2,010 research outputs found
Multispectral fingerprinting for improved in vivo cell dynamics analysis
Background:
Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC) as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks.
Results:
We found that multicolor nuclear cell labeling and multispectral imaging led to improved resolution of in vivo NC cell identification by providing a unique spectral identity for each cell. NC cell spectral identity allowed for more accurate cell tracking and was consistent during short term time-lapse imaging sessions. Computer model simulations predicted significantly better object counting for increasing cell densities in 3-color compared to 1-color nuclear cell labeling. To better resolve cell contacts, we show that a combination of 2-color membrane and 1-color nuclear cell labeling dramatically improved the semi-automated analysis of NC cell interactions, yet preserved the ability to track cell movements. We also found channel versus lambda scanning of multicolor labeled embryos significantly reduced the time and effort of image acquisition and analysis of large 3D volume data sets.
Conclusions:
Our results reveal that multicolor cell labeling and multispectral imaging provide a cellular fingerprint that may uniquely determine a cell's position within the embryo. Together, these methods offer a spectral toolbox to resolve in vivo cell dynamics in unprecedented detail
The pains of being unauthorized in the Netherlands
Ethnographic fieldwork amongst 105 unauthorized migrants in the Netherlands shows that unauthorized migrants suffer from the pains of being unauthorized. These migrants feel punished and are severely hurt by – amongst others – the deprivation of healthy and secure living conditions, social and geographical mobility and citizenship. These migrants’ pains are caused by current restrictive migration controls, something the Dutch authorities could and should be aware of given previous research that provides similar insights. While the Dutch authorities do provide – the legally required – provisions for unauthorized migrants, we argue on the basis of Hayes’ proximity model that these authorities accept the collateral consequences of (possibly) being subjected to migration controls and purposely inflict these pains on unauthorized migrants. This m
Exponential distribution of financial returns at mesoscopic time lags: a new stylized fact
We study the probability distribution of stock returns at mesoscopic time
lags (return horizons) ranging from about an hour to about a month. While at
shorter microscopic time lags the distribution has power-law tails, for
mesoscopic times the bulk of the distribution (more than 99% of the
probability) follows an exponential law. The slope of the exponential function
is determined by the variance of returns, which increases proportionally to the
time lag. At longer times, the exponential law continuously evolves into
Gaussian distribution. The exponential-to-Gaussian crossover is well described
by the analytical solution of the Heston model with stochastic volatility.Comment: 7 pages, 12 plots, elsart.cls, submitted to the Proceedings of
APFA-4. V.2: updated reference
Using Decision Analysis to Improve Malaria Control Policy Making
Malaria and other vector-borne diseases represent a significant and growing burden in many tropical countries. Successfully addressing these threats will require policies that expand access to and use of existing control methods, such as insecticide-treated bed nets (ITNs) and artemesinin combination therapies (ACTs) for malaria, while weighing the costs and benefits of alternative approaches over time. This paper argues that decision analysis provides a valuable framework for formulating such policies and combating the emergence and re-emergence of malaria and other diseases. We outline five challenges that policy makers and practitioners face in the struggle against malaria, and demonstrate how decision analysis can help to address and overcome these challenges. A prototype decision analysis framework for malaria control in Tanzania is presented, highlighting the key components that a decision support tool should include. Developing and applying such a framework can promote stronger and more effective linkages between research and policy, ultimately helping to reduce the burden of malaria and other vector-borne diseases
Natural course of neuropsychiatric symptoms in nursing home patients with mental-physical multimorbidity in the first eight months after admission
Objective: Aging societies will bring an increase in the number of long-term care patients with mental-physical multimorbidity (MPM). This paper aimed to describe the natural course of neuropsychiatric symptoms (NPS) in patients with MPM in the first 8 months after admission to a geronto-psychiatric nursing home (GP-NH) unit. Methods: Longitudinal cohort study among 63 patients with MPM no dementia living in 17 GP-NH units across the Netherlands. Data collection consisted of chart review, semi-structured interviews, and brief neuropsychological testing, among which our primary outcome measure the Neuropsychiatric Inventory (NPI). Descriptive and bivariate analyses were conducted. Results: Our study showed a significant increase of the NPI total score (from 25.3 to 29.3, p = 0.045), and the total scores of a NPI hyperactivity cluster (from 9.7 to 11.8, p = 0.039), and a NPI mood/apathy cluster (from 7.7 to 10.1, p = 0.008). Just over 95% had any clinically relevant symptom at baseline and/or six months later, of which irritability was the most prevalent and persistent symptom and the symptom with the highest incidence. Hyperactivity was the most prevalent and persistent symptom cluster. Also, depression had a high persistence. Conclusions: Our results indicate the omnipresence of NPS of which most were found to be persistent. Therefore, we recommend to explore opportunities to reduce NPS in NH patients with MPM, such as creating a therapeutic milieu, educating the staff, and evaluating patient's psychotropic drug use
Antenna Near-Field Probe Station Scanner
A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described
Development of bone marrow lesions is associated with adverse effects on knee cartilage while resolution is associated with improvement - a potential target for prevention of knee osteoarthritis: a longitudinal study
INTRODUCTION: To examine the relationship between development or resolution of bone marrow lesions (BMLs) and knee cartilage properties in a 2 year prospective study of asymptomatic middle-aged adults. METHODS: 271 adults recruited from the Melbourne Collaborative Cohort Study, underwent a magnetic resonance imaging scan (MRI) of their dominant knee at baseline and again approximately 2 years later. Cartilage volume, cartilage defects and BMLs were determined at both time points. RESULTS: Among 234 subjects free of BMLs at baseline, 33 developed BMLs over 2 years. The incidence of BMLs was associated with progression of tibiofemoral cartilage defects (OR 2.63 (95% CI 0.93, 7.44), P = 0.07 for medial compartment; OR 3.13 (95% CI 1.01, 9.68), P = 0.048 for lateral compartment). Among 37 subjects with BMLs at baseline, 17 resolved. Resolution of BMLs was associated with reduced annual loss of medial tibial cartilage volume (regression coefficient -35.9 (95%CI -65, -6.82), P = 0.02) and a trend for reduced progression of medial tibiofemoral cartilage defects (OR 0.2 (95% CI 0.04, 1.09), P = 0.06). CONCLUSIONS: In this cohort study of asymptomatic middle-aged adults the development of new BMLs was associated with progressive knee cartilage pathology while resolution of BMLs prevalent at baseline was associated with reduced progression of cartilage pathology. Further work examining the relationship between changes and BML and cartilage may provide another important target for the prevention of knee osteoarthritis
The lipid droplet protein DHRS3 is a regulator of melanoma cell state
Lipid droplets are fat storage organelles composed of a protein envelope and lipid rich core. Regulation of this protein envelope underlies differential lipid droplet formation and function. In melanoma, lipid droplet formation has been linked to tumor progression and metastasis, but it is unknown whether lipid droplet proteins play a role. To address this, we performed proteomic analysis of the lipid droplet envelope in melanoma. We found that lipid droplet proteins were differentially enriched in distinct melanoma states; from melanocytic to undifferentiated. DHRS3, which converts all-trans-retinal to all-trans-retinol, is upregulated in the MITFLO/undifferentiated/neural crest-like melanoma cell state and reduced in the MITFHI/melanocytic state. Increased DHRS3 expression is sufficient to drive MITFHI/melanocytic cells to a more undifferentiated/invasive state. These changes are due to retinoic acid mediated regulation of melanocytic genes. Our data demonstrate that melanoma cell state can be regulated by expression of lipid droplet proteins which affect downstream retinoid signaling
Small X-Band Oscillator Antennas
A small, segmented microstrip patch antenna integrated with an X-band feedback oscillator on a high-permittivity substrate has been built and tested. This oscillator antenna is a prototype for demonstrating the feasibility of such devices as compact, low-power-consumption building blocks of advanced, lightweight, phased antenna arrays that would generate steerable beams for communication and remotesensing applications
Dietary fatty acid intake affects the risk of developing bone marrow lesions in healthy middle-aged adults without clinical knee osteoarthritis: a prospective cohort study
INTRODUCTION: Fatty acids have been implicated in osteoarthritis (OA), yet the mechanism by which fatty acids affect knee structure and consequently the risk of knee OA has not been fully elucidated. Higher intakes of fatty acids have been shown to be associated with the risk of bone marrow lesions (BMLs) in a healthy population. The aim of this study was to examine the association between fatty acid consumption and the incidence of BMLs in healthy middle-aged adults without clinical knee OA. METHODS: Two hundred ninety-seven middle-aged adults without clinical knee OA underwent magnetic resonance imaging (MRI) of their dominant knee at baseline. BMLs were assessed. Of the 251 participants with no BMLs in their knee at baseline, 230 underwent MRI of the same knee approximately 2 years later. Intakes of fatty acids were estimated from a food frequency questionnaire. RESULTS: Increased consumption of saturated fatty acids was associated with an increased incidence of BMLs over 2 years after adjusting for energy intake, age, gender, and body mass index (odds ratio of 2.56 for each standard deviation increase in dietary intake, 95% confidence interval 1.03 to 6.37, P = 0.04). Intake of monounsaturated or polyunsaturated fatty acids was not significantly associated with the incidence of BMLs. CONCLUSIONS: Increased fatty acid consumption may increase the risk of developing BMLs. As subchondral bone is important in maintaining joint integrity and the development of OA, this study suggests that dietary modification of fatty acid intake may be one strategy in the prevention of knee OA which warrants further investigation
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