Typical Setting Research Articles

Source identification and health risk assessments of heavy metals in indoor dusts of Ilorin, North central Nigeria.

Exposure to heavy metals (HMs) in indoor dusts is a serious public concern that is linked to a myriad of deleterious health outcomes. The objectives of this study are to estimate the contamination levels of HMs in indoor dusts of different residential areas in Ilorin, Nigeria; identify HMs sources in different residential areas; and evaluate human health risks of HMs in selected residential areas. Indoor dust sampling was conducted in ten randomly selected from low, medium and high population density residential areas of Ilorin, Nigeria. Ten HMs concentration levels, their health risk implication and the associated potential ecological risks were evaluated. The mean concentration levels measured for Fe, Pb, Zn, As, Co, Cr, Cu, Cd, Mn and Ni were 38.99, 5.74, 3.99, 0.08, 2.82, 2.13, 0.47, 0.60, 6.45 and 1.09mg/kg, respectively. Positive Matrix Factorization (PMF) model was applied to ascertain sources of HMs in sampled indoor dust. Percentage contribution from oil-based cooking (29.82%) and transportation (29.77%) represented the highest source to HM concentrations among the six factors identified. The results of the various pollution indices employed showed that Pb, Zn, As, Co, Cr, Cu, Mn and Ni contributed moderately to HMs concentration levels in the sampled dusts. Cd had highest potential ecological risk factor of between 160 and 320. The average values of Enrichment Factors (EFs) obtained aside from Fe used as the reference metal, ranged between 8.46 (As) and 2521.61(Cd). Health risk assessment results revealed that children are the most susceptible to the risks associated with HMs bound indoor dust than the adults. The percentage risk contributions of Hazard Quotient via ingestion route (HQing) in Hazard Index (HI) for non-cancer risk of indoor HMs were 93.17% and 69.87% in children and adults, respectively. Likewise, the percentage cancer risks contribution through ingestion pathway (CRing) were higher than cancer risks through inhalation and dermal pathways (CRinh and CRdermal), accounting for 99.84% and 97.04% of lifetime cancer risk in children and adults, respectively. The contamination level of Cd recorded is of great concern and signifies very strong contribution from anthropogenic sources. This study has further revealed the levels of HMs in typical African residential settings that could be used by relevant stakeholders and policy makers in developing lasting control measures. The online version contains supplementary material available at 10.1007/s40201-021-00778-8.

No party, no drugs? Use of stimulants, dissociative drugs, and GHB/GBL during the early COVID-19 pandemic.

BackgroundThe COVID-19 pandemic is presumably having an impact on the consumption of psychoactive substances. Social distancing and lockdown measures may particularly affect the use of “party drugs” (e.g., stimulants, dissociatives, and GHB/GBL) through the absence of typical use settings. We aimed to analyse the use patterns of those substances and underlying motivations before and during the pandemic.MethodsA subsample of 1,231 users of stimulants (amphetamine, methamphetamine, MDMA/ecstasy, cocaine), dissociative drugs (ketamine, dextromethorphan, PCP), and GHB/GBL was assessed from 30th April to 4th August 2020 as part of the Corona Drug Survey, a cross-sectional international online survey in five languages that included a total of 5,049 participants. The reported use of distinct substances and the underlying motivations were ascertained before (retrospectively) and during the pandemic. Furthermore, associations between drug use as a coping mechanism, pandemic-related stressors, and substance use were examined.ResultsRegarding the reported frequency of use during the pandemic, 48.0–64.8% of the sample ceased or decreased, 11.9–25.5% maintained, and 23.6–29.1% increased their consumption. MDMA/ecstasy showed the strongest decrease and GHB/GBL and dissociatives the highest increase. Participants reported that price, quality, and supply were mostly unaffected by the pandemic. The most common motivations before and during the pandemic were mood-related factors, such as a desire to feel exhilarated, euphoric, high, or buzzed. The relevance of social purposes and mood-related motivators declined during the pandemic, whereas dealing with boredom increased. Overall, 16.4–35.6% perceived drug use as helpful for dealing with pandemic-related stressors, which were associated with an increased consumption frequency.ConclusionThe early stage of the COVID-19 pandemic was associated with major changes in the use of “party drugs”. Those who increased their level of drug use and perceived it as a coping strategy in particular might be targeted with adaptive preventive and therapeutic measures.

Sign and Spoken Language Processing Differences in the Brain: A Brief Review of Recent Research.

Background:It is currently accepted that sign languages and spoken languages have significant processing commonalities. The evidence supporting this often merely investigates frontotemporal pathways, perisylvian language areas, hemispheric lateralization, and event-related potentials in typical settings. However, recent evidence has explored beyond this and uncovered numerous modality-dependent processing differences between sign languages and spoken languages by accounting for confounds that previously invalidated processing comparisons and by delving into the specific conditions in which they arise. However, these processing differences are often shallowly dismissed as unspecific to language.Summary:This review examined recent neuroscientific evidence for processing differences between sign and spoken language modalities and the arguments against these differences’ importance. Key distinctions exist in the topography of the left anterior negativity (LAN) and with modulations of event-related potential (ERP) components like the N400. There is also differential activation of typical spoken language processing areas, such as the conditional role of the temporal areas in sign language (SL) processing. Importantly, sign language processing uniquely recruits parietal areas for processing phonology and syntax and requires the mapping of spatial information to internal representations. Additionally, modality-specific feedback mechanisms distinctively involve proprioceptive post-output monitoring in sign languages, contrary to spoken languages’ auditory and visual feedback mechanisms. The only study to find ERP differences post-production revealed earlier lexical access in sign than spoken languages. Themes of temporality, the validity of an analogous anatomical mechanisms viewpoint, and the comprehensiveness of current language models were also discussed to suggest improvements for future research.Key message:Current neuroscience evidence suggests various ways in which processing differs between sign and spoken language modalities that extend beyond simple differences between languages. Consideration and further exploration of these differences will be integral in developing a more comprehensive view of language in the brain.

Research on Design and Management of Community-Based Ecotourism Model in Aksu-Zhabagly Nature Reserve of Kazakhstan

This study investigates the community-based ecotourism (CBE) model using a sample of the Aksu-Zhabagly nature reserve (NR). The aim is to propose a suitable CBE model for Aksu-Zhabgly nature-based tourism destinations by employing a combination of field observation, examination, evaluation, and SWOT analysis. The study determines the strategic suggestions for CBE model designing by the results of SWOT analysis. It concludes that convenient transportation and superior location, diversified wild animals and plants, rich in ethnocultural resources, traditional and tranquil life in a typical rural setting, hospitality and positive attitude of locals to tourism and great potential of the region for sustainable development of ecotourism are the strengths. At the same time, the far residential location from the provincial cities, low-quality service, outdated facilities and shortage of skilled employees in tourism management are the main weakness. Another group of constraints to tourism development is lack of tourism marketing and promotion agencies, lack of transparency, poor institution arrangement and corruption, and lack of preferential policies for CBE development. Finally, the paper recommends that economic development, environmental protection, culture and heritage, marketing and image, favorable political environment, and local residents’ empowerment are the main essential to effectively implement the sustainable development of CBE in the Aksu-Zhabagly tourist destination.

Parkinson’s Disease Detection Using Smartphone Recorded Phonemes in Real World Conditions

Parkinson’s disease (PD) is a multi-symptom neurodegenerative disease. There are no biomarkers; the diagnosis and monitoring of the disease progression require clinical and functional symptom observation. Voice impairment is an early symptom of PD, and computerized analysis of voice has been proposed for early detection and monitoring of the disease. However, there is poor reproducibility of many studies, which is attributed to the experimental data having been collected under controlled conditions. To overcome the limitations of earlier works, this study has investigated three sustained phonemes: /a/, /o/, and /m/, which were recorded using an iOS-based smartphone from 72 participants (36 people with PD and 36 healthy) in a typical clinical setting. A number of signal features were obtained, statistically investigated, and ranked to identify the suitable feature sets. These were classified using machine learning models. The results show that a combination of phonemes /a/+/o/+/m/ was most suited to differentiate the voice of PD people from healthy control participants, with an average accuracy, sensitivity, and specificity of 100%, 100%, 100%, respectively, using leave-one-out validation. The findings of this study could assist in the clinical assessments and remote telehealth monitoring for people with parkinsonian dysarthria using smartphones.

Modular Framework for Constructing IoT-Server AKE in Post-Quantum Setting

Authenticated key exchange (AKE) allows two parties to authenticate each other and establish a secret session key to build a secure channel, and it has been well studied in the literature. With the approaching of quantum computers, designing post-quantum secure AKE schemes becomes an urgent task. Today, several KE schemes have been proposed while only a small number of AKE schemes exist. Very few of them have considered resource-constrained participants like IoT devices. In this paper, assuming a typical client-server setting where the client is an IoT device, we propose a modular framework that converts any post-quantum secure KE scheme into a post-quantum secure AKE scheme. Equipped with two authentication factors, the resulted AKE scheme provides a number of security guarantees including Perfect forward secrecy (PFS), Key compromise impersonation (KCI) resilience and Server compromise impersonation (SCI) resilience. We further instantiate the framework by selecting the most efficient KE scheme, namely NewHope Compact, and implement the scheme with some optimisation techniques and conduct relevant analysis and comparisons. In a nutshell, the computational time of the server side is 1.11 ms on a PC and 6.22 ms of the IoT device simulated on Raspberry Pi 3B+, and it seems to be efficient enough for most IoT application scenarios.

Probability, adaptability and time: some research-practice paradoxes in supply chain resilience and viability modelling

Modelling of resilience and viability became crucial and visible research avenues for decision-making support in case of supply chain disruptions. This article discusses some research-practice paradoxes stemming from typical problem settings and assumptions in supply chain resilience and viability modelling. We show that the categories of probability, adaptability, and time are major determinants of resilience and viability modelling in supply chains. As an example, we discuss how probability-based supply chain design models can be enhanced through inclusion of adaptability and connectivity characteristics of the network elements with consideration of time. We deduce some open questions the elaboration on which can provide novel and substantial contributions in future. In particular, we stress the importance of furthering our understanding of reliable suppliers, disruption probabilities, disruption time and ripple effect estimation, value-creation perspective of resilience, and viability of intertwined supply networks.

Using a condom or glove to improve pelvic exam visualization: A guide.

Pelvic exams are a cornerstone of gynecological care, necessary for both regular screenings and diagnostics. The collapse of lateral vaginal walls during a pelvic exam is a frequently encountered problem in clinical practice. Practitioners often utilize tools found in a typical clinical setting to counter this issue, such as a condom or glove over the speculum to prevent the lateral vaginal walls collapsing inward and obscuring cervical views. These techniques have been passed down from mentor to mentee over the years, though scarcely described in literature. This article aims to provide instructions on how to use these two methods in clinical practice to improve pelvic exams for the practitioner and the patient. Utilizing a condom or glove to prevent lateral vaginal wall collapse has the potential to improve pelvic exams for both practitioners and patients.

Adaptive Computation Offloading for Mobile Augmented Reality

Augmented reality (AR) underpins many emerging mobile applications, but it increasingly requires more computation power for better machine understanding and user experience. While computation offloading promises a solution for high-quality and interactive mobile AR, existing methods work best for high-definition videos but cannot meet the real-time requirement for emerging 4K videos due to the long uploading latency. We introduce ACTOR, a novel computation-offloading framework for 4K mobile AR. To reduce the uploading latency, ACTOR dynamically and judiciously downscales the mobile video feed to be sent to the remote server. On the server-side, it leverages image super-resolution technology to scale back the received video so that high-quality object detection, tracking and rendering can be performed on the full 4K resolution. ACTOR employs machine learning to predict which of the downscaling resolutions and super-resolution configurations should be used, by taking into account the video content, server processing delay, and user expected latency. We evaluate ACTOR by applying it to over 2,000 4K video clips across two typical WiFi network settings. Extensive experimental results show that ACTOR consistently and significantly outperforms competitive methods for simultaneously meeting the latency and user-perceived video quality requirements.

The Tax Cuts and Jobs Act of 2017 and the Gig Economy: Why the Employee vs. Contractor Debate Matters More than Ever

The issue of whether workers are independent contractors or employees has become even more relevant with recently enacted and proposed legislation and court cases in many jurisdictions seeking to impose employee status on many Gig economy workforce participants, such as ride-share drivers. This article emphasizes that the U.S. income tax rules, especially after tax reform effective in 2018, makes employee status extremely tax-inefficient for these workers. This article explains the relevant tax law changes and provides various examples of typical settings to confirm that workers with even small relative work expenses are often better off as contractors from a tax point of view.

Engineering Management Model Towards Enhancing Institutional Based Workshop Facilities

This paper is focused on the use of technical personnel in the typical setting of a workshop in higher educational institutions in Nigeria. The essence is to fully manage tools for more creativity in technical work. The case study is focused on woodwork engineering management where vending cost analysis and implications model is presented to enhance productivity and reduction of requisition cost. So far, wood work refurbishing and repairs are being carried out with existing tools such as CNC-MDF Chain Saw Machine, and Automatic Edge Banding Machines respectively in quite a number of higher educational institutions in Nigeria. Now the trend has changed, more efficacious wood work requiring the production of durable stools and other furniture is needed. CNC works on the Cartesian coordinate system (X, Y, Z) for 3D motion control and parts of a project can be designed in the computer with a CAD/CAM program, and then cut automatically using cutters to produce a finished part. So these engineering trend has to be fully managed in such a way that the functionalities of these tools are fully harnessed to ensure full operations; particularly to produce for high-volume local content, skills acquisition and entrepreneurial development. The resultant effect will be to remove costly and repetitive manufacturing steps for office and other relevant furniture, and to create opportunities with future expansion for revenue generation. Keywords: Technical Personnel, Nigerian Higher Educational Institutions, Wood Work Engineering, Vending Analysis, Entrepreneurial Development, Computer Numerical Control Machines.

An efficient adversarial example generation algorithm based on an accelerated gradient iterative fast gradient

Most existing deep neural networks are susceptible to the influence of adversarial examples, which may cause them to output incorrect prediction results. An adversarial example is the addition of small noise disturbances to the input data samples, which will deceive the classification. Generally, these modifications are very small noise disturbances, which are not easily noticed by the human eye. However, most existing adversarial attacks achieve only low success rates in typical black-box settings, where the attackers have no prior knowledge about the model structures and/or model parameters. To tackle this problem, we propose an iterative algorithm based on an acceleration gradient to enhance the adversary attack. Our method accumulates the gradient of the loss function in each iteration and uses the next gradient information to influence the future gradient. We also introduce the scaling invariance principle of a deep neural network to optimize the input images for black-box attacks. In addition, to handle the drawbacks of a traditional iterative fast gradient sign method, we further present two gradient optimization methods. Experimental results on the ImageNet dataset show that our attack methods can achieve good transferability. In addition, those models obtained by integrated adversarial training with strong defense capability are also quite vulnerable to our black-box attack.

Extracorporeal lung support for tracheoesophageal fistula surgical repair with free flap

Tracheoesophageal fistula results in persistent leakage of saliva into the trachea, prevents oral feeding, and predisposes to aspiration pneumonia. Large fistula closure may require a free flap to cover the defect. When the defect involves the tracheal area between the neck and the mediastinum, a tubeless field for optimal exposure can be advantageous. This article reports the use of veno-venous extracorporeal lung support, a known safe and efficient technique to support the patient’s respiratory function, for this purpose. The typical veno-venous extracorporeal lung support setting includes a femoro-jugular bypass. The patient cases reported here had characteristics that precluded the use of the jugular vein, such as neck radiation dermatitis, previous radical neck dissection, and poor accessibility. Therefore a more rarely described femoro-femoral approach was used. The cases of three patients with persistent tracheoesophageal fistula who had free flap surgeries (two bi-paddled radial forearm free flap and one latissimus dorsi muscle free flap) assisted by femoro-femoral veno-venous extracorporeal lung support are reported.

Estimate and reporting of longevity for cardiac implantable electronic devices: a proposal for standardized criteria

ABSTRACT Background Cardiac implantable electronic devices (CIEDs) are widely used according to consensus guidelines in various patient categories. The longevity of CIED is a major determinant of the frequency with which patients require device replacement. Given the mismatch between the useful life of the devices and patient survival, device replacement is often needed. There is a great variability in the criteria used by manufacturers to determine the longevity of pacemakers (PM), implantable defibrillators (ICDs), and devices for cardiac resynchronization therapy (CRT). Thus, a fair comparison and an effective device evaluation is often difficult. Methods The objective of this paper is to provide standardized criteria based on typical clinical settings for estimating the longevity of single and dual chamber ICDs, cardiac resynchronization defibrillators (CRT-D), single and dual chamber PMs, and cardiac resynchronization PMs (CRT- P) to be used in health technology assessment for an appropriate comparison among different devices. Results The proposed parameters, if applied to the current marketed devices, provide longevity values in the range 5–17.2 years. Conclusion The values of longevity with the non-standardized criteria used by the manufacturers result in higher maximum values respect to the proposed standardized criteria for CRT-D, CRTD-MPP, CRT-P, and Dual-chamber PM.

Exploring safety-related behaviours of e-cyclists on urban streets; an observational study

E-bikes provide a potential for improving sustainable urban mobility. However, there are concerns of e-cycling related injury. In this study, observational surveys of e-bikes were conducted in Israeli cities to explore their presence and safety-related behaviours, at typical urban settings. The results showed that e-bike presence in urban traffic was similar to that of regular bicycles. Mean speeds of e-cyclists were higher than those of regular cyclists, by 5 km/h, on average, but were lower on sidewalks. E-bikes moved slower than vehicles on roadways but were faster than pedestrians on sidewalks. At intersections, 20% of e-cyclists crossed on red. In general, the study showed a mixed use of urban facilities by e-bikes, with heterogeneous traffic both on vehicle and pedestrian settings and multiple risk factors. For a safer integration of e-bikes in Israeli cities, a wider application of cycling infrastructure, with separation from sidewalks and roadways, is needed.

Coulomb threshold rate-and-state model for fault reactivation: application to induced seismicity at Groningen

SUMMARY A number of recent modelling studies of induced seismicity have used the 1994 rate-and-state friction model of Dieterich 1994 to account for the fact that earthquake nucleation is not instantaneous. Notably, the model assumes a population of seismic sources accelerating towards instability with a distribution of initial slip speeds such that they would produce earthquakes steadily in the absence of any perturbation to the system. This assumption may not be valid in typical intraplate settings where most examples of induced seismicity occur, since these regions have low stressing rates and initially low seismic activity. The goal of this paper is twofold. First, to derive a revised Coulomb rate-and-state model, which takes into account that seismic sources can be initially far from instability. Second, to apply and test this new model, called the Threshold rate-and-state model, on the induced seismicity of the Groningen gas field in the Netherlands. Stress changes are calculated based on a model of reservoir compaction since the onset of gas production. We next compare the seismicity predicted by our threshold model and Dieterich’s model with the observations. The two models yields comparable spatial distributions of earthquakes in good agreement with the observations. We find however that the Threshold model provides a better fit to the observed time-varying seismicity rate than Dieterich’s model, and reproduces better the onset, peak and decline of the observed seismicity rate. We compute the maximum magnitude expected for each model given the Gutenberg–Richter distribution and compare to the observations. We find that the Threshold model both shows better agreement with the observed maximum magnitude and provides result consistent with lack of observed seismicity prior to 1993. We carry out analysis of the model fit using a Chi-squared reduced statistics and find that the model fit is dramatically improved by smoothing the seismicity rate. We interpret this finding as possibly suggesting an influence of source interactions, or clustering, on a long timescale of about 3–5 yr.

A tale of two signals: Global and local influences on the Late Pleistocene loess sequences in Bulgarian Lower Danube

In Central and Eastern Europe, research has been focused on loess associated with a plateau-setting, which preserves distinct and well-developed loess and palaeosol units linked to orbital scale changes. This has led to the view that during the last glacial period the Middle and Lower Danube predominantly experienced dry continental climates and supported steppic environments. However outside of the typical plateau setting, some authors have reported a presence of embryonic palaeosols within loess units suggesting sufficient moisture for short-term pedogenesis, and therefore either large scale moisture delivery systems and/or influence of local climatic and/geomorphic factors. Here the palaeoenvironmental and palaeoclimatic history is reconstructed based on two loess-palaeosol profiles in Slivata, North Bulgaria. The site is located in proximity to both the Carpathian and Balkan Mountains and rest on the Danube river terrace. To understand the timing of sediment deposition and dust fluxes chronological approaches combining quartz optically stimulated luminescence (OSL), feldspar post infrared-infrared stimulated luminescence (pIR-IRSL), and tephra correlation were applied. The results are coupled with high-resolution particle size and magnetic susceptibility analysis to provide an overview of past environmental conditions at the site. Finally, zircon U–Pb ages are used to understand potential changes to sediment delivery patterns, in the context of the site development.The investigated profile at Slivata 2 preserves a loess-palaeosol record spanning 52–30 ka, with a very complex sedimentary sequence that switches between periods of enhanced dust flux and sediment accumulation, and palaeosol development. The Slivata 2 sequence is also punctuated by multiple thin “palaeosol” like units that are interpreted as colluvial “soil” deposits on the basis of sedimentology, provenance, and geochronology, indicating a highly variable and dynamic landscape responding to the surrounding environment. The chronology shows very rapid sediment accumulation at Slivata 1 during LGM, with mass accumulation rates similar to sites in the Carpathian Basin, suggesting strong winds and high sediment supply rates. Yet LGM loess is punctuated by a thin palaeosol, which developed between 20–19 ka. This coincides with a temporary glacial retreat in the Carpathian Mountains and higher moisture availability in Eastern Carpathians, and therefore points to localised influences on loess-palaeosol development. Moreover data from Slivata 1 shows soil development and by extension landscape and climate stabilisation shortly prior to 14 ka. The pre-Holocene onset of pedogenesis at Slivata supports ecological and glacial evidence of weak Younger Dryas from the South Carpathian Mountains.Lastly this paper provides a geochemical analysis of the thin tephra horizon preserved in the Slivata 2 profile, which was correlated to the Cape Riva/Y-2 tephra. Consequently Slivata is the most northerly terrestrial site found to contain this tephra horizon, which has implications for the understanding of the size of the Santorini's Cape-Riva/Y-2 explosion. The identification of the Cape Riva (Y-2) tephra horizon and new remodelled age of 21.92 ± 0.56 cal ka BP provides a new tephrostratigraphic marker for eastern European LGM loess.

Dynamic transitions and bifurcations of 1D reaction–diffusion equations: The self‐adjoint case

This paper deals with the classification of transition phenomena in the most basic dissipative system possible, namely, the 1D reaction–diffusion equation. The emphasis is on the relation between the linear and nonlinear terms and the effect of the boundaries which influence the first transitions. We consider the cases where the linear part is self‐adjoint with second‐order and fourth‐order derivatives which is the case which most often arises in applications. We assume that the nonlinear term depends on the unknown function and its first derivative which is basically the semilinear case for the second‐order reaction–diffusion system. As for the boundary conditions, we consider the typical Dirichlet, Neumann, and periodic boundary settings. In all the cases, the equations admit a trivial steady state which loses stability at a critical parameter. We aim to classify all possible transitions and bifurcations that take place. Our analysis shows that these systems display all three types of transitions: continuous, jump and mixed. Moreover they exhibit transcritical, supercritical bifurcations with bifurcated states such as finitely many equilibria, circle of equilibria, and slowly rotating limit cycle. Many applications found in the literature are basically corollaries of our main results. We apply our results to classify the first transitions of the Chaffee–Infante equation, the Fisher‐KPP equation, the Kuramoto–Sivashinsky equation, and the Swift–Hohenberg equation.

Investigation of thermal comfort of room air conditioner during heating season

The main factors affecting field thermal comfort of convective terminals during the heating season have been widely studied in recent years. Since previous studies were conducted separately, this investigation aimed to analyze the thermal comfort under typical settings and integrated control strategies. A questionnaire, based on a field operation, was conducted to compare and find the main characteristics of different terminals. The contradiction of draft and vertical temperature difference and the continuous/intermittent feature control were the key factors investigated. The indoor environment distribution under different conditions was measured in laboratory cabins based on the different settings and control strategies of convective terminals. The thermal sensation vote (TSV) and thermal comfort vote (TCV) were conducted in an artificial chamber to show the characteristics of an indoor environment under different conditions. The results showed that people were more tolerant of drafting than vertical temperature differences (the TCV score decreased from 0.44 to 1.42 with different temperature non-uniformity and airspeed). In particular, the subjects’ perceived control significantly reduced the risk of discomfort. In addition, there was no significant difference between the different control strategies, including continuous operation and intermittent operation, except for a long-term control shutdown. The TCV result was 0.48 in the on-off control with a 5-min shutdown, showing statistical significance in paired-sample t-tests (p < 0.05).

Seasonality of enteric viruses in groundwater-derived public water sources

We investigated the seasonal prevalence of seven enteric viruses in groundwater-derived public water sources distributed across the dominant aquifers of England. Sampling targeted four periods in the hydrological cycle with typically varying microbial risks, as indicated using a decade of Escherichia coli prevalence data. Viruses were concentrated onsite by filtration of raw groundwater, and extracted nucleic acid (NA) was amplified by qPCR or RT-qPCR. Seven out of eight sources, all aquifers, and 31% of samples were positive for viral NA. The most frequently detected viral NA targets were Hepatitis A virus (17% samples, 63% sites), norovirus GI (14% samples, 38% sites), and Hepatitis E virus (7% samples, 25% sites). Viral NA presence was episodic, being most prevalent and at its highest concentration during November and January, the main groundwater recharge season, with 89% of all positive detects occurring during a rising water table. Seasonal norovirus NA detections matched its seasonal incidence within the population. Viral NA is arriving with groundwater recharge, as opposed to persisting for long-periods within the saturated zone. Neither total coliforms nor E. coli were significant predictors of viral NA presence-absence, and there was limited co-occurrence between viruses. Nevertheless, a source with an absence of E. coli in regularly collected historical data is unlikely to be at risk of viral contamination. To manage potential groundwater viral contamination via risk assessment, larger scale studies are required to understand key risk factors, with the evidence here suggesting viral NA is widespread across a range of typical microbial risk settings.