Nanolithography Using High Transmission Nanoscale Bowtie Apertures

Nano Letters ◽  
2006 ◽  
Vol 6 (3) ◽  
pp. 361-364 ◽  
Author(s):  
Liang Wang ◽  
Sreemanth M. Uppuluri ◽  
Eric X. Jin ◽  
Xianfan Xu
Keyword(s):  
High Transmission ◽  
Bowtie Apertures

scholarly journals Genotyping cognate Plasmodium falciparum in humans and mosquitoes to estimate onward transmission of asymptomatic infections

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kelsey M. Sumner ◽  
Elizabeth Freedman ◽  
Lucy Abel ◽  
Andrew Obala ◽  
Brian W. Pence ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Odds Ratio ◽  
Asymptomatic Malaria ◽  
Major Contributor ◽  
Western Kenya ◽  
High Transmission ◽  
Transmission Reduction ◽  
Asymptomatic Infections ◽  
Infection Types ◽  
Natural Settings

AbstractMalaria control may be enhanced by targeting reservoirs of Plasmodium falciparum transmission. One putative reservoir is asymptomatic malaria infections and the scale of their contribution to transmission in natural settings is not known. We assess the contribution of asymptomatic malaria to onward transmission using a 14-month longitudinal cohort of 239 participants in a high transmission site in Western Kenya. We identify P. falciparum in asymptomatically- and symptomatically-infected participants and naturally-fed mosquitoes from their households, genotype all parasites using deep sequencing of the parasite genes pfama1 and pfcsp, and use haplotypes to infer participant-to-mosquito transmission through a probabilistic model. In 1,242 infections (1,039 in people and 203 in mosquitoes), we observe 229 (pfcsp) and 348 (pfama1) unique parasite haplotypes. Using these to link human and mosquito infections, compared with symptomatic infections, asymptomatic infections more than double the odds of transmission to a mosquito among people with both infection types (Odds Ratio: 2.56; 95% Confidence Interval (CI): 1.36–4.81) and among all participants (OR 2.66; 95% CI: 2.05–3.47). Overall, 94.6% (95% CI: 93.1–95.8%) of mosquito infections likely resulted from asymptomatic infections. In high transmission areas, asymptomatic infections are the major contributor to mosquito infections and may be targeted as a component of transmission reduction.

Dielectric hole lattice for terahertz diffractive optics with high transmission

2014 ◽  
Author(s):  
Daniel Headland ◽  
Withawat Withayachumnankul ◽  
Michael Webb ◽  
Aditi Upadhyay ◽  
Madhu Bhaskaran ◽  
...  
Keyword(s):  
Diffractive Optics ◽  
High Transmission

scholarly journals Effectiveness of a national mass distribution campaign of long-lasting insecticide-treated nets and indoor residual spraying on clinical malaria in Malawi, 2018–2020

2021 ◽  
Vol 6 (5) ◽  
pp. e005447
Author(s):  
Hillary M Topazian ◽  
Austin Gumbo ◽  
Katerina Brandt ◽  
Michael Kayange ◽  
Jennifer S Smith ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Indoor Residual Spraying ◽  
Malaria Risk ◽  
Bed Nets ◽  
Insecticide Treated Nets ◽  
District Health ◽  
High Transmission ◽  
Limited Effectiveness ◽  
Mass Distribution Campaign ◽  
Distribution Campaign

IntroductionMalawi’s malaria burden is primarily assessed via cross-sectional national household surveys. However, malaria is spatially and temporally heterogenous and no analyses have been performed at a subdistrict level throughout the course of a year. The WHO recommends mass distribution of long-lasting insecticide-treated bed nets (LLINs) every 3 years, but a national longitudinal evaluation has never been conducted in Malawi to determine LLIN effectiveness lifespans.MethodsUsing District Health Information Software 2 (DHIS2) health facility data, available from January 2018 to June 2020, we assessed malaria risk before and after a mass distribution campaign, stratifying by age group and comparing risk differences (RDs) by LLIN type or annual application of indoor residual spraying (IRS).Results711 health facilities contributed 20 962 facility reports over 30 months. After national distribution of 10.7 million LLINs and IRS in limited settings, malaria risk decreased from 25.6 to 16.7 cases per 100 people from 2018 to 2019 high transmission seasons, and rebounded to 23.2 in 2020, resulting in significant RDs of −8.9 in 2019 and −2.4 in 2020 as compared with 2018. Piperonyl butoxide (PBO)-treated LLINs were more effective than pyrethroid-treated LLINs, with adjusted RDs of −2.3 (95% CI −2.7 to −1.9) and −1.5 (95% CI −2.0 to −1.0) comparing 2019 and 2020 high transmission seasons to 2018. Use of IRS sustained protection with adjusted RDs of −1.4 (95% CI −2.0 to −0.9) and −2.8% (95% CI −3.5 to −2.2) relative to pyrethroid-treated LLINs. Overall, 12 of 28 districts (42.9%) experienced increases in malaria risk in from 2018 to 2020.ConclusionLLINs in Malawi have a limited effectiveness lifespan and IRS and PBO-treated LLINs perform better than pyrethroid-treated LLINs, perhaps due to net repurposing and insecticide-resistance. DHIS2 provides a compelling framework in which to examine localised malaria trends and evaluate ongoing interventions.

A High-Transmission, Multiple Antireflective Surface Inspired from Bilayer 3D Ultrafine Hierarchical Structures in Butterfly Wing Scales

Small ◽  
2015 ◽  
Vol 12 (6) ◽  
pp. 713-720 ◽  
Author(s):  
Zhiwu Han ◽  
Zhengzhi Mu ◽  
Bo Li ◽  
Shichao Niu ◽  
Junqiu Zhang ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Butterfly Wing ◽  
High Transmission ◽  
Wing Scales

MODE ANALYSIS AND SYSTEMATICAL DESIGN OF WIDE-BANDWIDTH PHOTONIC CRYSTAL 60° WAVEGUIDE BENDS WITH HIGH TRANSMISSION

2012 ◽  
Vol 26 (26) ◽  
pp. 1250170 ◽  
Author(s):  
TAO CHEN ◽  
CAILONG ZHENG ◽  
JINXING LI
Keyword(s):  
Photonic Crystal ◽  
Expansion Method ◽  
Transmission Efficiency ◽  
Slab Waveguide ◽  
Mode Analysis ◽  
Two Dimensional ◽  
Photonic Crystal Slab ◽  
High Transmission ◽  
Index Approach ◽  
Waveguide Bend

We present a procedure to enhance the transmission efficiency of a photonic crystal slab waveguide bend by introducing an air hole with the same radius at the center of bend and optimizing the positions of three neighboring holes in the corner. The improvement relies only on the method of displacing holes which is technologically preferred to controlling variations in hole size or shape. We employ the effective refractive index approach and two-dimensional plane wave expansion method to analyze the guide modes of the straight waveguide and waveguide bend. The transmission character of bent waveguides is investigated using two-dimensional finite-difference time-domain method. Numerical studies demonstrate that the approximate method of mode analysis is unsuitable to our model. Alternatively, we systematically study the effect of different positions of the holes on the transmission. The optimized bends for the high transmission with broad bandwidth are proposed.

scholarly journals The epidemiology and detectability of asymptomatic Plasmodium vivax and Plasmodium falciparum infections in low, moderate and high transmission settings in Ethiopia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Elifaged Hailemeskel ◽  
Surafel K Tebeje ◽  
Sinknesh W. Behaksra ◽  
Girma Shumie ◽  
Getasew Shitaye ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
Age Groups ◽  
Diagnostic Tools ◽  
Asymptomatic Malaria ◽  
Rapid Diagnostics ◽  
Cross Sectional ◽  
Low Transmission ◽  
High Transmission ◽  
Study Sites

Abstract Background As countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, the epidemiology and detectability of asymptomatic Plasmodium falciparum and Plasmodium vivax infections were investigated in different transmission settings in Ethiopia. Method: A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA-based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API > 0 and < 5), moderate (API ≥ 5 and < 100) and high transmission (API ≥ 100) and detectability of infections was assessed in these settings. Results In community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95% CI] 1.6–7.2, P = 0.002) and high endemic settings (AOR = 5.1; 95% CI 2.6–9.9, P < 0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase = 0.95, 95% CI 0.9–1.0, P = 0.013) declined with age. Conclusions Conventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.

scholarly journals Asymptomatic malaria and anaemia among pregnant women during high and low malaria transmission seasons in Burkina Faso: household-based cross-sectional surveys in Burkina Faso, 2013 and 2017

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Toussaint Rouamba ◽  
Sékou Samadoulougou ◽  
Mady Ouédraogo ◽  
Hervé Hien ◽  
Halidou Tinto ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Pregnant Women ◽  
Malaria Transmission ◽  
Asymptomatic Malaria ◽  
Cross Sectional ◽  
Transmission Season ◽  
Low Transmission ◽  
High Transmission ◽  
Asymptomatic Carriage ◽  
Low Malaria Transmission

Abstract Background Malaria in endemic countries is often asymptomatic during pregnancy, but it has substantial consequences for both the mother and her unborn baby. During pregnancy, anaemia is an important consequence of malaria infection. In Burkina Faso, the intensity of malaria varies according to the season, albeit the prevalence of malaria and anaemia as well as their risk factors, during high and low malaria transmission seasons is underexplored at the household level. Methods Data of 1751 pregnant women from October 2013 to March 2014 and 1931 pregnant women from April 2017 to June 2017 were drawn from two cross-sectional household surveys conducted in 24 health districts of Burkina Faso. Pregnant women were tested for malaria in their household after consenting. Asymptomatic carriage was defined as a positive result from malaria rapid diagnostic tests in the absence of clinical symptoms of malaria. Anaemia was defined as haemoglobin level less than 11 g/dL in the first and third trimester and less than 10.5 g/dL in the second trimester of pregnancy. Results Prevalence of asymptomatic malaria in pregnancy was estimated at 23.9% (95% CI 20.2–28.0) during the high transmission season (October–November) in 2013. During the low transmission season, it was 12.7% (95% CI 10.9–14.7) between December and March in 2013–2014 and halved (6.4%; 95% CI 5.3–7.6) between April and June 2017. Anaemia prevalence was estimated at 59.4% (95% CI 54.8–63.8) during the high transmission season in 2013. During the low transmission season, it was 50.6% (95% CI 47.7–53.4) between December and March 2013–2014 and 65.0% (95% CI 62.8–67.2) between April and June, 2017. Conclusion This study revealed that the prevalence of malaria asymptomatic carriage and anaemia among pregnant women at the community level remain high throughout the year. Thus, more efforts are needed to increase prevention measures such as IPTp–SP coverage in order to reduce anaemia and contribute to preventing low birth weight and poor pregnancy outcomes.

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