Applications of Nanoparticle Image Velocimetry in Nanofluids

Particle Image Velocimetry (PIV) is an optical technique used for the visualization of fluid flow. PIV can be combined with other techniques to enhance the analysis of fluid flow. A novel far-field plasmonic resonance enhanced nanoparticle-seeded Particle Image Velocimetry (nPIV) has been demonstrated to measure the velocity in a micro channel. Chemically synthesized silver nanoparticles have been used to seed the flow. By using Discrete Dipole Approximation (DDA), plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15 nm to 200 nm in two media: water and air. The diffraction-limited plasmonic resonance enhanced images of silver nanoparticles at different diameters have been recorded. By using standard PIV techniques, the velocity within the micro channel has been determined from the images collected. The plasmonic resonance effects of nanoparticles from different media as compared to metal nanoparticles are also examined. Localized Surface Plasmon Resonance (LSPR) effects by naturally occurring Chinese yam particles are observed and quantified. Chinese yam particles are found by an atomic force microscope and a high-speed optical dark-field microscope. The particles with diameters greater than 200 nm are found to contribute most to UV-Vis absorption. LSPR effects of silver nanoparticles by the Chinese yam particles lead to the red shift of the extinction peaks of the silver nanoparticles. The wavelength shifts are quantitatively predicted based on DDA of the LSPR effects, which are sensitive to the local dielectric constant changed by the Chinese yam particles. This finding may open a new avenue to detect the biological sub-micron particles or virus in solution. PIV gives a new perspective on fluid flow that is otherwise difficult to see. An application of PIV studying the flagella movement of Giardia Lamblis trophozoites is examined. Standard PIV techniques are employed using a combination of high-contrast CytoViva ® imaging system to capture the images at high speeds and the Insight 3G software to measure the speed and direction of fluid motion generated by the microscale flagella. The PIV images illustrate how the flagella of the Giardia interact with each other and how they move in their environment

Understanding the reminiscence bump: A systematic review

One of the most consistently observed phenomena in autobiographical memory research is the reminiscence bump: a tendency for middle-aged and elderly people to access more personal memories from approximately 10–30 years of age. This systematic review (PROSPERO 2017:CRD42017076695) aimed to synthesize peer-reviewed literature pertaining to the reminiscence bump. The researchers conducted searches in nine databases for studies published between the date of inception of each database and the year 2017. Keywords used included: reminiscence, bump, peak, surge, blip, reminiscence effect, and reminiscence component. Sixty-eight quantitative studies, out of 523, met the inclusion criteria. The researchers implemented a thematic analytic technique for data extraction. Four main themes were generated: methods of memory activation/instruction for life scripts, types of memory/life scripts recalled, location of the reminiscence bump, and theoretical accounts for the bump. The two prevailing methods of memory activation implemented were the cuing method and important memories method. Three types of memories/life scripts were recalled: personal/autobiographical memory, memories for public events, and life script events. The findings illustrate differing temporal periods for the bump: approximately 10–30 years for memories for important events, approximately 5–30 years for memories that were induced by word cues, and 6–39 years for studies using life scripts. In explaining the bump, the narrative/identity account and cultural life script account received the most support

Far-Field Plasmonic Resonance Enhanced Nano-Particle Image Velocimetry within a Micro Channel

In this paper, a novel far-field plasmonic resonance enhanced nanoparticle-seeded Particle Image Velocimetry (nPIV) has been demonstrated to measure the velocity profile in a micro channel. Chemically synthesized silver nanoparticles have been used to seed the flow in the micro channel. By using Discrete Dipole Approximation (DDA), plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15nm to 200nm. Optimum scattering wavelength is specified for the nanoparticles in two media: water and air. The diffraction-limited plasmonic resonance enhanced images of silver nanoparticles at different diameters have been recorded and analyzed. By using standard PIV techniques, the velocity profile within the micro channel has been determined from the images.Comment: submitted to Review of Scientific Instrument

A review of autobiographical memory studies on patients with schizophrenia spectrum disorders

Background Patients suffering from schizophrenia spectrum disorders demonstrate various cognitive deficiencies, the most pertinent one being impairment in autobiographical memory. This paper reviews quantitative research investigating deficits in the content, and characteristics, of autobiographical memories in individuals with schizophrenia. It also examines if the method used to activate autobiographical memories influenced the results and which theoretical accounts were proposed to explain the defective recall of autobiographical memories in patients with schizophrenia. Methods PsycINFO, Web of Science, and PubMed databases were searched for articles published between January 1998 and December 2018. Fifty-seven studies met the inclusion criteria. All studies implemented the generative retrieval strategy by inducing memories through cue words or pictures, the life-stage method, or open-ended retrieval method. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement guidelines were followed for this review. Results Most studies reported that patients with schizophrenia retrieve less specific autobiographical memories when compared to a healthy control group, while only three studies indicated that both groups performed similarly on memory specificity. Patients with schizophrenia also exhibited earlier reminiscence bumps than those for healthy controls. The relationship between comorbid depression and autobiographical memory specificity appeared to be independent because patients’ memory specificity improved through intervention, but their level of depression remained unchanged. The U-shaped retrieval pattern for memory specificity was not consistent. Both the connection between the history of attempted suicide and autobiographical memory specificity, and the relationship between psychotic symptoms and autobiographical memory specificity, remain inconclusive. Patients’ memory specificity and coherence improved through cognitive training. Conclusions The overgeneral recall of autobiographical memory by patients with schizophrenia could be attributed to working memory, the disturbing concept of self, and the cuing method implemented. The earlier reminiscence bump for patients with schizophrenia may be explained by the premature closure of the identity formation process due to the emergence of psychotic symptoms during early adulthood. Protocol developed for this review was registered in PROSPERO (registration no: CRD42017062643)

Rac1 drives intestinal stem cell proliferation and regeneration

Adult stem cells are responsible for maintaining the balance between cell proliferation and differentiation within self-renewing tissues. The molecular and cellular mechanisms mediating such balance are poorly understood. The production of reactive oxygen species (ROS) has emerged as an important mediator of stem cell homeostasis in various systems. Our recent work demonstrates that Rac1-dependent ROS production mediates intestinal stem cell (ISC) proliferation in mouse models of colorectal cancer (CRC). Here, we use the adult Drosophila midgut and the mouse small intestine to directly address the role of Rac1 in ISC proliferation and tissue regeneration in response to damage. Our results demonstrate that Rac1 is necessary and sufficient to drive ISC proliferation and regeneration in an ROS-dependent manner. Our data point to an evolutionarily conserved role of Rac1 in intestinal homeostasis and highlight the value of combining work in the mammalian and Drosophila intestine as paradigms to study stem cell biology

Improving the Accuracy of Hydrodynamic Simulations in Data Scarce Environments Using Bayesian Model Averaging: A Case Study of the Inner Niger Delta, Mali, West Africa

In this paper, the study area was the Inner Niger Delta (IND) in Mali, West Africa. The IND is threatened by climate change, increasing irrigation, and dam operations. 2D hydrodynamic modelling was used to simulate water levels, discharge, and inundation extent in the IND. Three different digital elevation models (DEM) (SRTM, MERIT, and a DEM derived from satellite images were used as a source of elevation data. Six different models were created, with different sources of elevation data and different downstream boundary conditions. Given that the performance of the models varies according to the location in the IND, the variable under consideration and the performance criteria, Bayesian Model Averaging (BMA) was used to assess the relative performance of each of the six models. The BMA weights, along with deterministic performance measures, such as the Nash Sutcliffe coefficient (NS) and the Pearson’s correlation coefficient (r), provide quantitative evidence as to which model is the best when simulating a particular hydraulic variable at a particular location. After the models were combined with BMA, both discharge and water levels could be simulated with reasonable precision (NS > 0.8). The results of this work can contribute to the more efficient management of water resources in the IND

RNA Nanotherapeutics for the Amelioration of Astroglial Reactivity.

In response to injuries to the CNS, astrocytes enter a reactive state known as astrogliosis, which is believed to be deleterious in some contexts. Activated astrocytes overexpress intermediate filaments including glial fibrillary acidic protein (GFAP) and vimentin (Vim), resulting in entangled cells that inhibit neurite growth and functional recovery. Reactive astrocytes also secrete inflammatory molecules such as Lipocalin 2 (Lcn2), which perpetuate reactivity and adversely affect other cells of the CNS. Herein, we report proof-of-concept use of the packaging RNA (pRNA)-derived three-way junction (3WJ) motif as a platform for the delivery of siRNAs to downregulate such reactivity-associated genes. In vitro, siRNA-3WJs induced a significant knockdown of Gfap, Vim, and Lcn2 in a model of astroglial activation, with a concomitant reduction in protein expression. Knockdown of Lcn2 also led to reduced protein secretion from reactive astroglial cells, significantly impeding the perpetuation of inflammation in otherwise quiescent astrocytes. Intralesional injection of anti-Lcn2-3WJs in mice with contusion spinal cord injury led to knockdown of Lcn2 at mRNA and protein levels in vivo. Our results provide evidence for siRNA-3WJs as a promising platform for ameliorating astroglial reactivity, with significant potential for further functionalization and adaptation for therapeutic applications in the CNS.The authors wish to acknowledge J. Bernstock and G. Pluchino for their critical insights throughout the execution of the study. This work was funded by the European Research Council (ERC) under the ERC-2010-StG grant agreement n° 260511-SEM_SEM, the Bascule Charitable Trust (RG 75149 to SP), the International Foundation for Research in Paraplegia (RG 69318 to S.P.), Wings for Life (RG 82921 to S.P.) and a core support grant from the Wellcome Trust and Medical Research Council to the Wellcome Trust – MRC Cambridge Stem Cell Institute. LPJ was supported by a research training fellowship from the Wellcome Trust (RRZA/057 RG79423)

Performance of the TIMI risk score in predicting mortality after primary percutaneous coronary intervention in elderly women: Results from a developing country

Background: Despite women undergoing primary percutaneous coronary intervention (PPCI) having a higher rate of adverse outcomes than men, data evaluating prognostic risk scores, especially in elderly women, remains scarce. This study was conducted to validate the predictive value of Thrombolysis in Myocardial Infarction (TIMI) risk score in elderly female patients. Materials and Methods: This was a retrospective analysis of elderly (\u3e65 years) female patients who underwent PPCI for ST-elevated myocardial infarction (STEMI) from October 2016 to September 2018. Patients\u27 demographic details and elements of TIMI risk score including age, co-morbidities, Killip classification; weight, anterior MI and total ischemic time were extracted from hospital records. The primary outcome was in-hospital mortality and post-discharge mortality reported on telephonic follow-up. Results: A total of 404 elderly women with a median age of 70 years were included. The mean TIMI score was 5.25±1.45 with 40.3% (163) patients of TIMI score \u3e 5. In-hospital mortality rate was 6.4% (26) and was found to be associated with TIMI score (p\u3c0.001). The in-hospital mortality rate increased from 3.1% at TIMI score of 0-4 to 34.6% at the score of 8. On follow-up (16.43±7.40 months) of 211 (55.8%) patients, the overall mortality rate was 20.3%, and this was also associated with TIMI score (p\u3c0.001). The mortality rate increased from 5.6% at the score of 0-4 to 54.5% at the score of 8. The predictive values (area under the curve) of TIMI risk score for in-hospital and post-discharge mortality were 0.709 (95% CI 0.591-0.827; p \u3c0.001) and 0.689 (95% CI 0.608-0.770; p \u3c0.001), respectively. Conclusion: Increased adverse outcomes were observed with higher TIMI risk score for in hospital and post-discharge follow-up. Therefore, the prognostic TIMI risk score is a robust tool in predicting both in-hospital as well as post-discharge mortality in elderly females

Uptake of climate change adaptation research results in South Asia

Climate Resilience and National Resilience programs focus on formulating the Bangladesh National Adaptation Plan (NAP) for long-term adaptation investments and enhancing the national capacity to integrate climate change adaptation (CCA) in planning, budgeting, and financial tracking process. However, these programs and projects need a system-level quantitative tool to assess the requirement for adaptations at different scales and consequently decide on adaptation financing for these programs and projects. The current project is built on the earlier findings of the DECCMA project to address the above issues, with the target to add the necessary refinement through incorporating the equity, accessibility, adequacy, and gender dimensions to be useful at different scales of adaptation for climate change. The Dynamic Adaptation Model (DAM) is a product that has been developed gradually. It can be applied at different scales that can support the different communities and sectorial agencies/departments to guide local and national planning to adaptations while prioritizing in selecting appropriate options in different programs and projects to ensure the efficient use of available resources. DAM is developed based on strong mathematical formulation supported by field evidence. The model is calibrated and validated using field data to quantify the present-day adaptation need and now is being tested for some of the proposed adaptations in the NAP processes to assess its usefulness at the national level. Moreover, it is the home-grown model; therefore, the required customized version for different communities and agencies is possible through updates in the future with its extension for new areal coverage in collaboration with the developers and the alignment of the recent national initiatives. These are the ongoing processes essential to make it worthwhile for the mainstream national adaptation plan that needs further work

Post-Quantum Era Privacy Protection for Intelligent Infrastructures

As we move into a new decade, the global world of Intelligent Infrastructure (II) services integrated into the Internet of Things (IoT) are at the forefront of technological advancements. With billions of connected devices spanning continents through interconnected networks, security and privacy protection techniques for the emerging II services become a paramount concern. In this paper, an up-to-date privacy method mapping and relevant use cases are surveyed for II services. Particularly, we emphasize on post-quantum cryptography techniques that may (or must when quantum computers become a reality) be used in the future through concrete products, pilots, and projects. The topics presented in this paper are of utmost importance as (1) several recent regulations such as Europe's General Data Protection Regulation (GDPR) have given privacy a significant place in digital society, and (2) the increase of IoT/II applications and digital services with growing data collection capabilities are introducing new threats and risks on citizens' privacy. This in-depth survey begins with an overview of security and privacy threats in IoT/IIs. Next, we summarize some selected Privacy-Enhancing Technologies (PETs) suitable for privacy-concerned II services, and then map recent PET schemes based on post-quantum cryptographic primitives which are capable of withstanding quantum computing attacks. This paper also overviews how PETs can be deployed in practical use cases in the scope of IoT/IIs, and maps some current projects, pilots, and products that deal with PETs. A practical case study on the Internet of Vehicles (IoV) is presented to demonstrate how PETs can be applied in reality. Finally, we discuss the main challenges with respect to current PETs and highlight some future directions for developing their post-quantum counterparts