Feasibility of nanofluid-based optical filters

In this article we report recent modeling and design work indicating that mixtures of nanoparticles in liquids can be used as an alternative to conventional optical filters. The major motivation for creating liquid optical filters is that they can be pumped in and out of a system to meet transient needs in an application. To demonstrate the versatility of this new class of filters, we present the design of nanofluids for use as long-pass, short-pass, and bandpass optical filters using a simple Monte Carlo optimization procedure. With relatively simple mixtures, we achieve filters with <15% mean-squared deviation in transmittance from conventional filters. We also discuss the current commercial feasibility of nanofluid-based optical filters by including an estimation of today's off-the-shelf cost of the materials. While the limited availability of quality commercial nanoparticles makes it hard to compete with conventional filters, new synthesis methods and economies of scale could enable nanofluid-based optical filters in the near future. As such, this study lays the groundwork for creating a new class of selective optical filters for a wide range of applications, namely communications, electronics, optical sensors, lighting, photography, medicine, and many more

SWEET-HOME ICT technologies for the assessment of elderly subjects

International audienceFunctional assessments are designed to ascertain a person's ability to perform activities of daily living (ADL) and provide valuable diagnostic as well as care-planning information. Currently, the gold-standard for the assessment of functional ability involves clinical rating scales however scales are often limited in their ability to provide objective and sensitive information. In contrast, information and communication technologies (ICT) may overcome these limitations by capturing more fully the functional, well as behavioural and cognitive disturbances associated with Alzheimer disease (AD)

Growth of GaInTlAs layers on InP by molecular beam epitaxy

International audienceGrowth of GaInTlAs alloys on InP001 has been attempted by solid source molecular beam epitaxy. Thallium incorporation into Ga 1x In x As matrices was studied as a function of substrate temperature, arsenic overpressure, matrix composition, and growth rate. At high temperatures 350 °C thallium evaporates, whereas at intermediary temperatures 270-350 °C thallium segregates into droplets on the surface. Only in the low temperature range 180-260 °C can thallium be incorporated in some conditions, leading to mirror-like surfaces. Up to 18% Tl content was incorporated into a Ga 0.70 In 0.30 As matrix and up to 40% Tl into a GaAs matrix. For these high Tl concentrations, Tl droplets are avoided and Tl incorporation is achieved only when using high arsenic pressures. However, this limits surface adatom diffusion and leads to amorphous, polycrystalline, or twinned materials. Finally, a narrow window for single-crystal growth has been found for low Tl contents 4% using optimized growth conditions with low V/III pressure ratios and high growth rates

COVID-19 outbreak and increased risk of amblyopia and epidemic myopia: Insights from EUROCOVCAT group

The most common cause of vision impairment in children is amblyopia. It is defined as impaired visual acuity in one or both eyes that is present with no demonstrable abnormality of the visual pathway and is not immediately resolved by wearing glasses. After the World Health Organization (WHO) recognized COVID-19 as a global pandemic on March 11, 2020, widespread changes and restrictions to social and sanitary practices have presented significant issues in access to eye care during the COVID-19 pandemic. A reduction of more than 80% in pediatric eye care volume up to its total cessation has been observed in different departments. In this scenario, reduced or absent eyesight, due to delay in timely treatment of amblyopic conditions, could create major, long-lasting effects on all aspects of life, including daily personal activities, interacting with the community, school and work opportunities and the ability to access public services. Processes coming out of lockdown should be gradually easing restrictions giving priority to ophthalmology and eye care facilities so that amblyopia does not remain unattended and irreversible as in adults due to lack of timely treatments. If not reversible, this process could lead to a dramatic increase in disability and unsustainable social costs for many governments

The FLURESP European commission project. cost-effectiveness assessment of ten public health measures against influenza in Italy. is there an interest in COVID-19 pandemic?

Background: The FLURESP project is a public health research funded by the European Commission, with the objective to design a methodological framework to assess the cost-effectiveness of existing public health measures against human influenza pandemics. A dataset has been specifically collected in the frame of the Italian health system. As most of interventions against human influenza are relavant against other respiratory diseases pandemics, potential interests in COVID-19 are discussed. Methods: Ten public health measures against human influenza pandemics pandemic were selected to be also relevant to other respiratory virus pandemics such as COVID 19: individual (hand washing, using masks), border control (quarantine, fever screening, border closure), community infection (school closure, class dismissal, social distancing, limitation of public transport), reduction of secondary infections (implementation of antibiotic therapy guidelines), pneumococcal vaccination for at-risk people, development of Intensive Care Unit (ICU) capacity, implementation of life support equipments in ICU, screening interventions, vaccination programs targeting health professional and targeting general population. Results: Using mortality reduction as effectiveness criteria, the most cost-effective strategies are "reduction of secondary infections" and "implementation of life support equipment in ICU". The least cost-effective option whatever the level of pandemic events are screening interventions and mass vaccination. Conclusions: A number of intervention strategies against human influenza pandemics appears relevant against every respiratory virus, including the COVID-19 event. Measures against pandemics should be considered according to their expected effectiveness but also their costs for the society because they impose substantial burden to the population, confirming the interest of considering cost-effectiveness of public health measures to enlighten decision making

Global hybrids from the semiclassical atom theory satisfying the local density linear response

We propose global hybrid approximations of the exchange-correlation (XC) energy functional which reproduce well the modified fourth-order gradient expansion of the exchange energy in the semiclassical limit of many-electron neutral atoms and recover the full local density approximation (LDA) linear response. These XC functionals represent the hybrid versions of the APBE functional [Phys. Rev. Lett. 106, 186406, (2011)] yet employing an additional correlation functional which uses the localization concept of the correlation energy density to improve the compatibility with the Hartree-Fock exchange as well as the coupling-constant-resolved XC potential energy. Broad energetical and structural testings, including thermochemistry and geometry, transition metal complexes, non-covalent interactions, gold clusters and small gold-molecule interfaces, as well as an analysis of the hybrid parameters, show that our construction is quite robust. In particular, our testing shows that the resulting hybrid, including 20\% of Hartree-Fock exchange and named hAPBE, performs remarkably well for a broad palette of systems and properties, being generally better than popular hybrids (PBE0 and B3LYP). Semi-empirical dispersion corrections are also provided.Comment: 12 pages, 4 figure

Prognostic value of p53 gene mutations in a large series of node- negative breast cancer patients

The most important subgroup of breast cancer patients for which reliable prognostic factors are needed are women without axillary lymph node involvement. Although overall, these patients have a good prognosis, it is known that 20-30% will experience a recurrence of the disease. To determine the prognostic significance of P53 tumor suppressor gene mutation, specimens from 113 primary breast cancers were evaluated for the presence of P53 alterations, as detected by cDNA sequencing of the entire coding sequence of the gene. The median follow-up for patients was 105 months. P53 gene mutation was an independent prognostic marker of early relapse and death. Our results suggest that P53 gene mutations could be an important factor to identify node-negative patients who have a poor prognosis in the absence of adjuvant therapy. Prospective studies should be designed to determine which therapy should be performed in this subgroup of patients

A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

In support of NASAs ongoing effort to bring supersonic commercial travel to the public, NASA Dryden Flight Research Center and NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response. Such tests will go towards building a dataset that governing agencies like the Federal Aviation Administration and International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. Until WSPR, there had never been an effort that studied the response of people in their own homes and performing daily activities to non-traditional, low sonic booms.WSPR was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle. Other partners included Gulfstream Aerospace Corporation, Pennsylvania State University, Tetra Tech, and Fidell Associates, Inc.A major objective of the effort included exposing a community with the sonic boom magnitudes and occurrences expected in high-air traffic regions with a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data was collected using multiple survey methods. The research focused on essential elements of community response testing including subject recruitment, survey methods, instrumentation systems, flight planning and operations, and data analysis methods.This paper focuses on NASAs role in the efforts logistics and operations including human response subject recruitment, the operational processes involved in implementing the surveys throughout the community, instrumentation systems, logistics, flight planning, and flight operations. Findings discussed in this paper include critical lessons learned in all of those areas. The paper also discusses flight operations results. Analysis of the accuracy and repeatability of planning and executing the unique aircraft maneuver used to generate low sonic booms concluded that the sonic booms had overpressures within 0.15 pounds-per-square-feet of the planned values for 76 of t he attempts. Similarly, 90 of the attempts to generate low sonic booms within the community were successful

Crustal-scale degassing due to magma system destabilization and magma-gas decoupling at Soufrière Hills Volcano, Montserrat

Activity since 1995 at Soufrière Hills Volcano (SHV), Montserrat has alternated between andesite lava extrusion and quiescence, which are well correlated with seismicity and ground deformation cycles. Large variations in SO₂ flux do not correlate with these alternations, but high and low HCl/SO₂ characterize lava dome extrusion and quiescent periods respectively. Since lava extrusion ceased (February 2010) steady SO₂ emissions have continued at an average rate of 374 tonnes/day (± 140 t/d), and incandescent fumaroles (temperatures up to 610°C) on the dome have not changed position or cooled. Occasional short bursts (over several hours) of higher (∼ 10x) SO₂ flux have been accompanied by swarms of volcano-tectonic earthquakes. Strain data from these bursts indicate activation of the magma system to depths up to 10 km. SO₂ emissions since 1995 greatly exceed the amounts that could be derived from 1.1 km³ of erupted andesite, and indicating extensive partitioning of sulfur into a vapour phase, as well as efficient decoupling and outgassing of sulfur-rich gases from the magma. These observations are consistent with a vertically extensive, crustal magmatic mush beneath SHV. Three states of the magmatic system are postulated to control degassing. During dormant periods (10³ to 10⁴ years) magmatic vapour and melts separate as layers from the mush and decouple from each other. In periods of unrest (years) without eruption, melt and fluid layers become unstable, ascend and can amalgamate. Major destabilization of the mush system leads to eruption, characterized by magma mixing and release of volatiles with different ages, compositions and sources.RSJS acknowledges an ERC advanced grant (VOLDIES). JDB acknowledges ERC advanced grant CRITMAG and a Wolfson Research Merit Award.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2015GC00579

Impact of pre-Columbian 'geoglyph' builders on Amazonian forests

Over 450 pre-Columbian (pre-AD1492) geometric ditched enclosures ('geoglyphs') occupy ca. 13,000 km2 of Acre state, Brazil, representing a key discovery of Amazonian archaeology. These huge earthworks were concealed for centuries under terra firme (upland interfluvial) rainforest, directly challenging the 'pristine' status of this ecosystem and its perceived vulnerability to human impacts. We reconstruct the environmental context of geoglyph construction and the nature, extent and legacy of associated human impacts. We show that bamboo forest dominated the region for ≥6000 y and that only small, temporary clearings were made to build the geoglyphs; however, construction occurred within anthropogenic forest that had been actively managed for millennia. In the absence of widespread deforestation, exploitation of forest products shaped a largely forested landscape that survived intact until the late 20th century