Removal Trapping Research Articles

Hydrodynamic Analysis of an Eco-Trap to Improve Gross Pollutant Removal on Water Surface with CFD Simulation

The use of gross pollutant trap (GPT) as one of the primary treatment measures to remove coarse pollutants from water surfaces that should not enter sewers and waterways is widely recognized worldwide. Over the years, GPT designs have evolved significantly, from large and built-in devices to proprietary off-the-shelf products as a structural measure to curb river pollution. Nevertheless, most of the installed GPTs are poorly maintained, leading to many environmental problems such as odour, vermin, flooding and unsightly views. This study is interested in developing a removable gross pollutant trap, called Eco-trap, which can contribute to river cleaning without much complexity and cost. The hydrodynamic performance of the Eco-trap is evaluated using Computational Fluid Dynamics (CFD) simulations. To ensure the reliability of the simulations, grid independence tests were conducted with coarse, medium, fine and finer mesh sizes. Three different mesh sizes (0.10m x 0.05m, 0.20m x 0.10m and 0.30m x 0.15m) were tested in five velocity scenarios to evaluate their effectiveness in removing pollutants from stormwater runoff. The results provide important insights into the velocity distributions, pressure gradients and force distributions around and on the trap structure, which provides valuable information for optimizing the design of pollutant removal devices. By analysing the total deformation and equivalent stress, net weaknesses were identified for further improvements. This study contributes to the improvement of stormwater management in Malaysia by providing new insights into the hydrodynamic behaviour of gross pollutant removal devices and their potential applications to reduce water pollution in river ecosystems

Hantavirus Pulmonary Syndrome Outbreak Anticipation by a Rapid Synchronous Increase in Rodent Abundance in the Northwestern Argentina Endemic Region: Towards an Early Warning System for Disease Based on Climate and Rodent Surveillance Data.

Hantavirus pulmonary syndrome (HPS) is an American emerging disease caused by the rodent-borne virus genus Orthohantavirus (Family: Hantaviridae: Order: Elliovirales Class: Bunyaviricetes). In Argentina, almost half of the HPS infections occur in the northwestern endemic region. In this study, we monitored rodent abundance during 2022 and 2023 in three sites with different sampling methods (removal trapping, live trapping and hunted rodents by domestic cats) to evaluate their relationship with human infections. We found a similar pattern of variation in rodent abundance across time, and particularly a synchronous rise of rodent abundance that anticipated an HPS outbreak in 2023. Our dynamic regression models revealed a positive relationship between HPS cases and rodent abundance with a three-month lag, as well as rainfall with an eight-month lag. Our results provide a framework for the planning and implementation of public health prevention campaigns based on climatology and rodent monitoring. Domestic cats bringing rodents into houses can be an overlooked risk factor, particularly if viral shedding of infected rodents is magnified by stress. HPS is a disease of public health concern due to its high mortality rate, the lack of a specific therapeutic treatment and no vaccine. Thus, prevention of infections is of the utmost importance.

Development of an innovative and effective trap for rapid removal and collection of live adults of the pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae) from infested stored pulses, for research studies in the laboratory conditions

As per the records in scientific literature, there are several hundred species of insects that are associated with stored grains/ stored grain products out of which about 14 species are largely responsible for most of the damage. The insect pests of stored grains mainly include the beetles and moths, and the pulse beetle, Callosobruchus chinensis is one of the most economically important insect pests of stored grains mainly pulses such as green gram, kala chana, kabuli chana, etc. The orientation behavior of insects is a fascinating aspect of their survival and interaction with the environment. Elucidation of the factors governing the orientational responses of insect pests can help in their management. The findings of this study can be incorporated in the eco-friendly IPM pest management programs that work in harmony with insect behaviors. Such techniques work in multiple ways, viz. by disrupting orientation towards food source &/or by disrupting orientation of mates towards each other, etc. Interference with orientation along with feeding disruption ultimately affects subsequent growth and development, and establishment of the pest population. Thus, the methods that target the orientation behavior of insects help to manage them effectively. In this study, an effort was made to study the orientational responses of an economically important insect pest of stored grains, the pulse beetle or Callosobruchus chinensis (Coleoptera: Bruchidae). An important outcome of this small-scale study was the development of an innovative, effective and time-saving method to remove and trap the pulse beetles from the infested pulses in the laboratory conditions, and the same can be upscaled for commercial use with slight modifications in future.

Ectoparasite Fauna of Rodents and Shrews with Their Spatial, Temporal, and Dispersal along a Degradation Gradient in Mabira Central Forest Reserve.

Ectoparasites like fleas, mites, and ticks that are key carriers of harmful pathogens such as viruses, bacteria, cestodes, and nematodes live on rodents and shrews. It should be noted that rodents' ecological adaptability makes them suitable as parasite hosts. The main objective of the study was to determine the ectoparasite assemblages in rodents and shrews along a degradation gradient, while comparing infestation levels in different habitats with varying levels of degradation. The study was conducted in Mabira Central Forest Reserve. Ectoparasites were collected following rodent and shrew removal trapping which was done using Sherman's traps set along transects of 200 meters in three habitat strata that included adjacent forest habitats, degraded forest edge, and regenerating forest interior. Data was collected intermittently with a break every two months for one year from November 2018 to December 2019. A total of 1411 rodents and shrews were collected, yielding a total of 5692 ectoparasites from 22 host species (17 rodents and 5 shrews). The most prevalent group of ectoparasites was mites followed by fleas, lice, ticks, and earwig. Ectoparasite prevalence significantly differed depending on hosts species (P = 0.001) and host age (P = 0.022), but not host sex (P = 0.78), while mean infestation significantly varied basing on host species (P = 0.001), host sex (P = 0.001), season (P = 0.001), and habitat (P = 0.001). Prevalence (P = 0.001) and mean infestation (P = 0.001) significantly varied across studied habitats. The study has emphasized the significance of Praomys jacksoni and Hylomyscus stella as significant hosts for mites and S. congicus as a significant host for fleas. Additionally, environment and host characteristics have a bearing on prevalence and infestation of ectoparasites with habitat degradation playing a significant role in the occurrence of ectoparasites, thereby emphasizing its contribution to zoonotic outbreaks.

Parametric Design of a 3D-Printed Removable Common-Mode Trap for Magnetic Resonance Imaging.

Radiofrequency coils are utilized during transmit and receive of MRI signals. Cable traps remove common-mode current from the coaxial cable shield, which helps improve the image quality and reduces risks of burns to the patient. Traditional cable traps use wounded coaxial cables that limit the flexibility in the design process. Floating cable traps were introduced which eliminated any physical connection between the trap and coaxial cable, allowing complete flexibility in design and placement. However, the design process of floating cable traps is iterative and may take several rounds of 3D modeling. This work seeks to optimize the design process through the use of parametric design methodologies. The proposed methodology allows for 3D printing the floating cable trap after inputting the design parameters. The cable trap was able to attenuate currents in the coaxial shields to -48 dB, highlighting its performance and design robustness.

Rodent abundance, diversity and community structure in a bubonic plague endemic area, northern Tanzania

Abstract Rodent-borne diseases such as bubonic plague remain a significant threat to public health in tropical countries. In plague-endemic areas, little information exists on the factors triggering periodic bursts, thus rendering preparedness strategies for preventing the negative impacts of the deadly zoonosis difficult. In this study, we assessed how species richness, diversity, and community structure of rodents are associated with plague persistence in Mbulu District, Tanzania. Rodent data were collected using the removal trapping technique. We captured 610 rodents belonging to 12 species, with Mastomys natalensis recording highest abundance. There was significantly higher abundance and species richness in persistent than non-persistent plague locality. Also, house premises recorded significantly lower species richness than farm and forest habitats. Additionally, we found three broad rodent community structures that varied significantly between studied habitat types suggesting high rodent populations interaction at fine-scale resource abundance. The high abundance and diversity of plague-susceptible rodent reservoirs suggestively contribute to the plague persistence in the foci. These results may be useful to developing preparedness strategies in these areas to control plague outbreaks.

Prevalence of Yersinia pestis among rodents captured in a semi-arid tropical ecosystem of south-western Zimbabwe.

This study assessed the prevalence of plague bacterium (Yersinia pestis) among rodents captured in Umzingwane and Nkayi districts, south-western Zimbabwe. A total of 44 rodents were captured on three consecutive days per trapping session in the study sites using a removal trapping method in April 2018. Captured rodents were euthanized, and blood samples were collected. The Giemsa stain method was used to detect plague bacteria. The trapping success was not significantly different (χ² = 1.50, df = 1, P = 0.221), 8.5% for the Nkayi district, while in the Umzingwane district, it was 8%. Overall, only one rodent species, i.e., Mastomys natalensis, tested positive for Y. pestis in the Umzingwane district, thus yielding a prevalence rate of 2.3% for the entire study area. This was the most important finding of a Y. pestis-positive rodent in a non-endemic wild area in the Umzingwane district. These results point to a low prevalence of Y. pestis in the study area and the importance of an active plague disease surveillance and monitoring system.

Open removal models with temporary emigration and population dynamics to inform invasive animal management.

Removal sampling data are the primary source of monitoring information for many populations (e.g., invasive species, fisheries). Population dynamics, temporary emigration, and imperfect detection are common sources of variation in monitoring data and are key parameters for informing management. We developed two open robust‐design removal models for simultaneously modeling population dynamics, temporary emigration, and imperfect detection: a random walk linear trend model (estimable without ancillary information), and a 2‐age class informed population model (InfoPM, closely related to integrated population models) that incorporated prior information for age‐structured vital rates and relative juvenile availability. We applied both models to multiyear, removal trapping time‐series of a large invasive lizard (Argentine black and white tegu, Salvator merianae) in three management areas of South Florida to evaluate the effectiveness of management programs. Although estimates of the two models were similar, the InfoPMs generally returned more precise estimates, partitioned dynamics into births, deaths, net migration, and provided a decision support tool to predict population dynamics under different effort scenarios while accounting for uncertainty. Trends in tegu superpopulation abundance estimates were increasing in two management areas despite generally high removal rates. However, tegu abundance appeared to decline in the Core management area, where trapping density was the highest and immigration the lowest. Finally, comparing abundance predictions of no‐removal scenarios to those estimated in each management area suggested significant population reductions due to management. These results suggest that local tegu population control via systematic trapping may be feasible with high enough trap density and limited immigration; and highlights the value of these trapping programs. We provided the first estimates of tegu abundance, capture probabilities, and population dynamics, which is critical for effective management. Furthermore, our models are applicable to a wide range of monitoring programs (e.g., carcass recovery or removal point‐counts).

Interlayer-Confined Cu(II) Complex as an Efficient and Long-Lasting Catalyst for Oxidation of H2S on Montmorillonite

Removal of highly toxic H2S for pollution control and operational safety is a pressing need. For this purpose, a montmorillonite intercalated with Cu(II)-phenanthroline complex [Cu[(Phen)(H2O)2]2+ (Mt-CuPhen) was prepared to capture gaseous H2S under mild conditions. This hybrid material was simple to obtain and demonstrated an outstanding ability to entrap H2S at room temperature, retaining high efficiency for a very long time (up to 36.8 g of S/100 g Mt-CuPhen after 3 months of exposure). Sorbent and H2S uptake were investigated by elemental analysis, X-ray powder diffraction measurements, diffuse reflectance (DR) UV–Vis and infrared spectroscopy, thermal analysis and evolved gas mass spectrometry, scanning electron microscopy equipped with energy-dispersive X-ray spectrometer, and X-ray absorption spectroscopy. The H2S capture was studied over time and a mechanism of action was proposed. The entrapping involves a catalytic mechanism in which [Cu[(Phen)(H2O)2]2+ acts as catalyst for H2S oxidation to S0 by atmospheric oxygen. The low cost and the long-lasting performance for H2S removal render Mt-CuPhen an extremely appealing trap for H2S removal and a promising material for many technological applications.

Novel synthetic method for magnetic sulphonated tubular trap for efficient mercury removal from wastewater

Novel synthetic method for magnetic sulphonated tubular trap for efficient mercury removal from wastewater

Dual-Tuned Removable Common-Mode Current Trap for Magnetic Resonance Imaging and Spectroscopy.

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are preferred methods of gathering structural and metabolic information from the body due to their non-invasive approach to obtaining a diagnosis. Dual-tuned radiofrequency (RF) coils can detect signals produced by both hydrogen and a second atomic nuclei of interest. However, undesired electromagnetic coupling often confounds both the design and utilization of RF coils. Coaxial shield currents, also known as common-mode currents, can be induced during MR scans and cause image distortion and reduction in signal-to-noise ratio (SNR); furthermore, the energy dissipated from the cabling can create heat that poses a risk of patient burns if the routed too closely. Thus, common-mode currents must be suppressed in RF coils by employing non-magnetic current traps. In this paper, we present a novel dual-tuned current trap that is fully removable and does not require soldering directly to the cable. The design was manufactured with 3D printing to support rapid fabrication and distribution. Bench measurements at the 3T Larmor frequencies for hydrogen and phosphorous-31 demonstrate common-mode attenuation of -18 dB and -8.4 dB respectively.

The Consequences of Small Mammal Censuses by Method of Irreversible Removal

Experiments were performed to estimate the effect of removal trapping with Gero trap lines on resident population density and dispersal rate of Clethrionomys voles and Sorex shrews. Parameters of animal density and dispersal were calculated based on the results of live-trap censuses taken before and immediately after the removal trapping. Resident population density in the latter case was accounted for not only by animals that escaped removal but also by those that moved in from surrounding areas during the next few days. Local reduction of animal numbers resulted in increased dispersal. Parameters of dispersal obtained by the method of long-term removal may be overestimated.

Monolithic, 3D-Printed Microfluidic Platform for Recapitulation of Dynamic Tumor Microenvironments

We report the development of an entirely 3D-printed, monolithic microfluidic platform that provides a dynamic microenvironment for perfusing and sustaining tumor fragments from a biopsy sample. The finely featured, noncytotoxic, and transparent tumor trap is integrated with threaded connectors for rapid, leak-proof fluid interfacing, an in-line trap for removal of bubbles arising from oxygenated media flow or tumor loading procedures, and a network of microchannels for supplying media (and potentially immune cells) to the trapped tumor fragment. The devices were additively manufactured in Pro3dure GR-10 -a relatively new, high-resolution stereolithographic resin with properties suitable for biomedical applications requiring interrogation via fluorescence microscopy. Overlaid bright-field and fluorescence microscopy images demonstrate trapping of human tumor fragments by the printed microfluidic device, as well as visualization of individual cells within the fragment. A multi-day trapping experiment evidences the ability to sustain a live tumor fragment under dynamic perfusion within the device-a configuration capable of modeling of interactions between tumors and various drug treatments in the presence of circulating immune cells, e.g., for assessment of the efficacy of chemotherapy and immunotherapy treatments.

An Evaluation of Removal Trapping to Control Rodents Inside Homes in a Plague-Endemic Region of Rural Northwestern Uganda.

Rodents pose a significant threat to human health, particularly in rural subsistence farming communities in Africa, where rodents threaten food security and serve as reservoirs of human pathogens, including the agents of plague, leptospirosis, murine typhus, rat-bite fever, Lassa fever, salmonellosis, and campylobacteriosis. Our study focused on the plague-endemic West Nile region of Uganda, where a majority of residents live in Uganda government-defined poverty, rely on subsistence farming for a living, and frequently experience incursions of rodents into their homes. In this study, we show that rodent removal was achieved in a median of 6 days of intensive lethal trapping with multiple trap types (range: 0-16 days). However, rodent abundance in 68.9% of homesteads returned to pretreatment levels within a median of 8 weeks (range 1-24 weeks), and at least a single rodent was captured in all homesteads by a median of 2 weeks (range 1-16 weeks) after removal efforts were terminated. Results were similar between homesteads that practiced rodent control whether or not their neighbors implemented similar strategies. Overall, intensive lethal trapping inside homes appears to be effective at reducing rodent abundance, but control was short lived after trapping ceased.

Effectiveness of a field trap barrier system for controlling Aedes albopictus: a \u201cremoval trapping\u201d strategy

BackgroundAedes aegypti and Aedes albopictus are the main vectors for the transmission of several viral pathogens, in particular, dengue, Zika and chikungunya. In the absence of vaccines and treatment, control of Aedes mosquitoes is the only means of keeping these diseases in check. Aedes control is difficult, and it is, therefore, necessary to evaluate the efficacy of novel control methods, particularly those targeting adult and exophilic Ae. albopictus populations.MethodsWe carried out the first evaluation of the effectiveness of a field trap barrier system, i.e. a “removal trapping” outdoor control strategy for Ae. albopictus in southern France.ResultsThe removal trapping control strategy is an effective system, able to reduce to almost zero the biting rate of the tiger mosquito in and around houses with traps installed. This strategy has the advantage of being a non-chemical method, which is environmentally friendly and does not affect non-target fauna. Nevertheless, it has several constraints including the cost of the CO2 required for the system to function. However, the system could be optimized by reducing the costs and combining it with other control strategies within the framework of integrated vector management.ConclusionsWe provide the first evidence of the effectiveness of this trap barrier system, which is based on the combined effect of (i) removing adult mosquitoes living in the area, and (ii) hampering the migration of mosquitoes from outside into the treated area. Further investigation is needed to understand its efficacy for other species, other locations and at-risk communities, and to evaluate its application for reducing the prevalence of dengue, Zika and chikungunya diseases.

Intrinsic and extrinsic factors related to pathogen infection in wild small mammals in intensive milk cattle and swine production systems.

BackgroundUnderstanding the ecological processes that are involved in the transmission of zoonotic pathogens by small mammals may aid adequate and effective management measures. Few attempts have been made to analyze the ecological aspects that influence pathogen infection in small mammals in livestock production systems. We describe the infection of small mammals with Leptospira spp., Brucella spp., Trichinella spp. and Cysticercus fasciolaris and assess the related intrinsic and extrinsic factors in livestock production systems in central Argentina at the small mammal community, population and individual levels.Methodology/Principal findingsTen pig farms and eight dairy farms were studied by removal trapping of small mammals from 2008 to 2011. Each farm was sampled seasonally over the course of one year with cage and Sherman live traps. The 505 small mammals captured (14,359 trap-nights) included three introduced murine rodents, four native rodents and two opossums. Leptospira spp., anti-Brucella spp. antibodies and Trichinella spp. were found in the three murine rodents and both opossums. Rattus norvegicus was also infected with C. fasciolaris; Akodon azarae and Oligoryzomys flavescens with Leptospira spp.; anti-Brucella spp. antibodies were found in A. azarae. Two or more pathogens occurred simultaneously on 89% of the farms, and each pathogen was found on at least 50% of the farms. Pathogen infections increased with host abundance. Infection by Leptospira spp. also increased with precipitation and during warm seasons. The occurrence of anti-Brucella spp. antibodies was higher on dairy farms and during the winter and summer. The host abundances limit values, from which farms are expected to be free of the studied pathogens, are reported.Conclusions/SignificanceMurine rodents maintain pathogens within farms, whereas other native species are likely dispersing pathogens among farms. Hence, we recommend preventing and controlling murines in farm dwellings and isolating farms from their surroundings to avoid contact with other wild mammals.

Influence of Removal Sampling of Small Mammals on Abundance and Diversity Attributes: Scientific Implications

Terrestrial small mammals occupy a variety of temperate and boreal forests in North America and Eurasia and contribute to biodiversity within these ecosystems. Researchers commonly use a variation of removal trapping to sample small-mammal populations and communities in these systems. However, it is not known if recurrent removal sampling might bias abundance estimates or alter the very populations under study. We addressed 2 questions: (1) are estimates of population size and species richness and diversity gained from removal trapping different from those based on live-trapping? and (2) what residual impact does removal trapping have on small-mammal populations and communities, as revealed by live-trapping? In 2 experiments (summer 2004 and autumn 2005), we compared undisturbed controls (non-removal) with removal sampling for 5-, 10-, and 30-night periods. Total abundance estimates during removal periods were dramatically higher (up to 3-fold) on non-removal than removal sites in both experiments. Mean abundance of the 2 most common species, deer mouse (Peromyscus maniculatus) and northwestern chipmunk (Neotamias amoenus), were substantially higher on non-removal than removal sites in the autumn experiment. The longer the removal interval, the deeper the degree of departure from non-removal levels of abundance. Species richness during removal periods also followed the pattern of abundance, whereby new, uncommon species appeared on removal sites, but not non-removals, during the autumn experiment. The residual impact of removal trapping, as revealed by live-trapping, indicated that abundance estimates were up to 4.5-fold higher on non-removal than postremoval sites and continued for at least 1 month as the small mammal community reorganized itelf via immigration and settlement. Species diversity was still significantly different among removals 8 months after the autumn removal period. Removal-trapping over variable lengths (5 to 30 nights) may not provide an accurate picture of the abundance or diversity of small mammals.

Discharge determines production of, decomposition of and quality changes in dissolved organic carbon in pre-dams of drinking water reservoirs

Discharge determines production of, decomposition of and quality changes in dissolved organic carbon in pre-dams of drinking water reservoirs

Small Mammals from Three Mountain Ranges in Nuclear Central America

ABSTRACT Small mammal ecology and natural history are poorly known in Nuclear Central America. In an effort to gain information on small mammals (insectivorans, marsupials, and rodents), we sampled three cloud forest habitats in mountain ranges in Honduras (Cerro Celaque and Sierra de Agalta) and Guatemala (Sierra de las Minas). Small mammals were collected using removal trapping. A total of 789 specimens representing 23 species of small mammal was recorded from seven trapping sites. Trapping effort varied among sites, with a total of 18,117 total trap nights recorded. We describe the habitat at each trapping site, and report on species diversity, relative abundance, sex ratios, reproductive activity, and other natural history information on the mammals collected. In general, cloud forests in the three mountain ranges contained different communities of small mammals. We recorded only three species, Heteromys desmarestianus Gray, 1862, Peromyscus oaxacensis Merriam, 1898, and Scotinomys teguina (Alston, 18...

Mass mosquito trapping for malaria control in western Kenya: study protocol for a stepped wedge cluster-randomised trial.

BackgroundIncreasing levels of insecticide resistance as well as outdoor, residual transmission of malaria threaten the efficacy of existing vector control tools used against malaria mosquitoes. The development of odour-baited mosquito traps has led to the possibility of controlling malaria through mass trapping of malaria vectors. Through daily removal trapping against a background of continued bed net use it is anticipated that vector populations could be suppressed to a level where continued transmission of malaria will no longer be possible.Methods/designA stepped wedge cluster-randomised trial design was used for the implementation of mass mosquito trapping on Rusinga Island, western Kenya (the SolarMal project). Over the course of 2 years (2013–2015) all households on the island were provided with a solar-powered mosquito trapping system. A continuous health and demographic surveillance system combined with parasitological surveys three times a year, successive rounds of mosquito monitoring and regular sociological studies allowed measurement of intervention outcomes before, during and at completion of the rollout of traps. Data collection continued after achieving mass coverage with traps in order to estimate the longer term effectiveness of this novel intervention. Solar energy was exploited to provide electric light and mobile phone charging for each household, and the impacts of these immediate tangible benefits upon acceptability of and adherence to the use of the intervention are being measured.DiscussionThis study will be the first to evaluate whether the principle of solar-powered mass mosquito trapping could be an effective tool for elimination of malaria. If proven to be effective, this novel approach to malaria control would be a valuable addition to the existing strategies of long-lasting insecticide-treated nets and case management. Sociological studies provide a knowledge base for understanding the usage of this novel tool.Trial registrationTrialregister.nl: NTR3496 – SolarMal. Registered on 20 June 2012.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1469-z) contains supplementary material, which is available to authorized users.