Instantaneous Sampling Research Articles

Should Zoo Food Be Chopped for Ruffed Lemurs? It's Not so Black and White.

Whole food diets in zoos have the potential to reduce microbial contamination and keeper preparation time, whilst also reducing food nutrient breakdown. Given these benefits, it is important to determine whether there is any value in chopping up food. Lemurs (Family Lemuridae) are common in zoos, with over 7500 individuals housed globally. Given their regular occurrence in collections, plus the high incidence of frugivory, lemurs are an excellent taxon to investigate food presentation effects on behavior. A study was undertaken at Beale Wildlife Park on a group of four black-and-white ruffed lemurs (Varecia variegata) to investigate food presentation and preference. Animal behavior was recorded using instantaneous focal sampling at 60 s intervals to record state behaviors and continuous focal sampling to record event behaviors in 1-h sessions. Food preference was done by recording the first three food items consumed by individual lemurs. Overall, food manipulation was significantly increased during whole food presentation allowing the lemurs to display species-specific behaviors. Feeding and foraging were highest during very chopped food condition and inactivity was lowest in very chopped food presentation. When looking at aggressive interactions, there was an increase in stealing and locomotion with food during whole food presentation, whereas biting and startle were lower. Proving high-value food items chopped and low-value food items whole could reduce aggression while reduce aggression seen over high-value food items. For food preference, sweet potato was consistently in the top three food items for all lemurs, with beetroot being the second most-picked food item. This suggests that these individuals have a strong preference for food items high in carbohydrates. Keeper preparation time was significantly reduced during whole food preparation. Further research assessing a wider range of zoo-housed species would be beneficial to assess the effects of food presentation on behavior.

Research on underwater target signal orientation estimation based on smoothness priors approach

Purpose This paper aims to address the challenges in hydroacoustic signal detection, signal distortion and target localization caused by baseline drift. The authors propose a combined algorithm that integrates short-time Fourier transform (STFT) detection, smoothness priors approach (SPA), attitude calibration and direction of arrival (DOA) estimation for micro-electro-mechanical system vector hydrophones. Design/methodology/approach Initially, STFT method screens target signals with baseline drift in low signal-to-noise ratio environments, facilitating easier subsequent processing. Next, SPA is applied to the screened target signal, effectively removing the baseline drift, and combined with filtering to improve the signal-to-noise ratio. Then, vector channel amplitudes are corrected using attitude correction with 2D compass data. Finally, the absolute target azimuth is estimated using the minimum variance distortion-free response beamformer. Findings Simulation and experimental results demonstrate that the SPA outperforms high-pass filtering in removing baseline drift and is comparable to the effectiveness of variational mode decomposition, with significantly shorter processing times, making it more suitable for real-time applications. The detection performance of the STFT method is superior to instantaneous correlation detection and sample entropy methods. The final DOA estimation achieves an accuracy within 2°, enabling precise target azimuth estimation. Originality/value To the best of the authors’ knowledge, this study is the first to apply SPA to baseline drift removal in hydroacoustic signals, significantly enhancing the efficiency and accuracy of signal processing. It demonstrates the method’s outstanding performance in the field of underwater signal processing. In addition, it confirms the reliability and feasibility of STFT for signal detection in the presence of baseline drift.

High resolution concentration-discharge relationships in managed watersheds: A 30+ year analysis

Concentration-discharge (C-Q) relationships provide insight into solute transport and biogeochemical processes for watersheds. A 30+ year, high-resolution dataset from the North Appalachian Experimental Watershed (NAEW) offers an unparalleled opportunity to explore land use and land management impacts on C-Q relationships for small watersheds of varying land management histories (agricultural to forested). The NAEW was among the few hydrologic research sites where storm event runoff was sampled using proportional sampling. This method captures the concentration-discharge behavior associated with land use more effectively than instantaneous sampling, which favors rising limb or falling limb dynamics. In this study, we explore C-Q relationships by investigating baseflow and storm event flow across their total behavior. We also build a systems-understanding by comparing chemostatic behavior to soil geochemistry and land use history. Highly managed agricultural watersheds with no associated stream baseflow demonstrate near-chemostatic behavior for most solutes, while mixed use and forested watersheds with associated streams are more mutable depending on whether primary sources of water were groundwater or surface water. Using this unique high-resolution dataset, we show that concentration-discharge relationships are influenced by soil and baseflow geochemistry, pore fluid concentration, and land type/land use legacy effects.

Mantled howler monkeys (Alouatta palliata) alter activity and spatial cohesion across a continuous forest and forest fragment in Costa Rica.

Habitat loss due to deforestation is a primary threat to global biodiversity. Clearing tropical rainforests for agriculture or development leads to forest fragmentation. Forest fragments contain fewer large trees and provide lower food availability for primates compared to continuous forests. Mantled howler monkeys (Alouatta palliata) inhabit fragmented rainforests and may need to alter their activity budgets and spatial cohesion to mitigate competition and conserve energy in fragments where food quality is lower. We compared howler monkey activity and spatial cohesion across a small forest fragment (La Suerte Biological Research Station, LSBRS) and a large, continuous forest (La Selva Research Station) in Costa Rica. We predicted that monkeys at LSBRS would rest more, feed more, travel less, and be less spatially cohesive compared to La Selva to contend with fewer resources in the small fragment. Using instantaneous scan sampling at 2-min intervals during 30-min focal samples, we recorded activity and the number of individuals within 5m of the focal animal. We collected 1505h of data from 2017-2024. Monkey activity and spatial cohesion differed significantly across sites. As predicted, monkeys at LSBRS spent more time feeding than at La Selva, but contrary to our predictions, they rested less and traveled more. The mean number of individuals within 5m was significantly lower at LSBRS compared to La Selva. The ability to modify their activity and spatial cohesion in response to fragmentation provides insight into how primates can contend with fewer resources and higher competition in changing ecosystems worldwide.

Costs and benefits of allomaternal care to mothers and others in wild Phayre's leaf monkeys.

Allomaternal care (AMC) is suggested to be energetically beneficial to mothers and costly to allomothers. However, among primates, AMC is a heterogeneous phenomenon and its implications are less clear especially in female dispersal species. Here, we investigated infant care in a female dispersal species, Phayre's leaf monkeys (Trachypithecus phayrei crepusculus), to evaluate whether mothers were constrained by infant care and benefitted energetically from AMC, whether AMC was energetically costly for allomothers and how maternal experience was associated with AMC. Data were collected via instantaneous focal animal sampling between 2004 and 2005 for juvenile and adult females (N = 18) from two groups at the Phu Khieo Wildlife Sanctuary, Thailand (440 h). We used generalized linear mixed models to determine how infant care during the first month after birth affected the time mothers and allomothers spent feeding, socializing, resting, and locomoting and how AMC varied. In the first month, infants spent 26% of their time with an allomother. We found no differences in mothers' overall activity before versus after birth, although mothers fed significantly more and rested less when without their infant. Allomothers fed and rested less when with an infant. AMC varied between 0.0% and 20.5%, with immature females being most active. Mothers appear to benefit energetically from AMC such that their overall activity after birth remained unchanged. Costs and benefits for allomothers seem to be variable. Some very active immature females may be benefitting from learning-to-mother. The overall low cost of AMC may facilitate a reciprocal social network among unrelated females.

Stream salinity prediction in data-scarce regions: Application of transfer learning and uncertainty quantification

Scarcity of stream salinity data poses a challenge to understanding salinity dynamics and its implications for water supply management in water-scarce salt-prone regions around the world. This paper introduces a framework for generating continuous daily stream salinity estimates using instance-based transfer learning (TL) and assessing the reliability of the synthetic salinity data through uncertainty quantification via prediction intervals (PIs). The framework was developed using two temporally distinct specific conductance (SC) datasets from the Upper Red River Basin (URRB) located in southwestern Oklahoma and Texas Panhandle, United States. The instance-based TL approach was implemented by calibrating Feedforward Neural Networks (FFNNs) on a source SC dataset of around 1200 instantaneous grab samples collected by United States Geological Survey (USGS) from 1959 to 1993. The trained FFNNs were subsequently tested on a target dataset (1998-present) of 220 instantaneous grab samples collected by the Oklahoma Water Resources Board (OWRB). The framework's generalizability was assessed in the data-rich Bird Creek watershed in Oklahoma by manipulating continuous SC data to simulate data-scarce conditions for training the models and using the complete Bird Creek dataset for model evaluation. The Lower Upper Bound Estimation (LUBE) method was used with FFNNs to estimate PIs for uncertainty quantification. Autoregressive SC prediction methods via FFNN were found to be reliable with Nash Sutcliffe Efficiency (NSE) values of 0.65 and 0.45 on in-sample and out-of-sample test data, respectively. The same modeling scenario resulted in an NSE of 0.54 for the Bird Creek data using a similar missing data ratio, whereas a higher ratio of observed data increased the accuracy (NSE = 0.84). The relatively narrow estimated PIs for the North Fork Red River in the URRB indicated satisfactory stream salinity predictions, showing an average width equivalent to 25 % of the observed range and a confidence level of 70 %.

Comparing camera‐based ungulate density estimates: a case study using island populations of bighorn sheep and mule deer

AbstractCamera‐based abundance estimators are an alternative methodology of growing interest in both research and management applications. The statistical formulations of camera‐based abundance estimators using time‐lapse data should theoretically produce precise and unbiased estimates; however, production of unbiased results also requires meeting several important assumptions, and real‐world case studies evaluating such results remain relatively few. We applied instantaneous sampling (IS) and space‐to‐event (STE) estimators to remote camera data collected in April 2021 via time‐lapse sampling of closed populations of bighorn sheep (Ovis canadensis) and mule deer (Odocoileus hemionus) on Wild Horse Island in western Montana, USA, and compared results for bighorn sheep to aerial and ground‐based counts. Point estimates from camera‐based approaches underestimated bighorn sheep populations by 32–44% (IS estimator) and 62–69% (STE estimator) relative to aerial and ground counts. Patchy spatial distribution and group‐living behavior of sheep resulted in a high degree of noise surrounding the IS estimate. In comparison, a low point estimate with relatively narrow confidence intervals suggested potential sensitivity of the STE estimator to violating assumptions of independence among individual animals and sampling occasions. Estimates of mule deer had improved precision over sheep estimates, as indicated by lower estimated coefficients of variation of the mean (CVmean) derived from the analytic SE estimator. Using 15‐m viewsheds and the IS estimators, mule deer density estimates came with a 26% CVmean compared to 43% CVmean for bighorn sheep. This discrepancy may be a result of differences in distribution, behavior, and relative abundance between the 2 species. Accounting for group size and increasing time between sampling may improve accuracy of density estimates and adhere better to model assumptions when estimating precision. In addition, factors influencing viewshed and resulting density extrapolations must be considered carefully. While camera‐based methods theoretically provide an alternative way to estimate density when traditional methods are impractical, our results suggest that more work is needed to ensure density estimates are accurate and precise enough to inform population management.

Supersonic coaxial aerodynamic atomization dust removal technology

The high concentration of respirable dust pollution created during coal mining has long been known to be harmful to employee health. A water absorbing atomization device has certain advantages when spray trapping particle sizes of PM2.5–10. To further improve the PM0–2.5 trapping efficiency, supersonic coaxial pneumatic atomization dust removal technology has been developed. The effects of fog droplet characteristics on the instantaneous diffusion of dust were studied by numerical simulation and macro- and microexperiments for the first time, and the coupling characteristics of fog droplets and dust fields were obtained. The results show that with increasing aerodynamic pressure, the supersonic range extends along the axis toward the nozzle outlet, and the average velocity in the tube increases. Under different pressures, the droplet particle size in the supersonic coaxial atomizing nozzle is <6 μm and decreases with increasing aerodynamic pressure. When a droplet effuses from the nozzle, the transonic distribution of the flow field causes the droplet velocity to increase first and then decrease under the drag force. The droplet field characteristic distribution of supersonic coaxial atomization is determined by droplet evaporation, condensation, and migration. Under the same pressure, with increasing spray distance, the distribution of the droplet particle size increases in a stepwise manner, and the droplet velocity decreases according to an exponential function so that the droplet field produces a high-speed fine fog area. The range of droplets with higher velocities and smaller particle sizes is mainly influenced by migration and increases with increasing pressure. The coupling effect droplet field and dust field can be characterized by the instantaneous dispersion of dust and are determined by the distribution characteristics of the fog droplet field. The large range of high-speed fine fog produced by supersonic coaxial atomization technology easily traps respirable dust, and the classification efficiency of PM0–2.5 reaches 90%. In this study, a new dynamic microfog dust trapping technique was proposed, and a new method of instantaneous sampling combined with a microscopic dispersion test was adopted to characterize the temporal and spatial distributions of dust fields affected by fog droplet fields, reveal the generation of dynamic microfog and the mechanism of dust trapping, enrich the theory of fine dust trapping, and provide technical support for the safe production and utilization of coal.

Point-of-use filtration units as drinking water distribution system sentinels

Municipal drinking water distribution systems (DWDSs) and associated premise plumbing (PP) systems are vulnerable to proliferation of opportunistic pathogens, even when chemical disinfection residuals are present, thus presenting a public health risk. Monitoring the structure of microbial communities of drinking water is challenging because of limited continuous access to faucets, pipes, and storage tanks. We propose a scalable household sampling method, which uses spent activated carbon and reverse osmosis (RO) membrane point-of-use (POU) filters to evaluate mid- to long-term occurrence of microorganisms in PP systems that are relevant to consumer exposure. As a proof of concept, POU filter microbiomes were collected from four different locations and analyzed with 16S rRNA gene amplicon sequencing. The analyses revealed distinct microbial communities, with occasional detection of potential pathogens. The findings highlight the importance of local, and if possible, continuous monitoring within and across distribution systems. The continuous operation of POU filters offers an advantage in capturing species that may be missed by instantaneous sampling methods. We suggest that water utilities, public institutions, and regulatory agencies take advantage of end-of-life POU filters for microbial monitoring. This approach can be easily implemented to ensure drinking water safety, especially from microbes of emerging concerns; e.g., pathogenic Legionella and Mycobacterium species.

Stream chemical response is mediated by hydrologic connectivity and fire severity in a Pacific Northwest forest

AbstractLarge‐scale wildfires are becoming increasingly common in the wet forests of the Pacific Northwest (USA), with predicted increases in fire prevalence under future climate scenarios. Wildfires can alter streamflow response to precipitation and mobilize water quality constituents, which pose a risk to aquatic ecosystems and downstream drinking water treatment. Research often focuses on the impacts of high‐severity wildfires, with stream biogeochemical responses to low‐ and mixed‐severity fires often understudied, particularly during seasonal shifts in hydrologic connectivity between hillslopes and streams. We studied the impacts of the 2020 Holiday Farm Fire at the HJ Andrews Experimental Forest where rare pre‐fire stream discharge and chemistry data allowed us to evaluate the influence of mixed‐severity fire on stream water quantity and quality. Our research design focused on two well‐studied watersheds with low and low‐moderate burn severity where we examined long‐term data (pre‐ and post‐fire), and instantaneous grab samples collected during four rain events occurring immediately following wildfire and a prolonged dry summer. We analysed the impact of these rain events, which represent the transition from low‐to‐high hydrologic connectivity of the subsurface to the stream, on stream discharge and chemistry behaviour. Long‐term data revealed total annual flows and mean flows remained fairly consistent post‐fire, while small increases in baseflow were observed in the low‐moderately burned watershed. Stream water concentrations of nitrate, phosphate and sulfate significantly increased following fire, with variance in concentration increasing with fire severity. Our end member mixing models suggested that during rain events, the watershed with low‐moderate severity fire had greater streamflow inputs from soil water and groundwater during times of low connectivity compared to the watershed with low severity fire. Finally, differences in fire severity impacts on concentration‐discharge relationships of biogenic solutes were most expressed under low catchment connectivity conditions. Our study provides insights into post‐wildfire impacts to stream water quality, with the goal of informing future research on stream chemistry responses to low, moderate and mixed severity wildfire.

The Effects of Enrichment on Zoo-Housed Scarlet Ibis Behavior.

Good zoo animal welfare is commonly promoted with environmental enrichment; however, some species are less likely to be offered enrichment than others. This study tested the effect of enrichment on a group of scarlet ibises from Zoomarine Algarve, Portugal. The study consisted of a first baseline condition, followed by four types of enrichment displays with individual presentations, a post-enrichment condition, and a post-enrichment with all enrichment types presented simultaneously. The enrichment types chosen were physical, with a tidal simulation in the lakes of the enclosure; nutritional, presenting mussels in a plastic mesh tube; sensory, by playing scarlet ibises calls; and tactile, with brushes through the habitat. The data collection was performed for 21 days between January and March 2021, 3 times a day, using scan sampling and instantaneous time sampling every 2 min. The comparison between conditions revealed that most behaviors showed similarity between the baseline and post-enrichment conditions, suggesting that after removing the enrichment, the behaviors returned to their initial baseline. It was also found that each enrichment influenced different types of behaviors and these behaviors also changed depending on the time of day. Exploratory behavior was only associated with the presence of enrichment, and vocalizations were only heard after the sensory enrichment was performed. This study demonstrates that the use of physical and tactile enrichments increased activity and decreased stationary behaviors in this group of ibises and may be used to improve their lives in zoological contexts if included in the housing and husbandry protocols.

Volatile gas scavenging in the paediatric intensive care unit: Occupational health and safety assessment.

The use of volatile anesthetic agents in the paediatric intensive care unit (PICU) is experiencing increased interest since the availability of the miniature vapourizing device. However, the effectiveness of scavenging systems in the presence of humidifiers in the ventilator circuit is unknown. We performed a bench study to evaluate the effectiveness of the Deltasorb® scavenging system in the presence of isoflurane and active humidity by simulating both infant and child ventilator test settings. A total of four ventilators were set to ventilate test lungs, all with active humidity and a Deltasorb scavenging canister collecting exhaled ventilation gas. Two ventilators also had isoflurane delivered using the Anesthesia Conserving Device- small (ACD®-S) on the inspiratory limb (also called alternative ventilator configuration). We performed instantaneous measurements of isoflurane and continuous sampling with passive badges to measure average environmental exposure over a test period of 6.5 hours. Scavenging canisters were returned to the company, where desorption analysis showed the volume of water and isoflurane captured in each canister. Both instantaneous point sampling and diffusive sampling results were below the occupational exposure limit confirming safety. The canisters collected both isoflurane and a portion of the water vapour delivered; the percentage of captured water and isoflurane collected in infants was higher than the child ventilator test settings. The tested scavenging configuration was effective in maintaining a safe working environment with active humidity and inspiratory limb (alternative) ventilator configuration of the the miniature vapourizing device.

Mix it—cograzing with cattle reduces broiler losses and increases broiler range use

Pasture access allows broilers to perform a wide range of behaviors and is a prerequisite in organic poultry production, but exposes broilers to various potential hazards including predators. Co-grazing broilers with cattle can reduce land use and could offer protection from avian predation. Thus, we aimed to assess the effects of co-grazing on broiler losses, range use, performance, contact dermatitis and broilers’ manipulation of cow pats. To this end, across 5 replicates we compared each a treatment group of 54 to 61 broilers co-grazing with 10 young cattle and a similar sized control group of broilers on a pasture which had been grazed by cattle 2 weeks prior. Broilers had pasture access during civil daylight and were locked in the coop overnight. Continuous video recordings of the pastures were used to identify the cause when broilers were missing or found dead. On 2 days per week in 4 replicates, broiler distribution in the pasture and maintenance behaviour (i.e. foraging, standing, lying, locomotion) were observed directly using instantaneous scan sampling. Based on the broilers’ distance to the coop we calculated a group Ranging Distance Index (RDI). Cow pats were assessed weekly and contact dermatitis was scored before slaughter. Broilers in the treatment groups ranged further (p = 0.003) and higher percentages of birds tended to be outside (p = 0.09) compared to the control groups. Broiler losses due to predatory birds were consistently lower in treatment (median, range: 1, 0 to 3) than in control groups (3, 2 to 5, p = 0.025). Live weight before slaughter was slightly higher (p = 0.035) in treatment groups than in control groups. Feed conversion ratio (p = 0.174), maintenance behaviors and prevalence of contact dermatitis were not affected. No manipulation of cow pats by broilers was found or observed. Overall, co-grazing with cattle positively affected broiler range use, losses due to avian predation and weight gain.

Measuring rainfall using microwave links: the influence of temporal sampling

Abstract. Terrestrial microwave links are increasingly being used to estimate path-averaged precipitation by determining the attenuation caused by rainfall along the link path, mostly with commercial microwave links from cellular telecommunication networks. However, the temporal resolution of these rainfall estimates and the method to derive them are often determined by the temporal sampling strategy that is employed by the mobile network operators. Currently, the links are most often sampled at a temporal resolution of 15 min with a recording of the minimum and maximum values, while more recently, a form of instantaneous sampling with possible intervals up to 1 s has also been set up. For rainfall research purposes, often high temporal resolutions in combination with averaged values are preferred. However, it is uncertain how these various temporal sampling strategies affect the estimated rainfall intensity. Here we aim to understand how temporal sampling strategies affect the measured rainfall intensities using microwave links. To do so, we use data from three collocated microwave links, two 38 GHz and one 26 GHz, sampled at 20 Hz and covering a 2.2 km path over the city of Wageningen, the Netherlands. We aggregate the microwave link power levels to multiple time intervals (1 s to 60 min) and use a mean, instantaneous, and minimum and maximum value to characterize the signal. Based on the aggregated data, we compute rainfall intensities and compare these with 20 Hz rainfall estimates, such that we isolate errors and uncertainties caused by the sampling strategies from instrumental effects, such as different biases between instruments and representativeness errors. In general, our results show that for all sampling strategies, an increase in sampling time interval reduces the performance of the rainfall estimates, which especially holds for the instantaneous sampling strategy. Even the mean sampling strategy, which generally performs best of all strategies, is sensitive to this reduction in temporal resolution and could lead to significant underestimations. This sensitivity of the mean sampling to the temporal resolution seems to be largely affected by the non-linear relation between attenuation and rainfall. The min–max sampling strategy is mostly prone to minor underestimations or large overestimations of the path-averaged rainfall intensities. Moreover, our results, including a comparison with theoretical events, show that the attenuation due to wet antennas not only affects the comparison between the rainfall estimates obtained with a microwave link and another reference instrument but also has a significant influence on the performance of the rainfall retrieval algorithm, especially for devices with relatively long duration of the wet-antenna attenuation combined with the longer sampling time intervals. Overall, this study demonstrates the effect a selected sampling strategy can have on rainfall intensity estimates using (commercial) microwave links.

Effect of a Cat's Permanent Presence on the Health and Social Network of Older Adults With Alzheimer's Disease or Disabilities in a Nursing Home.

Our study analyzes the effects of the permanent presence of cats on the health and social network of residents with pathologies in nursing home. Fifty-three residents, thirty-six caregivers, and four cats in three Alzheimer's Disease units ("ADU") and one Disability unit ("DISU") were observed for 180 hours. Social networks were created via instantaneous sampling of physical proximities and social exchanges between residents, caregivers, and the cats. Our results showed that: (1) the four units behave similarly in the presence or absence of a cat (2) cats are placed at the periphery of the network and interact with residents showing a keen interest in them, and (3) caregivers who are in strong contact with the cat show a greater number of social interactions in their unit. This study, using for the first time a social network approach, opens up a new field of understanding of human-animal relationships in a care dimension.

210 Sleeping beauties: A daily time budget for individually housed research pigs at 6-d of age

Abstract The pre-wean period of development is difficult to manage and can impact the success of subsequent production stages. Behavior observations can provide insight into the health and welfare status of animals and allow for efficient and timely management interventions. A validated time budget can be utilized as a baseline for further comparisons and the detection of changes in behavior over time. In this project, 24-h of video data for 21 individually housed research pigs at 6 d of age was evaluated using a validated behavior ethogram. The behavior ethogram contained 5 main categories (inactive, consumption, exploratory, social, and other) and 23 behavior labels. The ethogram was applied using a validated sampling strategy, which included 5-min continuous sampling intervals at the start of each hour for active behaviors and 5-min instantaneous sampling intervals for inactive behaviors. The data from each behavior observation was quantified into durations and presented as percentage of observations spent performing a specific behavior label within the observation period. The daily time budget revealed the following time occupation across the 5 main behavior categories: inactive, 98.60% (lying, 85.43%; not lying, 13.14%); consumption, 0.30%; exploratory, 0.97%; social, 0.01%, and other, 0.12%. As expected for very young pigs, most of the day was inactive, with almost 21 h lying. The most performed behavior was “lying socially”, and this behavior represented 38.48% of the overall daily time budget. The remaining 46.95% of time spent lying was spent “lying sternal”, “lying lateral”, or “lying on an object” in the pen. The pigs are housed individually, but they are able to see, hear, and smell a neighboring pig through a plexiglass barrier. The behavior observation “lying socially” is defined as follows: “The piglet is lying (sternal or lateral) touching the plexiglass barrier. The piglet in the adjacent pen is lying directly on the other side of the barrier, and the piglets would be touching each other if the barrier was not in place.” This observation provides insight into the importance of social resting for young pigs.

Passive eDNA sampling facilitates biodiversity monitoring and rare species detection

Environmental DNA (eDNA) technology has revolutionized biomonitoring, but challenges remain regarding water sample processing. The passive eDNA sampler (PEDS) represents a viable alternative to active, water filtration-based eDNA enrichment methods, but the effectiveness of PEDS for surveying biodiverse and complex natural water bodies is unknown. Here, we collected eDNA using filtration and glass fiber filter-based PEDS (submerged in water for 1 d) from 27 sites along the final reach of the Yangtze River and the coast of the Yellow Sea, followed by eDNA metabarcoding analysis of fish biodiversity and quantitative PCR (qPCR) for a critically endangered aquatic mammal, the Yangtze finless porpoise. We ultimately detected 98 fish species via eDNA metabarcoding. Both eDNA sampling methods captured comparable local species richness and revealed largely similar spatial variation in fish assemblages and community partitions between the river and sea sites. Notably, the Yangtze finless porpoise was detected only in the metabarcoding of eDNA collected by PEDS at five sites. Also, species-specific qPCR revealed that the PEDS captured porpoise eDNA at more sites (7 vs. 2), in greater quantities, and with a higher detection probability (0.803 vs. 0.407) than did filtration. Our results demonstrate the capacity of PEDS for surveying fish biodiversity, and support that continuous eDNA collection by PEDS can be more effective than instantaneous water sampling at capturing low abundance and ephemeral species in natural waters. Thus, the PEDS approach can facilitate more efficient and convenient eDNA-based biodiversity surveillance and rare species detection.

A Eulerian Monte Carlo method for the numerical solution of the multivariate population balance equation

Statistical descriptions of particulate phases and granular media based on the notion of a property distribution are particularly advantageous for dense, many-particle dispersions since they support the direct evaluation of Eulerian property statistics, permit a kinematically simple treatment of particle collisions and feature a model complexity that is independent of the number of physical particles. On the minus side, the property distribution is governed by a high-dimensional population balance equation (PBE) whose moment reduction is accompanied by a challenging closure problem and engenders intricate dynamical nonlinearities. Circumventing both the curse of dimensionality and the moment closure problem, we present a Eulerian Monte Carlo (EMC) solution method that harnesses a representation of the property distribution in terms of an ensemble of property samples and is based on a statistical enforcement of the spatially and temporally discretized PBE. After application of a kinetic finite volume scheme, the PBE is subjected to a fractional steps decomposition that separates spatial transport from transport in property space. Conceptually, spatial transport is emulated by assembling the ensemble in one spatial grid cell from samples drawn from the ensembles in neighbouring cells at the previous time point. In this regard, we propose a two-level sampling scheme that is sensitive to large-scale features of the marginal velocity distribution and effectively reduces the instantaneous sampling error. The property transport step, by contrast, is based on the method of characteristics and involves the propagation of individual samples as property characteristics in time. While the sampling error afflicting the property statistics needs to be controlled using a top-level time or ensemble averaging, the EMC method remains well-conditioned for an arbitrary number of samples, is easy to implement and involves a computational expense that scales only linearly with the number of particle properties. Based on two benchmark examples, we analyze the spatial and statistical convergence properties of the EMC method and demonstrate its capacity to capture multiple crossings of particle trajectories. A third example involves the two-way coupled transport of size-polydispersed inertial particles in an inhomogeneous flow field.

Investigation of organic micropollutant pollution in İzmit Bay: a comparative study of passive sampling and instantaneous sampling techniques.

In this study, we used a comprehensive array of sampling techniques to examine the pollution caused by organic micropollutants in İzmit Bay for the first time. Our methodology contains spot seawater sampling, semi-permeable membrane devices (SPMDs) passive samplers for time-weighted average (TWA), and sediment sampling for long-term pollution detection in İzmit Bay, together. Additionally, the analysis results obtained with these three sampling methods were compared in this study. Over the course of two seasons in 2020 and 2021, we deployed SPMDs for 21days in the first season and for 30days in the second season. This innovative approach allowed us to gather sea water samples and analyze them for the presence of polycyclic aromatic hydrocarbons (Σ15 PAHs), polychlorinated biphenyls (Σ7 PCBs), and organochlorine pesticides (Σ11 OCPs). Using SPMD-based passive sampling, we measured micropollutant concentrations: PAHs ranged from 1963 to 10342pg/L in 2020 and 1338 to 6373pg/L in 2021; PCBs from 17.46 to 61.90pg/L in 2020 and 8.37 to 78.10pg/L in 2021; and OCPs from 269.2 to 8868pg/L in 2020 and 141.7 to 1662pg/L in 2021. Our findings revealed parallels between the concentrations of PAHs, PCBs, and OCPs in both SPMDs and sediment samples, providing insights into the distribution patterns of these pollutants in the marine ecosystem. However, it is worth noting that due to limited data acquisition, the suitability of spot sampling in comparison to instantaneous sampling remains inconclusive, highlighting the need for further investigation and data collection.

Feeding adaptation of François' langurs (Trachypithecus francoisi) to the fragmented limestone habitats in Southwest China.

Limestone forests are an unusual habitat for primates, especially fragmented limestone habitats. However, while some research has been conducted on François' langurs (Trachypithecus francois) in these habitats, there is still a need to improve the understanding of their behavioral adaptations to the fragmented limestone habitat. We collected data on the diet of François' langurs in a fragmented limestone habitat in Encheng National Nature Reserve, southwestern Guangxi, China using instantaneous scanning sampling, and their feeding adaptations to the fragmented forest were examined. The results indicated that a total of 101 species of plants were consumed by the langurs. They also fed on two non-plant components, including cliff minerals and at least one species of insect. The langurs ate a higher number of food species in Encheng when compared with the other geographic populations, and they maintained a high level of food diversity and ate more vines. Moreover, they were highly selective in their use of vegetation in their home range, and fewer plants provided a high-quality food source. During the season when food resources were scarce, the consumption of fruits and young leaves decreased as their availability decreased. This led to the use of other food components, such as mature leaves and seeds. The findings support that François' langurs adjust their feeding behavior to cope with seasonal and micro-variations in their dietary requirements and to adapt to their particular environment.