scholarly journals Challenges to Implementing Environmental-DNA Monitoring in Namibia

2022 ◽  
Vol 9 ◽  
Author(s):  
Iain Perry ◽  
Ifan B. Jâms ◽  
Roser Casas-Mulet ◽  
Josefina Hamutoko ◽  
Angela Marchbank ◽  
...  
Keyword(s):  
Reference Data ◽  
Sampling Technique ◽  
Environmental Dna ◽  
Cost Effective ◽  
Trophic Levels ◽  
Arid Ecosystems ◽  
Test Field ◽  
Local Conditions ◽  
Promising Tool ◽  
High Turbidity

By identifying fragments of DNA in the environment, eDNA approaches present a promising tool for monitoring biodiversity in a cost-effective way. This is particularly pertinent for countries where traditional morphological monitoring has been sparse. The first step to realising the potential of eDNA is to develop methodologies that are adapted to local conditions. Here, we test field and laboratory eDNA protocols (aqueous and sediment samples) in a range of semi-arid ecosystems in Namibia. We successfully gathered eDNA data on a broad suite of organisms at multiple trophic levels (including algae, invertebrates and bacteria) but identified two key challenges to the implementation of eDNA methods in the region: 1) high turbidity requires a tailored sampling technique and 2) identification of taxa by eDNA methods is currently constrained by a lack of reference data. We hope this work will guide the deployment of eDNA biomonitoring in the arid ecosystems of Namibia and neighbouring countries.

E-Voting Kepala Desa dan Modal Sosial

2019 ◽  
Vol 2 (6) ◽  
pp. 759
Author(s):  
Khaulah Afifah ◽  
Lala M Kolopaking ◽  
Zessy Ardinal Barlan
Keyword(s):  
Social Capital ◽  
Random Sampling ◽  
Qualitative Data ◽  
Sampling Technique ◽  
Cost Effective ◽  
Simple Random Sampling ◽  
Community Based ◽  
Time Saving ◽  
The Social ◽  
Voting System

Head of a village election with e-voting system is a new thing for community The success level of e-voting system can be reached by fulfil several principles in order to the implementation going effective and the result of the election can be accepted by all. The objectives of this research is to analyze the relation between the success level of e-voting system with social capital of the community. This research is carried out with the quantitative approach and supported by qualitative data. This research takes 60 respondents using simple random sampling technique. The results showed that the success level of e-voting has a correlation with the level of social capital of the community. Based on the field study, the social capital of the community is classified as high. The high social capital makes the implementation of e-voting successful and the success level is also high, because in the election ten years ago occurred a conflict. The community considers e-voting easier and more practical, cost effective and time-saving, and the results of e-voting are also reliable. A practical and fast of e-voting system can be a solution especially for “rural-urban” community who are busy or work outside the village.Keywords: E-voting, the success level of the system, social capital Pemilihan kepala desa dengan sistem e-voting merupakan hal yang baru bagi masyarakat. Keberhasilan penerapan sistem e-voting dilihat dari terpenuhinya beberapa prinsip agar penerapannya berlangsung efektif dan hasilnya dapat diterima oleh seluruh masyarakat. Penelitian ini bertujuan untuk menganalisis hubungan tingkat keberhasilan sistem e-voting dalam pemilihan kepala desa dengan tingkat modal sosial masyarakat. Bentuk penelitian ini adalah penelitian kuantitatif yang didukung oleh analisis data kualitatif. Penelitian ini mengambil enam puluh responden dengan teknik simple random sampling. Hasil penelitian menunjukkan bahwa tingkat keberhasilan e-voting memiliki hubungan dengan tingkat modal sosial masyarakat. Berdasarkan kajian di lapang, modal sosial masyarakat tergolong tinggi. Tingginya modal sosial tersebut membuat pelaksanaan e-voting berhasil dan tingkat keberhasilannya juga tergolong tinggi karena pada pemilihan sepuluh tahun silam sempat terjadi konflik. Masyarakat menganggap sistem evoting lebih mudah dan praktis, hemat dalam segi biaya dan waktu, serta hasil dari pemilihan juga dapat dipertanggungjawabkan. Sistem e-voting yang praktis dan cepat dapat menjadi solusi khususnya bagi masyarakat daerah “desa-kota” yang memiliki kesibukan atau pekerjaan di luar desa.Kata Kunci: E-voting, keberhasilan sistem, modal sosial. 

Estimating the area under a receiver operating characteristic curve using partially ordered sets

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ehsan Zamanzade ◽  
Xinlei Wang
Keyword(s):  
Roc Curve ◽  
Characteristic Curve ◽  
Partially Ordered Sets ◽  
Sampling Technique ◽  
Real Data ◽  
Cost Effective ◽  
Ordered Sets ◽  
Operating Characteristics ◽  
Partially Ordered ◽  
Receiver Operating

AbstractRanked set sampling (RSS), known as a cost-effective sampling technique, requires that the ranker gives a complete ranking of the units in each set. Frey (2012) proposed a modification of RSS based on partially ordered sets, referred to as RSS-t in this paper, to allow the ranker to declare ties as much as he/she wishes. We consider the problem of estimating the area under a receiver operating characteristics (ROC) curve using RSS-t samples. The area under the ROC curve (AUC) is commonly used as a measure for the effectiveness of diagnostic markers. We develop six nonparametric estimators of the AUC with/without utilizing tie information based on different approaches. We then compare the estimators using a Monte Carlo simulation and an empirical study with real data from the National Health and Nutrition Examination Survey. The results show that utilizing tie information increases the efficiency of estimating the AUC. Suggestions about when to choose which estimator are also made available to practitioners.

scholarly journals The effect of silica desiccation under different storage conditions on filter-immobilized environmental DNA

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Michael J. Allison ◽  
Jessica M. Round ◽  
Lauren C. Bergman ◽  
Ali Mirabzadeh ◽  
Heather Allen ◽  
...  
Keyword(s):  
Silica Gel ◽  
Storage Temperature ◽  
Environmental Dna ◽  
Cost Effective ◽  
Storage Conditions ◽  
Systematic Evaluation ◽  
Silica Bead ◽  
Gel Beads ◽  
Polymerase Chain

Abstract Objective Silica gel beads have promise as a non-toxic, cost-effective, portable method for storing environmental DNA (eDNA) immobilized on filter membranes. Consequently, many ecological surveys are turning to silica bead filter desiccation rather than ethanol preservation. However, no systematic evaluation of silica bead storage conditions or duration past 1 week has been published. The present study evaluates the quality of filter-immobilized eDNA desiccated with silica gel under different storage conditions for over a year using targeted quantitative real-time polymerase chain reaction (qPCR)-based assays. Results While the detection of relatively abundant eDNA target was stable over 15 months from either ethanol- or silica gel-preserved filters at − 20 and 4 °C, silica gel out-performed ethanol preservation at 23 °C by preventing a progressive decrease in eDNA sample quality. Silica gel filter desiccation preserved low abundance eDNA equally well up to 1 month regardless of storage temperature (18, 4, or − 20 °C). However only storage at − 20 °C prevented a noticeable decrease in detectability at 5 and 12 months. The results indicate that brief storage of eDNA filters with silica gel beads up to 1 month can be successfully accomplished at a range of temperatures. However, longer-term storage should be at − 20 °C to maximize sample integrity.

scholarly journals DNA aptamer-based detection of prostate cancer

2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Pawan Jolly ◽  
Nello Formisano ◽  
Pedro Estrela
Keyword(s):  
Prostate Cancer ◽  
Point Of Care ◽  
Specific Antigen ◽  
Analytical Techniques ◽  
Cost Effective ◽  
Dna Aptamer ◽  
Clinical Samples ◽  
Gradual Transition ◽  
Long Term Stability ◽  
Promising Tool

AbstractThe use of aptamers in biosensing has attracted considerable attention as an alternative to antibodies because of their unique properties such as long-term stability, cost-effectiveness and adjustability to various applications. Among cancers, the early diagnosis of prostate cancer (PCa) is one of the greatest concerns for ageing men worldwide. One of the most commonly used biomarkers for PCa is prostate-specific antigen (PSA), which can be found in elevated levels in patients with cancer. This review presents the gradual transition of research from antibody-based to aptamerbased biosensors, specifically for PSA. A brief description on aptamer-based biosensing for other PCa biomarkers is also presented. Special attention is given to electrochemical methods as analytical techniques for the development of simple, sensitive and cost-effective biosensors. The review also focuses on the different surface chemistries exploited for fabrication and their applications in clinical samples. The use of aptamers represents a promising tool for the development of point-ofcare biosensors for the early detection of prostate cancer. In view of the unmatched upper hand of aptamers, future prospects are also discussed, not only in the point-of-care format but also in other novel applications.

scholarly journals Estimation accuracy of species abundance based on environmental DNA with relation to its production source, state, and assay methodology suggested by meta-analyses

2021 ◽  
Author(s):  
Toshiaki Jo ◽  
Hiroki Yamanaka
Keyword(s):  
Meta Analysis ◽  
Empirical Studies ◽  
Species Abundance ◽  
Environmental Dna ◽  
Efficient Estimation ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Abundance Estimation ◽  
Natural Environments ◽  
Promising Tool

Environmental DNA (eDNA) analysis is a promising tool for non-disruptive and cost-efficient estimation of species abundance. However, its practical applicability in natural environments is limited because it is unclear whether eDNA concentrations actually represent species abundance in the field. Although the importance of accounting for eDNA dynamics, such as transport and degradation, has been discussed, the influences of eDNA characteristics, including production source and state, and methodology, including collection and quantification strategy and abundance metrics, on the accuracy of eDNA-based abundance estimation were entirely overlooked. We conducted a meta-analysis using 56 previous eDNA literature and investigated the relationships between the accuracy (R2) of eDNA-based abundance estimation and eDNA characteristics and methodology. Our meta-regression analysis found that R2 values were significantly lower for crustaceans than fish, suggesting that less frequent eDNA production owing to their external morphology and physiology may impede accurate estimation of their abundance via eDNA. Moreover, R2 values were positively associated with filter pore size, indicating that selective collection of larger-sized eDNA, which is typically fresher, could improve the estimation accuracy of species abundance. Furthermore, R2 values were significantly lower for natural than laboratory conditions, while there was no difference in the estimation accuracy among natural environments. Our findings shed a new light on the importance of what characteristics of eDNA should be targeted for more accurate estimation of species abundance. Further empirical studies are required to validate our findings and fully elucidate the relationship between eDNA characteristics and eDNA-based abundance estimation.

scholarly journals Global Trends of Benthic Bacterial Diversity and Community Composition Along Organic Enrichment Gradients of Salmon Farms

2021 ◽  
Vol 12 ◽  
Author(s):  
Larissa Frühe ◽  
Verena Dully ◽  
Dominik Forster ◽  
Nigel B. Keeley ◽  
Olivier Laroche ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Bacterial Diversity ◽  
Community Composition ◽  
Environmental Dna ◽  
Community Diversity ◽  
Rrna Gene ◽  
Local Conditions ◽  
Global Trends ◽  
Bacterial Taxon ◽  
Metabolic Properties

The analysis of benthic bacterial community structure has emerged as a powerful alternative to traditional microscopy-based taxonomic approaches to monitor aquaculture disturbance in coastal environments. However, local bacterial diversity and community composition vary with season, biogeographic region, hydrology, sediment texture, and aquafarm-specific parameters. Therefore, without an understanding of the inherent variation contained within community complexes, bacterial diversity surveys conducted at individual farms, countries, or specific seasons may not be able to infer global universal pictures of bacterial community diversity and composition at different degrees of aquaculture disturbance. We have analyzed environmental DNA (eDNA) metabarcodes (V3–V4 region of the hypervariable SSU rRNA gene) of 138 samples of different farms located in different major salmon-producing countries. For these samples, we identified universal bacterial core taxa that indicate high, moderate, and low aquaculture impact, regardless of sampling season, sampled country, seafloor substrate type, or local farming and environmental conditions. We also discuss bacterial taxon groups that are specific for individual local conditions. We then link the metabolic properties of the identified bacterial taxon groups to benthic processes, which provides a better understanding of universal benthic ecosystem function(ing) of coastal aquaculture sites. Our results may further guide the continuing development of a practical and generic bacterial eDNA-based environmental monitoring approach.

scholarly journals Design and Operational Innovations in Adapting the Existing Merchant River Fleet to Cost-Effective Shipping

2019 ◽  
Vol 26 (4) ◽  
pp. 157-164 ◽  
Author(s):  
Teresa Abramowicz-Gerigk ◽  
Zbigniew Burciu
Keyword(s):  
Air Pollution ◽  
Fuel Consumption ◽  
Cost Effective ◽  
Progressive Decrease ◽  
Propulsion Systems ◽  
Local Conditions ◽  
River Transport ◽  
Multimodal Transport ◽  
Smart Technologies ◽  
Minimum Costs

Abstract Modernisation of the existing river fleet adapted for the local conditions of the Middle and Lower Vistula can be considered as a solution to slow down the progressive decrease of river transport in this area. The implementation of technical improvements, smart technologies and enhancement of transport performance may partially solve the problem of growing demand for multimodal transport of containers and oversized loads in a shorter perspective than the expected period of planned revitalisation of the river. The paper presents investigations on the modernisation of river convoys adapted to the current navigational conditions of the Lower Vistula. The different options have been discussed by the authors with river fleet operators and the best recognised solution was agreed to be the use of river convoys combining modernised motor barges and the pushed barges previously used in this area. Improvement of the transport profitability, reduction of fuel consumption, air pollution and noise can be achieved at minimum costs by modernisation of the main power-propulsion systems of outdated motor barges and the implementation of innovative steering systems on pushed barges. The demand for power-propulsion and manoeuvring performance of modernised convoys is discussed in the paper.

scholarly journals Assessment of Factors Associated with Dropout for Pentavalent Vaccine in Tertiary Care Hospital of Kathmandu, Nepal

2020 ◽  
Vol 22 (3) ◽  
pp. 106-110
Author(s):  
Supri Raj Shrestha ◽  
B Shakya ◽  
R Oli
Keyword(s):  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
College Teaching ◽  
Sampling Technique ◽  
Cost Effective ◽  
Dropout Rate ◽  
Care Hospital ◽  
Vaccine Preventable Diseases ◽  
Factors Associated ◽  
Pentavalent Vaccine

Immunization is one of the most cost-effective public health measures as it has helped in huge reduction of disease, disability and death from different infectious diseases in children by protecting them from vaccine preventable diseases. The current study aimed to study factors associated with dropout for pentavalent vaccine in tertiary care hospital of Kathmandu. A longitudinal observational study using purposive sampling technique was conducted among 196 infants. The information was obtained using self-constructed structured questionnaire from parents visiting Community Medicine OPD of Nepal Medical College Teaching Hospital. The information regarding socioeconomic characteristics of mother, gender of the infant, place of delivery of child, birth order and reasons for dropout of pentavalent third dose were taken. The dropout of third dose pentavalent vaccine was mainly seen in infant of parents living in rented house and according to gender wise, dropout was high among male infants. The different reasons for dropout of vaccine were busy parents, forgotten date, visit to other immunization centres and sick infants. Among these, the main reason for dropout of vaccine was due to infants getting sick during the time of immunization. The dropout rates between first and third dose of pentavalent vaccine were 26.3% and 30.4% respectively for two consecutive months and the overall dropout rate was 28.35%. Also, literacy level of the mother was directly associated with the immunization visit of the infant as, maximum number of infants of illiterate mother were absent for third dose of pentavalent vaccine as opposed to no absentee among master degree holding mothers. Thus, the present study provides valuable information regarding the factors associated with dropout for pentavalent vaccine.

scholarly journals Towards environmental DNA-based bioassessment of freshwater reservoirs with small volumes of water: robust molecular protocols

2021 ◽  
Author(s):  
Rebecca Ker Loh ◽  
Sujatha Narayanan Kutty ◽  
Darren Chong Jinn Yeo ◽  
Rudolf Meier
Keyword(s):  
Water Sample ◽  
Environmental Dna ◽  
Cost Effective ◽  
Sampling Time ◽  
Small Water ◽  
Tropical Reservoirs ◽  
Frequent Monitoring ◽  
Planktonic Crustaceans ◽  
Water Volumes ◽  
Dna Template

Bioassessment of freshwater quality via eDNA is rapidly developing into a powerful alternative to traditional methods involving collecting, sorting, and identifying macroinvertebrates based on morphology. Particularly attractive would be methods that can use remote-controlled boats for sampling because it would allow for cost-effective, and frequent monitoring at multiple sites. The latter will be particularly important for tropical reservoirs that require year-around surveillance. We here optimize molecular protocols for capturing reservoir-specific differences in metazoan communities based on small water volumes (15 mL). The optimization is based on samples from two freshwater reservoirs with very different water qualities ("reservoir signal"). Each reservoir was sampled at three sites ("biological replicates"). For each water sample, the DNA was extracted twice ("technical replicates"). We then tested how much DNA template (0.1 ng to 15 ng) and how many PCR cycles (25 or 35) minimized variance between technical replicates. We find that 15 mL is sufficient for capturing the reservoir signal regardless of sampling time, template amounts, or PCR cycle numbers. Indeed, extrapolation from our results suggests that <1 mL would be sufficient because only 17 of 59 metazoan mOTUs (mainly planktonic crustaceans and rotifers) detected with a 313bp COI minibarcode were shared. We find that the use of 35 PCR cycles significantly lowered the number of detected species and that template amounts <0.5 ng yielded somewhat higher variance between technical replicates. Despite extensive trials, the variance between technical replicates remained high (Bray-Curtis: 5-20%; Jaccard: 10-40%) and we predict that it will be difficult to reduce this variance further. However, the overall reservoir differences are so strong that all biological and technical replicates can be correctly assigned.

scholarly journals Analysis of High Impedance Faults Current Using Fourier, Wavelet and Stockwell Transforms

2020 ◽  
Author(s):  
Gabriela N. Lopes ◽  
Luiz H. P. C. Trondoli ◽  
José Carlos M. Vieira
Keyword(s):  
Distribution Systems ◽  
Test Field ◽  
Medium Voltage ◽  
Detection Techniques ◽  
Promising Tool ◽  
High Impedance ◽  
Random Behavior ◽  
Key Characteristics ◽  
High Impedance Faults ◽  
High Degree

Detection of high impedance faults (HIFs) in distribution systems is a challenging task, which has attracted the interest of the researchers for decades. The HIF current random behavior and its lowmagnitude cause difficulties for a reliable detection by traditional protection methods. Therefore, the hazards for grid devices, people and animals safety, associated with HIFs, motivate the research of new detection techniques. However, there is no fully efficient solution for this problem. In this context, this paper aimed to characterize HIFs by a set of real measurements considering different type of soils employing Fourier (FT), Wavelet (WT) and Stockwell Transforms (ST). The measurements were performed at the fault spot in a medium voltage test field specially built for this purpose. The idea is to highlight key characteristics of the HIF current waveforms pointed out by each of transform and assess which ones can be used as a promising tool for HIF detection. The results showed that the HIF current can be characterized by the interharmonic behavior during the fault, extracted by FT and by the high degree of energy variations at specific decomposition levels of WT and ST.

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