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Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
TaeHyung Kim ◽  
Q-Han Park

Abstract Nanoscale particles and structures hold promise in circular dichroism (CD) spectroscopy for overcoming the weakness of molecular CD signals. Significant effort have been made to characterize nanophotonic CD enhancement and find efficient ways to boost molecular chirality, but the best solution is yet to be found. In this paper, we present a rigorous analytic study of the nanophotonic CD enhancement of typical nanoparticles. We consider metallic and dielectric nanoparticles capped with chiral molecules and analyze the effect of multipolar nanoparticles on the molecular CD. We identify the spectral features of the molecular CD resulting from the electric and magnetic resonances of nanoparticles and suggest better ways to boost molecular chirality. We also clarify the contribution of particle scattering and absorption to the molecular CD and the dependence on particle size. Our work provides an exact analytic approach to nanophotonic CD enhancement and offers a rule for selecting the most efficient particle for sensitive molecular chirality detection.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Guan-Hong Wang ◽  
Robert M. Brucker

AbstractA germ-free rearing system is a crucial method for host–microbiota interactions using Nasonia as a model system. The previous rearing media in 2012 introduced toxic factors like bleach and antibiotics, required significant effort and volume of media preparation, and the rearing protocols in 2012 and 2016 often resulted in embryos, larvae, and enclosing pupae drowning, underfed, or desiccating. In this work, we optimize the germ-free rearing media that excludes the toxic factors and provide a substrate for the developing animals to have constant access to media without the risk of drowning or desiccation. The new process resulted in an increase in full maturation of larvae to adults from 33 to 65%, with no effect on the rate of growth or final adult size. This significantly improves the applicability of germ-free rearing of Nasonia and potentially other parasitoids.


2021 ◽  
Vol 8 (4) ◽  
pp. 381-392
Author(s):  
Ignacio Alvarez Placencia ◽  
Diana Sánchez-Partida ◽  
José-Luis Martínez-Flores ◽  
Patricia Cano-Olivos

This case study presents the analysis through the use of sales estimation tools for planning demand for aggregate level as a finished product in a leading industrial products company in the market in Mexico. First, it aligned the demand plan and the supply plan, recommending the best execution scenario to increase operational efficiency and reduce the cost of operating the supply chain to increase the company's productivity and stay competitive. Then, after analysing the behaviour of the demand for selected products, the authors determined as the main affectation the inadequate precision of the method forecasting and the lack of an aggregate forecasting strategy that allows reducing the variation. Due to this, the most significant effort was concentrated on determining a better-forecasting model and the decision to aggregate the demand based on three relevant criteria: the demand pattern based on the Soft, Intermittent, Erratic or Irregular quadrant, the best method of the forecast for each product and the time in quarters. As a result, a reduction between 20% and 46% in the forecast variation can be obtained from the above.


Hydrology ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 5
Author(s):  
Evangelos Rozos ◽  
Panayiotis Dimitriadis ◽  
Vasilis Bellos

Machine learning has been employed successfully as a tool virtually in every scientific and technological field. In hydrology, machine learning models first appeared as simple feed-forward networks that were used for short-term forecasting, and have evolved into complex models that can take into account even the static features of catchments, imitating the hydrological experience. Recent studies have found machine learning models to be robust and efficient, frequently outperforming the standard hydrological models (both conceptual and physically based). However, and despite some recent efforts, the results of the machine learning models require significant effort to interpret and derive inferences. Furthermore, all successful applications of machine learning in hydrology are based on networks of fairly complex topology that require significant computational power and CPU time to train. For these reasons, the value of the standard hydrological models remains indisputable. In this study, we suggest employing machine learning models not as a substitute for hydrological models, but as an independent tool to assess their performance. We argue that this approach can help to unveil the anomalies in catchment data that do not fit in the employed hydrological model structure or configuration, and to deal with them without compromising the understanding of the underlying physical processes.


2021 ◽  
Author(s):  
◽  
Benjamin Mark Mandinka Deeble

<p>Azasugars are structural analogues of carbohydrates whereby the oxygen in the heterocyclic ring is substituted for a nitrogen. These carbohydrates are an important class of compounds with medicinal bioactivities and have shown potential for the treatment of diabetes, viral-infection, cancers, and lysosomal storage diseases. 1-deoxymannojirimycin (DMJ), is a mannosidase inhibiting azasugar which has shown anti-cancer and anti-viral activity. There has been significant effort put towards developing methodology to produce this compound and libraries of its derivatives. This thesis presents the synthesis of DMJ and a selection of its derivatives via an efficient 4 step methodology from a carbohydrate starting material, exploiting chemo and regioselective reactions to allow for a total synthesis with minimal use of protecting groups. The synthesis of DMJ, using the methodology developed herein, surpasses published syntheses in efficiency. This synthetic strategy was then used for the preparation of N-functionalised DMJ derivatives without the requirement of additional synthetic steps. To illustrate the versatility of this methodology, a selection of derivatives incorporating different functionalities have been synthesised.</p>


2021 ◽  
Author(s):  
◽  
Benjamin Mark Mandinka Deeble

<p>Azasugars are structural analogues of carbohydrates whereby the oxygen in the heterocyclic ring is substituted for a nitrogen. These carbohydrates are an important class of compounds with medicinal bioactivities and have shown potential for the treatment of diabetes, viral-infection, cancers, and lysosomal storage diseases. 1-deoxymannojirimycin (DMJ), is a mannosidase inhibiting azasugar which has shown anti-cancer and anti-viral activity. There has been significant effort put towards developing methodology to produce this compound and libraries of its derivatives. This thesis presents the synthesis of DMJ and a selection of its derivatives via an efficient 4 step methodology from a carbohydrate starting material, exploiting chemo and regioselective reactions to allow for a total synthesis with minimal use of protecting groups. The synthesis of DMJ, using the methodology developed herein, surpasses published syntheses in efficiency. This synthetic strategy was then used for the preparation of N-functionalised DMJ derivatives without the requirement of additional synthetic steps. To illustrate the versatility of this methodology, a selection of derivatives incorporating different functionalities have been synthesised.</p>


Author(s):  
Björn Oskarsson ◽  
Nicholas Maragakis ◽  
Richard S Bedlack ◽  
Namita Goyal ◽  
Jenny A Meyer ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with motor neuron loss as a defining feature. Despite significant effort, therapeutic breakthroughs have been modest. MN-166 (ibudilast) has demonstrated neuroprotective action by various mechanisms: inhibition of proinflammatory cytokines and macrophage migration inhibitory factor, phosphodiesterase inhibition, and attenuation of glial cell activation in models of ALS. Early-phase studies suggest that MN-166 may improve survival outcomes and slow disease progression in patients with ALS. This article describes the rationale and design of COMBAT-ALS, an ongoing randomized, double-blind, placebo-controlled, multicenter Phase IIb/III study in ALS. This study is designed to evaluate the pharmacokinetics, safety and tolerability and assess the efficacy of MN-166 on function, muscle strength, quality of life and survival in ALS.


2021 ◽  
Author(s):  
Wenjin Xue ◽  
Owen Miller

Abstract There has been a significant effort to design nanophotonic structures that process images at the speed of light. A prototypical example is in edge detection, where photonic-crystal-, metasurface-, and plasmon-based designs have been proposed and in some cases experimentally demonstrated. In this work, we show that multilayer optical interference coatings can achieve visible-frequency edge detection in transmission with high numerical aperture, two-dimensional image formation, and straightforward fabrication techniques, unique among all nanophotonic approaches. We show that the conventional Laplacian-based transmission spectrum may not be ideal once the scattering physics of real designs is considered, and show that better performance can be attained with alternative spatial filter functions. Our designs, comprising alternating layers of Si and SiO2 with total thicknesses of only 1 µm, demonstrate the possibility for optimized multilayer films to achieve state-of-the-art edge detection, and, more broadly, analog optical implementations of linear operators.


2021 ◽  
Author(s):  
Judith Uche Oguzie ◽  
Udoka Nwangwu ◽  
Paul Oluniyi ◽  
Testimony Olumade ◽  
Uwem George ◽  
...  

Abstract Mosquito vectors are a tremendous public health threat as one in six diseases worldwide is vector-borne transmitted mainly by mosquitoes. In the last couple of years, there have been active Yellow fever virus (YFV) outbreaks in many settings in Nigeria, and nationwide, entomological surveillance has been a significant effort geared towards understanding these outbreaks. In this study, we used a metagenomic sequencing approach to characterize viruses present in vector samples collected during various outbreaks of Yellow fever (YF) in Nigeria between 2017 and 2020. Mosquito samples were grouped into pools of one to fifty mosquitoes, each based on species, sex and location. Twenty-five pools of Aedes spp and one pool of Anopheles spp collected from nine states were sequenced and metagenomic analysis was carried out. We identified a wide diversity of viruses belonging to various families in this sample set. Seven different viruses detected included: Fako virus, Phasi Charoen-like virus, Verdadero virus, Chaq like-virus, Aedes aegypti totivirus, cell fusing agent virus and Tesano Aedes virus. Although there are no reports of these viruses being pathogenic, they are an understudied group in the same families and closely related to known pathogenic arboviruses. Our work shows the revolutionary power of genomics to help detect the presence of viruses in mosquito vectors and unravel their pathogenic potential. This can help develop diagnostics and vaccines to help prevent the diseases caused by these viruses before they cause outbreaks in human populations.


2021 ◽  
Vol 892 (1) ◽  
pp. 012006
Author(s):  
D K S Swastika ◽  
Saptana ◽  
E Gunawan

Abstract Potato’s farming in Indonesia is thought to be profitable. However, its competitiveness in global production is questionable. The purpose of this study is to analyze the financial feasibility of potato’s farming in Indonesia and its competitiveness in global production. The data used were the results of National Farmers Panel (PATANAS) surveys in 2008, 2011 and 2017. The cost and benefit analysis were used to analyze the financial feasibility. In addition, productivity and producer price were used to measure its global competitiveness. The results showed that potato’s farming during the period of 2008 to 2017 was highly profitable. The R/C ratios were high and continued to increase. These results showed that potato’s farming in the study area is profitable and feasible to be done. In contrast, although potato’s farming in the study area is very profitable, it has no competitiveness in global production, due to the relatively low yield and high cost shown by producer price. The highest cost component was seed. Therefore, there should be a significant effort to find out the efficient use of seed, as well as to increase the capacity of farmers in producing good quality seeds efficiently. It is a challenge for breeding research to produce potato’s varieties with higher yields than currently exist in Indonesia. Another challenge is the research on the use of cut seed into pieces with minimum of two shoots per section.


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