR, 0.981; 95% CI, 0.975–0.987).
A stewardship-driven FQ restriction program stopped overall declining FQ susceptibility rates for all species except E. coli. For 3 species (ie, Acinetobacter spp, E. cloacae, and P. aeruginosa), susceptibility rates improved after implementation, and this improvement has been sustained over a 10-year period.
Semantic memory may be impaired in clinically recognized states of cognitive impairment. We investigated the relationship between semantic memory and depressive symptoms (DS) in patients with cognitive impairment.
323 cognitively healthy controls and 848 patients with subjective cognitive decline (SCD), mild cognitive impairment (MCI), and Alzheimer's disease (AD) dementia were included. Semantic knowledge for famous faces, world capitals, and word vocabulary was investigated.
Compared to healthy controls, we found a statistically significant difference of semantic knowledge in the MCI groups and the AD group, respectively. Results of the SCD group were mixed. However, two of the three semantic memory measures (world capitals and word vocabulary) showed a significant association with DS.
We found a difference in semantic memory performance in MCI and AD as well as an association with DS. Results suggest that the difference in semantic memory is due to a storage loss rather than to a retrieval problem.
Health-related quality of life (HRQOL) is an important issue in the context of dementia care. The purpose of this study was to investigate the association between HRQOL and depressive symptoms in patients with subjective cognitive decline (SCD) and subtypes of mild cognitive impairment (MCI) and Alzheimer´s disease (AD).
In this cross-sectional, observational study, a control group and four experimental groups (SCD, non-amnestic MCI, amnesticMCI, AD) were compared. Neuropsychological measurers (NTBV) and psychological questionnaires were used for data collection.
The control group scored higher than patients with SCD, naMCI, aMCI, or AD for the Mental Health Component Score (MHCS) of the Short Form of the Health Survey (SF-36). The Physical Health Component Score (PHCS) of the SF-36 differed only between some groups. Furthermore, cognitive variables were more strongly associated with the physical aspects of HRQOL, whereas depressive symptoms were more strongly related with the mental aspects of HRQOL.
HRQOL and depressive symptoms are closely related in patients with cognitive impairments. Therefore, it is of great importance to assess patients with subjective impairment carefully in terms of depressive symptoms.
Deficits in facial emotion recognition (FER) have been shown to substantially impair several aspects in everyday life of affected individuals (e.g. social functioning). Presently, we aim at assessing differences in emotion recognition performance in three patient groups suffering from mild forms of cognitive impairment compared to healthy controls.
Performance on a concise emotion recognition test battery (VERT-K) of 68 patients with subjective cognitive decline (SCD), 44 non-amnestic (non-aMCI), and 25 amnestic patients (aMCI) with mild cognitive impairment (MCI) was compared with an age-equivalent sample of 138 healthy controls all of which were recruited within the framework of the Vienna Conversion to Dementia Study. Additionally, patients and controls underwent individual assessment using a comprehensive neuropsychological test battery examining attention, executive functioning, language, and memory (NTBV), the Beck Depression Inventory (BDI), and a measure of premorbid IQ (WST).
Type of diagnosis showed a significant effect on emotion recognition performance, indicating progressively deteriorating results as severity of diagnosis increased. Between-groups effect sizes were substantial, showing non-trivial effects in all comparisons (Cohen's ds from −0.30 to −0.83) except for SCD versus controls. Moreover, emotion recognition performance was higher in women and positively associated with premorbid IQ.
Our findings indicate substantial effects of progressive neurological damage on emotion recognition in patients. Importantly, emotion recognition deficits were observable in non-amnestic patients as well, thus conceivably suggesting associations between decreased recognition performance and global cognitive decline. Premorbid IQ appears to act as protective factor yielding lesser deficits in patients showing higher IQs.
Germany has been an officially bovine tuberculosis (bTB)-free (OTF) country since 1996. Gradually rising numbers of bTB herd incidents due to Mycobacterium bovis and M. caprae in North-Western and Southern Germany during the last few years prompted the competent authorities to conduct a nationwide bTB survey in 2013/2014. This led to the detection of a dairy herd in which as many as 55 cattle reacted positively to consecutive intra vitam testing. Test-positive animals lacked visible lesions indicative of bTB at necropsy. Extensive mycobacterial culturing as well as molecular testing of samples from 11 tissues for members of the M. tuberculosis complex (MTC) yielded negative results throughout. However, caseous lymphadenitis of Ln. mandibularis accessorius was observed during meat inspection of a fattening pig from the same farm at regular slaughter at that time. Respective tissue samples tested MTC positive by polymerase chain reaction, and M. tuberculosis T1 family were identified by spoligotyping. Four human reactors within the farmer's family were also found to be immunoreactive. As exposure of livestock to M. tuberculosis is not generally considered, its impact may result in regulatory and practical difficulties when using protocols designed to detect classical bTB, particularly in OTF countries.
We describe a laboratory plasma physics experiment at Los Alamos National Laboratory that uses two merging supersonic plasma jets formed and launched by pulsed-power-driven railguns. The jets can be formed using any atomic species or mixture available in a compressed-gas bottle and have the following nominal initial parameters at the railgun nozzle exit: ne ≈ ni ~ 1016 cm−3, Te ≈ Ti ≈ 1.4 eV, Vjet ≈ 30–100 km/s, mean charge
≈ 1, sonic Mach number Ms ≡ Vjet/Cs > 10, jet diameter = 5 cm, and jet length ≈20 cm. Experiments to date have focused on the study of merging-jet dynamics and the shocks that form as a result of the interaction, in both collisional and collisionless regimes with respect to the inter-jet classical ion mean free path, and with and without an applied magnetic field. However, many other studies are also possible, as discussed in this paper.
The goals of this study were to establish prevalence of subjective memory complaints (SMC) and depressive symptoms (DS) and their relation to cognitive functioning and cognitive status in an outpatient memory clinic cohort.
Two hundred forty-eight cognitively healthy controls and 581 consecutive patients with cognitive complaints who fulfilled the inclusion criteria were included in the study.
A statistically significant difference (p < 0.001) between control group and patient group regarding mean SMC was detected. 7.7% of controls reported a considerable degree of SMC, whereas 35.8% of patients reported considerable SMC. Additionally, a statistically significant difference (p < 0.001) between controls and patient group regarding Beck depression score was detected. 16.6% of controls showed a clinical relevant degree of DS, whereas 48.5% of patients showed DS. An analysis of variance revealed a statistically significant difference across all four groups (control group, SCI group, naMCI group, aMCI group) (p < 0.001). Whereas 8% of controls reported a considerable degree of SMC, 34% of the SCI group, 31% of the naMCI group, and 54% of the aMCI group reported considerable SMC. A two-factor analysis of variance with the factors cognitive status (controls, SCI group, naMCI group, aMCI group) and depressive status (depressed vs. not depressed) and SMC as dependent variable revealed that both factors were significant (p < 0.001), whereas the interaction was not (p = 0.820).
A large proportion of patients seeking help in a memory outpatient clinic report considerable SMC, with an increasing degree from cognitively healthy elderly to aMCI. Depressive status increases SMC consistently across groups with different cognitive status.
The current research examined the association between state disfavoured tax on soda (i.e. the difference between soda sales tax and the tax on food products generally) and a summary score representing the strength of state laws governing competitive beverages (beverages that compete with the beverages in the federally funded school lunch programme) in US schools.
The Classification of Laws Associated with School Students (CLASS) summary score reflected the strength of a state's laws restricting competitive beverages sold in school stores, vending machines, school fundraisers and à la carte cafeteria items. Bridging the Gap (BTG) is a nationally recognized research initiative that provided state-level soda tax data. The main study outcome was the states’ competitive beverage summary scores for elementary, middle and high school grade levels, as predicted by the states’ disfavoured soda tax. Univariate and multivariate analyses were conducted, adjusting for year and state.
Data from BTG and CLASS were used.
BTG and CLASS data from all fifty states and the District of Columbia from 2003 to 2010 were used.
A higher disfavoured soda sales tax was generally associated with an increased likelihood of having strong school beverage laws across grade levels, and especially when disfavoured soda sales tax was >5 %.
These data suggest a concordance between states’ soda taxes and laws governing beverages sold in schools. States with high disfavoured sales tax on soda had stronger competitive beverage laws, indicating that the state sales tax environment may be associated with laws governing beverage policy in schools.
Resonant coupling of an optical mode confined within a microcavity and an emitter is the basic prerequisite for the observation of Bose-Einstein condensation phenomena and the development of novel optical devices based on cavity polaritons.
We demonstrate highly spatially resolved 2” wafer characterization of the reflectivity and emission properties of a nitride based multi quantum well semi microcavity (i.e. structure without top Bragg reflector) to verify resonant regions. Photoluminescence and reflectivity spectra recorded at the same positions on the wafer exhibit a strong spatial dependence of the multi quantum well emission and the center wavelength of the stop band of the bottom Bragg reflector across the sample. Resonance, i.e., matching of the emission and the center wavelength of the stop band, is found in a region 8 mm off the center of the wafer.
The thickness profile across the AlInN/GaN Bragg reflector and multi quantum well layers was obtained by x-ray mappings over the full wafer. A perfect correlation between the local optical properties and the x-ray thickness distribution is found. Additional transmission electron microscopy investigations indicate a complete crack free structure and smooth interfaces between the layers within the Bragg reflector making the structure appropriate for strong coupling applications.
Fourier transform infrared (FTIR) spectroscopy has gained significant attention among the forensic scientists because it shows high sensitivity and selectivity, and offers near-real-time detection. Application of the multivariate statistical techniques for the analysis of the spectra is necessary in order to enable feature extraction, proper evaluation and identification of obtained spectra. In this paper we show the development of a feasible procedure for the characterization of spectroscopic signatures of the explosive materials in the remnants after explosion. In our research especially designed and prepared sample catchers were used during the blasts of three various high explosives: C-4, TNT and PETN. Principal component analysis (PCA) was performed using broad spectral data range (600–4000 cm−1) for sample classification into separate classes. Most of the information contained in spectral data was compressed by PCA in few relevant principal components that explain most of the variance of spectral data. The results show that FTIR spectroscopy in combination with multivariate methods are well suited for identification and differentiation purposes even in very large data sets and could be employed by forensic laboratories for rapid screening analysis.
The meta-foil is an all-metal self-supported electromagnetic metamaterial that features a space-grid that is locally stiff, yet globally flexible. Owing to its mechanical, thermal, chemical and radiative robustness, it lends itself to widespread applications.