Polymicrobial oral biofilm models: simplifying the complex

Over the past century, numerous studies have used oral biofilm models to investigate growth kinetics, biofilm formation, structure and composition, antimicrobial susceptibility and host–pathogen interactions. In vivo animal models provide useful models of some oral diseases; however, these are expensive and carry vast ethical implications. Oral biofilms grown or maintained in vitro offer a useful platform for certain studies and have the advantages of being inexpensive to establish and easy to reproduce and manipulate. In addition, a wide range of variables can be monitored and adjusted to mimic the dynamic environmental changes at different sites in the oral cavity, such as pH, temperature, salivary and gingival crevicular fluid flow rates, or microbial composition. This review provides a detailed insight for early-career oral science researchers into how the biofilm models used in oral research have progressed and improved over the years, their advantages and disadvantages, and how such systems have contributed to our current understanding of oral disease pathogenesis and aetiology

Monitored Indoor Environmental Quality of a Mass Timber Office Building: A Case Study

A broad range of building performance monitoring, sampling, and evaluation was conducted periodically after construction and spanning more than a year, for an occupied office building constructed using mass timber elements such as cross-laminated timber (CLT) floor and roof panels, as well as glue-laminated timber (GLT) beams and columns. This case study contributes research on monitoring indoor environmental quality in buildings, describing one of the few studies of an occupied mass timber building, and analyzing data in three areas that impact occupant experience: indoor air quality, bacterial community composition, and floor vibration. As a whole, the building was found to perform well. Volatile organic compounds (VOCs), including formaldehyde, were analyzed using multiple methods. Formaldehyde was found to be present in the building, though levels were below most recommended exposure limits. The source of formaldehyde was not able to be identified in this study. The richness of the bacterial community was affected by the height of sampling with respect to the floor, and richness and composition was aected by the location within the building. Floor vibration was observed to be below recognized human comfort thresholds

The African Lion (Panthera leo leo): A Continent-Wide Species Distribution Study and Population Analysis

Human population growth and land conversion across Africa makes the future of wide-ranging carnivores uncertain. For example, the African lion (Panthera leo leo) once ranged across the entire continent – with the exception of the Sahara Desert and rainforests. It now lives in less than a quarter of its historic range. Recent research estimates a loss of nearly half of the lions in the past two decades. Some sources put their numbers as low as 20,000 individuals. Given these declines, conservation organizations propose to list the African lion as “endangered” under the U.S. Endangered Species Act and to upgrade the species’ CITES protections from Appendix II to Appendix I. To establish the lion’s current conservation status, I analyzed the size, distribution, and potential connections of populations across its range in Africa. It is particularly important to identify connected sub-populations and areas that can serve as corridors between existing protected areas. I compile the most current scientific literature, comparing sources to identify a current population estimate. I also use these sources to map known lion populations, potential habitat patches, and the connections between them. Finally, I assess the long-term viability of each lion population and determine which qualify as “lion strongholds.” The lion population assessment in this study has shown that over 30,000 lions remain in approximately 3,000,000 km2 of Africa. Lions are distributed across a total of 78 habitat patches in 27 countries. Since 2002, five countries have lost their lion populations. However, more than half of the remaining lions in Africa reside in 11 viable populations contained within protected areas that have stable or increasing lion population trends (lion strongholds). Therefore lions are not currently threatened with extinction and it is unlikely that the total population of free-ranging lions in Africa will drop below 20,000 individuals. Given these findings, it is clear that new data based on field surveys are necessary to appropriately evaluate the legal status of the African lion

Conservation and behavior of Africa's "Big Five"

Abstract We examine the conservation status of Africa’s “Big Five”: lion, leopard, buffalo, black and white rhinoceros and elephant, and the role of behavioral knowledge in their conservation. Efforts to conserve these flagship species consist of in situ conservation, captive breeding and reintroductions. With a few exceptions, we find limited evidence that knowledge of behavior informs conservation programs targeted at these species. For management in the wild, knowledge of infanticide and ranging can provide guidelines for realistic hunting quotas and corridors between protected areas, respectively. For ex situ and reintroduction programs, behavioral knowledge is chiefly focused on improved animal husbandry. Despite a formidable understanding of these species’ behavior, the practicalities of using such knowledge may be diminished because exploitation of these species is so forceful and the bulk of efforts aimed at conserving these species (and indeed most other African species) are primarily in situ where behaviorally driven interventions are limited. Our comparative findings suggest that behavior has been of rather narrow use in the conservation of these flagship species [Current Zoology 60 (4): 486–499, 2014].</jats:p

Structural connectivity at a national scale: Wildlife corridors in Tanzania.

Wildlife corridors can help maintain landscape connectivity but novel methods must be developed to assess regional structural connectivity quickly and cheaply so as to determine where expensive and time-consuming surveys of functional connectivity should occur. We use least-cost methods, the most accurate and up-to-date land conversion dataset for East Africa, and interview data on wildlife corridors, to develop a single, consistent methodology to systematically assess wildlife corridors at a national scale using Tanzania as a case study. Our research aimed to answer the following questions; (i) which corridors may still remain open (i.e. structurally connected) at a national scale, (ii) which have been potentially severed by anthropogenic land conversion (e.g., agriculture and settlements), (iii) where are other remaining potential wildlife corridors located, and (iv) which protected areas with lower forms of protection (e.g., Forest Reserves and Wildlife Management Areas) may act as stepping-stones linking more than one National Park and/or Game Reserve. We identify a total of 52 structural connections between protected areas that are potentially open to wildlife movement, and in so doing add 23 to those initially identified by other methods in Tanzanian Government reports. We find that the vast majority of corridors noted in earlier reports as "likely to be severed" have actually not been cut structurally (21 of 24). Nonetheless, nearly a sixth of all the wildlife corridors identified in Tanzania in 2009 have potentially been separated by land conversion, and a third now pass across lands likely to be converted to human use in the near future. Our study uncovers two reserves with lower forms of protection (Uvinza Forest Reserve in the west and Wami-Mbiki Wildlife Management Area in the east) that act as apparently crucial stepping-stones between National Parks and/or Game Reserves and therefore require far more serious conservation support. Methods used in this study are readily applicable to other nations lacking detailed data on wildlife movements and plagued by inaccurate land cover datasets. Our results are the first step in identifying wildlife corridors at a regional scale and provide a springboard for ground-based follow-up conservation

Structural connectivity at a national scale: Wildlife corridors in Tanzania.

Wildlife corridors can help maintain landscape connectivity but novel methods must be developed to assess regional structural connectivity quickly and cheaply so as to determine where expensive and time-consuming surveys of functional connectivity should occur. We use least-cost methods, the most accurate and up-to-date land conversion dataset for East Africa, and interview data on wildlife corridors, to develop a single, consistent methodology to systematically assess wildlife corridors at a national scale using Tanzania as a case study. Our research aimed to answer the following questions; (i) which corridors may still remain open (i.e. structurally connected) at a national scale, (ii) which have been potentially severed by anthropogenic land conversion (e.g., agriculture and settlements), (iii) where are other remaining potential wildlife corridors located, and (iv) which protected areas with lower forms of protection (e.g., Forest Reserves and Wildlife Management Areas) may act as stepping-stones linking more than one National Park and/or Game Reserve. We identify a total of 52 structural connections between protected areas that are potentially open to wildlife movement, and in so doing add 23 to those initially identified by other methods in Tanzanian Government reports. We find that the vast majority of corridors noted in earlier reports as likely to be severed have actually not been cut structurally (21 of 24). Nonetheless, nearly a sixth of all the wildlife corridors identified in Tanzania in 2009 have potentially been separated by land conversion, and a third now pass across lands likely to be converted to human use in the near future. Our study uncovers two reserves with lower forms of protection (Uvinza Forest Reserve in the west and Wami-Mbiki Wildlife Management Area in the east) that act as apparently crucial stepping-stones between National Parks and/or Game Reserves and therefore require far more serious conservation support. Methods used in this study are readily applicable to other nations lacking detailed data on wildlife movements and plagued by inaccurate land cover datasets. Our results are the first step in identifying wildlife corridors at a regional scale and provide a springboard for ground-based follow-up conservation

Locations of least-cost corridors linking protected areas in and adjacent to Tanzania.

<p>Least-cost corridors are shown representing the lowest 10% (orange) cumulative-cost cells. Numbers refer to protected area names listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0187407#pone.0187407.g001" target="_blank">Fig 1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0187407#pone.0187407.s002" target="_blank">S1 Table</a>.</p