scholarly journals Large Constellations of Small Satellites: A Survey of Near Future Challenges and Missions

Aerospace ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 133 ◽  
Author(s):  
Giacomo Curzi ◽  
Dario Modenini ◽  
Paolo Tortora
Keyword(s):  
Cost Effective ◽  
Satellite Constellations ◽  
Small Satellites ◽  
Emerging Trends ◽  
Large Numbers ◽  
Future Challenges ◽  
Coordinated Flight ◽  
Applications Of Machine Learning ◽  
The Moment ◽  
Statistical Trends

Constellations of satellites are being proposed in large numbers; most of them are expected to be in orbit within the next decade. They will provide communication to unserved and underserved communities, enable global monitoring of Earth and enhance space observation. Mostly enabled by technology miniaturization, satellite constellations require a coordinated effort to face the technological limits in spacecraft operations and space traffic. At the moment in fact, no cost-effective infrastructure is available to withstand coordinated flight of large fleets of satellites. In order for large constellations to be sustainable, there is the need to efficiently integrate and use them in the current space framework. This review paper provides an overview of the available experience in constellation operations and statistical trends about upcoming constellations at the moment of writing. It highlights also the tools most often proposed in the analyzed works to overcome constellation management issues, such as applications of machine learning/artificial intelligence and resource/infrastructure sharing. As such, it is intended to be a useful resource for both identifying emerging trends in satellite constellations, and enabling technologies still requiring substantial development efforts.

MEASLES VIRUS ELIMINATION: RESOLVED ISSUES AND FUTURE CHALLENGES

2020 ◽  
pp. 83-88
Author(s):  
Kseniia Artemivna Veklych
Keyword(s):  
Measles Virus ◽  
Disease Outbreaks ◽  
Vaccination Schedule ◽  
Successful Implementation ◽  
Complete Elimination ◽  
Virus Elimination ◽  
Vaccination Programs ◽  
Future Challenges ◽  
The Moment ◽  
Measles Outbreaks

Measles is a highly contagious infectious disease caused by an RNA−containing virus of the family Paramyxoviridae and Morbillivirus genus. The most proper way to stop it is a total vaccination. At the moment, live attenuated strains of the Enders − Schwartz measles virus are used to conduct it. Although they were developed more than 50 years ago, the vaccines in use today are effective enough to create a proper immune protection that can defend against an infection for decades, if the vaccination schedule is followed. The vast majority of measles outbreaks that have been reported in Europe over the last seven years have been caused by a lack of an immune response resulting from the unprecedented coverage of the population with vaccination. The measles outbreak observed in the adult and child population of Ukraine since December 2018 indicates the need and urgency of additional efforts to curb the spread and complete elimination of the measles virus. It has been determined that more than 95 % of the population should be vaccinated to ensure an elimination of measles virus and prevent the disease outbreaks after the virus has been imported from the countries that are still endemic to measles. It is noted that as a result of successful implementation of vaccination programs, the public's attention to measles is diminished even among physicians who sometimes have a rather dubious understanding of the disease symptoms. Ensuring a complete elimination of the measles virus requires the development and implementation of additional laboratory tests for immunity, development and realization of new, more polyvalent vaccines that are more readily accepted by population, increased awareness on safety and necessity of vaccination, as well as regulation. Key words: measles, immunity, elimination, epidemiological control, vaccination.

scholarly journals Tailoring photosensitive ROS for advanced photodynamic therapy

2021 ◽  
Author(s):  
Duc Loc Sai ◽  
Jieun Lee ◽  
Duc Long Nguyen ◽  
Young-Pil Kim
Keyword(s):  
Photodynamic Therapy ◽  
Reactive Oxygen Species Generation ◽  
Cost Effective ◽  
Molecular Medicine ◽  
Oxygen Species ◽  
Significant Progress ◽  
Tumor Treatment ◽  
Innovative Strategies ◽  
Tumor Microenvironments ◽  
Future Challenges

AbstractPhotodynamic therapy (PDT) has been considered a noninvasive and cost-effective modality for tumor treatment. However, the complexity of tumor microenvironments poses challenges to the implementation of traditional PDT. Here, we review recent advances in PDT to resolve the current problems. Major breakthroughs in PDTs are enabling significant progress in molecular medicine and are interconnected with innovative strategies based on smart bio/nanomaterials or therapeutic insights. We focus on newly developed PDT strategies designed by tailoring photosensitive reactive oxygen species generation, which include the use of proteinaceous photosensitizers, self-illumination, or oxygen-independent approaches. While these updated PDT platforms are expected to enable major advances in cancer treatment, addressing future challenges related to biosafety and target specificity is discussed throughout as a necessary goal to expand the usefulness of PDT.

scholarly journals The High Capacity Expanding Lifeboat HiCEL – Meeting the Modern SAR Challenge

2018 ◽  
Author(s):  
J R E Wright ◽  
G E Payne
Keyword(s):  
Large Scale ◽  
High Capacity ◽  
Cost Effective ◽  
Second World War ◽  
Concept Design ◽  
Small Vessels ◽  
Large Numbers ◽  
Cost Effective Alternative ◽  
Operational Envelope ◽  
Second World

The Mediterranean migrant crisis has resulted in the highest population displacement since the Second World War. In 2016 alone, over one million made the journey across the sea. Since 2013 over 15,000 have died as a result of this journey. Small vessels such as wooden fishing boats and RIBs are commonly used by smugglers as transport. These are often unseaworthy and filled with numbers of passengers far exceeding their intended capacity. When failure occurs, rescues are typically conducted by the nearest available vessel. These vessels are often ill-equipped for a large-scale Search and Rescue (SAR) operation making it highly dangerous for all involved.  The size and quantity of lifeboats available are often insufficient for the large numbers of people to be rescued; as a result, repeat journeys are required, making the rescue process slow, inefficient and hazardous. This paper outlines a novel solution to this problem. A concept design is presented for a rapidly expandable lifeboat capable of holding large numbers of passengers, whilst still fitting into the operational envelope of common davits. The unique inflatable design can be deployed quickly from a range of vessels and aeroplanes offering an immediate platform from which disembarkation onto a suitable vessel can be achieved. CONOPS are outlined along with the required capabilities of the design. Drop stitch technology is identified as a viable means of manufacturing the large inflatable platforms. Finally, the paper discusses an alternative solution, retrofitting existing enclosed lifeboats with the solution to offer a more cost-effective alternative.  

scholarly journals Enhancing Non-intrusive Occupant Load Monitoring through Occupancy Matrix

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Hamed Nabizadeh Rafsanjani
Keyword(s):  
Energy Use ◽  
Cost Effective ◽  
Behavior Intervention ◽  
Built Environments ◽  
Load Variations ◽  
Office Space ◽  
Cost Effective Approach ◽  
Load Monitoring ◽  
Energy Consuming ◽  
The Moment

It has been universally accepted that energy consumption in commercial buildings is highly related to occupant behaviors. Improving occupants’ energy-use behaviors is regarded as the most cost-effective approach to enhance overall energy saving in commercial built environments. However, effective behavior intervention pursuits rely on the availability of occupant-specific energy-use information, which is extremely expensive to capture with existing technologies. In this context, the author’s previous studies proposed the non-intrusive occupant load monitoring (NIOLM) approach that captures individual occupants’ energy-consuming information at their entry and departure events in an economically feasible manner. The NIOLM assigns energy-load variations (ev) of a building to individual occupants and relies on two variables: Time delay intervals and magnitudes of ev. This paper extends the existing NIOLM concept with the inclusion of a new variable, the occupancy matrix which manifests the information of present occupants at the moment of ev. An experiment has been conducted in an office space to validate the feasibility and accuracy of the proposed approach. Outcomes of this research could be a great help for studies on occupant energy-use behaviors intervention and simulation. 

scholarly journals Risk of Spreading Soft Rot Through Cutting Dips Against Whiteflies in Greenhouse-Grown Poinsettia

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2262-2268
Author(s):  
Rosemarije Buitenhuis ◽  
Anissa Poleatewich ◽  
Mark Jandricic ◽  
Michael Brownbridge
Keyword(s):  
Disease Incidence ◽  
Cost Effective ◽  
Soft Rot ◽  
Cross Contamination ◽  
Large Numbers ◽  
Growing Medium ◽  
Cost Effective Technique ◽  
Dipping Process ◽  
Carotovorum Subsp ◽  
Insecticidal Treatment

Dipping is a quick and cost-effective technique to reduce pest infestations on unrooted cuttings of greenhouse ornamental crops. Large numbers of cuttings are immersed in an insecticidal treatment, e.g., biopesticides and/or insecticidal soap, before they are stuck in the growing medium and rooted. This research investigated the risk of cross-contamination of poinsettia cuttings with Pectobacterium carotovorum subsp. carotovorum, a potentially devastating pathogen causing soft rot, through the dipping process. Sampling at four commercial greenhouses showed that P. carotovorum subsp. carotovorum was present in all dip suspensions during and after processing poinsettia cuttings; concentrations up to 1 × 105 CFU/ml were detected. A laboratory experiment determined that P. carotovorum subsp. carotovorum-infected cuttings could contaminate clean dip suspensions to similar levels. These results indicated that there is potential for disease transfer during dipping. The potential for cross-contamination of healthy cuttings was evaluated by immersing poinsettia cuttings in dip suspensions artificially inoculated with P. carotovorum subsp. carotovorum (from 1 × 103 to 1 × 107 CFU/ml). Disease incidence increased as P. carotovorum subsp. carotovorum concentrations in the dip suspension increased and the variety ‘Prestige Red’ was more susceptible than ‘Freedom White.’ However, even at the highest P. carotovorum subsp. carotovorum concentration of 1 × 107 CFU/ml, the proportion of diseased cuttings was low at 6% for var. ‘Freedom White,’ but higher at 21% for var. ‘Prestige Red.’ We conclude that P. carotovorum subsp. carotovorum transfer among unrooted poinsettia cuttings through the dipping process is relatively low although some varieties are sensitive to high levels of inoculum. Even so, strict sanitation practices are still important to prevent build-up of inoculum in the dip treatment.

Neuropsychological Testing: Evolution and Emerging Trends

CNS Spectrums ◽  
2002 ◽  
Vol 7 (4) ◽  
pp. 307-312 ◽  
Author(s):  
Christopher Randolph
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neuropsychological Testing ◽  
Cost Effective ◽  
Diagnostic Reliability ◽  
Emerging Trends ◽  
Motor Testing ◽  
Attention Memory ◽  
Psychometric Quality ◽  
Lesion Localization

ABSTRACTNeuropsychological (NP) test batteries have evolved as an amalgam of intelligence tests, various individual measures of “biological” cognition, and sensory and motor testing. The early emphasis of NP testing was to identify “organicity” and central nervous system lesion localization. More recent approaches have emphasized the profiling of performance across individual neurocognitive domains (eg, attention, memory, and language) to facilitate diagnosis and treatment planning. However, the field is still hampered by the use of many tests that are antiquated, excessively long, or of dubious psychometric quality. Some of these problems may have contributed to the current under-utilization of NP testing in diagnostic workups of neuropsychiatric disorders. This paper reviews some of the recent changes in the field that hold promise for substantially shortening assessments, improving diagnostic reliability, and making NP testing more cost-effective and practical.

scholarly journals Thermal Management Systems for Civil Aircraft Engines: Review, Challenges and Exploring the Future

2018 ◽  
Vol 8 (11) ◽  
pp. 2044 ◽  
Author(s):  
Soheil Jafari ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Thermal Management ◽  
Cost Effective ◽  
Alternative Methods ◽  
Management Systems ◽  
Engine Efficiency ◽  
Future Challenges ◽  
Aero Engines ◽  
Historical Coverage ◽  
Electrical Components

This paper examines and analytically reviews the thermal management systems proposed over the past six decades for gas turbine civil aero engines. The objective is to establish the evident system shortcomings and to identify the remaining research questions that need to be addressed to enable this important technology to be adopted by next generation of aero engines with complicated designs. Future gas turbine aero engines will be more efficient, compact and will have more electric parts. As a result, more heat will be generated by the different electrical components and avionics. Consequently, alternative methods should be used to dissipate this extra heat as the current thermal management systems are already working on their limits. For this purpose, different structures and ideas in this field are stated in terms of considering engines architecture, the improved engine efficiency, the reduced emission level and the improved fuel economy. This is followed by a historical coverage of the proposed concepts dating back to 1958. Possible thermal management systems development concepts are then classified into four distinct classes: classic, centralized, revolutionary and cost-effective; and critically reviewed from challenges and implementation considerations points of view. Based on this analysis, the potential solutions for dealing with future challenges are proposed including combination of centralized and revolutionary developments and combination of classic and cost-effective developments. The effectiveness of the proposed solutions is also discussed with a complexity-impact correlation analysis.

An enzyme-linked immunosorbent assay for the detection of Rathayibacter toxicus, the bacterium involved in annual ryegrass toxicity, in hay

2006 ◽  
Vol 57 (7) ◽  
pp. 731 ◽  
Author(s):  
A. M. Masters ◽  
A. R. Gregory ◽  
R. J. Evans ◽  
J. E. Speijers ◽  
S. S. Sutherland
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Specific Antigen ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Annual Ryegrass ◽  
Capture Assay ◽  
Large Numbers ◽  
Soluble Polysaccharide ◽  
Annual Ryegrass Toxicity

An enzyme-linked immunosorbent assay (ELISA) for Rathayibacter toxicus is described. The development of a monoclonal antibody for a specific antigen from R. toxicus and a polyclonal antibody raised against the same R. toxicus preparation enabled a capture assay format. The assay is specific for a soluble polysaccharide produced by the bacterium and was found to be sensitive enough to detect antigen equivalent to less than one gall per kilogram of hay. The applicability of the assay to samples of pasture or hay is demonstrated. Cost-effective testing of large numbers of samples for the presence of R. toxicus is possible with the ELISA. This will assist stockowners, hay producers, and hay exporters in the management of the risk of annual ryegrass toxicity.

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