Remote Sites Research Articles

Partial and cost-minimized computation offloading in hybrid edge and cloud systems

Nowadays, numerous mobile devices (MDs) provide nearly anytime and anywhere services, running on top of various computation-intensive applications. However, bearing limited battery, bandwidth, computing, and storage resources, MDs cannot completely execute all tasks of such applications in real-time. Cloud data centers (CDCs) possess enormous resources and energy, which can help execute tasks offloaded from MDs. Nonetheless, CDCs reside in remote sites, thereby leading to long transmission latency. In recent years, small base stations (SBSs) have emerged to offer close proximity, high bandwidth, and low latency services to their nearby and limited MDs. However, it becomes a new challenge to minimize the total system cost in a complex and heterogeneous architecture. To address it, this work proposes an energy-minimized partial computation offloading technique. First, a limited optimization problem of cost minimization for the system is formulated. Afterward, an improved hybrid meta-heuristic algorithm is developed, which synergistically combines a Metropolis acceptance criterion of simulated annealing and genetic operations. One uniqueness of the proposed algorithm is that it simultaneously determines task allocation among MDs, an SBS, and a CDC, the transmission power of MDs, and bandwidth allocation of wireless channels between MDs and SBS. Experiments with real-life tasks from Google data centers have shown that the proposed Genetic Simulated-annealing-based Particle swarm optimization (GSP) significantly achieves lower system cost and faster convergence speed than benchmark peers.

Tangible document sharing: handing over paper documents across a videoconferencing display.

Conventional techniques for sharing paper documents in teleconferencing tend to introduce two inconsistencies: 1) media inconsistency: a paper document is converted into a digital image on the remote site; 2) space inconsistency: a workspace deliberately inverts the partner's handwriting to make a document easy to read. In this paper, we present a novel system that eliminates these inconsistencies. The media and space inconsistencies are resolved by reproducing a real paper document on a remote site and allowing a user to handover the paper document to a remote partner across a videoconferencing display. From a series of experiments, we found that reproducing a real paper document contributes to a higher sense of information sharing. We also found that handing over a document enhances a sense of space sharing, regardless of whether the document is digital or paper-based. These findings provide insights into designing systems for sharing paper documents across distances.

Proximity Effects on the Reactivity of a Nonheme Iron (IV) Oxo Complex in C-H Oxidation.

Precise control of substrate positioning and orientation (its proximity to the reactive unit) is often invoked to rationalize the superior enzymatic reaction rates and selectivities when compared to synthetic models. Artificial nonheme iron (IV) oxo (Fe(IV)=O) complexes react with C(sp3)-H bonds via a biomimetic Hydrogen Atom Transfer/Hydroxyl Rebound mechanism, but rates, site-selectivity and even hydroxyl rebound efficiency (ligand rebound versus substrate radical diffusion) are smaller than in oxygenases. Herein, we quantitatively analyze how substrate binding modulates nonheme Fe(IV)=O reactivity by comparing rates and outcomes of C-H oxidation by a pair of Fe(IV)=O complexes that share the same first coordination sphere but only one contains a crown ether receptor that recognizes the substrate. Substrate binding makes the reaction intramolecular, exhibiting Michaelis-Menten kinetics and increased reaction rates. In addition, C-H oxidation occurs with high site selectivity for remote sites. Analysis of Effective Molarity reveals that the system operates at its maximal theoretical capability for the oxidation of these remote sites. Remarkably, substrate positioning also affects Hydroxyl Rebound, whose efficiency only increases on the sites placed in proximity by recognition. Overall, these observations provide evidence that supramolecular control of substrate positioning can effectively modulate the reactivity of oxygenases and its models.

Proximity Effects on the Reactivity of a Nonheme Iron (IV) Oxo Complex in C−H Oxidation

AbstractPrecise control of substrate positioning and orientation (its proximity to the reactive unit) is often invoked to rationalize the superior enzymatic reaction rates and selectivities when compared to synthetic models. Artificial nonheme iron (IV) oxo (Fe(IV)=O) complexes react with C(sp3)−H bonds via a biomimetic Hydrogen Atom Transfer/Hydroxyl Rebound mechanism, but rates, site‐selectivity and even hydroxyl rebound efficiency (ligand rebound versus substrate radical diffusion) are smaller than in oxygenases. Herein, we quantitatively analyze how substrate binding modulates nonheme Fe(IV)=O reactivity by comparing rates and outcomes of C−H oxidation by a pair of Fe(IV)=O complexes that share the same first coordination sphere but only one contains a crown ether receptor that recognizes the substrate. Substrate binding makes the reaction intramolecular, exhibiting Michaelis–Menten kinetics and increased reaction rates. In addition, C−H oxidation occurs with high site selectivity for remote sites. Analysis of Effective Molarity reveals that the system operates at its maximal theoretical capability for the oxidation of these remote sites. Remarkably, substrate positioning also affects Hydroxyl Rebound, whose efficiency only increases on the sites placed in proximity by recognition. Overall, these observations provide evidence that supramolecular control of substrate positioning can effectively modulate the reactivity of oxygenases and its models.

Monitoring a high mountain glacier through georeferenced time-lapse photography: Tapado, Dry Andes of Chile (30°S)

ABSTRACT Glaciers and snow cover provide freshwater for irrigated agriculture and urban consumption in the Dry Andes. Given the aridity of this environment, sublimation losses are significant, making precise monitoring techniques crucial in estimating glacier changes. Continuous monitoring of glaciers is typically conducted through the use of automatic weather stations (AWS). However, these stations may not capture the full extent of glacier changes, warranting the use of additional monitoring techniques such as close-range remote sensing and satellite imagery. This study utilizes time-lapse photography acquired from 2013 to 2015 to examine the temporal and spatial albedo variations across the Tapado Glacier, along with the surface changes in the debris-covered section. Sequential orthorectified images were used to observe the spatial evolution of ice cliffs and supraglacial ponds as they changed over time. High-resolution displacement measurements were obtained using feature tracking methods on the debris-covered glacier. Additionally, distributed albedo maps were produced by comparing photographic data with point albedo measurements from an AWS. The results indicate decreased albedo values during summer, along with the expansion of supraglacial ponds and ice cliffs in the debris-covered region. The study also proposes a cost-effective remote site monitoring approach using time-lapse photography for continuous observation and data collection.

Formation of In‐Cloud Aqueous‐Phase Secondary Organic Matter and Related Characteristic Molecules

AbstractThe formation process of in‐cloud aqueous‐phase secondary organic matter (aqSOM) and its characteristics are unclear. Herein, water‐soluble inorganic ions, oxalate, and water‐soluble organic carbon (WSOC) were determined in cloud water and aerosol (PM2.5) samples simultaneously collected at a remote mountain site in southern China during spring 2018 and winter 2020. The molecular compositions of water‐soluble organic matter (WSOM) in cloud water and aerosols were analyzed by a Fourier transform ion cyclotron resonance mass spectrometer in negative electrospray ionization (ESI‐) mode. The results showed that the mean concentration of WSOC was 6.27–8.54 mg C L−1 in cloud water and 0.60–1.37 μg C m−3 in aerosols. The strong correlation observed between WSOM and aqueous secondary matter (e.g., NO3− and oxalate), the positive matrix factorization results, and the elevated WSOM/K+ ratios observed in cloud water suggested enhanced aqSOM formation in cloud water. According to random forest analysis, the factors related to in‐cloud WSOM variation mainly included secondary ions, K+, cloud water pH, and atmospheric NOx. Additionally, 37 characteristic in‐cloud aqSOM molecules, classified as ‐Ox, ‐NOx, ‐N2Ox, and ‐N1‐2OxS, mainly consisting of dicarboxylic acids, nitrophenols, and dinitrophenols, were identified using linear discriminant analysis effect size (LefSe). The characteristic N‐ and S‐containing molecules in in‐cloud aqSOM with carbon numbers >10 had low or extremely low volatility; therefore, they might contribute to secondary organic aerosol formation after droplet evaporation. The results revealed the modifying effects of in‐cloud processes on aerosol organic composition at the molecular level and could improve our understanding of aerosol–cloud interactions.

Middle East oil and gas methane emissions signature captured at a remote site using light hydrocarbon tracers

The observational characterization of anthropogenic methane (CH4) emissions in the Eastern Mediterranean and Middle East (EMME) region, known for its significant oil and gas (OG) production, remains limited. Light alkanes, such as ethane (C2H6), are co-emitted with CH4 by OG activities and are promising tracers for identifying the CH4 emissions from this sector at the wider regional scale. In this study, in-situ measurements of CH4 and alkanes (C2–C8 were collected during a field campaign at a regional background site (Cape Greco, Cyprus). A mobile laboratory housed the instrumentation at the south-eastern edge of the island between December 2021 and February 2022. This specific location and time of year were selected to capture air masses originating from distant southern and eastern regions, primarily impacted by sources from the Middle East. Based on these observations we 1) evaluate the significance of long-range transported versus local sources in Cyprus, 2) identify and document regional anthropogenic CH4 sources with the help of the concomitant alkane measurements, and 3) assess the accuracy of the EDGAR sectoral emission inventory over the EMME region. The highest alkane mixing ratios observed were associated with the Middle Eastern OG CH4 signal. Surprisingly, the Middle Eastern emissions of CH4 were found to be heavily influenced by the breeding and waste management sectors. By investigating the measured CH4 mixing ratios together with an atmospheric dispersion model (FLEXPART), we derive a comprehensive characterization of the pollution sources at a regional scale over the Eastern Mediterranean region. Our results indicate that CH4 emissions from the Middle Eastern OG sector are likely underestimated by ca. 69 %. These findings underscore the efficacy of using experimental observations of alkanes for CH4 source identification at receptor sites. This tracer approach would also benefit from a substantial revision of light hydrocarbon emission inventories.

Metal concentrations in fish tissues from Kara, Bolshoi Patok, and Maly Patok River basins, Northeastern European Russia

Fish and fish tissue are effective bioindicators due to their sensitivity to pollution and are frequently used for assessing aquatic ecosystem health. Establishing baseline metal concentrations in freshwater fish tissues within aquatic ecosystems is important prior to establishing industrial activities to help determine potential future industrial impacts. Historically, North-Eastern European Russia has been an area with relatively low levels of industrial development and is still in pristine condition. In this region, the noise-to-background ratio for industrial contaminants may be disproportionately high. This study measured baseline metal concentrations in freshwater fish tissues collected from three study sites (the Bolshoi Patok, Maly Patok and Kara Rivers) in northeastern European Russia as bioindicators of overall aquatic ecosystem health. Seven fish species, namely, European Grayling, Arctic Char, Whitefish, Perch, Pike, Roach, and Peled, were studied over a three-year period between 2000 and 2003. The copper (Cu), lead (Pb), cadmium (Cd), and zinc (Zn) concentrations were analysed in fish tissue samples. Metal concentrations measured in fish tissues in this study were comparable to those measured at remote sites in Alaska, the United States and Slovenia. Despite the small variation between the sampling sites, the metal concentrations were relatively low and considered to be in pristine condition. Metal concentrations measured in fish tissues in this study represent baseline conditions, which will be important for comparison against monitoring programmes should the region experience future industrial development.

Processing water birds for food at the Island of Kökar in the Baltic Sea during the medieval and early modern period (ca. CE 1400–1700)

AbstractFew studies have been made of the specific importance of waterfowl as food in the Baltic Sea during the late medieval and early modern period. This study shows the seasonal importance of water birds to island and coastal inhabitants living in the middle of the Baltic Sea during the late medieval and early modern periods (ca. CE 1400–1700) and practical implementations for interpretation of cut and chop marks. The paper is based on a bird bone assemblage retrieved from a remote ecclesial site on the island group of Kökar, which is part of the Åland Islands, as well as historical documents and local specialist knowledge. The site was established by Franciscan friars somewhere in the mid‐15th century. Documents indicate that the friars had landownership, income from taxing nearby fisheries, and the right to seal tithe. These assets were taken over by the crown in the mid‐16th century due to the Reformation and a parish church was established on the same site after the friary was dissolved. The bone assemblages from the site include birds, mammals, and fish. The material shows a relatively small number of chicken bones in relation to waterfowl, allowing one to look closer into the structural food economy around water birds for the area. The bones also show several cut and chop marks, which have been analyzed to explore the possible processing of these birds. The results show that fowling was concentrated to a couple of species most likely during spring when these species were abundant. The placement of the cut and chop marks indicates that a large number of birds were likely processed at the same time.

Novel Resource Allocation Technique for DVB-RCS Compliant Satellite Terminals

Satellite communication is advantageous for several reasons such as broad coverage, small installation time of remote user sites, and network services in inhospitable terrains, where installing terrestrial infrastructure is costly. With the advent of broadband multimedia satellites such as Ku and Ka band satellites, multimedia services to the satellite terminals are gaining momentum. Digital Video Broadcast Return Channel via Satellite (DVB-RCS) is an open standard developed by ETSI which has further standardized, commercialized and solved the problem of inter-operability of Ku Band satellite terminals. Satellite bandwidth is scarce therefore treated as precious resource. In the present paper, authors aim to develop and realize the resource allocation techniques in return link channel for DVB-RCS compliant satellite terminals. The paper provides method for giving preference to real time application in terms of early processing of allocation request generated against the real time traffic to reduce delay and also provides method to avoid parallel connection arises due to transmission of terminal on more than one frequency at a time. Authors have realised DVB-RCS resource allocation technique and have given simulation results.

Abstract 993: Comprehensive immunophenotypic strategies to enable equity in remote settings for improved cancer prognosis

Abstract Improved cancer prognosis begins with insights obtained from high quality data during clinical trials. Execution of longitudinal clinical trials in flow cytometry is complex, primarily due to logistical challenges in high quality sample collection. For instance, highly remote indigenous population centers are both disadvantaged in access to healthcare and often underrepresented in clinical trials. This paradox is highlighted in the case of Australian First Nations communities, for which lung cancer prevalence peaks in males at twice the magnitude of the general population. Our group has developed a novel blood “immune signature” that robustly predicts failure to make a clinical response to checkpoint therapies targeting the PD-1/PD-L1 pathway. Encouraged by these groundbreaking findings, which were achieved through applying a comprehensive 38-plex immunophenotyping CyTOF panel to biobanked cancer samples, recent advances in CyTOF technology now give us the opportunity to expand our clinical implementation to remote settings, with a further expanded panel to 50+ markers. CyTOF is the only technology that allows easily implemented remote asynchronous sample collection and the largest immunophenotyping panel that yields reproducible results. Asynchronous collection is uniquely enabled using a stable lyophilized large-scale staining panel and achieving comprehensive marker coverage in one panel minimizes blood sample required. Furthermore, the new technology enables a highly simplified workflow including blood collection and processing in remote locations to enable the simplest clinical trial infrastructure complexity and cost, easily implemented in current hospital lab environments. As such, this study is designed to ultimately demonstrate both clinical impact of the large panel and utility of CyTOF technology for highly simplified and robust workflow for multi-site clinical trials. This project has 3 phases; i) implementation and evaluation of the collection, analysis technique and data management of this new approach across multiple sites, ii) collection of samples for analysis both pre- and post- initiation of therapy to establish efficacy and optimize as necessary, and iii) blinded clinical trial. We will report on the first phase of this project which is implementing new workflow across clinical collection site, data integration and analysis. This workflow would enable highly simplified collection to access indigenous and under-served populations spread across remote sites in Australia. Citation Format: Natalie J. Smith, Michael Cohen, Julie Alipaz, Christina Loh, David King, Barbara Fazekas de St Groth, Helen M. McGuire. Comprehensive immunophenotypic strategies to enable equity in remote settings for improved cancer prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 993.

Exploiting the temporal characteristics of tidal stream power for green ammonia production

Green ammonia, a promising zero-carbon energy storage vector, has never been produced using solely tidal stream energy despite its predictable characteristics. Combining tidal stream sites with a phase difference (tidal phasing) facilitates anticorrelation between these sites’ power profiles, enabling a more consistent power output. Green ammonia production benefits from a steady and predictable power input. The objective of this paper is to determine if nearby tidal sites have a large enough phase difference (anticorrelation) to reduce the cost of ammonia production. Moreover, producing green ammonia from underutilized or unutilized remote and grid-constrained tidal stream sites may enable viability of these sites. This paper is the first analysis of green ammonia production using solely tidal stream energy and the first analysis of tidal phasing for green fuel production. Two UK case studies are presented in i) the North Channel of the Irish Sea and ii) Orkney. There are tidal sites in each which have a phase difference (e.g. the Mull of Kintyre/Sound of Islay, and Graemsay/North Ronaldsay with correlation coefficients of 0.17 and −0.02 respectively), utilising this phase difference reduces the levelized cost of ammonia by 8% in the Irish Sea and by 12% in Orkney.

Effects of Source Directivity and Nonlinear Soil Behavior During the January, 1 2024 Noto Earthquake (Mw = 7.5)

The earthquake of January 1, 2024 with the epicenter at Noto Peninsula of Ishikawa Prefecture, Japan, and the moment magnitude Mw = 7.5 obviously represents an intermediate case between weaker earthquakes with relatively small sources, like the 1995 Kobe and 2000 Tottori earthquakes (Mw ~ 6.7-6.8), showing nonlinear soil response and soil softening (reduction of shear moduli) and stronger earthquakes, like the 2003 Tokachi-Oki and Tohoku earthquakes (Mw ~ 8.3-9.0) with extended sources and source directivity effects, accompanied by soil hardening and generation of high peak ground accelerations (PGA) > 1 g. In this research, based on KiK-net vertical array records (11 sites), models of soil behavior in the near-fault zones of the 2024 Noto earthquake are constructed, i.e. vertical distributions of stresses and strains in soil layers changing with time during strong motion, which showed nonlinear soil response and reduction of shear moduli in the near-fault zones. At the same time, the waveforms of acceleration time histories indicate the effects of source directivity, when seismic waves, radiated by the crack tip propagated along a~rather long section of the fault plane, arrived to remote sites almost simultaneously, overlap, harden subsurface soils and generate high accelerations on the surface, PGA ~ 2828 Gal at remote ISK006 station.

Monitoring solutions for remote locations: A data gathering approach for remote nature-based solution sites

Nature-based solutions have gained popularity as an approach to tackling hydro-meteorological hazards (HMHs) in both urban and rural settings. Despite this popularity, challenges persist regarding the evidence base for their effectiveness and data scarcity at the feature or site scale. Flood modelling is a common approach to quantifying the effectiveness of NbS; however, the accuracy of these models heavily depends on the accuracy of the DEM, land cover, and hydraulic/hydrological data utilised. Remote and rural settings often face data scarcity due to the challenging nature of data collection, and insufficient funding for monitoring. Additionally, NbS features vary in size and scale, with many being small (<1 m in width), posing challenges for accurate representation in national LiDAR datasets. Technological advancements in remote sensing technologies, such as unmanned aerial vehicles, handheld LiDAR, and GPS-GNSS, offer opportunities to gather high-resolution, high-accuracy data in these challenging locations. This article proposes a methodological framework for collecting elevation data at remote NbS sites that can tackle areas affected by both sparse and dense vegetation cover. This approach proves valuable in both pre-NbS implementation, through facilitating NbS opportunity and environmental risk identification, and post-NbS implementation, through aiding in geo-spatial feature location, improving existing DEM data for flood modelling, and monitoring temporal changes.

A Clinical-Anatomical-Radiological Study of Extraperitoneal Spaces: A Case Series.

Complications can arise secondary to anorectal suppurative diseases, with infections spreading along the extraperitoneal space, such as the peri-vesical, prevesical, pre-sacral, and pararectal spaces, resulting in abscesses at remote sites, which can make diagnosis more challenging. Due to the absence of peritonitis symptoms, there is a delay in presentation among such patients. Comprehending the intricacies of these areas and the way infection can spread within them is crucial for promptly identifying and effectively draining the extraperitoneal abscess. We present a case series of six patients with a mean age of 45, all males. A total of three patients had undergone incision and drainage after being diagnosed with anorectal suppurative disease and remained symptomatic after the initial surgical intervention of incision and drainage. Two patients initially diagnosed with anterior abdominal abscesses patients, after being treated with incision and drainage, continued to have purulent discharge from the drainage site. Finally, the last patient continued to present with perianal pain after an open hemorrhoidectomy. CTscans of all six patients showed collections in the extraperitoneal spaces correlated with the observed complications. To deepen our understanding of pelvic extraperitoneal spaces, cadaver dissections were conducted and compared with CT images. Through cadaver dissections and CT imaging, the study provides insights into the anatomy and interconnections of pelvic extraperitoneal spaces, emphasizing the importance of early CT scans for diagnosis. Understanding these intricate anatomical structures is essential for accurate diagnosis and efficient and effective treatment. Timely diagnosis is vital to prevent prolonged illness and reduce the risk of complications and mortality. The importance of early CT scans in suspected patients is underscored, which is highly important to expedite appropriate actions.

A three-level regulatory mechanism of the aldo-keto reductase subfamily AKR12D

Modulation of protein function through allosteric regulation is central in biology, but biomacromolecular systems involving multiple subunits and ligands may exhibit complex regulatory mechanisms at different levels, which remain poorly understood. Here, we discover an aldo-keto reductase termed AKRtyl and present its three-level regulatory mechanism. Specifically, by combining steady-state and transient kinetics, X-ray crystallography and molecular dynamics simulation, we demonstrate that AKRtyl exhibits a positive synergy mediated by an unusual Monod-Wyman-Changeux (MWC) paradigm of allosteric regulation at low concentrations of the cofactor NADPH, but an inhibitory effect at high concentrations is observed. While the substrate tylosin binds at a remote allosteric site with positive cooperativity. We further reveal that these regulatory mechanisms are conserved in AKR12D subfamily, and that substrate cooperativity is common in AKRs across three kingdoms of life. This work provides an intriguing example for understanding complex allosteric regulatory networks.

Tropical tropospheric aerosol sources and chemical composition observed at high altitude in the Bolivian Andes

Abstract. The chemical composition of PM10 and non-overlapping PM2.5 was studied at the summit of Mt. Chacaltaya (5380 m a.s.l., lat. −16.346950°, long. −68.128250°) providing a unique long-term record spanning from December 2011 to March 2020. The chemical composition of aerosol at the Chacaltaya Global Atmosphere Watch (GAW) site is representative of the regional background, seasonally affected by biomass burning practices and by nearby anthropogenic emissions from the metropolitan area of La Paz–El Alto. Concentration levels are clearly influenced by seasons with minima occurring during the wet season (December to March) and maxima occurring during the dry and transition seasons (April to November). Ions, total carbon (EC + OC), and saccharide interquartile ranges for concentrations are 558–1785, 384–1120, and 4.3–25.5 ng m−3 for bulk PM10 and 917–2308, 519–1175, and 3.9–24.1 ng m−3 for PM2.5, respectively, with most of the aerosol seemingly present in the PM2.5 fraction. Such concentrations are overall lower compared to other high-altitude stations around the globe but higher than Amazonian remote sites (except for OC). For PM10, there is dominance of insoluble mineral matter (33 %–56 % of the mass), organic matter (7 %–34 %), and secondary inorganic aerosol (15 %–26 %). Chemical composition profiles were identified for different origins: EC, NO3-, NH4+, glucose, and C2O42- for the nearby urban and rural areas; OC, EC, NO3-, K+, acetate, formate, levoglucosan, and some F− and Br− for biomass burning; MeSO3-, Na+, Mg2+, K+, and Ca2+ for aged marine emissions from the Pacific Ocean; arabitol, mannitol, and glucose for biogenic emissions; Na+, Ca2+, Mg2+, and K+ for soil dust; and SO42-, F−, and some Cl− for volcanism. Regional biomass burning practices influence the soluble fraction of the aerosol between June and November. The organic fraction is present all year round and has both anthropogenic (biomass burning and other combustion sources) and natural (primary and secondary biogenic emissions) origins, with the OC/EC mass ratio being practically constant all year round (10.5 ± 5.7, IQR 8.1–13.3). Peruvian volcanism has dominated the SO42- concentration since 2014, though it presents strong temporal variability due to the intermittence of the sources and seasonal changes in the transport patterns. These measurements represent some of the first long-term observations of aerosol chemical composition at a continental high-altitude site in the tropical Southern Hemisphere.

Chemical characterization and sources of background aerosols in the eastern Mediterranean

Measurements of the composition of the gas and particulate phases were conducted from May 9 to June 4 of 2016 at the Finokalia (Greece) remote coastal site in the eastern Mediterranean, continuing the effort to track long term changes of the atmospheric chemical composition in the area. Finokalia is influenced by air masses arriving in the site from regional sources in Europe, Africa, and other locations. In this study, a series of instruments and analysis techniques were used for the first time at the Finokalia site to characterize the composition of the organic aerosol (OA). The PM1 was composed of ammonium sulfate/bisulfate (60%), followed by organics (35%) and black carbon (BC) (4%). The OA was highly oxidized with an average oxygen-to-carbon (O:C) ratio of 0.81. Source apportionment of high-resolution organic aerosol mass spectra via positive matrix factorization (PMF) identified four factors: less oxidized oxygenated organic aerosol (LO-OOA), more oxidized oxygenated organic aerosol (MO-OOA), marine-related oxygenated organic aerosol (marine-OOA) and hydrocarbon-like organic aerosol (HOA). The LO-OOA (O:C = 0.92) was the dominant factor for most of the campaign (51% of the PM1 OA), while the MO-OOA (O:C = 1.1) was responsible for 11% of the OA. The marine-OOA factor was also highly oxidized (O:C = 1.03), contributing on average 24% to the total OA and was found to be well correlated with sulfate (R2 = 0.83). The anthropogenic HOA factor (O:C = 0.36) was related to activities in the island of Crete. Its mass spectrum was quite similar (R2 = 0.86–0.95) to those of other HOA factors in the literature and its average concentration was 0.2 μg m−3 (14% of OA). High molecular weight compounds were found, suggesting the presence of oligomers in agreement with the presence of a highly oxidized quenching agent. Aromatic VOCs, like benzene, toluene, and xylenes were on average 0.17, 0.66 and 0.36 ppb, respectively with toluene concentrations indicating the presence of a local source despite the remote nature of the site. New particle formation (NPF) was observed during 26% of the days. The air masses during NPF events passed over the island of Crete and the Balkans and were characterized by a low condensation sink (5.9 ± 2.2 10−3 s−1). Nucleation mode particle concentrations during NPF days had an additional evening peak between 17:00 and 22:00, which was accompanied by an HOA peak implying the influence of a source of sub-25 nm particles in the extended area. These findings show that even a relatively remote site like Finokalia is occasionally affected by sources located tens of kilometers away, something that should be taken into account in the interpretation of past and future measurements in this location.

Promoting equitable and patient-centred care: an analysis of patient satisfaction in urban, rural and remote primary care sites in the Philippines

ObjectivesThis study measured changes in patient satisfaction levels before and after the introduction of primary care system strengthening interventions in urban, rural, and remote sites in the Philippines.MethodsA previously validated...

Modelled sources of airborne microplastics collected at a remote Southern Hemisphere site

Airborne microplastics have emerged in recent years as ubiquitous atmospheric pollutants. However, data from the Southern Hemisphere, and remote regions in particular, are sparse. Here, we report airborne microplastic deposition fluxes measured during a five-week sampling campaign at a remote site in the foothills of the Southern Alps of New Zealand. Samples were collected over 24-hour periods for the first week and for 7-day periods thereafter. On average, atmospheric microplastic (MP) deposition fluxes were six times larger during the 24-hour sampling periods (150 MP m−2 day−1) than during the 7-day sampling periods (26 MP m−2 day−1), highlighting the importance of sampling frequency and deposition collector design to limit particle resuspension. Previous studies, many of which used weekly sampling frequencies or longer, may have substantially underestimated atmospheric microplastic deposition fluxes, depending on the study design. To identify likely sources of deposited microplastics, we performed simulations with a global dispersion model coupled with an emissions inventory of airborne microplastics. Modelled deposition fluxes are in good agreement with observations, highlighting the potential for this method in tracing sources of deposited microplastics globally. Modelling indicates that sea-spray was the dominant source when microplastics underwent long-range atmospheric transport, with a small contribution from road dust.