Estimating tadpole-detection rates using visual field surveys: effects of survey time, tadpole species and tadpole density

2017 ◽  
Vol 44 (2) ◽  
pp. 147 ◽  
Author(s):  
N. Iwai
Keyword(s):  
Visual Field ◽  
Detection Probability ◽  
Detection Rate ◽  
Negative Relationship ◽  
Visual Observation ◽  
Target Species ◽  
Detection Rates ◽  
Field Surveys ◽  
Detection Probabilities ◽  
Species Occupancy

Context When understanding species occupancy, estimation of detection probability for the target species is often required, provided by repeated surveys. However, if the actual detection probability of the species is determined experimentally, such estimates are not required, and the reliability of the occupancy data obtained by a particular survey effort can be determined. Aims The aim of this study was to determine the detection rate of tadpoles using visual field surveys, as well as to explore the effects of survey time, species and tadpole density on the tadpole-detection rate. The suitability of visual surveys for detecting tadpole occupancy was also assessed. Methods Batch-identified tadpoles were released into several pools and repeatedly counted over successive days to calculate detection rates using visual observation. In Experiment 1, the effects of tag colour, survey time (morning vs night) and species on the detection rates of two species of tadpoles (Babina subaspera and Odorrana splendida) were examined. In Experiment 2, the effects of tadpole density on O. splendida were examined. Key results Detection rates varied by survey time, species and tadpole density; mean rates ranged from 0.2 to 0.6 for B. subaspera and 0.4 to 0.8 for O. splendida, with higher rates at night. There was a negative relationship between detection rate and tadpole density. Based on these detection rates, it was calculated that single visual surveys of O. splendida tadpoles can achieve detection probabilities near 1.0 when more than four individuals occur in a patch. Conclusions Variations in detection probability should be considered in field surveys. If the factors that cause variations in detection rates are controlled, visual surveys of tadpoles should, at least in some species, provide detection probabilities near 1.0. Implications When repeated surveys to estimate species occupancy are not practicable, determination of the actual detection probability of the target species using real detection rates provides a robust alternative approach.

Detection of medium-sized ground-dwelling mammals using infrared digital cameras: an alternative way forward?

2010 ◽  
Vol 32 (2) ◽  
pp. 165 ◽  
Author(s):  
Andrew W. Claridge ◽  
David J. Paull ◽  
Simon C. Barry
Keyword(s):  
Detection Rate ◽  
Detection Efficiency ◽  
Digital Cameras ◽  
Target Species ◽  
Detection Rates ◽  
Reporting Rates ◽  
Swamp Wallaby ◽  
Over Time

Infrared digital cameras were used to examine temporal detection rates of medium-sized ground-dwelling mammals in a coastal woodland landscape. From three successive deployments at fixed stations, a range of mammals was detected, including three target species: the long-nosed bandicoot, the long-nosed potoroo and the southern brown bandicoot. Reporting rates of target species were largely consistent and in some cases high. The swamp wallaby was the most commonly detected species, ranging from 47–67% of cameras on any given deployment. Long-nosed bandicoots were detected at 37–53% of cameras, long-nosed potoroos 13–23% and southern brown bandicoots 10–17%. In total, bandicoots and potoroos were detected at 23 of 30 sites (77%) while forage-diggings of these mammals were universally present. There were differences in the detection rate of bandicoots and potoroos in relation to 24-hourly cycles: all three species were less likely to be detected between dawn and dusk than dusk and dawn. Otherwise, with few exceptions, the rate at which bandicoots and potoroos were detected over time within a deployment did not vary markedly. Infrared digital cameras offer great potential as sampling devices for bandicoots and potoroos because of their greater detection efficiency relative to other techniques.

scholarly journals Evaluation of undetected cases during the COVID-19 epidemic in Austria

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
C. Rippinger ◽  
M. Bicher ◽  
C. Urach ◽  
D. Brunmeir ◽  
N. Weibrecht ◽  
...  
Keyword(s):  
Detection Probability ◽  
Major Part ◽  
Detection Rate ◽  
Temporal Dynamic ◽  
Agent Based ◽  
Prevalence Studies ◽  
Detection Probabilities ◽  
Age Dependent ◽  
Antibody Tests ◽  
Epidemic Wave

Abstract Background Knowing the number of undetected cases of COVID-19 is important for a better understanding of the spread of the disease. This study analyses the temporal dynamic of detected vs. undetected cases to provide guidance for the interpretation of prevalence studies performed with PCR or antibody tests to estimate the detection rate. Methods We used an agent-based model to evaluate assumptions on the detection probability ranging from 0.1 to 0.9. For each general detection probability, we derived age-dependent detection probabilities and calibrated the model to reproduce the epidemic wave of COVID-19 in Austria from March 2020 to June 2020. We categorized infected individuals into presymptomatic, symptomatic unconfirmed, confirmed and never detected to observe the simulated dynamic of the detected and undetected cases. Results The calculation of the age-dependent detection probability ruled values lower than 0.4 as most likely. Furthermore, the proportion of undetected cases depends strongly on the dynamic of the epidemic wave: during the initial upswing, the undetected cases account for a major part of all infected individuals, whereas their share decreases around the peak of the confirmed cases. Conclusions The results of prevalence studies performed to determine the detection rate of COVID-19 patients should always be interpreted with regard to the current dynamic of the epidemic wave. Applying the method proposed in our analysis, the prevalence study performed in Austria in April 2020 could indicate a detection rate of 0.13, instead of the prevalent ratio of 0.29 between detected and estimated undetected cases at that time.

scholarly journals Seasonal monitoring of Hida salamander Hynobius kimurae using environmental DNA with a genus-specific primer set

2020 ◽  
Vol 43 ◽  
pp. 341-352
Author(s):  
T Jo ◽  
S Tomita ◽  
Y Kohmatsu ◽  
M Osathanunkul ◽  
A Ushimaru ◽  
...  
Keyword(s):  
Detection Rate ◽  
Habitat Restoration ◽  
Site Occupancy ◽  
Environmental Dna ◽  
Taqman Probe ◽  
Morphological Identification ◽  
Target Species ◽  
Amphibian Species ◽  
Detection Rates ◽  
Occupancy Probability

The diversity and the abundance of amphibians have dramatically declined globally over the past 30 years, and the monitoring and conservation of their habitats is essential. However, traditional methods such as bait trapping and mark-recapture are costly, and morphological identification usually requires a high level of taxonomic expertise. Here, seasonal surveillances of Hida salamander Hynobius kimurae were performed by means of environmental DNA (eDNA) analysis with Hynobius-specific primers and a species-specific TaqMan probe. Water sampling and visual surveys were conducted seasonally in a stream in Kyoto Prefecture, Japan. Detection rates of eDNA were then calculated by real-time PCR, and eDNA site occupancy probability was estimated by multi-scale occupancy modeling. The eDNA-based detection rate of Hida salamander was 76.7%, whereas the visual survey-based detection rate was 23.3%, and target eDNA was detected at almost all sites where the presence of target species was visually confirmed. Moreover, factors relating to the site- and sample-level occurrence probabilities of the target eDNA differed depending on the developmental stage of the target species. Our findings support previous studies showing that eDNA analysis enables an effective assessment of amphibian distributions without damaging the organisms or their habitat, and we compare for the first time the site occupancy probability of amphibian eDNA throughout the life cycle of an amphibian species. The present study contributes to the development of eDNA analysis as a tool for understanding the distribution and seasonal activity of amphibian species and will thus aid in the planning of conservation measures and habitat restoration for these species.

scholarly journals Detection Rate of Bird Species and What It Depends on: Tips for Field Surveys

2022 ◽  
Vol 9 ◽  
Author(s):  
Federico Morelli ◽  
Vojtěch Brlík ◽  
Yanina Benedetti ◽  
Raphaël Bussière ◽  
Lucie Moudrá ◽  
...  
Keyword(s):  
Body Mass ◽  
Detection Rate ◽  
Bird Species ◽  
Imperfect Detection ◽  
Detection Rates ◽  
Field Surveys ◽  
Species Detection ◽  
Total Species Richness ◽  
Number Of Individuals ◽  
Total Species

Bird counting inevitably suffers from imperfect detection, which varies across species, habitats, period of the day, and seasons. Although various modeling techniques have recently been developed to account for this phenomenon, the biological basis of natural variation in detection remains insufficiently known. This study examined the bird species’ detection rate throughout the day, considering their body mass and diet type, concerning the environment and weather characteristics. Species detection rates were significantly affected by the number of individuals of that species but were unrelated to body mass. Overall, species with the highest detection rate were Corn bunting, Blackbird, European robin, House sparrow and Common chiffchaff. Granivores-insectivores and insectivores showed significant differences in detection rates throughout the day among habitats, with higher detection rates in grasslands during the afternoon. Insectivores showed higher detection rates in farmland during midday (warmest time of the day). Granivores, omnivores and scavengers did not show changes in detection rates in different day periods. Such patterns in daily detection rates were significant even when considering abundance and total species richness in each community. Finally, cloudiness was unrelated to the overall detection rate of birds, while temperature and wind affected detection rates in some guilds. Our findings provide some advice for choosing a suitable ornithological sampling method by considering the avian communities composition in combination with the type of environment, the diet of bird species, and the period of the day.

scholarly journals Training: improving antenatal detection and outcomes of congenital heart disease

2018 ◽  
Vol 7 (4) ◽  
pp. e000276 ◽  
Author(s):  
Orhan Uzun ◽  
Julia Kennedy ◽  
Colin Davies ◽  
Anthony Goodwin ◽  
Nerys Thomas ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Detection Rate ◽  
Congenital Heart ◽  
Training Programme ◽  
Referral Rate ◽  
Cardiac Anomaly ◽  
Cardiac Ultrasound ◽  
Detection Rates ◽  
Antenatal Detection ◽  
The Uk

ObjectivesThis study describes the design, delivery and efficacy of a regional fetal cardiac ultrasound training programme. This programme aimed to improve the antenatal detection of congenital heart disease (CHD) and its effect on fetal and postnatal outcomes.Design setting and participantsThis was a prospective study that compared antenatal CHD detection rates by professionals from 13 hospitals in Wales before and after engaging in our ‘skills development programme’. Existing fetal cardiac practice and perinatal outcomes were continuously audited and progressive targets were set. The work was undertaken by the Welsh Fetal Cardiovascular Network, Antenatal Screening Wales (ASW), a superintendent sonographer and a fetal cardiologist.InterventionsA core professional network was established, engaging all stakeholders (including patients, health boards, specialist commissioners, ASW, ultrasonographers, radiologists, obstetricians, midwives and paediatricians). A cardiac educational lead (midwife, superintendent sonographer, radiologist, obstetrician, or a fetal medicine specialist) was established in each hospital. A new cardiac anomaly screening protocol (‘outflow tract view’) was created and training on the new protocol was systematically delivered at each centre. Data were prospectively collected and outcomes were continuously audited: locally by the lead fetal cardiologist; regionally by the Congenital Anomaly Register and Information Service in Wales; and nationally by the National Institute for Cardiac Outcomes and Research (NICOR) in the UK.Main outcome measuresPatient satisfaction; improvements in individual sonographer skills, confidence and competency; true positive referral rate; local hospital detection rate; national detection rate of CHD; clinical outcomes of selected cardiac abnormalities; reduction of geographical health inequality; cost efficacy.ResultsHigh levels of patient satisfaction were demonstrated and the professional skill mix in each centre was improved. The confidence and competency of sonographers was enhanced. Each centre demonstrated a reduction in the false-positive referral rate and a significant increase in cardiac anomaly detection rate. According to the latest NICOR data, since implementing the new training programme Wales has sustained its status as UK lead for CHD detection. Health outcomes of children with CHD have improved, especially in cases of transposition of the great arteries (for which no perinatal mortality has been reported since 2008). Standardised care led to reduction of geographical health inequalities with substantial cost saving to the National Health Service due to reduced false-positive referral rates. Our successful model has been adopted by other fetal anomaly screening programmes in the UK.ConclusionsAntenatal cardiac ultrasound mass training programmes can be delivered effectively with minimal impact on finite healthcare resources. Sustainably high CHD detection rates can only be achieved by empowering the regional screening workforce through continuous investment in lifelong learning activities. These should be underpinned by high quality service standards, effective care pathways, and robust clinical governance and audit practices.

scholarly journals Analysis of Low Probability of Detection Capability for Chaotic Standard Map-Based FH-OFDMA System

2021 ◽  
Vol 11 (5) ◽  
pp. 2198
Author(s):  
Junwoo Jung ◽  
Jaesung Lim ◽  
Sungyeol Park ◽  
Haengik Kang ◽  
Seungbok Kwon
Keyword(s):  
Detection Probability ◽  
Probability Of Detection ◽  
Lower Probability ◽  
Symbol Sequence ◽  
Ofdma System ◽  
Standard Map ◽  
Detection Probabilities ◽  
Low Probability ◽  
Transmitted Symbol ◽  
Basic Symbol

A frequency hopping orthogonal frequency division multiple access (FH-OFDMA) can provide low probability of detection (LPD) and anti-jamming capabilities to users against adversary detectors. To obtain an extreme LPD capability that cannot be provided by the basic symbol-by-symbol (SBS)-based FH pattern, we proposed two FH patterns, namely chaotic standard map (CSM) and cat map for FH-OFDMA systems. In our previous work, through analysis of complexity to regenerate the transmitted symbol sequence, at the point of adversary detectors, we found that the CSM had a lower probability of intercept than the cat map and SBS. It is possible when a detector already knows symbol and frame structures, and the detector has been synchronized to the FH-OFDMA system. Unlike the previous work, here, we analyze whether the CSM provides greater LPD capability than the cat map and SBS by detection probability using spectrum sensing technique. We analyze the detection probability of the CSM and provide detection probabilities of the cat map and SBS compared to the CSM. Based on our analysis of the detection probability and numerical results, it is evident that the CSM provides greater LPD capability than both the cat map and SBS-based FH-OFDMA systems.

scholarly journals Mortality due to primary brain tumours in China and detection rate in people with suspected symptoms: a nationally representative cross-sectional survey

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Bin Jiang ◽  
Hongmei Liu ◽  
Dongling Sun ◽  
Haixin Sun ◽  
Xiaojuan Ru ◽  
...  
Keyword(s):  
Brain Tumour ◽  
Brain Tumours ◽  
Detection Rate ◽  
Epidemiological Data ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Detection Rates ◽  
Primary Brain Tumours ◽  
Symptom Screening ◽  
Nationally Representative

Abstract Background and purpose Epidemiological data on primary brain tumours (PBTs) are lacking due to the difficulty in case ascertainment among the population. Thus, we aimed to estimate mortality due to PBTs in China nationwide and the detection rate in people with suspected symptoms. Methods A multistage, complex sampling survey regarding mortality due to PBTs in Chinese individuals was carried out by reviewing all causes of death within a year. The detection rates in people with suspected symptoms were estimated based on PBT symptom screening and neurologist reviews and compared between groups by logistic regression analysis. Results Weighted mortality due to PBT was 1.6 (0.8–3.3) per 100,000 population in Chinese individuals, 1.8 (0.7–4.6) per 100,000 population in men, and 1.5 (0.5–4.5) per 100,000 population in women. Among 14,990 people with suspected symptoms, the PBT detection rate was 306.9 (95% CI 224.7–409.3) per 100,000 population in the total population, 233.0 (95% CI 135.7–373.1) per 100,000 population in men, and 376.9 (95% CI 252.4–546.3) per 100,000 population in women. People with an unsteady gait (OR 2.46; 95% CI 1.09–5.51; P=0.029), visual anomalies (3.84; 1.88–7.85; P<0.001), and headache (2.06; 1.10–3.86; P=0.023) were more likely to have a brain tumour than those without corresponding symptoms, while people with dizziness/vertigo were less likely to have a brain tumour than those without corresponding symptoms (0.45; 0.23–0.87; P=0.017). Conclusions Mortality due to PBT in China was low, with a nationwide estimate of 21,215 (10,427–43,165) deaths attributable to PBTs annually. However, the detection rate of PBTs can be greatly improved based on symptom screening in the population.

scholarly journals The Effects of Social Distancing Policies on non-SARS-CoV-2 Respiratory Pathogens

2021 ◽  
Author(s):  
Jeff Nawrocki ◽  
Katherine Olin ◽  
Martin C Holdrege ◽  
Joel Hartsell ◽  
Lindsay Meyers ◽  
...  
Keyword(s):  
Public Health ◽  
Influenza A ◽  
Detection Rate ◽  
Respiratory Illness ◽  
Respiratory Pathogens ◽  
Public Health Response ◽  
Mixed Effect ◽  
Detection Rates ◽  
Social Distancing ◽  
The Impact

Abstract Background The initial focus of the US public health response to COVID-19 was the implementation of numerous social distancing policies. While COVID-19 was the impetus for imposing these policies, it is not the only respiratory disease affected by their implementation. This study aimed to assess the impact of social distancing policies on non-SARS-CoV-2 respiratory pathogens typically circulating across multiple US states. Methods Linear mixed-effect models were implemented to explore the effects of five social distancing policies on non-SARS-CoV-2 respiratory pathogens across nine states from January 1 through May 1, 2020. The observed 2020 pathogen detection rates were compared week-by-week to historical rates to determine when the detection rates were different. Results Model results indicate that several social distancing policies were associated with a reduction in total detection rate, by nearly 15%. Policies were associated with decreases in pathogen circulation of human rhinovirus/enterovirus and human metapneumovirus, as well as influenza A, which typically decrease after winter. Parainfluenza viruses failed to circulate at historical levels during the spring. Total detection rate in April 2020 was 35% less than historical average. Many of the pathogens driving this difference fell below historical detection rate ranges within two weeks of initial policy implementation. Conclusion This analysis investigated the effect of multiple social distancing policies implemented to reduce transmission of SARS-CoV-2 on non-SARS-CoV-2 respiratory pathogens. These findings suggest that social distancing policies may be used as an impactful public health tool to reduce communicable respiratory illness.

scholarly journals Comparison of colonoscopy after colonic diverticulitis and positive fecal immunochemical tests for the detection of colorectal neoplasia

2021 ◽  
Vol 09 (03) ◽  
pp. E331-E337
Author(s):  
Dai Nakamatsu ◽  
Tsutomu Nishida ◽  
Shinji Kuriki ◽  
Li-sa Chang ◽  
Kazuki Aochi ◽  
...  
Keyword(s):  
Detection Rate ◽  
Colorectal Neoplasia ◽  
Acute Diverticulitis ◽  
Colonic Diverticulitis ◽  
Detection Rates ◽  
Positive Group ◽  
Asymptomatic Patients ◽  
Polyp Detection Rate ◽  
Adenoma Detection ◽  
Acute Colonic Diverticulitis

Abstract Background and study aims The relationship between acute colonic diverticulitis and colorectal cancer (CRC) is unclear, but colonoscopy is recommended to exclude malignancy. We compared the detection rates for colorectal neoplasia in patients with colonic diverticulitis and asymptomatic patients who had positive fecal immunochemical tests (FITs). Patients and methods In total, 282 patients with acute colonic diverticulitis were hospitalized in our hospital from February 2011 to December 2019. Of them, 143 patients with diverticulitis and 1819 with positive FITs patients during the same period underwent colonoscopy without a prior colonoscopy within 5 years. We retrospectively compared these patients in terms of the invasive CRC rate, advanced neoplasia detection rate (ANDR), adenoma detection rate (ADR), and polyp detection rate (PDR). Results Compared to the diverticulitis group, the FIT-positive group had a significantly higher CRC rate (0 vs 2.7 %, P = 0.0061), ANDR (5.6 vs. 14.0 %, P = 0.0017), ADR (19.6 vs. 53.2 %, P < .0001), and PDR (44.1 vs. 91.0 %, P < .0001). Using 1:1 propensity score matching based on age and sex, we obtained 276 matched patients in both groups. After matching, no difference was found in the CRC rate (0 vs 0.7 %) or ANDR (5.8 vs 7.3 %) between groups, but the ADR and PDR were significantly higher in the FIT-positive group (20.3 vs 43.5 %, P < .0001; 45.7 % vs 86.2 %, P < .0001). Conclusion Patients with acute diverticulitis had lower ADRs and PDRs than patients with positive FITs.

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