Airborne Organisms Research Articles

Aeroconservation for the Fragmented Skies

AbstractFrom birds to bacteria, airborne organisms face substantial anthropogenic impacts. The airspace provides essential habitat for thousands of species, some of which spend most of their lives airborne. Despite recent calls to protect the airspace, it continues to be treated as secondary to terrestrial and aquatic habitats in policy and research. Aeroconservation integrates recent advances in aeroecology and habitat connectivity, and recognizes aerial habitats and threats as analogous to their terrestrial and aquatic counterparts. Aerial habitats are poorly represented in the ecological literature and are largely absent from environmental policy, hindering protection of aerial biodiversity. Here, we provide a framework for defining aerial habitats to advance the study of aeroconservation and the protection of the airspace in environmental policy. We illustrate how current habitat definitions explicitly disadvantage aerial species relative to non‐aerial species, and review key areas of conflict between aeroconservation and human use of the airspace. Finally, we identify opportunities for research to fill critical knowledge gaps for aeroconservation. For example, aerial habitat fragmentation may impact biodiversity and ecosystem function similarly to terrestrial habitat fragmentation, and we illustrate how this can be investigated by extending existing methods and paradigms from terrestrial conservation biology up into the airspace.

Electromagnetic Model Reliably Predicts Radar Scattering Characteristics of Airborne Organisms.

The radar scattering characteristics of aerial animals are typically obtained from controlled laboratory measurements of a freshly harvested specimen. These measurements are tedious to perform, difficult to replicate, and typically yield only a small subset of the full azimuthal, elevational, and polarimetric radio scattering data. As an alternative, biological applications of radar often assume that the radar cross sections of flying animals are isotropic, since sophisticated computer models are required to estimate the 3D scattering properties of objects having complex shapes. Using the method of moments implemented in the WIPL-D software package, we show for the first time that such electromagnetic modeling techniques (typically applied to man-made objects) can accurately predict organismal radio scattering characteristics from an anatomical model: here the Brazilian free-tailed bat (Tadarida brasiliensis). The simulated scattering properties of the bat agree with controlled measurements and radar observations made during a field study of bats in flight. This numerical technique can produce the full angular set of quantitative polarimetric scattering characteristics, while eliminating many practical difficulties associated with physical measurements. Such a modeling framework can be applied for bird, bat, and insect species, and will help drive a shift in radar biology from a largely qualitative and phenomenological science toward quantitative estimation of animal densities and taxonomic identification.

Extracting Migrant Flight Orientation Profiles Using Polarimetric Radar

Seasonal animal migration is characterized by aligned flight of airborne organisms across large spatial expanses. This large-scale alignment results in azimuthal patterns in polarimetric radar products. The following overviews some such patterns and introduces a technique for obtaining vertical profiles of migrant flight orientation by exploiting azimuthal symmetries in the polarimetric radar product of copolar correlation coefficient $\rho_{HV}$ . This method is compared with several Doppler-velocity-based techniques for measuring flight direction, and a sensitivity analysis is performed. Finally, the method is applied to a case of nocturnal migration over the Southern Great Plains, demonstrating the utility of the technique in the study of animal migratory behavior within the airspace.

Mechanistic modeling of seed dispersal by wind over hilly terrain

Seed dispersal is the main movement mechanism used by plants. The last decade saw rapid progress in understanding the underlying processes, especially for dispersal by wind, in part due to new mechanistic modeling approaches that account for turbulent fluctuations. Yet, current wind dispersal models stop short of explicitly incorporating the effects of landscape topography on the main transporting vector – wind, so that the effects of wind variability over hills on dispersal patterns remain by and large unstudied.A new mechanistic model was developed that combines Eulerian wind statistics derived from a simplified analytical approach of flow over gently sloped forested hills with a Lagrangian seed trajectory model. Model runs were used to explore the effects of seed release location along the hill on dispersal kernels predicted by the new model in relation to their flat-terrain counterparts. The model was parameterized for a Pinus taeda plantation, and a range of seed motion capacities represented by terminal velocity and release height, and realistic topographic variation were then explored.To evaluate model performance, computed kernels were compared to kernel measurements collected in a large flume for spherical ‘seeds’ released near the top of a rod canopy covering gentle cosine hills. The evaluation showed that the model reproduced the key experimental differences in dispersal patterns for releases at the hill crest and bottom.The simulations revealed several novel findings. For seeds released within the canopy, both median and 99th percentile dispersal distances on the hill upwind side were up to two times longer than on flat terrain for the same motion capacity. Seeds released on the lee side traveled mostly toward the hill crest – following the local within-the-canopy wind direction. This direction was contrary to the ‘regional’ wind direction set by the flow conditions above the canopy. There, the directionality of the long-distance dispersal was additionally dependent on uplifting probability, affected by seed motion capacity.It was demonstrated that neglecting the effects of even gentle topography in mechanistic seed dispersal models can lead to biased estimates of dispersal distances and directionality on hilly terrain. These results are pertinent to plant population demography, connectivity and spread on hills. More broadly, the approach developed here can be extended to movement of pollen and various airborne organisms over hills.

Disinfection effectiveness of slightly acidic electrolysed water in swine barns

To evaluate the disinfection effectiveness of slightly acidic electrolysed water (SAEW, pH 6·25-6·53), a new environmental friendly agent for inactivating micro-organisms adhered to the facility and aerosolized in the air of the swine barns and to explore the application of SAEW in livestock industries. Bacteria and fungi were isolated from the swine house air and treated by SAEW. The SAEW solution was flushed onto surfaces and sprayed within the whole swine barn. SAEW with an available chlorine concentration (ACC) of 300mgl(-1) can inhibit isolated microbes completely. The usage of SAEW (300mgl(-1) ) resulted in a significant (P<0·05) reduction in microbes on the wall, rail and floor after flushing disinfection. Additionally, spraying SAEW at an ACC of 300mgl(-1) reduced 59% of the airborne organisms in 30min and kept the population of microbes at a reduced level for at least 8h. SAEW treatment also reduced pathogens on surfaces (P<0·03) after spraying disinfection except on the surface of the wall. SAEW may be a potential alternative disinfectant to reduce infections in swine barns. The results of this study provide information on the antimicrobial efficiency of SAEW on the airborne bacteria and fungi in swine barns.

Genome Sequence of Aerococcus viridans LL1

Aerococcus viridans is a catalase-negative Gram-positive bacterium and has been described as an airborne organism widely distributed in the hospital environment or in clinical specimens. We isolated A. viridans strain LL1 from indoor dust samples collected by a patient. Here, we prepared a genome sequence for this strain consisting of 31 contigs totaling 1,994,039 bases and a GC content of 39.42%.

Partly Cloudy with a Chance of Migration: Weather, Radars, and Aeroecology

Aeroecology is an emerging scientific discipline that integrates atmospheric science, Earth science, geography, ecology, computer science, computational biology, and engineering to further the understanding of biological patterns and processes. The unifying concept underlying this new transdisciplinary field of study is a focus on the planetary boundary layer and lower free atmosphere (i.e., the aerosphere), and the diversity of airborne organisms that inhabit and depend on the aerosphere for their existence. Here, we focus on the role of radars and radar networks in aeroecological studies. Radar systems scanning the atmosphere are primarily used to monitor weather conditions and track the location and movements of aircraft. However, radar echoes regularly contain signals from other sources, such as airborne birds, bats, and arthropods. We briefly discuss how radar observations can be and have been used to study a variety of airborne organisms and examine some of the many potential benefits likely to arise from radar aeroecology for meteorological and biological research over a wide range of spatial and temporal scales. Radar systems are becoming increasingly sophisticated with the advent of innovative signal processing and dual-polarimetric capabilities. These capabilities should be better harnessed to promote both meteorological and aeroecological research and to explore the interface between these two broad disciplines. We strongly encourage close collaboration among meteorologists, radar scientists, biologists, and others toward developing radar products that will contribute to a better understanding of airborne fauna.

Quantifying animal phenology in the aerosphere at a continental scale using NEXRAD weather radars

One of the primary ecological manifestations of climate change is a shift in the timing of events in a species' annual cycle. Such phenological shifts have been documented in numerous taxa, but data for animals have been derived primarily from human observers rather than networks of instruments used for remote sensing. The potential to use the network of weather radars in the United States (NEXRAD) to remotely sense animal phenologies could advance our understanding of the spatiotemporal scaling of phenologies in relation to shifts in local and regional climate. We tested the utility of NEXRAD radar products for quantifying the phenology of the purple martin (Progne subis) at summer roost sites in the United States. We found that the maximum radar reflectivity value in the hour before local sunrise above purple martin roost sites contained a strong phenological signal of significantly increased radar reflectivity during June, July, and August 2010. The seasonal pattern in this radar signal matched our expectation of the timing of formation and dissipation of these seasonal roosts. Radar reflectivity was greater and less variable when considering roosts close to NEXRAD stations (&lt;25 km) than when including all 358 documented roosts; there was a negative relationship between maximum reflectivity and the distance between a roost and the nearest NEXRAD. Our results suggest that: (1) mosaicked NEXRAD radar products are a valuable source of information on the phenology of bioscatter in the aerosphere; (2) citizen scientists who document the locations of roosts on the ground are providing critical information for advancing our understanding of animal phenology and aeroecology; and (3) ongoing research that examines spatiotemporal relationships among radar‐derived phenologies in airborne organisms, climate, and land cover change are likely to provide further insights.

Energy Efficient Hospitals Air Conditioning Systems

Energy Efficiency and Indoor Air Quality in the healthcare applications and particularly in surgical operating theatres are important features in modernized designs. The various reasons for deviation from obtaining optimum IAQ and energy efficient buildings are listed. The air conditioning systems serving the operating rooms require careful design to minimize the concentration of airborne organisms. Numerical approach is an appropriate tool to be utilized to adequately identify the airflow patterns temperatures and relative humidity distributions and hence energy efficient designs.

Migration by soaring or flapping: numerical atmospheric simulations reveal that turbulence kinetic energy dictates bee-eater flight mode

Aerial migrants commonly face atmospheric dynamics that may affect their movement and behaviour. Specifically, bird flight mode has been suggested to depend on convective updraught availability and tailwind assistance. However, this has not been tested thus far since both bird tracks and meteorological conditions are difficult to measure in detail throughout extended migratory flyways. Here, we applied, to our knowledge, the first comprehensive numerical atmospheric simulations by mean of the Regional Atmospheric Modeling System (RAMS) to study how meteorological processes affect the flight behaviour of migrating birds. We followed European bee-eaters (Merops apiaster) over southern Israel using radio telemetry and contrasted bird flight mode (flapping, soaring-gliding or mixed flight) against explanatory meteorological variables estimated by RAMS simulations at a spatial grid resolution of 250 × 250 m(2). We found that temperature and especially turbulence kinetic energy (TKE) determine bee-eater flight mode, whereas, unexpectedly, no effect of tailwind assistance was found. TKE during soaring-gliding was significantly higher and distinct from TKE during flapping. We propose that applying detailed atmospheric simulations over extended migratory flyways can elucidate the highly dynamic behaviour of air-borne organisms, help predict the abundance and distribution of migrating birds, and aid in mitigating hazardous implications of bird migration.

Airborne microeukaryote colonists in experimental water containers: diversity, succession, life histories and established food webs

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 62:139-152 (2011) - DOI: https://doi.org/10.3354/ame01463 Airborne microeukaryote colonists in experimental water containers: diversity, succession, life histories and established food webs Savvas Genitsaris1, Maria Moustaka-Gouni1,*, Konstantinos A. Kormas2 1Department of Botany, School of Biology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece 2Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, 384 46 Nea Ionia, Magnisia, Greece *Corresponding author. Email: mmustaka@bio.auth.gr ABSTRACT: Airborne freshwater and marine microeukaryotes in the city of Thessaloniki, situated in Thermaikos Bay, Greece, were examined as sources of colonization of experimental water containers during the period autumn 2007 to spring 2008. The microeukaryote composition of the plankton in the nearby aquatic systems (distance <1 km) was also examined. Airborne microeukaryotes were examined by morphology and 18S rRNA gene diversity. A total of 29 species of airborne microeukaryotes were identified, most of them commonly observed in aerobiological studies. Airborne organisms of only 8 taxa were also detected in the nearby aquatic systems. The algae Haematococcus lacustris, a Chlorella-like taxon, and Scenedesmus cf. obliquus, the heterotrophic nanoflagellates (HNF) Bodo sp., Cafeteria minuta and Rynchomonas nasuta, and the ciliate Pattersoniella vitiphila were present in all 3 seasons, indicating capabilities of successful dispersal and colonization under a wide range of meteorological conditions. Rapid colonization of the water containers by the microeukaryotes occurred at the beginning of the experiment, but the rate of colonization quickly stabilized. The initial phase of colonization was dominated by HNF; subsequently, members of the Chlorophyta were the dominant autotrophs. The heterotrophic and autotrophic colonists established similar food webs in all 3 seasons, with P. vitiphila being the common top predator. KEY WORDS: Airborne microeukaryotes · Colonization · Diversity · Food web · Haematococcus · Pattersoniella Full text in pdf format Supplementary material PreviousNextCite this article as: Genitsaris S, Moustaka-Gouni M, Kormas KA (2011) Airborne microeukaryote colonists in experimental water containers: diversity, succession, life histories and established food webs. Aquat Microb Ecol 62:139-152. https://doi.org/10.3354/ame01463 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 62, No. 2. Online publication date: January 19, 2011 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2011 Inter-Research.

Complete genome sequence of Intrasporangium calvum type strain (7 KIPT)

Intrasporangium calvum Kalakoutskii et al. 1967 is the type species of the genus Intrasporangium, which belongs to the actinobacterial family Intrasporangiaceae. The species is a Gram-positive bacterium that forms a branching mycelium, which tends to break into irregular fragments. The mycelium of this strain may bear intercalary vesicles but does not contain spores. The strain described in this study is an airborne organism that was isolated from a school dining room in 1967. One particularly interesting feature of I. calvum is that the type of its menaquinone is different from all other representatives of the family Intrasporangiaceae. This is the first completed genome sequence from a member of the genus Intrasporangium and also the first sequence from the family Intrasporangiaceae. The 4,024,382 bp long genome with its 3,653 protein-coding and 57 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

Some aspects of the airborne transmission of infection

The relationship between the human body and the dissemination of potentially pathogenic particles and droplets is described. Airborne transmission of infection in operating theatres and a burns unit and the part played by the human microclimate and its interaction with ventilating air flows is discussed. The mechanisms by which different garment assemblies used for surgery can enhance particle dispersion are illustrated and the way that floor cleaning can increase the concentration of airborne organisms is described. The development of the successful use of ultra-clean air systems in orthopaedic implant surgery is reviewed. Relationships between contact and airborne transmission of disease are explored and ways by which containment strategies and metrics used in pharmaceutical and electronics manufacturing can be applied to the design and monitoring of healthcare areas is discussed. It is suggested that currently available techniques involving architectural, ventilation and operational aspects of healthcare provision, when properly applied, can markedly improve treatment outcomes that may otherwise be compromised by hospital-acquired infections involving both bacteria and viruses.

WHO publishes the third edition of guidelines for the prevention and control of air-travel-associated tuberculosis

Air travel has increased over the last few decades resulting in greater risk of the spread of infectious diseases carried by infectious travellers. The risk of transmission of pathogens is particularly important for airborne organisms raising concern among public health agencies and the public. Despite limited research on the risk of tuberculosis associated with air travel, several reports have published evidence of the transmission of tuberculosis infection, including multidrug-resistant tuberculosis (MDR-TB) [1, 2].

Botrytis cinerea spore balance of a greenhouse rose crop

Fungal pathogens are among the most virulent bioagressors of protected crops. For sustainable plant production and to protect the crop against these airborne organisms one must determine their origin, i.e. whether they come from outside the greenhouse or are produced inside it. We considered Botrytis cinerea spore concentration as a particular physical species which is transported by air in the same way as heat, CO 2, water vapour or any tracer gas. We constructed a mass balance of the viable Botrytis spores on the whole-greenhouse volume to assess the inside production of spores and their exchanges. The different elements in the spore balance are considered and are determined experimentally: • spore transfer into or out of the greenhouse is deduced from the difference between the inside and outside spore concentrations, measured by spore traps, multiplied by the whole-greenhouse ventilation rate; • spore deposition on soil and crop and spore impaction on the plants is deduced from observations made using Petri dishes; • inside spore production is the differential term deduced from the whole-greenhouse volume balance. The first measurements and calculations have shown that the presence of insect-proof nets across the greenhouse openings strongly influences the spore balance, as the nets intercept the B. cinerea spores proportionally to the nets’ solidity. Based on wind tunnel experiments, the interception capacity of the nets was quantified and the whole model completed in consequence. These results show the diurnal Botrytis spore balance over 3–4-week periods in the autumn and spring season for a young rose plantation. In agreement with visual observations of B. cinerea sporulation within the greenhouse, it is shown that the origin of the inocula is predominantly internal (2/3 in quantity). However, due to outside climate and greenhouse opening, it can vary widely from one period to another, with a tendency to become predominantly internal as the crop ages.

Infection Control in Jails and Prisons

At the end of 2005, approximately 7 million people (or 1 of every 33 American adults) were either in jail, in prison, or on parole. Compared with the general public, newly incarcerated inmates have an increased prevalence of human immunodeficiency virus infection, hepatitis B virus infection, hepatitis C virus infection, syphilis, gonorrhea, chlamydia, and Mycobacterium tuberculosis infection. While incarcerated, inmates are at an increased risk for the acquisition of blood-borne pathogens, sexually transmitted diseases, methicillin-resistant Staphylococcus aureus infection, and infection with airborne organisms, such as M. tuberculosis, influenza virus, and varicella-zoster virus. While incarcerated, inmates interact with hundreds of thousands of correctional employees and millions of annual visitors. Most inmates are eventually released to interact with the general public. Tremendous opportunities exist for infectious diseases specialists and infection-control practitioners to have an impact on the health of correctional employees, the incarcerated, and the communities to which inmates return. This article presents a brief review of some of the most important infection-control challenges and opportunities within the correctional setting.

Mycobacterium tuberculosis DNA Not Detected by Polymerase Chain Reaction In Air Samples From Hospital Rooms of Tuberculosis Patients.

Background: As the incidence of tuberculosis (TB) increased in the United States, the risk of occupational and nosocomial TB also increased. Airborne Mycobacterium tuberculosis (MTB) is difficult to measure directly. Quantifying MTB DNA by polymerase chain reaction in air samples obtained from isolation rooms of patients with TB would provide a measure of the number of airborne organisms produced by a patient and the efficacy of ventilation, and might predict when an individual patient is no longer infectious. Methods and Results: The air was sampled through cellulose ester filters from the isolation room of a patient with newly diagnosed pulmonary TB, from a patient on therapy for 14 days, and from adjacent offices, and an attempt was made to detect MTB DNA; however, MTB DNA was detected only on positive control filters. Conclusions: Mycobacterium tuberculosis was not detected by polymerase chain reaction in air samples from the rooms of two patients with pulmonary TB. This may have been due to the large number of room air changes with resultant rapid clearance of airborne droplet nuclei or to the limited air volume sampled. A sensitive molecular assay of airborne MTB could be used to monitor the efficacy of infection control measures by sampling a sufficient volume of isolation room air and could aid in determining when an individual patient was no longer infectious.

Avian Influenza and UV-B Blocked by Biomass Smoke

Washam (2005) described various poultry inoculation strategies being considered for controlling the spread of avian influenza in Southeast Asia and China. Longini et al. (2005) proposed that a future avian influenza A pandemic might be contained at the source by targeted prophylaxis, quarantine, and prevaccination. Washam (2005) correctly noted that “Asian farmers, though, are running out of options.” I propose a new option: Avian influenza might be controlled by a substantial reduction in regional scale biomass smoke in Southeast Asia that will allow natural solar ultraviolet-B radiation (UV-B) to suppress the virus before infection occurs. Influenza viruses and various non-pigmented bacteria are killed by UV-B wavelengths in sunlight (Hollaender and Oliphant 1944). Biomass smoke significantly suppresses natural levels of UV-B, and severe smoke pollution reduced UV-B by up to 95% during the burning seasons in Brazil in 1995 (Mims 1996) and 1997 (Mims FM III, White B, unpublished data). Reduced UV-B on 6 days in August 1997 was well correlated (r2 = 0.83) with an increase in the ratio of nonpigmented bacteria vulnerable to UV-B to pigmented bacteria that are protected from UV-B (Mims and White 1998). Although airborne influenza viruses were not measured, 1997 hospital admission records at Alta Floresta, Brazil, showed that influenza incidence was highest during the burning season (de Castro GC, personal communication). Human cases of avian influenza in Thailand and Vietnam peaked during the winter burning seasons of 2003 and 2004 (Thailand Ministry of Public Health 2005). Assuming similar optical properties of biomass smoke in Southeast Asia and Brazil, where UV-B and optical depth are highly correlated, optical depth measurements over Thailand and Vietnam by NASA’s Terra and Aqua satellites suggest highly suppressed UV-B during these avian influenza outbreaks (Mims FM III, unpublished data). Human cases of avian influenza in Thailand and Vietnam since December 2003 have peaked during both the rainy season and the burning season. Thus, periods of prolonged cloudiness and severe smoke pollution could play a role in initiating avian and other influenza outbreaks by attenuating the solar UV-B that might otherwise suppress influenza viruses in outdoor air exposed to sunlight. The transmission of avian influenza to people during these periods is enhanced by the fact that poultry raised for human consumption are often kept within several meters of where people live (World Health Organization 2004).

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Estimating the probability of recontamination via the air using Monte Carlo simulations

Recontamination of food products can cause foodborne illnesses or spoilage of foods. It is therefore useful to quantify this recontamination so that it can be incorporated in microbiological risk assessments (MRA). This paper describes a first attempt to quantify one of the recontamination routes: via the air. Data on the number of airborne microorganisms were collected from literature and industries. The settling velocities of different microorganisms were calculated for different products by combining the data on aerial concentrations with sedimentation counts assuming that settling is under the influence of gravity only. Air movement is not explicitly considered in this study. Statistical analyses were performed to clarify the effect of different products and seasons on the number of airborne microorganisms and the settling velocity. For both bacteria and moulds, three significantly different product categories with regard to the level of airborne organisms were identified. The statistical distribution in these categories was described by a lognormal distribution. The settling velocity did not depend on the product, the season of sampling or the type of microorganism, and had a geometrical mean value of 2.7 mm/s. The statistical distribution of the settling velocity was described by a lognormal distribution as well. The probability of recontamination via the air was estimated by the product of the number of bacteria in the air, the settling velocity, and the exposed area and time of the product. For three example products, the contamination level as a result of airborne recontamination was estimated using Monte Carlo simulations. What-if scenarios were used to exemplify determination of design criteria to control a specified contamination level.